4...
The Norwegian Poems of Lithothamnion
By
M. Foslie.
- With 23 Plates.
(Reprinted from Det kgl. norske Videnskabers Selskabs Skrifter 1894). Ke
Trondhjem. Aktietrykkeriet. 1895,
The Norwegian Forms of Lithothamnion.
By M. E'oslie.
(With 23 Plates).
The following account is intended to comprise all the species of the algal genus Lathothammon (including Lithophyllum) at present known to occur on the coast of Norway. It is founded on a considerable number of specimens (more thousand), most of which I have gathered myself in different tracts especially along the northern part of the coast. However, of some of the species I have seen only a few, or even but a solitary specimen. The most northern part of the coast is in this respect tolerably well known, except Lofoten and Vesteraalen in Nordland’s Amt and the greater part of Tromso Amt. The Christiania- and the Trondhjem Fjord also is rather well known. But the other parts and especially the very long western and south-western stretch of coast from Hite- ren or Christiansund N. to Lindesnes and eastward off Christiania is very littie searched and long stretches quite unknown. There- fore, still much remains to be done, not only in regard to the Lithothamnia, but the marine alge in all.
The limits between the species are as a rule not easily drawn, and often still more difficult without a greater number of specimens from different tracts for comparison. A form may appear rather Well marked in one locality, but in another transitions to other forms may be rather common, and one and the same species often
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varying between wide limits, approaching not only nearly allied species, but even species which in their typical development are quite different. This may, not seldom, depend partly on local relations, partly and more frequently caused by attack of animals, as saxicavous sponges, or worms and especially boring-muscles, destroying particularly the lower or inner parts, or numerous other animals fastened to or living on the plant. The consequence of it is often an alteration in the development of the individuals in their struggle for existence by a tendency to overlap the animals, or other external objects, and thereby assuming much varying forms.!) Individuals attacked by boring-muscles may occasionally be quite destroyed thereby, that their growth has not been able to keep pace with the destructive work of the muscles. J have seen numerous individuals, especially densely branched ones lying loose on the bottom, in their inner parts so filled with boring- muscles, that only a thin peripherical portion has been left, forming what may be called a common testa around the colony of muscles. Together with these muscles is also to be found numerous per- forated and broken pieces or branches of the plant. By a feeble pressure, a push, or by the continued labour of the muscles the remaining peripherical portion gets broken, and the whole plant collapses. In specimens more attacked towards the one than the other side an opening often is produced, through which other not perforating muscles and other animals push their way into the plant. However, such specimens apparently seldom get quite destroyed, as the other parts of the plant becomes more vigorously developed, but, on the contrary, they sometimes assume peculiar forms much differing from the typical ones. Most of the specimens that I have examined have, moreover, been infested with numerous perforating alge, which in general rather destroy chiefly the lower layers of tissue. Growing in shallow water, from or a little below extreme low-water mark to a depth of about 2—3 fathom, in narrow sounds with somewhat strong currents, or else in places
1) In one locality especially I met with numerous killed or dying muscles (Mytilus modiolus) caused thereby, that the Lithothamnia encompass the shells. Cp. Contrib. II, p. 3, and Alg. og Musl. p. 17.
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with rather rapid tides densely branched and typically developed globular or hemispherical individuals, especially of the larger forms, very often assume a more depressed shape; and the apex of the branches become truncate or assume disc-shaped, not seldom con- fluent or nearly confluent and even crustlike expansions, while the part turning towards the bottom bears branches of another and apparently typical shape. On the other hand, in more sparsely branched individuals living in sounds with rapid tides, the apex of most of the branches are often denudated or biten off. This I have not seen on greater depths than about 5 fathom, although in certain localities it probably also takes place farther down.
It appears not to be excluded, that hybrids arise from some of the species growing together in banks. The Lithothamnia ge- nerally grow gregarious in great masses, sometimes and most often only one or two species, sometimes more, together. I have seen widely extended banks, once even as far as about 3 kilometer in length, composed of millions of individuals of up to four or five species, not only of the smaller forms, but large ones up to nearly 2 feet in diameter. It has, however, not been possible in this varying group of species to decide with any degree of cer- tainty, whether hybrid forms really occur. I certainly possess spe- cimens which, in my opinion, probably are hybrids, but these I do not quote here, as on closer examination I did not arrive at any satisfactory result. However, a solitary one is mentioned under L. fruticulosum f. flexuosa.
Specimens of more species are frequently to be found fastened to one and the same substratum, growing together, covering each other, or one fastened to and growing over the other. Branched individuals growing together not unfrequently continue their growth together even being loosened from the substratum, and without any defined limit, not seldom looking as a solitary individual.
The greatest difficulty in regard to the identifying especially of many of the branched Lithothamnia consists, however, therein, that proportionally very few specimens of these are to be found with reproductive organs. In some species the very greatest number of the specimens gathered in summer have been sterile, only now
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and then a specimen richly provided with the named organs, and all the other ones from the same place and time quite sterile. Specimens collected in autumn, winter and spring have now and then been fertile, but still the greater number sterile. Thus the development of the reproductive organs, at least in some of the species, with us probably takes place nearly all the year, but in proportion to the number of individuals always in apparently few of them. Only a couple of species are more commonly to be found fertile in summer. I have examined hundreds of specimens of other species from different localities and at different seasons, but only met with a couple or very few ones bearing the named organs, and those not well developed. In species, by which the conceptacles of sporangia always grow down into the frond, I often also met with specimens with the very greatest number of branches not showing overgrown conceptacles. I am,_ therefore, inclined to suppose, that at any rate in some of the branched Species, and especially specimens much attacked by animals, the development of the organs of propagation in all rather seldom takes place. Moreover, from a certain age the plant appears not to develop reproductive organs, though the vegetative part still continue its growth, the plant being alive.
The crustaceous species are on the other hand more com- monly furnished with organs of propagation, mostly sporangia.
The named organs after being founded appear in their further development also to be checked by attack of animals, especially the conceptacles of sporangia, but probably also those of antheridia and cystocarps. I have seen rather numerous superficial concept- acles of sporangia filled with animals or animal substance, and still more overgrown, many of which apparently attacked before growing down into the frond. Besides, the sporangia themselves may often be infested with small perforating alge, or animals.
The colour of the Lithothamnia also is subject to much va- riation. In deep water it nearly always seems to get darker than in more shallow, but, on the other hand, less varying. Growing n shallow water especially with sandy or else light bottom it gets very light, and the part turning upwards even whitish in summer,
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but dark in winter, and in this respect showing a great difference. Thereby even the colour of a fracture of the plant becomes rather varying. On the other hand, specimens living in the litoral region, on the bottom of deeper and shady rock-pools, or else in the named region covered with Mucaceew and other alge, appear to be less varying in colour. However, being much exposed to the light, or changing strong light and shade the colour here some- times seems to be even more variable than in the upper part of the sublitoral region. Some specimens change their colour much in drying, others less, and are, as a rule, rather fading.
I have subsumed the genus Lithophyllum as a subgenus of Lnthothamnion, and the Lithothamnia proper I propose to name Eulithothamnion. The former was originally established as a genus by Philippi’), by him, however, only characterized from the external shape. In the same sense Ktitzing?) afterwards quoted both as sections of his genus Spongites, however, species of Lithophyllum in some cases referred to Mastophora Dcsne.*). Areschoug*) was the first, who pointed out certain peculiarities in the development, and regarded Lithothammion and Lithophyllum as co-ordinate genera. Rosanoff?®) followed him and drew more thoroughly the limits between them.
However, according to Rosanoff 1. c. and Solms-Laubach’) there is no definite distinction in the development of the organs of propagation between both the named genera. Strémfelt*) sup- poses, that the walls of the sporangia in Lithothammion are formed all but simultaneous, but in Lithophyllum successively. It is already shown by Kolderup Rosenvinge®) that this cannot be the case. I have seen in more species of the former bearing four- parted sporangia numerous not fully developed ones, and the parti-
1) In Wiegm. Archiv, p. 387.
2) Phyc. gener. p. 386.
3) Kitz. Spec. Alg. p. 696.
4) In J. Ag. Spec. Alg. Il, p. 520. 5) Mélob. p. 97.
8) Corall. Monogr. p. 62.
TY) Algveg. Isl. p. 22.
8) Grenl. Havalg. p. 780.
to
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tion, so far as 1 have been able to judge, always taking place successively. In some species, and especially those provided with superficial conceptacles, it appears, however, that the walls of the tetrasporic sporangia are founded in a more quickly succession. In others, on the contrary, and especially in species with immersed conceptacles, the partition takes place in a more slow succession, and the middle wall often appears to be fully or nearly fully developed before the two other walls are founded. Thus it often looks, as if the sporangia were only bisporic, sometimes with a well developed wall, sometimes even looking fully developed, but others in the same conceptacle or in other ones of the same spe- cimen showing more or less indistinct partition of the one or both cells; or one or both other interwalls partly so far founded partly more developed, and the partition at first issuing only from the one side.t) Once I have seen the middie transverse wall later developed than the two other walls. And in the same group of species I also have seen overgrown sporangia only two-parted, probably not fully developed before they, together with the con- ceptacle, grew down into the frond. It is in this connection to be remarked, that I, on the other hand, have not seen anything which with probability seems to suggest, that a species produces both bisporic and tetrasporic sporangia. If perhaps it may now and then occur, that a species provided with the one kind of sporangia also bears fully developed sporangia of the other kind, this must most probably be considered only an abnormal develop- ment. So also in regard to the three-parted and irregularly three- or four-parted sporangia which occasionally may be met with, though in all seldom and, so far as I] have seen, only in species of the section Innate.
Thus the only distinction between the named genera consists in a difference as to the vegetative part of the plant. In this re- spect I refer to Solms-Laubach 1. c, who has shown almost fully transitions between both.*) Moreover, Rosenvinge mentions
1) Cp. under ZL. orbiculatum, L. coralloides and other species.
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2) Mentioning Lithothamnion Solms-Laubach remarks |. c. p. 26: ,Bei consequenter Anwendung des unterscheidenden Merkmals wiirden freilich.
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l. c., that in thin crusts of Lvthothamnion tenue Rosenv. (L. Strémfeltz2 mihi) the structure may rather approach that of Litho- phyllum Lenormand: (Aresch.). 1 found in the former the struc- ture occasionally so nearly approaching, or even almost fully coin- ciding with that of the last named species, that in my opinion any true limit cannot be drawn. Other and coarser species of both genera seem to approach one another much in habit, and probably they are also as to the structure nearly related. Lithoph. crispa- tum Hauck, Meeresalg. p. 270, t. Il, fig. 3 reminds one much of certain forms of Lithoth. imcrustans f. Harveyt (L. polymorphum Harv.), and Mr. Batters informs me, that the latter often comes near to Lithoph. expanswm (Phil.) in appearance. On the other hand Lithoth. dendatum (Kiitz.) Aresch. seems as well to be referrible to Lithophyllum as coarser forms of Lithoph. cristatum (Menegh.), supposing the structure of these species stands in the same relation as Lithoph. decussatum and Lithoph. expansum to other species of Lithothamnion. Cp. Hauck 1. c. t. Il, fig. 2,5 and Solms-Laubach 1. c. L. mvestiens occasionally reminds one of certain forms of Lithoph. lichenoides in habit, and even as to the structure much approaching, or perhaps nearly coinciding with that of the named species. 1, however, have not had the Opportunity to examine any of the coarser forms of Lithophyllum. The structure is in all rather varying, and also the size of the cells may be somewhat differing in specimens of one and the same species.
I, therefore, consider Lithophyllum a not well characterized subgenus of Lithothamnion. Ihave, on the contrary, been in doubt whether it ought not, perhaps, to be drawn in even as such. Farlow!) subsumes it under Melobesia, and Batters?) considers
hierher auch die meisten Lithophyllen zu rechnen sein. Bei L. decussatum
und L. expansum tritt ein derartiges Dickenwachsthum, wennschon in rudi- mentarer Form, gewdbnlich auf; dasselbe kann soweit gehen, dass die ersterzeugten Conceptacula ins Gewebe versenkt, und dass ttber ihnen neue gebildet werden. Zwei dergleichen Ubereinander gelegene Schichten fanden sich Gfters, drei erinnere ich mich bei L. decussatwm nur selten gesehen zu haben“.
1) Mar. Alg. New Engl. p. 179.
2) Mar. Alg. Berw. p. 139.
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it a subgenus of Melobesva, but the latter is probably to be re- garded a rather well defined genus, to which Lithophyllwm is less related than to Lithothammion.)
I have divided Hulithothammon into two sections, Innate and Hvanide, the one comprising species by which the concept- acles of sporangia grow down into the frond, the other species by which this is not the case. There is, certainly, not any de- fined limit between these two sections, as transitions now and then are to be found, but that appears rather to be conditioned by external causes. Sometimes in species of the first named sec- tion, by which the thickening meristema of the frond apparently is superficial, overlapping the roofs of the conceptacles and the latter growing down into the frond the cavity may be found filled with new-formed tissue. That is, however, so far as I have seen, nearly always formed by new local formations and most often in species by which the conceptacles are not much immersed, and the whole roof for some reason fallen away, or dissolved. Toge ther with the overyrown conceptacles is to be found some sporan- gium not escaped, or sometimes even ail or nearly all the sporangia formed, partly apparently mature partly but little developed. In species of the other section, with the thickening meristema of the frond apparently lying below the basal surface of the conceptacles, I have never seen overgrown ones, not even in Species with im- mersed conceptacles.
The conceptacles of cystocarps and antheridia always use to be superficial, or as a rule very little immersed. The former ge- nerally do not grow down into the frond, the whole roof falling away and leaves a cup-shaped scar in most cases with elevated edges. The latter, probably, do not, as a rule, become overgrown. I have in four species of the section Innate (L. dehiscens, L. fruticulosum, L. polymorphum and L. flavescens) seen overgrown conceptacles of cystocarps. This is caused thereby, that the roof
1) .Wenn schon zwischen Melobesia und Lithophylium intime Beziehungen bestehen, so lassen sich diese Gattungen doch im entwickelten Zustand wenigstens an bestimmten Merkmalen erkennen“. Solms-Laubach |. ec. 1p A6),
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either is not dissolved and has become overlapped by a new thicke- ning layer of the frond, or, at maturity, only the uppermost part of the roof is fallen away, and the cavity under the remaining part gets overgrown by a new thickening layer or a local new formation; or, as in L. polymorphum and probably also in L. merustams, by the conceptacles frequently being somewhat im- mersed, and in such cases perhaps always getting overgrown. In species of the section Evanide I have also seen the roof of the cystocarpic conceptacles only in part dissolved, but at the same time the cavity effaced by a new thickening layer of the frond and, therefore, the conceptacles not become overgrown, nor a sec- tion of older parts of the frond showing scars after conceptacles nlled by local formations of tissue. This, no doubt, corresponds with the above mentioned difference in regard to the thickening meristema of the frond.
In reference to the character of species I have, besides the general appearance and development of the plant, particularly laid stress upon the shape and size of the conceptacles of sporangia, which, in my opinion, affords a good and in most cases recogni- zable characteristic. But the size of the sporangia themselves is, on the other hand, rather varying, and in shape they are in ge- neral much varying even within one and the same conceptacle. Therefore, they cannot as a rule in this respect serve as an identi- fying character, setting aside their partition. The conceptacles of -cystocarps are often uniform in different species, in others again there may be some difference, though in most cases only as to the size. The carpospores are so uniform in the different species examined and, on the other hand, mutually so varying in shape as well as size, that I have in the character of species taken no account of them. The conceptacles of antheridia are, so far as I have seen, always of the same or nearly the same shape as the cystocarpic conceptacles, but probably always smaller. The sper- matia are, 1 expect, equal in variation to the carpospores, and in this respect the one species nearly resembling the other. Cp. Born. et Thur. Etud. Phyc. p. 99. It should, however, be remarked, that 1 have not seen or examined any great number of the last
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named ones, nor of the carpospores, and it may be, that those I have seen have not always been fully developed.
Besides the Lithothamnia collected by myself, I have had the opportunity to examine a rather great number of other specimens from different localities and herbaria, also from abroad, and among these several original specimens, which, I hope, has enabled me to give to the following list of species a degree of accuracy it could not otherwise have possessed. I would here express my sincere thanks to Professor A. Blytt for his permission to exa- mine the collection of alge in the University’s botanical Museum at Christiania and fossil Lithothamnia collected by him at Bode; to Cand. real. P. Boye for specimens from the west coast; to Cand. med. O. Bugge for fossil specimens from Bodo; Mr. Kr. Dahl for numerous specimens from the harbour of Varde obtained by the harbours stirring up mud; the Rev. Gunnar Frette for winter-specimens from Fréjen; Cand. real. H. H. Gran for various species from the west coast and the Christiania Fjord; Docent B. Hansteen for specimens from the west coast; Stud. techn. Sig- vald Schmidt-Nielsen for specimens from the outer part of the Trondhjem Fjord; Conservator Sparre Schneider some species found in a zoological collection from Spitzbergen brought together by Capt. Niels Johnsen of Tromsg; Stud.med. Kr. Schreiner specimens collected at Heré in Helgeland and summer- as well as winter-specimens from the Christiania Fjord; the head-master A. C. Ullmann specimens from the botanical collection in Kragero Mid- delskole; and Professor Dr. N. Wille specimens collected at Mandal. I am particularly indebted to Mad. A. Weber van Bosse of Amsterdam for several original specimens from the late Dr. F. Hauck’s herbarium for comparison; to Mr. E. A. L. Batters of Wormley for several British specimens and informations as to Harvey's Lithothamnia in Phyc. Brit.; Dr. Ed. Bornet of Paris for an original specimen from Crouan’s exciccata for examination, and various other French specimens; Mr. F.S. Collins of Malden, Mass. for American specimens; Professor W. G. Farlow of Cam- bridge, Mass. one of the species quoted in his Mar. Alg. New Engl.; Professor Dr. Chr. Gobi and Mr. C. Deckenbach of St.
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Petersbourg specimens from the White Sea; Professor Dr. F. R. Kjellman of Upsala a fragment of what he supposes to be L. fasciculatum Aresch.; Dr. P. Kuckuck of Helgoland several specimens there collected; Dr. Kolderup Rosenvinge of Copen- hagen the species described in his Grenl. Havalg.; Professor van Tieghem and Mr. P. Hariot of Paris original specimens for comparison from Crouan’s collection in Museum d'Histoire Na- turelle; Mr. Geo. Will. Traill of Edinburgh for British specimens ; and to Professor Dr. V. Vittrock of Stockholm for permission to examine the late Professor J. E. Areschoug’s herbarium in the Riksmuseum.
I have previously distributed several Lithothamnia and quoted most of the northern species in Contrib. I and II. As it appears from the following, my apprehension of some of the species or their limits is, however, not the same as then. I want, therefore, to remark that specimens hereafter distributed will be accompanied by a reference to the present paper.
Trondhjem 27. il. 1895.
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Gen. Lithothamnion Phil. in Wiegm., Arch. p. 387; Aresch. in J. Ag. Spec. Alg. 2) ps ol9; Rosan. Melob. p. 96.
Subgen. Eulithothamnion Fosl. mscr. Lithothamnion s. s. auct.
Sectio I. Innatee Fos]. mscr.
Conceptaculis sporangiferis demum innatis.
Lithothamnion boreale Fosl. Contrib. H, p. 2. Descr. et Fig. Lithothamnion boreale Fosl. 1. c. et t. 1.
Syn. Apora polymorpha Gunn. in Act. Nidros. p. 70; ex parte?
Remark on the species and its synonomy. Of this vigorously developed species no other specimen has been found than the solitary and sterile one described 1. c. A fragmentary one from Mehavn in East-Finmarken may perhaps be referrible to the pre-
ent species. The latter, however, only forms the uppermost part of the branch-system of a larger specimen, and, therefore, it cannot be determined with certainty.
In Gunnerus’ zoological collection in the Museum (Scientific Society) here are four specimens of Lithothamnion'), one or two of which probably being nearly related or referrible to L. boreale. They are, however, fragmentary and sterile, forming a part of a larger specimen like the above mentioned, and, as no locality is known, not even wheter they are collected on the Norwegian coast,. I have not examined them more closely.
elation to other species. The plant appears to be nearly related to certain forms of ZL. glaciale. However, it must be considered a separate species, even if the organs of propagation may prove to be identic, characterized especially by its vigorous
1) Cp. under L. fruticuloswm.
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and long branches. Besides, from the lower part of the hypothallus at first apparently crustlike and pretty strongly developed in a later stage of development coarse and ocsasionally decumbent branches issue, so that the hypothallus by and by forms a subcentral main axis, which never appears to be due to L. glaciale.
Habitat. The species apparently lives in the lowest part of the sublitoral region, or in the elitoral one. It is said to have been picked up by fishermen from a depth of 20—30 fathom.
Occurrence. Hitherto with certainty only found at Gjesveer in the neighbourhood of the North Cape, a solitary specimen.
Lithothamnion glaciale Kjellm.
N. Ish. Algfl. p. 123 (93).
f. typiea Fosl. mscr.
f. ramis conicis, obtusis vel subcylindricis, usque 7—8 mm. altis, inferne diametro usque 5 mm. Fig. Lithothamnion glaciale Kjellm. 1. c. t. 2—3.
f. torosa Fosl. mscr.
f. crusta tuberculis subhemisphzericis, 0.5—1 cm. magnis in- structa. Tab. nostr. 1.
Syn. Lithothamnion calcareum Kjellm. Vinteralg. p. 64.
Kleen, Nordl. Ale. p. 11; sec. Kjellm.
: fasciculatum Aresch. Obs. Phyc. 3, p. 5 (ex parte); sec. Kjellm.
i Gobi, Algenfl. Weiss. Meer. p. 22.
H s Kjellm. Spetsb. Thall. 1, p. 3, Algenv. Murm. Meer. p. 7.
‘ glaciale Fosl. Contrib. I, p. 7.
3 5 Strémf. Algveg. Isl. p. 18.
‘ . Roseny. Grénl. Havalg. p. 773.
Remark on the species and the defimtion of the form. The most extreme forms of this species are rather differing. It probably includes more than the above quoted ones, but they are on the other hand not well defined, as transitions frequently are to be found. The form figured by Kjellman 1. c. I consider to be the ' typical one, characterized by its mostly numerous conical branches in the crust as well as the lobes. Smaller specimens of this form
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sometimes approach L. varzans f. verrucosa in habit and may be even difficult to separate in a sterile state. On the other side it passes into the form torosa, in which the crust and lobes bear more or less subhemispherical, smaller or larger processes, in some respects corresponding with the form aregulare of L. varians, being, however, a much larger and coarser plant than the latter. At Kjelm6 in East-Finmarken I also met with a form, in which the simple branches are rather thicker than in the typical one carrying more or less numerous wart-like processes, and now and then even forming bundles, in all most closely related to the named form. I, however, did not succeed in finding the sporangia, but the conceptacles fully resemble those in LZ. glaciale. Cp. pl. 2, fig. 2, a specimen anastomosed with L. breviaxe. The species is, in the Arctic Sea, one of the largest of the genus, attaining a dia- meter of at least 0.5 m.
The conceptacles of sporangia frequently are, in the specimens that I have seen, somewhat larger than those quoted by Kjellman l. c., or the circular or oblong and convex roof up to 400 p, most frequently about 300—350 p» in diameter. It is intersected with 50—70 canals, which are crowded in the middle of the roof. After the central or greater portion of the roof is nearly dissolved, this portion often gets somewhat depressed, and then it looks, in a certain stage, as if the conceptacles were surrounded by an annular border. Sometimes the whole roof falls away, and the scar be- comes effaced by a local formation of tissue. The sporangia ap- pear to be much varying in size. I found them up to 180 p long and 80 ye broads i Con kG elite:
I have not seen cystocarpic conceptacles in typical specimens of this species, but some few ones found in a form apparently referrible to f. typica are conical, low and about 400 p in diameter at the base. Some other conceptacles are about 250—300 yp in diameter at the base, probably antheridian ones, and in shape agreeing with the former.
Relation to other species. The present plant is a true hyper- borean Lithothamnion, that has probably originated within the Arctic Sea, and not unlikely more species have issued from it and been
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developed in a more southward direction, for inst. LZ. boreale, L. varums and L. colliculosum. As mentioned above, smaller indi- viduals of the species in question may be confounded with L. varians, but the sporangia are not yet well known in the last named species. On the other hand, as remarked by Kjellman 1c. it shows some affinity to L. fruticulesum (L. mtermedium Kjellm.). Although they are in general easily distinguished by the external shape, one or the other sometimes assumes forms which in a steril state may be difficult to identify, or easily con- founded.
Habitat. Along the coast of Finmarken the species generally lives on a depth of 10—20 fathom, and here it apparently prefers sandy and shingly bottom. It is found on open shore as well as in sheltered places, and it penetrates rather far up the fjords. Here, I occasionally met with it on a depth of only 3—5 fathom. Spe- cimens collected in July and August have partly been sterile partly richly provided with ripe sporangia, or newly emptied conceptacles.
Occurrence. With us. the species apparently is most com- monly dispersed along the coast of East-Finmarken. Here it has been found at several places, partly even abundant. I met with it at Kjelm6, pretty plentiful but local, Vard6, Mehavn, Kjollefjord, and at Lebesby in Laxefjord, local but abundant. It appears also to be dispersed along the whole coast of West-Finmarken, but here apparently less numerous, except perhaps in the most eastern part of this district. It has been found at Kistrand in Porsangerfjord (f. typica and f. torulosa), Kjelvik, Mageré Sound, Maas6, Gjes- ver, Kvalsund (f. torwlosa) and Bergsfjord. Within Tromsé Amt Kjellman collected it at Karls6, and I found a small specimen in Polden in the inner part of the Lyngen Fjord. I also met with some few specimens at Troms6 and Mestervik in Malangen, but they are sterile and rather uncertain. Within Nordlands Amt Kleen I. c. quotes it from Fleinver and Giver, not far from Bod6, and I gathered a specimen, however, uncertain at Borgever in Lofoten, apparently anastomosing with LZ. varians and mentioned under this species.
Geogr. Distribution. Spitzbergen and the west coast of No-
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vaya Zemlya (Kjellman); the coast of Russian Lapland (Gobi); Greenland (Rosenvinge); Iceland (Strémfelt).
Lithothamnion breviaxe Fosl. mscr.
L. fronde initio plerumque circum lapides vel conchas effusa(?),. demum libera in fundo jacente, diametro usque 20 cm., irregu- lariter subdichotome ramosa, ramis brevibus, confertis, subcylindri- cis, 2 mm. crassis, plus minus coalitis, parte superiore uno alterove ramulo brevissimo, verruceeformi szepe preeditis, apicibus obtusis; conceptaculis sporangiferis convexiusculis at parum prominentibus, diametro a superficie visa 350—450 »; conceptaculis cystocarpi- feris depresso-conicis, diametro 400—500 . Sporangtis quaternas sporas foventibus, circa 160 » longis, 45 p latis. Tab. 2.
Description of the species. Of this plant I have seen but an old specimen, and a younger one probably belonging to the same form, and besides 1 met with some few others anastomosing with a form of L. glaciale. However, this anastomose was in most cases so thoroughly, that any limit is impossible to draw especially in the central or lower part of the plants. Pl 2 snes 25 i tise named younger specimen appears not to have been fastened to: any harder object, subglobose and branched from the centre, but here the branches rather anastomosed in an apparently early stage of development. The other and old specimen appears to have at least in part encompassed a stone or another object, which later is fallen out. It is about 22 cm. long, 15 cm. broad at the broadest part and *8-—10°cm. im “‘thickmess, “Pl) 2) “tie? 1) Sit iseeioeepaee somewhat hollow, and has apparently at first been provided with a thinner crustlike hypothallus, but shows in an older stage only here and there a tendency to continue a crustlike development of this hypothallus, or is in part rather rubbed. The specimen is branched in an irregular subdichotomous or trichotome manner, with very short axes. The branches are densely crowded in the upper part as well as in that turning towards the bottom, sub- cylindrical and about 2 mm. thick, partly rather straight partly somewhat bent and frequently fastigiate, and the ends as a rule
17)
optuse. The upper part of the branches offen carry some short, wartlike process, and especially the lower part rather anastomosing.
The structure of the frond accords with that of LZ. fruticulo- sum. The cup-shaped layers of tissue are rather regular and distinct.
The conceptacles of sporangia are convex, but little prominent, seen from the surface 350—450 in diameter and scattered in the upper part of the branches, more seldom somewhat crowded. The roof is intersected with 60-—70 muciferous canals, rather thin and gets occasionally quite dissolved, and the scar effaced by local formations of tissue, frequently, however, only the central portion, as in most other species of this section. I succeeded in finding but some few sporangia, however, not all fully developed. Mature ones are four-parted, about 160 » long and 45 p broad. Over- grown conceptacies are very scarce in the specimens that | have examined.
The conceptacles of cystocarps are conical, low, traversed by a canal at the summit, and 400—500 p in diameter at the base. I found some few ones on a younger branch developed in the outer part of the cavity of the plant. I have not seen the carpospores.
elation to other species. This plant seems to be closely related to L. fruticulosum, or in some respects forming an inter- mediate species between this and ZL. glaciale, more nearly allied, however, to the former and sometimes apparently difficult to di- stinguish. In habit it stands between ZL. fruticulosum f. typica and f. fastigiata, and is separated especially as regards the con- ceptacles of sporangia and its tendency to form a crustlike hypo- thallus.
Habitat. The species grows on hard bottom on a depth of 5—6 fathom, found together with L. glaciale and L. fruticulosum in a somewhat sheltered harbour. Specimens taken in the begin- ning of August were rather richly furnished with conceptacles of sporangia, most of which, however, emptied, and others with in part apparently ripe sporangia.
Occurrence. Only found at Kjelm6 in East-Finmarken, where it appears to be rare.
18
Lithothamnion fruticulosum (Kiitz.) Fosl. mscr. Spongites fruticulosa Kitz. Polyp. calcif. p. 33; Spec. Alg. p. 699. Litho- thamnion fasciculatum Hauck, Meeresalg. p. 274; excl. syn. plur. f. typica Fos). mscr. Descr. Lithothamnion fasciculatum # fruticulosum Hauck 1. c. p. 274. Fig. i " Peta iy 000 s6ex, IG), ti, W/. fig. 4—5. ‘ Spongites fruticulosa Kutz. Tab. Phyc. 19, t. 99. 5 Lithothamnion fruticulosum f. typica tab. nostr. 3 et 4, fig. 1—2. f. fastegeata Fosl. mscr. f. ramis valde coalitis, fastigiatis, apicibus obtusis vel truncatis.. alloy, ).
f. omtermedia (Kjellm.) Fosl. mscr. Lithothamnion intermedium Kjellm. N. Ish. Algfl. p. 127 (7). Descr. et Fig. Lithothamnion intermedium Kjellm. 1. c. et t. 4, fig. 2.
f. nana Fosl. Contrib. II, p. 6. Descr. et Fig. Lithothamnion intermedium f. nana Fosl. 1. c. et t. 3, fig. 6.
f. glomerata Fosl. mscr.
f. fasciculis subglobosis e parte centrali solida undique egre- dientibus, ramis brevissimis. Tab. 4, fig. 3.
f. corymbiformis Fosl. mscr.
f. fasciculis subcorymbosis e parte centrali lobata undique egredientibus; ramis superioribus non vel parce coalitis, circa 2.5, mm. crassis. Tab. 6.
f. curvirostra Fosl. mscr. f. ramis superioribus curvatis, plerumque elongato-conicis vel
subulatis, apicibus obtusis vel acuminatis. Fig. Spongites ramulosa Kiitz. Tab. Phyc. 19, t. 99 (excl. concept. sporang.).
f. flexuosa Fosl. mscr. Descr. Lithothamnion fasciculatum s. s. Hauck 1. c. Fig. ‘ 5 4 Ten WO ater, WL te, Whee, Bh. % ° fruticulosum f, flexuosa tab. nostr. 7—8.
Syn. Apora polymorpha Gunn. in Act. Nidros. IV, p. 71; ex parte; t. 15, fig. 1°
Nullipora polymorpha Johnst. Brit. Spong. and Lithoph. p. 238; ex parte pl. 24, fig. 2?
Melobesia fasciculata Harv. Phyc. Brit. pl. 74; Man. p. 108; ex parte®
19
Syn. Lithothamnion ramulosum Phil. in Wiegm. Arch. p. 388; Kiitz. Tab. Phyc. 19, p. 35; Aresch. in J. Ag. Spec. Alg. 2, p. 524? Lithothamnion ramulosum Solms Laub. Corall. p. 19; ex parte?
s fasciculatum Farl. New Engl. Alg. p. 182; ex parte. $ Ungeri Kjellm. N. Ish. Algfl. p. 120 (91); excl. syn.; Fosl. Contrib. I, p. 8. As intermedium Strémf. Algveg. Isl. p. 19; Fosl. Contrib. I, Bo. Oe 5 5 Rosenyv. Grénl. Havalg. p. 774?
Remark on the determination of the species. As quoted below under L. crassum I consider L. fasciculatum (Lam.) to be most nearly connected or probably identic with that species. I conse- quently do not adopt this name for the plant, that Hauck l. c. more nearly describes under the name of L. fasciculatum. Judging from authentic specimens of the latter that I have seen, it in my opinion appears not to be identic with Lamarck’s plant, although probably nearly related to it. JI on the other hand agree with Hauck, that his plant most probably is to be referred to the same series of forms as L. fruticuloswm (Kiitz.), considered by Hauck a variety of his L. fasciculatum, though in part rather differing from that. Taking ZL. fruticuloswm (Kiitz.) in the same sense as Hauck it appears to constitute the typical form of a Lithotham- nion, which on the one side approaches ZL. glaciale and other species in habit, on the other side being closely related to L. cras- sum Phil., and I regard the named typical L. fasciculatum Hauck as one of the most extreme forms of this species, the above f. flexuosa.
However, the limits between this species and L. crassum are not easily drawn neither in regard to the external shape nor to the structure. Hauck remarks |. c. ,Manche Formen sind schwer von L. erassum zu unterscheiden“. I have seen too few specimens of the latter, an apparently more southern species, to be able to get any clear idea of their affinity to each other. In their typical forms they certainly are easily distinguished and even more diffe- ring than several other species of this genus. But on the other hand ZL. fruticuloswm is much varying and shows in its most extreme forms close affinity chiefly to L. crassum, and even to various other species which in their typical development are quite
20
different. They appear, so far as 1 have seen, to be distinguished especially as to the shape and size of the conceptacles of sporangia.
Remark on the definition of the form. The present plant includes numerous forms, the principal of which are quoted above. A couple of these might perhaps be regarded as separate species, but it has not been possible to draw any true limit, and I, there- fore, regard them as forms of the species in question, to which they appear at least to be closely related.
Through the kindness of Mad. A. Weber van Bosse I have had the opportunity to examine three specimens from Ha uck’s herbarium of his LZ. fasciculatuu 8 fruteculosum. One of these fully accords with specimens in my collection of the above f. typica. . Cp. pl. 3. The second is a younger individual, probably belonging to the same form. The third may perhaps also be re- ferrible to this form, but on the other hand it rather reminds one of LZ. nodulosum in habit, nor did I succeed in finding overgrown conceptacles of sporangia. The form is somewhat varying, but in general easily recognized. The branches more or less densely crowded are in Hauck’s as well as in my specimens generally 1.5—2 mm. thick, rather anostomosing especially in older individu- als, and frequently carrying short and wart-like or longer and branch-like processes. Pl. 3 and Hauck |. c. Much attacked by boring-muscles it occasionally becomes more or less hollow and opened in the lower part, but it apparently never assumes a cup- shaped form like several other Lithothamnia. In old specimens growing in shallow water with strong currents the upper branches frequently become more or less denudated, or biten off, the rest afterwards in part anastomosing, forming crustlike expansions, or here and there with new branches in development. PI. 3, fig. 6 and pl. 4, fig. 1—2. This form is in general to be found freely developed on the bottom, seldom encompassing shells or smaller stones. It attains a diameter of about 15 cm., more frequently, however, about 10 cm. or less.
The form fastigiata is nearly connected with the typical form. Pl. 5, fig. 7 represents a specimen somewhat approaching the latter. It also commonly develops freely on the bottom, sometimes fastened
21
_ to but seldom encompassing smaller stones. However, growing more scattered, or in the periphery of a greater bank it often fastens itself, apparently in a somewhat advanced stage of develop- ment, to smaller stones, but later again it appears to loosen itself from the stone. Pl. 5, fig. 4. Occasionally different individuals become confluent.. Pl. 5, fig. 3. In shallow sounds with rapid tides the frond often gets rather compressed, forming subdhemis- - pherical masses, that attain a diameter of 12 cm., more commonly, however, globose or subglobose and about 8 cm. in diameter, or less. The branches are short, generally shorter than in f. typrca, very densely crowded, straight and level-topped, and towards the apex nearly always carrying short and wart-like processes. It is much anastomosing especially in the central portion and here now and then forming lobes, however, the anastomose frequently ex- tending pretty far upwards, and here and there even nearly to the tip of the branches. The ends are as a rule obtuse or almost truncate; but particularly if being under the influence of rapid tides they become quite truncate in the part turning upwards, or also in the part turning towards the bottom, but, so far as I have seen, more seldom only in the last named part, and sometimes nearly disc-shaped. Under such conditions the upper part of the branches occasionally gets denudated, as in the typical form, however, appa- rently more seldom than in the latter. The plant frequently is much attacked chiefly by boring-muscles, and, as is common at least in nearly all the northern Lithothamnia, intersected with numerous passages made by worms, occasionally leaving only a thin peripherical portion; or a part of the plant, or even the whole plant collapses. PI. 5, fig. 4.
I have not been able to draw any limit at all between the plant that Kjellman 1. c. describes under the name of L. inter- medium and the present species, and I, therefore, consider it a form of this species. Specimens determined by Kjellman himself show transitions especially to the typical form of L. fruticuloswm, and, as I apprehend Kjellman’s description of his plant. it in part includes the named form. Thus fig. 1 on pl. 4 1. c. can scarcely
be separated from L. fruticulosum f. typica in the sense the latter 3%
i)
pa)
(5)
is taken by me. Cp. pl. 3. I on the other hand regard the plant delineated |. c. pl. 4, fig. 2 as typical or nearly typical f. mter- media. This form is characterized by its central or lower portion forming coarse and clumsy lobes, which are coarser than such ones in f. typica, or sometimes being nearly solid. From the named lobes issue simple and rather coarse, most often conically cylindrical branches with obtuse ends, now and then carrying wart- like processes. This form frequently encompasses smalier stones, and it apparently seldom attains any considerable size.
The form nana is in the cited paper recorded as little inde- pendent. It is rather characteristic in its typical development, but intermediate forms between this one and partly f. typica partly f. intermedia and occasionally even f. curvirostra are more generally to be found than quite typical specimens. It frequently is only O0.5—1.5 cm. in diameter. ;
The form glomerata is characterized by its generally solid central portion or occasionally coarse lobes, from which issue in all directions subglobose bundles of branches. These bundles are composed of very short branches, in their upper part carrying wart-like processes, and nearly always rather anastomosing, often even towards the apex. PI. 4, fig. 3. The ends are rounded or obtuse. If not much attacked by animals the central part is con- tinuing thick and solid, or intersected with cavities and canals, encompassing smaller stones, or not, but if attacked especially in a younger stage it forms coarse and clumsy lobes, and the plant sometimes at length becomes quite hollow. It attains a diameter of about 10 cm.
A rather independent plant is f. corymbiformis, and it, perhaps, ought to be regarded as a separate species. However, I have seen but few specimens of this form. On the one side it appears to pass into the typical form and on the other is nearly connected with f. glomerata, or even showing close affinity to f. flexwosa. It never forms a solid central portion, but coarser lobes, although not so coarse as in the preceding form. From the named lobes issue subcorymbose clusters of branches, which are far less ana- stomosing than in f. glomerata, but on the other hand coarser,
23
about 2.5 mm. in diameter, with longer and branch-like or shorter and wart-like processes. The ends are obtuse or, not seldom, some- what spherically thickened. Pl. 6, fig. 1. This form also becomes more or less hollow, caused by animals, especially boring muscles. Pl. 6, fig. 2 represents the upper part of a specimen, by which most of the branches are denudated, and rather more than those of the lower part of the plant. Fig. 3 on the same plate shows the lower and much denudated portion of a specimen most nearly related to this form, but in the upper and not denudated part not forming distinct bundles. It is hollow, and the cavity occupied by Mytilus, Pecten and other animals.
The form that I have named f. curvirostra so nearly accords in habit with the plant figured by KUtzing |. c., that I have referred to it. It is ZL. ramulosum Phil, and Kiitzing got the specimen from Philippi himself. Cp. 1. c. p. 35. I, however, am not sure whether my form in fact may be identic with that, as the apparently numerous conceptacles of sporangia, scattered or partly crowded over the whole plant in Kiitzing’s figure, do not agree with my specimens, being larger and apparently more superficial. Hauck 1. c. certainly refers this plant to his L. fas- ciculatwm, and it appears rather probable that they are identic and the conceptacles only delineated too large in Ktitzing’s figure. However, | do not adopt that name for the form in question, until an authentic specimen has been examined, as besides more species probably have been recorded under the same name. ‘This form is, most commonly, at first fastened to smaller stones, but it soon loosens itself and lies free on the bottom, then forming roundish balls about 4—5 cm. in diameter. It seldom encompasses stones. The lower branches are more or less anastomosing, the upper ones rather spreading and most often curved, at the base about 2mm. thick, elongated conical and acute in typically developed specimens. In others, however, the branches are often conically cylindrical and obtuse, seldom nearly cylindrical, and in the upper part occasionally bearing some wart-like process. Such specimens form transitions to f. flexuosa, and in part nearly related especially to Adriatic specimens of the last named form, which frequently
24
appear to be smaller than northern ones, and, being more densely branched, even to f. typica. It seems not to be any well defined form, although it deserves to be specially mentioned.
As quoted above, I consider the typical L. fasciculatum Hauck to be one of the most extreme forms of the precent species, the above f. flexwosa. I have seen 3 authentic specimens determined by Hauck as ,L. fasciculatum.“ The one of these agrees with specimens in my collection referred to f. typica. The two others accord with the form fleawosa, smaller but otherwise fully resembling the specimen represented pl. 7, fig. 1. This form apparently gets much larger with us than in the Adriatic Sea, attaining a diameter of up to 15 cm., or more, and as a rule freely developed on the bottom. I very seldom met with it fastened to or encompassing shells. The branches are less crowded than in f. typica, in the lower or central portion rather coarse, or forming smaller lobes, and more or less anastomosing, though far less than in the named form. They are rather spreading in the peripherical portion, much bent and about 2mm. in diameter, cylindrical, or sometimes slightly tapering towards the obtuse ends, which, however, now and then may be a little roundish-thickened. Pl. 7, fig. 1—2. It sometimes is rather rubbed in the part turning towards the bottom, and now and then in part hollow. PI. 7, fig. 3 represents a transition to f. typica, partly with’ the upper branches somewhat denudated. The form occasionally is provided with an apparently coarse hypo- thallus. Cp. pl. 8, fig. 1. This is, however, produced by epiphytic Lithothamnia, mostly L. flavescens. The specimen that Hauck delineates |. c. t. V, fig. 3 looks coarser than the specimens which I have seen from his herbarium, on the one side resembling and probably identic with f. flexwosa in the sense here taken, but on the other side reminding one of certain forms of L. tophaforme. A similar, but larger, form is represented on pl. 8, fig. 2. This also is coarser than typical f. flexwosa, closely related to or pro- bably identic with the latter, but on the other hand it coincides in several particulars with LZ. tophiforme. I met with this form in one locality growing in company with f. typica, typical specimens of f. flexwosa and L. tophiforme. In another locality I found the
oe.
AS
latter, f. typeea and transitions to f. flexuosa growing together. It is not unlikely that this form in part constitutes a hybrid between L.. fruticulosum and L. tophiforme, but on the other hand, as remarked p. 3, it appears nearly impossible in this extremely varying eroup Of species to decide whether hybrids in fact arise. The figured specimen exhibits transition to typical f. flexwosa, however, also closely approaching certain forms of L. tophiforme, that a
limit is very difficult to draw, and I possess several sterile speci-
mens which I have not been able to identify with certainty, as also J. tophiforme shows a tendency to develop itself in the same direction. It is nearly always sterile, or some other specimen very scantily provided with conceptacles of cystocarps and sporangia, the latter in this as well as in typical specimens of f. flexuosa sometimes approaching those of L. tophiforme. 1, however, have not succeeded in finding the sporangia in the named most extreme form, and it may be that this form in fact represents a Separate species.
The structure of the frond is described by Kjellman lc. I here only want to remark, that the inner cells of the cup-shaped layers in the branches or processes frequently appear to be about 10—12 p» long and 5—6 p thick. The named layers are more or less regular, in part depending on older overgrown concept- acles of sporangia.
The reproductive organs of this species are also described by Kjellman |. c. The conceptacles of sporangia in f. typica, f. fastigiata, f. imtermedia, f. glomerata and f. cwrvirostra resemble each other. ‘They are scattered especially in the processes or upper part of the branches or occasionally somewhat crowded, very little prominent, in part not distinctly marked, and the slightly convex roof frequently about 250—300 yp in diameter, more seldom only about 200 y. The roof is rather thick, and the muciferous canals appear to be visible from the surface first in a rather late stage of development of the conceptacles. In some specimens I partly found the central or greater portion of the roof thinly decorticated, and the canals visible and distinct in a number of about 30—40, partly not decorticated and the canals not visible. However, in
26
other specimens I found the roof apparently not decorticated, but the canals visible, so that this decortication perhaps may be atten- ded on external causes. Later the middle part of the roof gets quite dissolved, more seldom the whole roof. The sporangia I frequently found to be 110—140 p long, occasionally only about 90 or up to 150 », and 35—45 p» broad, seldom even up to 60 p. The thickness apparently is about +/, of the breadth, or more.) In f. nana the conceptacles as well as the sporangia themselves are slightly smaller than is general in the above quoted forms. In f. flexwosa they frequently agree with those in the other forms, but on the other hand sometimes a little larger, more distinct and more prominent, the roof up to 350 p in diameter, thinner and more easily dissolvable or falling away than in any of the other forms. Hauck 1. c. records the conceptacles to be ,,flach-warzenformig™ , which, so far as I have seen, accords rather better with those of L. crassum. In one of his specimens of f. flexuosa I found some few very little prominent, convex, but in part not sharpiy marked and in all fully agreeing with typical ones of the present species. In f. corymbiformis I have only seen overgrown conceptacles, which in a median section are of about the same size as in f. typica. Overgrown conceptacles in general are to be found only in the peripherical portion of the branches or processes, rather seldom in any greater number. The appear to be proportionally most common in the forms fastegzata, intermedia, nana, glomerata and curvirostra. In f. typica they sometimes are rather numerous, sometimes very few or apparently wanting, which appears to relate to the fact that the plant does not probably always develop the named organs, or that the whole roof occasionally falls away and the conceptacle becomes effaced by local formations of tissue, as for inst. in LZ. glaciale. In f. flexwosa overgrown conceptacles
1) ‘he sporangia of the present genus altogether appear to be convex-concave
and thickest in the middle, and, therefore, the measures of the thickness only are approximate. They appear partly to be thicker partly and appa- rently more frequently thinner in proportion to the breadth than above quoted, but more exactly measures are not to be got without dissecting the sporangia, which, however, may not be required in a systematic point of view, as they also in this respect seem to be rather varying,
yh
partly and most often occur in small numbers, partly not, and especially in the most extreme form of this type the overgrown as well as superficial ones appear to be very scarce. Also in Adriatic specimens of the two last named forms older grown-in organs of this kind seem to be scarce. Now and then occur apparently two-parted overgrown sporangia in this species, but these probably have not been fully deveioped before they together with the conceptacles grew down into the frond.
The cystocarpic conceptacles are in the present species conical, low, seldom somewhat acute, about 400—500 p in diameter at the base. Some other conceptacles, only 2CO—300 y in diameter at the base and in shape coinciding with the former, probably are those of antheridia. I have not seen the carpospores, nor the spermatia. These organs are on the whole scarce in the specimens that I have collected, and scattered in the branches without any order. Also in this respect the form flexwosa in part rather differs from the typical development, as | found the conceptacles of cysto- carps in some cases to be more acute than ever in f. typica or in other and more typical specimens of f. flexwosa as well as in Adriatic specimens of the latter, somewhat reminding one of these organs in L. topliforme.
femark on the synonomy. I suppose that Gunnerus referred to his Apora polymorpha all the Lithothamnia then known to him. Among the 4 specimens mentioned under L. boreale apparently from his own collection!) are two which, no doubt, belong to the present species, the one nearly according with the cited figure in Act. Nidros., referrible to the form fastgiata.
The figures that Johnston l.c. gives of his L. polymorphum are much differing from each other and most probably designate different species, and even still more judging from his list of syno- nymes. Thus the plant that he delineates 1. c. pl. 24, fig. 2 very much reminds one of f. intermedia of the present species, to which it probably belongs. The other forms referred by him to the same species will be mentioned under ZL. crassum and L. incrustans.
As remarked below under Z. crasswm Phil. I consider Z.
Yt) Cp. Wittrup, Catal. p. 88.
I8
fasciculatum Harv. in the main to be referrible to that species. By the liberal communications of Mr. Batters as to Harveys Lithothamnia there are, so far as he knows, no really authentic specimens in existence. I, however, got under the name of JZ. fasciculaiwm two specimens gathered by Mr. G. W. Traill at Falmouth, where the plant according to Mr. Batters has grown in the same locality since Harvey's time. They unfortunately are dead, bleached and rather rubbed, probably found cast on shore, and they cannot be determined with certainty, very likely, however, belonging to L. fruticulosum and most closely related to the typi- cal form.
I in part refer L. fasciculatwm Farl. to the species in gue- stion, on the authority of Mr. F. S. Collins, who kindly sent me a specimen stated to be the form recorded by Farlow |. c. under hat name. It is said to be ,common in pools at low-water mark along the coast of Maine“. However, it appears, as if the speci- men that I got has been washed ashore from the sublitoral region. This specimen I without any doubt refer to Lh. fruticulosum, stan- ding between f. typzca and f. intermedia, however, most nearly related to the latter. It is only 2—3 cm. in diameter, having appa- rently at first nearly surrounded a stone or another hard object, which is fallen out, and the cavity appears partly being effaced by new-formed tissue. The conceptacles are very little prominent and slightly convex, the roof about 250 » in diameter, intersected with about 30 canals, and they finally grow down into the frond. The four-parted sporangia age 90—115 p long and 35—45 p broad. A specimen kindly sent me by Prof. Farlow himself will be men- tioned under L. colliculosum.
Another specimen that I received from Mr. Collins most pro- bably belongs to the form fastagzata. Collins’ coll. A. ,Eagle Island, Maine. In pools at dead low water“. It is sterile and fragmentary, but has apparently been small, about 2—3 cm. in diameter. The lower part shows a tendency to form lobes, the branches fastigiate, with short axes, and rather anastomosing. The ends are obtuse or truncate, but in part somewhat denudated. The structure also accords with that of Z. fruticuloswm. Overgrown
29
conceptacles are numerous, and in one of these I found a solitary sporangium, about 100 » long and 50 p broad, but I was not able to determine the partition.
Prof. Kjellman records |. c. a Lithothamnion under the name of L. Ungeri, which he, among others, got from me, gathered at Troms6. He identifies this plant with LZ. byssoides Unger, Leitha- tenet 920) td. ie. tS, In Contrib. 1) es 1 followed Kyjelr man and quoted the plant under the same name from East-Fin- marken, by comparison of specimens determined by Kjellman himself. However, I then perhaps referred to it some specimens now considered to belong to another species. Later I have had the advantage of seeing Unger’s description, and I also brought together greater and better materials as then for the classification of these much varying alge. Two fragmentary specimens that I got back from Prof. Kjellman denominated as above agree with the form typica of the present species, the one, however, showing transition to f. corymbifornus and provided with an apparently coarse hypothalius like the above mentioned specimen figured pl. 8, fig. 1, but also this infested with an epiphytic Lithothamnion. He remarks, that the conceptacles of sporangia never grow down into the frond. I, however, found in the named specimens older grown-in organs of this kind, but they are scarce, which, as quoted above, is often the case in f. typica. It may be that Kjellman's plant includes also another species, or, more likely, the overgrown conceptacles escaped his observations. ‘The speci- mens then known were sterile. I on the other hand do not coin- cide with Kjellman, that this form may be considered identic with the named species described by Unger 1. c. This appears to be a smaller plant, with thinner branches, but otherwise cer- tainly somewhat reminding one of L. fruticulosum f. typica. 1 think it identic with L. gracilescens described below.
elation to other species. This species apparently has origi- nated in more southern wathers than for inst. LZ. glaceale, and it is not unlikely that several other Lithothamnia have issued from it, as L. crasswm, or vice-versa, L. breviaxe, L. divergens, L. apiculatum, L. dimorphum and perhaps also L. mamilloswm, and
‘~ 3.” . /
30
others. It is, as remarked above, nearly connected with J. eras- sum, but shows closer affinity also to the other named species, as well as L. glaciale in habit, and sterile specimens are some- times not easily separated from the latter. The form amtermedia may especially in a younger stage even be confounded with JZ. colliculosum. The distinction between the present plant and L. divergens, L. apicalatum and L. dimorphum will be quoted under the named species.
I have seen three authentic specimens of L. mamillosum Hauck, Meeresalg. p. 272, which I propose to name L. Hauckiz*), a species closely related to L. fruticulosum in habit, and probably sterile specimens may often only with difficulty be separated from the typical form of this. /@p. Tauck 1c. tos tiers However, it appears to be somewhat coarser, the apex of the branches sometimes rather acute and also showing some diversities of structure, the latter apparently coarser than in L. fruieculosum. Specimens bearing cystocarpic conceptacles are identified at a glance. These organs | found in the named specimens commonly to be 500—800 p. in diameter at the base, sometimes a little more, and of a considerable height. Hauck 1. c. quotes them in general being about 1 mm. in diameter. The elongated tip seems to fall easily away, and then the conceptacles look rather low, though still higher than in £. fruteculoswm. Besides, 1 found some other in shape similar conceptacles only about 300 » in diameter, which perhaps are those of antheridia. Conceptacles of sporangia appear to be unknown.
Habitat. The plant lives in the upper part of the sublitoral region, on a depth of 1—10 fathom. It prefers sheltered places and rather hard bottom, partly more scattered (especially f. anter- media, f. nana, f. glomerata, f. corymbiformis) partly abundant or in great masses (especially f. typica, f. fastegiata and partly also f. flexuosa), not seldom in sounds with strong currents. Sporangia-bearing specimens have been taken in June, July and
") Gumbel, Die sogen, Nullip. p. 41 records a fossil Lithotnamnion by the
name of L. manvilosum and, therefore, I propose the species to be named after the late Dr. F. Hauck.
31
August, and scantily provided with conceptacles of sporocarps in July and August.
Occurrence. The species, as understood in the above men- tioned comprehensive sense, is not unlikely dispersed nearly along the whoie of the Norwegian coast. It has been found at Kjelm6é in Sydvaranger, pretty plentiful but local (f. typiea); Bugénes, washed ashore (f. itermedia?); Vads6, cast on shore in rather ereat numbers (f. typica and f. intermedia); Vardd (f. typica, f. glomeraia); Hayningberg, washed ashore (f. mtermedia); Lebesby, apparently rather scarce (f. intermedia); Kistrand, rare (f. glome- rata); WHonningsvaag, washed ashore (f. intermedia?); Sopnes in Altenfjord, rare (an uncertain form, perhaps f. flexuosa); Skorpen in Kveenangen, scattered an £ ae er scarce (f. typica, f. mtermedia, f. nana, f. curvirosira); Karls6 (Kjellman), scattered (f. enter- media); Lyngo, rare (f. oe a Tromsd, abundant but rather local (f. typica, f. mtermedia, f. flexwosa, f. corymbifornus); Mester- vik in Malangen (an uncertain form, perhaps f. flexwosa); Borgeveer in Lofoten, cast on shore (f. typiea); Herd in Helgeland (Kr. Schreiner), apparently not uncommon (f. typica and f. wter- media}; Beian, abundant but rather local (f typeca and f. faste- giaia); and Moltuen (Vernes) in the Trondhjem Fjord (Sigvald Schmidt-Nielsen), apparently scarce (f. cwrvirosira). It probably also occurs along the south-western coast, however, principally but some few and smaller Lithothamnia are known from there.
Geogr. Distribution. Iceland (Stromfelt); Greenland (Rosen- vinge)? Britain (Harvey, Johnston, Traill)? The Mediterra- nean Sea (Ktitzing); the Adriatic Sea (Hauck); the Atlantic coast of North America (Farlow, Collins).
Lithothamnion crassum Phil.
in Wiegm. Arch. p, 388; Hauck, Meeresalg. p. 273.
f. typica Fosl. mscr.
f. ramis tenuioribus, in parte superiore sepe subcompressis, non vel parce coalitis.
Fig. Lithothamnion crassum Hauck |. «. t. 1, fig. 1, 3.
f. capitellata Fosl. mscr.
32
f. ramis plerumque crassioribus, validis, valde coalitis, apicibus. crassis, rotundatis. Fig. Lithothamnion crassum Hauck 1. c. t. 1, fig. 2.
Syn. Millepora fasciculata Lam. Hist. Anim. 2, p. 311? Nullipora i Johnst. Brit. Spong. and Lithoph. p. 240, pl. 24, fig. 6. 5 polymorpha Johnst. 1. c. p. 238; ex parte; t. 24, fig. 1, 3.
Melobesia fasciculata Harv. Phyc. Brit. pl. 74; Man. p. 108; saltem
ex parte.
Spongites crassa Kutz. Tab. Phyc. 19, p. 38, t. 99.
‘ fasciculata Ktitz. Spec. Ale. p. 699; fide syn.
Lithothamnion fasciculatum Aresch. in J. Ag. Spec. Alg. 2, p. 522;
ex parte fide syn. - Craw inisth yp. wliolee racemus Aresch. an J. Ag! Ic) pi o21e ii Crnemlcene= 151; Solms Laub. p. 17; ex parte?
Remark on the determination of the species. There can be no doubt as to the identity of this species. The figure by Kiitzing l. c. is from a specimen that he got from Philippi himself, and it on the other hand accords well with Hauck’s description and figures. Through the kindness of Mad. A. Weber van Bosse I have had the opportunity to examine three authentic specimens. from Hauck’s herbarium. Two of these nearly coincide with fig. 1 and 31.c, the above f. typzca, and the third one forming transition or most nearly related to f. capztellata. The species seems to be rather varying and probably includes more forms. |, however, have seen but some few specimens.
Remark on the form and addition to the descpruption of the species. The form that I apprehend as the typical one is densely branched, but the branches appear to be rather thin and apparently less anastomosing, probably most often only in the lower or inner part, always, however, thickening towards the apex, and especially here often somewhat compressed, with the ends frequently rather obtuse or nearly truncate, or even depressed in the centre. This form has not been found with us.
A solitary specimen from Mandal nearly agreeing with fig. 2 by Hauck lc. I refer to the above f. eapitellata, as well as another one found washed ashore at Krageré and scantily provided
oo)
with conceptacles of sporangia. The named form is characterized by its in general apparently more vigorous and coarse branches, which probably as a rule become much anastomosing and in part even nearly to the apex, the latter being thick and rounded.
The structure of the frond agrees in the main with that of L. fruticulosum. ‘The cup-shaped layers of tissue are rather regular. The inner cells of these layers are about 12—16 » long and 6—8 p-thick, thus in general apparently a little larger, and often a little thicker in proportion to the length than in the named species. Overgrown conceptacles are partly scarce partly numerous.
The cystocarpic conceptacles, which are mentioned by Hauck ]. c., are conical, low, and about 400 p» in diameter at the base. They are at the summit intersected with a canal, which, contrary to most other species, appear to be formed in a rather advanced state of the development of the conceptacles, as in others and apparently nearly fully developed ones the canal was not visible. I, however, have seen but some few ones in one of Hauck’s specimens of the typical form. The carpospores are much varying both in shape and size.
I found conceptacles of sporangia in the above mentioned specimen of the form capitellata from Hauck’s herbarium. They are scattered or somewhat crowded towards the apex of the branches, slightly prominent and in general rather flattened, 350— 450 » in diameter, seldom less. A British specimen mentioned below has been richly provided with conceptacles of sporangia, scattered and in part crowded nearly over the whole frond, but it is dead and the roofs quite dissolved except some few according to those quoted. However, judging also from the holes after the conceptacles, they seem to have been a little smaller, or about 350—400 p in diameter. In the above named Norwegian specimen I also found some similar conceptacles. The canals appear not to be numerous. I have numbered about 30—40. The sporangia, of which I have seen but some few, are four-parted and about 160 p» long and 40 p broad. .
Remark on the synonomy. It is a fact, that in Lathotham- mion the various species have been more confounded and diffe-
A
(62)
rently understood by different authors than in any other genus of the higher algze. It is, therefore, in many cases impossible, without having access to original specimens, to determine what an author has meant by a species recorded. In this respect L. fasciculatum (Lam.) affords a striking example. It has been very differently understood, and under this name have been quoted more sharply distinguished species. Even by Areschoug, the monographer of the Corallineze, this species is taken in a wide sense probably in- cluding at least 3—4 species now separated, for inst. L. glaciale, L. crassum (L. fasciculatum Harv.), L. tophiforme (L. soriferum Kjellm.) and L. apiculatum. Cp. Kjellm. 1. c. and below under the named species. The plant to which this name was originally applied by Lamarck is considered by Kjellman 1. c. to be a species nearly related to L. tophiforme (L. soriferum), but in some respects different. It certainly is impossible to know what has really here been stated. I agree with Kjellman, that the character ,ramis . . . apice incrassatis, obtusis“ does not in general accord with L. tophiforme, although the last named species includes a form a little thickened towards the apex of the branches, and the latter even truncate or nearly truncate. This form I, however, regard a merely local one, of which I have seen some few speci- mens from Finmarken. The plant that Kjellman from oral infor- mation considers to be identic with LZ. fascoculatwm will be men- tioned under LZ. dimorphum. In my opinion L. (Millepora) fas- ciculatum Lam. is identic with the present plant, the characters quoted on the whole pretty well according with certain forms of this species, and appears to have been apprehended in like manner by Johnston, Harvey and Crouan.
Melobesia fasciculata Harv. 1 suppose most essentially being included in the species in question, and is considered by Harvey himself not unlikely to be the same as L. crassum Phil. It is by Hauck 1. c. referred to his L. fascoculatum (L. fruticulosum), but this i think rather to be a slip of the pen. The figure 1 in Phyc. Brit. 1. c. much reminds one of L. crassum, and fig. 2 appears also to be a form of the same species, if not, perhaps, more nearly related to L. incrustans f. Harvey. Besides, Harvey remarks
30
l. ¢., that the branches are ,remarkably truncated at the tips, which are moreover depressed in the centre. These broad, flat- tened or subconcave tips are the least variable character of the species*. So far as my experiences goes, this is not due to any form of L. fruticulosum, or any other species hitherto known but LI. erassum, in the latter, however, apparently often occurring. So also in regard to one of Hauck’s specimens of the typical form. I got a specimen collected at Falmouth by Mr. R. N. Tellan and determined by Mr. Batters as L. crassum, also by him considered in part identic with Harvey's plant. It has a nearly solid central portion, and the densely crowded and nearly fastigiate, rather coarse branches are very short and almost simple, with rounded- thickened ends, and in all most closely connected with the above f. capitellata.
Nullipora fasciculata Johnst. doubtlessly belongs to the same series of forms. Cp. 1. c. pl. 24, fig. 6. Besides, probably also in part his L. polymorphwm. ‘Thus pl. 24, fig. 1 and 3 l.c. appear likewise to be referrible to the present species.
Of L. fasciculatwm Crn. I have seen some fragments of an authentic specimen from Crouan’s collection in Museum d'Histoire Naturelle of Paris. They are, however, too small to be determined. with certainty, as they are also sterile. The specimen appears to have been very nearly related to fig. 2 by Harvey 1. c., not unlikely being a form of the present species, or perhaps referrible to L. incrustans f. Harvey.
LI. racemus auct. appears to be a very uncertain plant. Hauck, who has perhaps seen original specimens, refers the form recorded. by Solms-Laubach 1. c. to L. erassum. The plant, to which the name was originally applied by Lamarck I. c. p. 311 I, however, should be most inclined to refer to LZ. fruticulosum.
Relation to other species. As quoted under L. fruticuloswm these two species are closely related to one another. However, if the shape and size of the conceptacles of sporangia may prove to be as a general rule like those described above, the species must be considered rather well defined. Also L. crasswm appears to show some affinity to certain forms of L. glaciale, but is separated.
36
by essential characteristics. It apparently sometimes even approaches L. incrustans {, Harveyt in habit.
Habitat. Unknown to me. The specimens found with us are picked up from the sublitoral region, or found washed ashore. It bears sporangia in summer.
Occurrence. Only known from the most southern part of the coast, gathered at Mandal (Wille) and at Kragerd.
Geogr. Disiribution. Britain (Johnston, Harvey, R. N. Tellan); the Atlantic coast of France (Crouan)? The Mediter- ranean Sea (Philippi); the Adriatic Sea (Hauck).})
Lithothamnion fornicatum Fosl.
Contrib. Il, p. 3; excl. var.
f. typica Fosl. mscr. Deser. Lithothamnion fornicatum Fosl. |. ¢c.; excl. var. Fig. 5 _ : PB ta 2) (Once):
f. robusta Fosl. mscr.
f. ramis subcylindricis vel seepe parum incrassatis, 3—5 mm. crassis, apicibus obtusis vel interdum truncatis. Tab. 9. :
Addition to the description of the species. 1 recorded 1. c., that the conceptacles of sporangia in this species do not grow down into the frond. I then examined several specimens destitute of grown-in organs of that kind. Later, however, I found such ones in small number especially in the form robusta, but also in f. typica, although they appear frequently not to be found. This may partly depend thereon, that probably old specimens of the plant in all rather seldom develop reproductive organs, partly that the conceptacles of sporangia apparently do not occur in the same individuals bearing those of cystocarps, which do not become over- grown. Besides, the whole roof of the conceptacles of sporangia seems easily to fall away, although they are very little prominent and the roof apparently nearly as thick as in L. fruticuloswm, and
1) Aftér this was in the hands of the printer I got some Lithothamnia from Mr. P. Hariot of Paris, gathered on the coast of California. Among these is a specimen of the present species, according with Adriatic specimens of f. typica. It will be recorded in a separate paper.
oy
in such cases the conceptacles perhaps do not grow down. In one specimen I found numerous small and disc-shaped, slightly projecting, whitish and easily dissolvable processes which probably are local formations that efface scars after emptied conceptacles, but do not accord with similar formations that frequently occur in this and other species, and I do not know whether they may have been conceptacles of sporangia or cystocarps, probably, however, the former. I have occasionally seen scars after filled concevtacles on a section, overlapped by a new thickening layer of the frond.
What I have named f. typica is represented in Contrib. 1. c. pl. 2 (not the specimen under the same name on pl. 1) and is in a full-grown stage easily recognized. But on the other hand it is rather varying and assumes more or less irregular forms in its struggle for existence, with more irregular and more anastomosing branches bearing more numerous smaller and wart-like or occasio- nally longer and branch-like processes, or even showing a tendency to form smaller bundles. The branches frequently are 2.5—3 mm. thick.
The form robusta perhaps ought to be considered a separate species, but in the materials at my disposal, with nearly all the Specimens sterile, | have not succeeded in drawing any true limit. Nor have | seen old specimens of this form, but in its development at least it very nearly accords with f. typica, and the reproductive organs appear to be similar in both, but the branches frequently are much coarser, more regular, with smoother surface.
Also this form is in general at first fastened to shells, forming a very thin crust, which soon produces densely crowded protu- berances growing out into short branches divided in a subdichoto- mous manner. By and by it completely surrounds the object and becomes subspherical or hemispherical, attaining a diameter of about 15 cm., at length loosening itself and lies free on the bottom. The crust always is thin, never, so far as I have seen, increasing in thickness, but on the contrary by and by disappearing. The plant has, like the typical form, a tendency to get hollow and opening itself in the part turning towards the bottom, which, however, ap-
parently is advanced by attack by boring-muscles entering the central 4*
38
portion. Pl. 9, fig. 1 represents a specimen which is hollow, but has not yet opened itself, and fig. 3 a younger specimen nearly covering the one half of a muscle (Mytilus modiolus). The other (lower) half not visible in the figure is in part covered with Z. delapsum described below, and both species grow over an earlier founded specimen of L. Strémfeltu. Hollow, or in the lower side opened or cup-shaped specimens are here much rubbed and the interwalls between the branch-systems visible. The subdichoto- mously divided branches are short, with axes of at least two orders, probably more, but the lower have always disappeared in older specimens. They are terete or nearly terete, erect, fastigiate and straight, 3—5 mm. thick, frequently slightly enlarged towards the apex, seldom slightly tapering with rounded ends, most often obtuse and occasionally truncate or nearly truncate. The branches are more or less anastomosing, always in their lower part, but often also farther up and nearly to the apex, at or below the latter now and then provided with wart-like processes.
There is a considerable difference in general appearance be- tween typically developed specimens with the tip of the branches obtuse or rounded and those, in which the apex is truncate and even rather disc-shaped. Cp. pl. 9, fig. 4. This appears, however, to be caused by local relations, the part of the plant turning to- wards the bottom, or other branches of such specimens showing a typical development without any limit at all. I, therefore, do not record this form a separate and named one.
The named form as well as the typical also develops freely on the bottom. In this case it is branched from the centre, the branches more or less anastomosing eSpecially outwards, and it also then gets hollow and at length cup-shaped, but apparently in a later stage than if surrounding other objects, or keeping a spherical shape for a longer time, if too much attacked by boring-muscles. Ely Sh sila 2,
With regard to structure both forms agree with one another. The inner cells of a section parallel with the longitudinal axis of a branch are nearly squarish or rectangular, frequently about 10 / long and 6 p thick, or a little shorter in proportion to the thickness
39
than for inst. in LZ. fruticulosum. The regular stratification does not become much disturbed by burried conceptacles, which, as remarked, partly appear to be wanting, especially in f. typzca, partly and most often to be found only in the peripherical portion of the branches, very seldom in any great number.
I have seen but few conceptacles of sporangia. They rather resemble those in L. fruticuloswm, and are scattered or somewhat crowded in the upper part of the branches, convex but very little prominent, about 250—300 p in diameter seen from the surface, and not sharply marked. The sporangia are tetrasporic, 120—130 » long and 40—55 p broad.
The conceptacles of cystocarps, of which I have also seen but few, appear in other individuals than the first named organs. They are conical, frequently rather low, but higher than in DL. frutecu- losum and apparently not fully developed, about 400 » in diameter at the base. Besides I met with a couple of smaller ones, together with the former and of the same shape as these, but only about 200 » in diameter at the base. They probably are conceptacles of antheridia.
A couple of specimens found washed ashore at Krageré pro- bably belong to this species.. They are fragmentary, but appear to coincide with L. fornicatum in development. The branches are 3—4 mm. in thickness, fastigiate, in one here and there somewhat rubbed also in the part that has turned upwards, in another with occasionally slightly compressed branches and the surface smooth. However, some newly emptied conceptacles of sporangia are more sharply marked than appear to be usual in the present species and frequently about 300 y in diameter, sometimes less sometimes a little more. As remarked above I certainly have seen but some few conceptacles of sporangia in this species, and it may be, that they were not fully developed, although at least some of the sporangia themselves appeared to be so, and apparently not larger than above quoted, judging from scars after emptied ones.
fielation to other species. This species shows greater affinity to L. fruticulosum, but it on the other hand distinguishes itself
AO
by essential characteristics even in a sterile stage. Cp. the three following species.
Habitat. In the only certain locality hitherto known it forms banks on a depth of 3—5 fathom, in a current in the inner part of a fjord, in company with other species. Among numerous speci- mens collected in the later half of September only a couple were provided with reproductive organs in development, or partly sho- wing scars after emptied conceptacles of sporangia and cystocarps.
Occurrence. Found at Mestervik in Malangen (Troms6 Amt), local but abundant. A sterile and fragmentary specimen gathered in the middle of June at Lyngé near Troms6 probably belongs to the same species. So also a couple of specimens found cast on shore at KragerO on the south coast.
Lithothamnion dimorphum Fosl. mscr.
L. fronde libera in fundo jacente, sphzerica vel subspheerica, roseo-purpurea, decomposito-subdichotome ramosa, ramis e centro solido, exiguo, undique egredientibus, uno alterove ramulo brevis- simo preeditis, plus minus coalitis, teretibus vel subcompressis, subeequalibus vel apicem versus parum incrassatis, vel interdum attenuatis, 2—2.5 mm. crassis, fastigiatis, apicibus in parte thalli inferiore plerumque obtusis vel truncatis vel interdum rotundatis, in parte superiore plerumque truncatis vel interdum obtusis vel demum disciformibus; conceptaculis sporangiferis convexiusculis vel seepe plano-convexis, parum prominentibus, infra apices ramorum creberrimis, a superficie visis diametro 400—450 4; sporangiis quaternas sporas foventibus, 100—140 p longis, 40—60 yp latis. Alaina: :
Description of the species. The frond is in a younger stage rather regularly spherical, but older occasionally getting somewhat compressed, or forming subspherical or nearly hemispherical masses, that attain a diameter of 10 cm., more commonly, however, about 8 cm. The colour is in winter, or the darker time of the year, a dark pink with a purplish tinge, and nearly the same shade of colour as deep-water specimens of ZL. tophiforme. In summer, on he contrary, it gets much bleached, like most other Lithothamnia
4]
growing in shallow water, the part of the plant turning upwards whitish or brownish-yellow, and the part turning towards the bottom in general slightly darker, with a rather feeble rosy tinge, seldom any stronger colour, but occasionally here and there getting a little darker in drying, if dried in the shade, or under cover. It apparently always develops itself freely on the bottom. Among numerous specimens that I have seen, I have not met with any fastened to or encompassing a stone or any other harder object. Most of the specimens examined have been attacked by boring- muscles especially in the centre of the frond and partly hollowed. However, the solid central mass appears always to be insignificant, but an anastomose of the branches often takes place in a rather early stage of development. The frond is repeatedly subdichoto- mously branched, with axes of at least three orders, and the lower axes frequently rather long. The branch-systems issue in all direc- tions from the centre of the frond. In typically developed speci- mens the branches are erect, fastigiate and straight, terete or a little compressed, either cylindrical or slightly enlarged towards the tip, more seldom feebly tapering in the part turned towards the bottom, 2—2.5 mm. in diameter, here and there furnished with short branch- like or wart-like processes. In others, and especially if much attacked by animals, the branches are rather irregular, somewhat bent and more anastomosing. They are in the part of the plant turned downwards occasionally a little spreading, and not so regu- larly level-topped as in the part turned upwards, or in typically developed specimens. The ends are, as a rule, in the first named part obtuse, or here and there truncate, seldom thoroughly truncate (pl. 10, fig. 2—4), but sometimes rounded especially in somewhat spreading branched specimens. In the part turning upwards they are nearly always at least partly truncate, or even disc-shaped. Pl. 10, fig. 1, 5. In this part the tip of the branches may occa- sionally be rather denudated, sometimes even in the lower part of the plant, but now and then developing wart-like processes from a truncate or denudated apex. Pl. 10, fig. 5—6.
As remarked above, the plant nearly always is attacked by animals, especially boring-muscles destroying the central portions,
42
sometimes even nearly towards the peripherical portion, and then the branches often become still denser and more anastomosed than if not or only a little attacked. Pl. 10, fig. 3. Therefore, it fre- quently becomes rather hollowed, or the cavity filled with boring- muscles, seldom intersected, but occasionally opened either in the part turned upwards or in the lower part and rubbed, or even getting a nearly cup-shaped form, and the interwalls between the branch-systems visible from this side. However, this appears only to be caused by the animals, in part together with the compres- sing and denudating influence of rapid tides, as the plant apparently not exhibits any tendency to open and to develop itself in this direction, like some other Lithothamnia. In such specimens the branches of the peripherical portion around the opening often get rather denudated, so that only the half of a branch or less may be left in a longitudinal direction of the axis, which also appears to be caused by the influence of the water, and so also partly in regard to the much varying shape of the tip of the branches. The surface of the frond is in general smooth, sometimes, however, the apex of the branches, or other and especially denudated parts of the plant are furnished with scaly thickenings, or new local for- mations of tissue.
The structure of the frond frequently appears to be a little coarser than for inst. in LD. fornecatum. The cup-shaped layers of tissue are, in a longitudinal section of a branch, shown to be distinct and rather regular, if not too much disturbed by the bur- ried conceptacles of sporangia. The inner cells of the named layers are about 12—16 p long and 6—8 yp thick.
I have seen but some few specimens bearing conceptacles of sporangia, and I have not met with cystocarpic ones. ‘The first named organs occupy a frequently sharply defined zone below the tip of the branches, and apparently most often in great numbers, . as in L. tophiforme, and the roofs’ sometimes even confluent, often much resembling the conceptacles in the latter, however, in general a little smaller, or 400—450 p in diameter, seldom less. In a younger stage of development they are convex, very little promi- nent and not distinctly marked, and, therefore, easily confounded
43
with the conceptacles of other species, especially L. fruticulosum, as they in this stage sometimes look apparently fully developed. However, fully developed ones are distinctly marked and more easily perceptible than in most other species, but slightly convex and little prominent, the central portion or greater part of the roof being frequently somewhat flattened, and traversed by 60—70 muciferous canals.
The conceptacles finally grow down into the frond, and are frequently to be found in the peripherical portion of a branch, sometimes numerous and crowded, sometimes very scarce, the latter probably being connected with the fact, that the roofs are thin and easily dissolvable, and, therefore, often falling away, leaving nearly cup-shaped scars with somewhat elevated edges. Such scars occasionally become effaced by local formations of tissue, and these formations again covered with a new thickening layer of the frond, so that they are visible on a section as small cup- shaped layers of about half the size of an overgrown conceptacle. The sporangia are four-parted, about 100—140 » long and 40—60 p broad. I have seen but some few ones.
elation to other species. The present species on the one side appears to be rather nearly related to L. fruticulosuwm f. fa- siigiatad and on the other side rather approaching L. dehiscens. Younger as well as sterile specimens may be confounded with the first named form. It is, however, separated thereby, that it never forms lobes, the branches frequently being coarser, with longer axes and less anastomosing, and the conceptacles of sporangia are different. It is more easily confused with certain and younger forms of L. dehiscens described below, but separated in its develop- ment and other characters quoted under this species. In habit it occasionally even reminds one of younger individuals of L. form- catum, but is separated by essential characteristics.
A fragment of a specimen from an unknown locality kindly transmittet to me by Prof. Kjellman, from oral informations sup- posed by him perhaps to be identic with L. fasciculatum (Lam.) Aresch., very closely accords with the species in question. It may be, that this one is the same as described by Lamarck under the
4A
above name, and perhaps also included in Areschoug’s L. fasci- culatum, which comprehends more species, but, as remarked under L. crassum, 1 am most inclined to refer Lamarck’s plant to the latter. ‘The named fragment is sterile, apparently branched in the same manner as L. dimorphum, the branches being of the same thickness as in the latter, with truncate tips. I found a solitary sporangium in an overgrown conceptacle also agreeing with that of the last named species, tetrasporic and about 90 p» long and 40 p broad.
Habitat. The plant lives on sandy and stony bottom, from a little below extreme low-water mark to a depth of about 3. fathom, hitherto with certainty only found in a sheltered sound with rather rapid tides. Specimens gathered in January were partly sterile partly richly furnished with conceptacles of sporangia, most of which emptied, and others with ripe sporangia. Among nume- rous specimens collected in the former half of July a couple are provided with the named organs in development.
Occurrence. The only known locality is Fréjen (Rottingsundet) in S6ndre Trondhjem’s Amt, local but abundant and forming banks.
Lithothamnion dehiscens Fosl. mscr.
L. fronde libera in fundo jacente, subglobosa, hemispheerica vel demum cava, fornicata, roseo-purpurea, irregulariter subdicho- tome ramosa, ramis initio e centro solido, exiguo, undique egredi- entibus, demum inferioribus erasis, uno alterove ramulo brevissimo preeditis, preecipue superioribus plus minus coalitis, teretibus, 2 mm. crassis; conceptaculis sporangiferis convexiusculis, at parum pro- minentibus, infra apices ramorum plerumque creberrimis, a superficie visis diametro 300—350 p; conceptaculis cystocarpiferis et anthe- ridiferis conicis, acutis, his diametro 250—300 yp, illis 400—500 uw. Sporangiis quaternas sporas foventibus, 120—180 p» longis, 45—80 p- latis.
f. typica Fosl. mscr.
f. ramis subzequalibus vel in parte thalli inferiore seepe subat- tenuatis, apicibus rotundatis vel obtusis, parte superiore fastigiatis, — apicibus plerumque obtusis. Tab. 11—12.
45
f. grandifrons Fosl. mscr. f. ramis superioribus fasciculos minutos, confertos, e ramis brevissimis compositos formantibus. Tab. 13.
Description of the species. This plant is much varying, and, in the sense here taken, it perhaps includes more than one species, but nearly all the specimens that I have seen are sterile and, there- fore, the limits difficult to draw. Like the preceding it in a younger stage also has a nearly spherical shape, but it apparently sooner becomes subhemispherical, at length hollow and assumes a cup- shaped appearance. It attains a diameter of at least 50 cm., fre- quently, however, smaller, the form grandifrons in general larger than the typical one, but also the latter attains a considerable size. The colour accords with that of Z. dimorphum, in winter probably also getting as dark as this species, however, in summer now and then with a stronger colour than specimens of the named species at the same season, but apparently only depending on the locality where it grows. I have even seen specimens. with a yellowish- green colour, thus in this respect much varying. The species ap- parently always develops itself freely on the bottom. Although often growing on stony bottom I never met with it fastened to or encompassing stones or other hard objects. The frond is some- what. irregularly branched in a subdichotomous manner, with axes of at least four orders. The branch-systems at first issue in all directions from the centre of the frond, and the solid central mass appears always to be insignificant. In a more or less advanced stage the central or inner portions by and by disappear, which, however, may be forced by attack of animals, the peripherical portion developed in a more horizontal direction, and the plant opening itself in the part turning towards the bottom, seldom in the upper part, at length assuming a frequently depressed cup- shaped form, rubbed in the part turned downwards, with the inter- walls between the branch-systems visible from this side, most often subcircular in circumference, and then only about 2 cm. thick. The figure on pl. 11 represents an old but fragmentary specimen, the longest diameter about 32 cm., depressed cup-shaped and rub- bed in the part that has turned towards the bottom, here burdened
46
with numerous shells of Balanide, Serpula and other animals. Sometimes it is intersected in the middle, or even assuming a more or less whorl-shaped appearence. PI. 12, fig. 2.
There is a considerable difference between younger individuals, or such branched from the centre of the frond, spherical or hemi- spherical, and old ones with the lower branch-systems disappeared, depressed cup-shaped or sometimes nearly flattened. In the former the branches are more or less bent, or even somewhat contorted, especially in the lower part not or only a little, but in the upper part always more or less anastomosing. In the latter the axes are very short, always much anastomosing, and even the upper- most part of the branches in old specimens often somewhat denu- dated. The branches are 2 mm. in diameter, or less, sometimes in the part of not opened specimens turned towards the bottom slightly attenuating, with rounded or obtuse ends (pl. 12, fig. 1), and in the part turned upwards either cylindrical, here and there bearing short branch-like or wart-like processes, or, more frequently, slightly enlarged apex, or towards the apex, more regularly fasti- giate than in the lower part, and the ends as a rule obtuse, more seldom nearly truncate, the latter also being due to the upwards turned part of old and cup-shaped specimens of f. typica. Pl. 11.
In the form grandifrons the uppermost branches form minute and rather densely crowded bundles, composed of very short, more or less anastomosing branches and wart-like processes. Pl. 13, fig. 1—2. These branches are often rather thin, sometimes even but 1 mm., the bundles occasionally rather depressed, or in part denudated, with wart-like processes issuing from the denudated and often more or less truncate bundles. Cp. Pl. 13, fig. 3, seen from the side that has turned towards the bottom. In the part that has turned upwards it is rather rubbed and the branches somewhat coarser, here and there denudated. Of this form I only have seen old or rather old specimens. It appears, as if the named bundles are not unfrequently developed from an older and somewhat denu- dated frond, rather reminding one of the new branches developed from the lower and rubbed part of other specimens. It is in its typical form rather characteristic, but on the other hand apparently
47
little independent, and, perhaps, it might merely be regarded as a monstrosity than a difference of type. In this as well as the typi- cal form the edges of a hollow and in the lower part opened Specimen, partly involucrated partly not, often grow inwards and by and by replenish the opening, forming a somewhat concave base. However, now and then the plant may open itself in the part turning upwards. So also in regard to old and cup-shaped Or whorl-shaped individuals. Even here the edges often grow in- wards, or new but frequently short branches issue from the lowe r and more or less rubbed part of the plant, by and by even deve- loping more vigorous branch systems, though frequently composed of short and thinner branches.
I met with a form growing in very dense banks and closely related to the typical form of this species, partly in the same partly in another locality than the latter. It keeps a hemispherical shape for a longer time and often not opening itself or getting hollow, but the lower part even developed more downwards than usual and on the other hand rather rubbed and denudated in the part that has turned upwards, or here even concave, often with some- What coarser, very dense and upwards much anastomosing bran- ches, with obtuse ends. In the part that has turned towards the bottom and otherwise it accords with f. typica, therefore, I do not record it an independent, but merely a local form of the species, caused thereby that the individuals have been closely heaped together.
“\ coarser form from Hus6 inSogn may perhaps be referrible to this species. 1, however, have seen but two fragmentary, stunted and in the part turned upwards somewhat denudated specimens, collected in a ,,deep litoral lagoon“ by P. Boye. As they also are sterile, they cannot be determined with any degree of certainty.
With reference to the structure the present plant most nearly accords with L. dimorphum or the species resembling it. In a longitudinal section of a branch the cup-shaped layers of tissue are distinct and pretty regular, with the inner cells frequently rect- angular, 1O—15 p» long and 6—9 yp. broad.
The conceptacles of sporangia are partly somewhat scattered
48
in the upper part of the branches partly and apparently more often densely crowded near the apex, or forming a border around the: branches at or a little below the apex. They even sometimes are so densely crowded, that the roofs become angular, and in all rather resembling those of LZ. dimorphum, but smaller and, as in the latter, in a younger stage easily confounded with conceptacles of other species. They are slightly convex and little prominent, but never, so far as I have seen, flattened in the central portion, as often is the case in the named species, the roof 300—350 # in diameter, seldom more. The sporangia are four-parted, 120— 180 » long and 45—80 » broad. Among numerous specimens collected in summer only some few were furnished with these organs.
The named conceptacles at length become overgrown, com- monly to be found only in the peripherical portion of a branch, but always in less numbers than in the preceding species, and in several specimens examined I have not found older grown-in or- gans of this kind. This probably is in part caused thereby, that . the roof is rather thin and easily dissolvable, though apparently thicker than in L. dimorphum, and often falling away. I more frequently met with overgrown conceptacles effaced by local forma- tions of tissue than in the named species, and in the same manner as mentioned under this one. Besides, the conceptacles of anthe- ridia and cystocarps appear not to be found in the same individual bearing conceptacles of sporangia. These organs do not as a rule become overgrown, although now and then only the upper part of the roof falls away at maturity, the rest perhaps partly being filled with local formations of tissue partly not, and the whole covered with a new thickening layer of the frond, as remarked in regard to the conceptacles of sporangia.
The cystocarpic conceptacles are conical, acute, 400—500 in diameter at the base. They are up to 300 p» high, with a single orifice, but the upper portion easily falls away, then forming a low, nearly hemispherical or sometimes even convex conceptacle, in the middle intersected with a coarser canal about 30 p in dia- meter, and at maturity this middle portion first falls away, and
49
then often resembles emptied conceptacles of sporangia, later as a tule the whole roof. The conceptacles are in a median section internally about 300 y in diameter at the base and about 100 p high. The carpospores appear to be much varying, about 85 p long and 35 » broad.
The organs that I suppose to be conceptacles of antheridia fully resemble the cystocarpic conceptacles in shape, and occur in the same individual bearing the latter. They are 250—300 p in diameter at the base and up to 200 p» high. In a median section I found them to be about 230 p» in diameter at the base and 80 p high, and also here the upper and thicker portion at least some times falls away. I have not seen the spermatia.
fielaiion to other species. It in some sespects stands near to LL. dimorphum, and younger individuals, or not opened ones may easily be confounded with that species. It is, however, separated by its branches being in general thinner and less regular, and the ends seldom or not at all truncate, being a much larger plant. Besides, it differs with reference to the development of the frond, as well as the conceptacles of sporangia. The species may also be confounded with certain forms of L. fruticuloswm, and in habit sometimes rather resembling the form fastzgeata of that species. This, however, is only due to younger individuals. Older or cup- shaped ones are quite different, and merely showing closer affinity to L. fornicatum, from which it is separated by its thinner branches, coarser structure, frequently larger conceptacles of sporangia and apparently different cystocarpic conceptacles.
Habitat. The species grows in the uppermost part of the sublitoral region on a depth of 1—4 fathom, on stony and some- what clayish bottom. It apparently prefers places with rather rapid tides. The very greatest number of specimens collected in July were sterile, some few ones partly scantily, partly more richly furnished with conceptacles of sporangia, some of which were emptied and others with ripe sporangia. Other specimens taken in July and August were richly provided with conceptacles of cy- stocarps and probably also antheridia, partly emptied and partly in
50
development. It frequently appears to form widely extended and more or less dense banks.
Occurrence. Herd in Helgeland, rather local but abundant (Kr. Schreiner); Hestver at Froderne in Sondre Trondhjem’s Amt, local but abundant; the Skjérn Fjord (a branch of the Trondhjem. Fjord), rather local but abundant, forming great banks especially at ,,Dalséren™.
Lithothamnion delapsum Fosl. mscr.
L. fronde initio circum lapides vel conchas effusa, demum libera, fornicata, parte centrali solida vel lobata, vel demum crustam. tenuissimam formante, ramis brevissimis, subdichotome ramosis, plerumque valde coalitis, 1—1.5 mm. crassis instructa, apicibus. obtusis; conceptaculis sporangiferis convexiusculis vel seepe plano- convexis, parum prominentibus, a superficie visis diametro 350— 400 »; sporangiis (binas sporas foventibus?) 120—160 p longis, 40—60 yp. latis.
f. abbreviata Fosl. mscr.
f. ramis confertis, fastigiatis. Tab. 14, fig. 1—3.
f. conglutinata Fosl. mscr. f. ramis fasciculos breves, minores formantibus. Tab. 14, fig. 4.
Syn. Lithothamnion fornicatum var. Fosl. Contrib. 2. p. 5, t. 1.
Remark on the species. In Contrib. 1. c. I mentioned under L. fornicatum a couple of forms partly reminding one of and growing together with the named species partly approaching JL. Ungert (L. fruticulosum in the present paper), and one of these: were figured |. c. The organs of propagation then were unknown in both. By closer examination of these specimens | found con- ceptacles of sporangia, and I also found the latter growing down into the frond. These forms I here record as a distinct species, but I am not sure whether they ought not, perhaps, to be consi- dered as two separate species, as they somewhat differ in their development. However, judging from the scanty materials at my disposal they seem to belong to one and the same species.
Description of the form of the species. The form abbreviata
Dll
in its development fully accords with. LZ. fornicatwm. It at first fastens itself to, encompasses or nearly encompasses shells, stones or Other hard objects, being closely and firmly attached to its substratum. Pl. 14, fig. 2. It forms a thin crust, or now and then smaller lobes, from which issue short and simple, or once or twice divided branches, with very short axes, much anastomosing in their lower part. Sometimes the crust increases in thickness, though never much, but apparently more frequently getting thinner or disappearing, which not unlikely is caused by attack of animals. The plant by and by gets hollow, loosens itself from the substratum (pl. 14, fig. 3) and at length assumes a more or less depressed cup-shaped form, attaining a diameter of up to 25 cm. PI. 14, fig. 1. The inner or lower side of such specimens partly becomes somewhat rubbed, so that the interwalls here and there are visible from this side, partly and probably more commonly is still provi- ded with a thin crust, or a new and in part local crust-like for- mation developed from this side. In the part turning upwards the branches always are short and much anastomosing, especially in younger specimens often looking like simple and short processes issuing from an apparently rather thick crust-like hypothallus, ho- wever, in the main composed of anastomosed branches or pro- cesses. The edges of opened specimens sometimes bend and grow inwards, and together with branches afterwards developed from the inner or lower side of the plant by and by appear to replenish at least a part of the cavity or concave base. The branches or processes are terete and cylindrical, seldom slightly attenuating to- wards the tip, straight and fastigiate, in general 1—1.5 mm. thick, with obtuse or thickened obtuse ends.
A solitary and sterile specimen, in habit as well as in structure fully agreeing with the named form, seems to have developed itself freely on the bottom. «It is nearly hemispherical, the longest dia- meter about 15, the shortest about 9 cm., but the central portions fully destroyed and filled by numerous boring-muscles leaving a peripherical portion about 1—1.5 cm. in thickness. The branches of this portion are much anastomosing. Thus it appears, as if
52
also this species in certain cases keeps its spherical shape for a longer time, if much attacked by animals.
The form conglutinata is characterized by its more or less remoted, short bundles composed of very short and much anasto- mosed branches and wart-like processes. ‘The crust partly some- what increases in thickness, though apparently not more than up to about 3 mm., or the central portions of not opened specimens forms lobes, from which the named bundles issue. Pl. 14, fig. 4 represents a specimen forming rather coarse lobes, with a smaller cavity in the part that has turned towards the bottom, looking, however, as if a larger cavity has been nearly replenished. An- other and cup-shaped specimen is provided with a distinct and about 3 mm. thick crust, with new and crust-like formations in the part turned downwards, and in the part turned upwards with short branches or wart-like processes, or small bundles. Two other and cup-shaped specimens apparently stand between f. abbreviata and f. lobata. The part turned upwards most closely resembles the latter, forming, however, more indistinct bundles, but the lower part is Sometimes furnished with a thin crust, sometimes rubbed, or here and there with new branches in development.
The colour is a light pink with a purplish tinge, which after- wards often passes into faint brownish-yellow.
A longitudinal section of a branch shows partly rather distinct partly undistinct cup-shaped layers of tissue, with the inner cells about 1O—14 p long and 6—8 p broad.
The conceptacles of sporangia are sometimes scattered, some- times rather densely crowded especially somewhat below the tip of the branches. They are convex, but very little prominent, often scarcely raised above the surface of the frond and rather flattened. The circular roof is 350—400 p in diameter, occasionally even a little more. It is intersected with 45—60 mauciferous canals. Over- grown conceptacles are partly numerous partly scarce. Also in this species I have seen some few filled with local formations of tissue, but the roof is apparently not so easily to be dissolved as for inst. in L. dehiscens, and, therefore, probably nearly all the conceptacles become overgrown. The sporangia appear to be two-
De
parted. I certainly did not meet with a great many, but those I have seen in superficial as well as overgrown conceptacles were bisporic. However, it may be, that they were not fully developed, and in such cases the partition cannot be stated with certainty until a greater number of conceptacles in different specimens have been examined. Thus in other species I have seen several not fully developed sporangia growing down into the frond together with the conceptacles, and overgrown ones very likely never have been mature. Often I have also seen two-parted and apparently fully developed sporangia in superficial conceptacles of species, by which the named organs typically are tetrasporic, and, as remarked before, such ones have probably in fact not been fully developed. The sporangie are in both the above forms about 120—160 p» long and 40—60 p broad.
Relation to other species. The form abbreviata shows greater affinity to L. fornicatwm, and cup-shaped specimens, rubbed in the lower part, may without closer examination be confounded with smaller specimens of that species bearing thinner branches than usual. It appears, on the other hand, to be more nearly connected with the preceding species, and particularly through the form represented by the above mentioned freely developed specimen it exibits close relation at least to younger specimens of this spe- cies. It, however, differs by its branches being thinner than general in L. dehiscens, frequently larger and flattened conceptacles and, above all, by its tendency to form a crust-like hypothallus. Still, younger individuals of f. abbreviata as well as the form congluti- nata much reminds one of certain forms of L. fruteculoswm, the former rather resembling L. fruticulosum f. fastigiata or forms which are most nearly related to this, and the latter in its most extreme form apparently connected with L. fruteculoswm f. glo- meratd. However, it is plainly distinct from this species not only with reference to its development, but the conceptacles of sporangia also are different. The species probably includes more forms than the above mentioned.
Habitat. 1 met with this plant in the same bank as L. for-
nicutum and other species, and apparently growing scattered, the yes
54
bank chiefly composed of the last named species. It appears often to anastomose with Z. fornicatum, one of the specimens gathered even nearly encompassed by the latter. Specimens taken in June and in the later half of September were provided with partly emptied conceptacles of sporangia partly apparently ripe sporangia. Some scars a little larger in diameter than the conceptacles of sporangia seem not unlikely to be those from dissolved cystocarpic con- ceptacles.
Occurrence. Hitherto only found at Mestervik in Malangen (Tromse Amt), scarce.
Lithothamnion apiculatum Fosl. mscr.
L. fronde libera vel lapidibus affixa, diametro usque ad 5 cm., roseo-purpurea vel dilute rosea, decomposito-ramosa; ramis e centro solido, exiguo, undique egredientibus, vel omnino liberis vel plus minus coalitis, interdum parte centrali sublobata, teretibus, sub- eequalibus, apicibus rotundatis vel plerumque obtusis; conceptaculis svorangiferis convexiusculis, parum prominentibus, sparsis vel infra apices ramorum crebris, a superficie visis diametro 200—250 p; sporangiis quaternas sporas foventibus, 90—110 yp longis, 35—50 p- latis; conceptaculis cystocarpiferis depresso-conicis, apiculatis, diametro 350—450 p.
f. typica Fosl. mscr.
f. ramis non vel parce coalitis, fastigiatis, apicibus rotundatis velmobtusis) Wabe lor amie wl 4s
f. parvicocca Fosl. mscr.
f. parte centrali sublobata vel ramos inferne plus minus coa- litos, superiores nodulos vel fasciculos minutos formanti. Tab. 15, 1 D9.
f. connata Fosl. mscr. f. parte centrali sublobata vel ramis valde coalitis, brevissimis, fastigiatis, apicibus obtusis. Tab. 15, fig. 9—13.
f. patula Fosl. mscr. Descr. Lithothamnion norvegicum f. globulata Fosl. Contrib. II, p. 7.
Eig. ” y 5 my eG te Sh, ies, 7/8 allo, iavOSIKE. 15, fig. 14—19.
‘ heer 5 ss)
55
Syn. Lithothamnion fasciculatum Aresch. Obs. Phyc. 3, p. 5; ex parte sec. spec.
Remark on the species. In Contrib. 1. c. I recorded a Litho- thamnion under the name of L. norvegicum f. globulata, considering it to be a form of the named species analogous to the form glo- bosa of L. tophiforme (L. soriferum). Later I met with the same form also at other places together with another one, that consti- tutes the typical form of an undescribed species, the above L. apieulatum, to which the named f. globulata (the above f. patula) appears to be more closely related than to L. norvegicum (L. corallowdes in the present paper), taking the latter in a more con- fined sense than then. On the other hand it is not unlikely that this form may perhaps be the type of a separate species, as in some particulars it rather differs from typical L. apiculatum, al- though it in habit as well as structure is very difficult to distinguish from the latter, but the reproductive organs are not yet well known, the cystocarpic conceptacles even unknown.
Description of the form of the species. The limits between most of the above quoted forms are not easily drawn, as inter- mediate forms nearly as often appear to occur as typically deve- loped specimens of the one or other form, but the latter are on the other hand so well marked, that they ought to be specially mentioned. What I consider to be the typical form of the species, forms spherical or nearly spherical balls, freely developed on the bottom, seldom fastened to or encompassing smaller stones. It attains a diameter of 5 cm., frequently, however, about 3 cm. The colour partly is a darker partly a lighter pink, more or less fading in drying, now and then with a purplish tinge, or even rosy. The solid central mass always.-is insignificant, and ramifi- cation sets in at an early stage of growth. The frond is branched partly in a subdichotomous manner partly more irregular, with axes of two or three orders. The upper branch-systems sometimes are arranged obpyramidal. In typically developed specimens the branches are erect, fastigiate and straight, in others they are some- what bent, but always fastigiate, often furnished with some wart- like process. They are terete or nearly terete, either cylindrical
56
or slightly tapering, or a little enlarged towards the tip, with the ends rounded or more frequently obtuse or nearly obtuse, 1.2— 1.8 mm. in diameter. Now and then the branches anastomose below, but more often they are free in the central portions and somewhat anastomosed in the peripherical portion of the frond, or not anastomosing at all. Pi. 15, fig. i—4. The surface of the frond is partly rather smooth partly and most frequently provided with local, scaly thickenings especially in the upper part of the branches.
The form parvicocca is nearly connected with the typical form. It differs by its more anastomosing branches, the central portions often forming smaller lobes or coarse and somewhat lobe-like branches, from which issue small bundles of brachlets, or the upper branches bearing more or less numerous smaller and wart-like PROCeESSCSH a ely alo. iS oes
Another form probably belonging to the same species is f. connata. It often fastens itself to or encompasses small stones. It is less branched and the branches are shorter than in the typi- cal form, much anastomosing especially in the lower part, or it forms a rather solid central portion or smaller lobes. The branches frequently are slightly enlarged towards the tip, fastigiate and often furnished with some wart-like process. The ends are as a rule ObLuses: Rip io. tees9 Salts:
The form patula on the one side is closely connected with the typical form in habit, and the limits often nearly impossible to draw, but on the other side showing transition to f. connata, also being difficult to distinguish from this form. It forms small spheri- cal or nearly spherical masses about 2 cm. in diameter. The solid central portion is insignificant and the branches more or less Spreading, but in general rather straight, fastigiate or nearly fasti- giate, slightly thickened towards the tip, seldom a little tapering, and most frequently with obtuse ends. Pl. 15, fig. 14—19. Ho- wever, the branches often are more crowded, forming transition to f. typica, anastomosing below or even nearly towards the apex, or encompassing small stones, furnished with some wart-like pro- cess, and such specimens forming transitions to f. connata. The
57
surface of the frond appears commonly to be smoother than in f. typica, and in all less furnished with local, scaly thickenings than the other forms. However, this apparently often depends on the locality where the plant grows, and I met with specimens which in this respect fully coincide with f. typica. Also in other species I have seen specimens sometimes quite smooth and rather shining sometimes furnished with numerous scaly thickenings. These thicke- nings appear in all to be more common in specimens growing in shallow water with somewhat clayish bottom, or in places with rather rapid tides, and wanting or more seldom to be found in Specimens growing in deeper water with harder bottom.
With reference to the structure the present plant accords in the main with Z. fruticuloswum and other nearly allied species. The cup-shaped layers of tissue are, in a longitudinal section of a branch, more or less regular and rather distinct, and the inner Gellseare about o__ 10 # lon= and) 5—7/ thick. | Thus’ they are somewhat shorter in proportion to the thickness than those of the named species, often being nearly squarish. In f. patula they are frequently a little coarser than in f. typica, but, so far as I have Seen, not exceeding 10 p» in length and 7 p in thickness, and any limit is in this respect impossible to draw, the cells being as a rule rather varying even in one and the same specimen.
The very greatest number of specimens that I have seen have been sterile, only some few ones provided with conceptacles of sporangia or cystocarps. The first named organs are scattered over the whole frond or somewhat crowded below the tip of the branches, convex but slightly prominent, more os less distinctly marked, seen from the surface about 200—250 yp in diameter. In this respect f. patula somewhat differs from the other forms, as the conceptacles frequently appear to be a little larger, or up to 300 », which, howewer, now and then also is the case in the other forms. The roof is intersected whit about 30—40 muciferous canals, which are rather crowded in the central portion, and espe- cially in the form patula it appears apt to fall away. Ihave seen but some few sporangia. The are four-parted, 90—110 p long and 35—50 p broad.
58
The conceptacles finally grow down into the frond. Over- grown ones are more common in specimens with a more solid central portion or much anastomosing branches than in specimens the branches of which are free, but never to be found in any great number, often, on the contrary, apparently wanting. I occasionally met with grown-in organs of that kind filled with local formations of tissue. In a form of the species standing nearest to f. connata I found in overgrown conceptacles rather numerous sporangia, most of which were bisporic, probably not being fully developed before they grew down together with the conceptacles.
Cystocarpic conceptacles are only known in f. typica and f. parvicocca. They are conical, low and at the summit abruptly passing into a short and thin tip, which easily falls away, 350— 450 » in diameter at the base, scattered or somewhat crowded without any order, sometimes in pairs. I have not seen the car- pospores.
Remark on the synonomy. A specimen in Areschoug’s herbarium under the name of L. fasciculatwm | refer to the pre- sent species. It is scantily provided with conceptacles of sporangia, collected at Christiansund N. by F.L. Ekman. Cp. Aresch. I. c.
ftelation to other species. It appears to be most closely related to L. fruticulosum, f. typica analogous to f. typica, f. connata analogous to f. fastigiata, and f. patula, or an intermediate form between this one and f. connata analogous to f. nana of that species, and on the other hand standing between the named spe- cies and the following one, LZ. gracilescens, the form parvicocca nearly connected with the latter. The species distinguishes itself from L. fruticulosum especially by its in general thinner branches and smaller conceptacles of sporangia, shorter cells and different conceptacles af cystocarps. It is in all a much smaller plant than the named one. From JL. gracilescens it is separated by charac- ters quoted under this species. The form patula in its most ex- treme form reminds one much of certain forms af L. corralloides. It is, however, distinguished by its ticker, more straight and more regular branches, a little coarser structure, as well as a little smaller conceptacles of sporangia.
ae
59
Habitat. The species lives in the upper part of the sublitoral region, on a depth of 3—8 fathom. It chiefly is met with in the fjords, preferring somewhat sheltered places, and is to be found best developed on hard bottom. It partly grows scattered partly forming smaller banks together with other species. Specimens collected in July, September and October have been very scantily provided with conceptacles of sporangia, some of which with ap- parently ripe sporangia. Specimens bearing cystocarpic conceptacles have been taken in July.
Occurrence. The typical form found at Bejan, local but abundant, and together with it some specimens of f. parvicocca. <A form closely related to the former has been collected at Munkholmen near Trondhjem, scarce, and at Christiansund, N. (Ekman). The form connata is known from Drdbak in the Christiania Fjord {Gran), apparently’ scarce; Storfosen near Bejan, scarce; and a form most nearly connected with this at Roberg in the Trondhjem Fjord, scarce. Typical specimens of f. patula have been collected at Skorpen in Troms6 Amt, Skjdrn and Bejan in the Trondhjem Fjord, local but pretty plentiful, and especially at the two last named places together with transitions to f. typeca and f. connata.
Lithothamnion gracilescens Fosl. mscr.
L. fronde libera vel interdum lapidibus affixa, subglobosa, dia- metro usque 6 cm., obscure rosea, irregulariter ramosa; ramis e centro solido, exiguo, undique egredientibus, teretibus, subcylindricis, superioribus plerumque nodulosis, fasciculos plus minus remotos formantibus, apicibus obtusis; conceptaculis sporangiferis convexius- culis, parum prominentibus, infra apices ramorum crebris, a super- ficie visis diametro 350—400 p; sporangiis quaternas sporas foven- tibus, 120—150 p longis, 45—60 yp latis; conceptaculis cystocar- piferis conicis, diametro 300—350 yp. Tab. 15, fig. 20—27.
Syn. Lithothamnion byssoides Unger, Leithakalk p. 19, t. 5, fig. 1—8.
Description of the species. The plant forms spheroidical or somewhat irregular masses attaining a diameter of about 6 cm., in general freely developed on the bottom, but now and then fastened to or nearly encompassing small stones. The colour is a dark
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pink, most often with a purplish tinge, in winter, however, a brow- nish pink, but nearly always getting much lighter when dry. The frond is branched in a rather irregular, or sometimes nearly sub- dichotomous manner. ‘The branches frequently issue in all directions from the centre of the frond, always with short axes, in the lower part more or less bent, in the upper part often rather straight, frequently forming more or less remoted bundles, which are com- posed of short branches bearing more or less numerous and wart- like processes or short branchlets. They are terete or nearly terete, 1—1.3 mm. thick, sometimes of nearly the same thickness throug- hout, sometimes a little thicker below, here and there somewhat anastomosing, buth never much, often with slightly thickened and frequently nearly obtuse ends. Pl. 15, fig: 20—27. Whe frond occasionally may be rather compressed, in part corresponding with the form alcicormis of L. tophiforme and f. flabelligera of L. coralloides, but the specimens that I have seen of this form are not so distinctly marked as to make it possible to draw any de- finite limit, and I, therefore, at present do not record it at deno- minated form of the species.
As to the structure the species coincides with ZL. corailoides. In a longitudinal section of a branch the inner cells of the cup- shaped layers of tissue are about 7—9 » long and 4—6 vp thick.
I have examined numerons summer- as well as winter spe- cimens, but only one or two met with bearing organs of propa- gation. The conceptacles of sporangia frequently appear to be rather crowded below the tip or in the upper part of the branches. They are convex, but very little prominent, distinctly marked, seen from the surface 350—400 » in diameter, sometimes, however, only 300 ». The roof is traversed by 60—70 muciferous canals. The sporangia that I have seen were not fully developed, sometimes without any partition sometimes two-parted with an apparently well developed wall. However, in some of the latter I found in one or both cells partly a just founded partly a more developed transverse wall issuing from the one side, and once I found one of the two cells parted into two by an entire but rather indistinct wall. Therefore, mature sporangia no doubt are tetrasporic. They
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are about 120—150 or up to 160 p long and 45—60 vp broad, seldom broader.
The conceptacles grow down into the frond, but overgrown ones are very scarce in the specimens that I have examined, and ‘in most cases I did not find such ones. Also in this species the roof appears apt to fall away, leaving a rather deep scar, which sometimes becomes filled with local formations of tissue. Such filled conceptacies now and then are to be seen on a Section, in shape and partly also in size fully resembling not filled ones, and distinctly marked.
The organs supposed to be cystocarpic conceptacles I found in other individuals than those bearing conceptacles of sporangia. They are comparatively small, conical and rather acute, about 300 —350 p» in diameter at the base, but probably not fully developed. I have not seen the spores.
Remark on the synonomy. As mentioned under L. fruti- culosum | consider L. byssoides Unger not referrible to any form of that species. It appears to me most probably being identic with the species in question, and in all agreeing well with typi- cally developed specimens. On the other hand it reminds one of L. apiculatum f. parvicocca and even certain forms of LZ. nodu- losum described below, but the latter is in general a larger and coarser plant.
Felation to other species. This plant forms an intermediate species between L. apiculatwm and L. corralloides. In its typical form it is easily recognised, but it often assumes forms, which in a sterile state are very difficult or nearly impossible to sepa- rate from the one or other of the named species. ‘The reproductive organs are, however, different. As to the vegetative parts it di- stinguishes itself from L. apiculatum f. parvicocca, the most nearly allied form of that species, by its less anastomosing branches and in general more numerous wart-like nodes, but it sometimes even approaches L. apiculatum f. typica in habit. Cp. Pl. 15, fig. 27. Now and then it appears to be less densely branched, or the branches even rather spreading, the nodes or short branchlets few in number, and then much approaching JL. coralloides f. norvegica.
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Habitat. The species occurs in somewhat sheltered places, on a depth of 5—8 fathom. I met with it on rather hard but somewhat clayish bottom, forming smaller banks in company with I. coralloides. A couple of specimens gathered in June and July were provided with reproductive organs in development, or bearing scars after emptied conceptacles of sporangia.
Occurrence. Found at Mandal (Wille), Drébak (Gran) and at Rotvold near Trondhjem, at the latter place local but in consi- derable abundance.
Lithothamnion coralloides Crn.
Fl. Finist. p. 151, t. 20, gen. 133, fig. 8—9; Spongites coralloides Alg. mar. Finist. No. 242; excl. syn.
f. norvegica (Aresch.) Fosl. mscr.
Lithothamnion calcareum var. norvegicum Aresch. Obs. Phyc. 3, p.4; ex parte.
f. subglobosa, diametro circa 3 cm., ramosissima, ramis 1— 1.3 mm. crassis, subattenuatis, apicibus plerumque rotundatis. Tab. NO, ater, Wil,
f. saxatilis Fosl. mscr.
f. lapidibus affixa vel demum interdum libera, scabriuscula, ramis brevioribus, 1—1.8 mm. crassis, apicibus rotundatis vel sub- ObtuSis, slab: Woy tomo.
f. australis Fosl. mscr. f. parce ramosa, ramis szepe longioribus, teretibus vel subcom- pressis, 15—2 mm«zvcrassis..- Pab! lo; fies 24 ole
f. flabelligera Fosl. mscr. f. ramis brevibus, flabellatim dispositis, liberis vel plus minus coalitis, compressis vel subcylindricis. Tab. 16, fig. 32—37.
f. subsimplex Batt. in Journ. Bot. 1892, p. 8; Grevillea Vol. 21, p. 23. Descr. Lithothamnion coralloides f. subsimplex Batt. 1. c. Fig. i s ns tab. nostr. 16, fig. 38—42.
Syn. Apora polymorpha Gunn. in Act. Nidros. 4, p. 70; ex parte; t. 15, fig. 2. Nullipora calcarea Johnst. Brit. Spong. and Lithoph. p. 240; ex parte; pl. 24, fig. 5? Lithothamnion gracile Phil. in Wiegm. Arch. p. 388; Aresch. in J. Ag. Spec. Alg. 2, p. 524?
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Syn. Lithothamnion rubrum Phil. 1. c.; Aresch 1. c. > norvegicum Kjellm. N. Ish. Algfl. p. 122 (93), pl. 5, fig. 9—10, 3 Fs Fosl. Contrib. Il, p. 7; ex parte. coralloides Batt. in Journ. Bot. 1892, p. 7.
Remark on the determination of the species. Through the kindness of Dr. Bornet I have had the opportunity to examine the specimen distributed by Crouan | c. under the name of Spongites coralloides. It is, however, too fragmentary to be deter- mined with certainty, but not unlikely it is identic with the above quoted f. flabelligera, and it agrees with this form in regard to the structure. The form of the species delineated in Fl. Finist. 1. c., no doubt, is identic with or at least closely related to the above f. australis. Specimens of both these forms have been gathered in one of the localities quoted by Crouan and kindly communi- cated to me by Dr. Bornet. The plant described by Areschoug under the name of ZL. calcarewm var. norvegicum partly also in- cludes the last named form. Areschoug originally recorded his plant as LZ. coralloides Cr.1), but later (in Obs. Phyc. |. c.) he considered it a variety of LZ. caleareum. ‘The latter is, however, a coarser plant and in my opinion belonging to L. tophiforme, judging from the description by Harvey in Phyc. Brit., but the plant recorded under the same name by Johnston lL. c. perhaps nin Pate inelides=the! present Species. Co. Kijjellm: i) c)) W have not been able to draw any true limit between the quoted forms, and I, therefore, here adopt the name given by Crouan as the older one. However, it may be remarked, that the French and British specimens that I have seen, as well as those which underlie Areschoug’s description, gathered at Haugesund, are sterile. Solms-Laubach remarks (Corall. p. 19), considering Areschoug’s plant identic with L. coralloides Cr., that the species is characte- rized, besides in habit, by ,nicht Uber die Thallusflache hervorra- genden Conceptacula“. This does not accord with the below men- tioned shape of the reproductive organs found in other Norwegian specimens.
1) Akademiske forelasningar héstterminen 1872. (Unprinted),
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Remark on the form of the species. Among the named spe- cimens from Haugesund are.some more densely branched, others coarser and more sparsely branched, the former nearly according with the most common form along the Norwegian coast, the above f. norvegica, not unlikely being the typical form of the species, and the latter partly agreeing with the form that I have called f. australis partly forming intermediate forms. The form norvegica. is characterized by its much branched frond, frequently forming subspherical masses about 3 cm. in diameter, the branches always. rather bent, more or less spreading, about 1— 1.3 mm. thick, sel- dom a little anastomosing below and in general slightly attenuating towards the tip, and the ends frequently rounded. The surface of the frond is most commonly smooth, but now and then rather uneven on account of local, scaly thickenings. Pl. 16, fig. 1—11. This form frequently grows gregarious in considerable abundance.
The form saxatilis is nearly connected with the latter. It appears always to grow more or less scattered, never in any great number. It fastens itself to small stones, but in a more advanced stage of development it occasionally detaches itself and lies free on the bottom. It often rather resembles the preceding form in habit, but it never attains the size of that form, being less bran- ched, with shorter axes, but the branches nearly always more or less bent, as in the named form. The branches often also are coarser, up to about 1. mm. in thickness, not or slightly attenua- ting upwards, with rounded or nearly obtuse ends. Pl. 16, fig. 12—23. ‘The surface is rather uneven, finely rugged, with more or less numerous local and scaly thickenings.
Another form also nearly connected with f. morvegzea is the form that I have named f. australis. It frequently is somewhat coarser than f. norvegica, sparsely branched, the branches partly short partly and more often rather long, 1.5—2 mm. thick, much Spreading, terete or somewhat compressed, cylindrical or slightly attenuating towards the tip, with rounded ends, or now and then with the tips rather compressed and the ends rounded or even nearly truncate. Some specimens that I received from Dr. Bornet ,dragué a l'embouchure de la reviére de Morlaix (Finistére)“ belong
65
to this form and in part according well in habit with the cited figure by Crouan. Some other specimens gathered at ,Ile Ho- lavre, dans le Golfe du Morbihan“ are nearly related to f. australis, but much smaller, the branches slightly thinner and very short, thus somewhat differing from typical specimens of the form, and ought perhaps to be considered as a separate form of the species. The plant recorded by Batters 1. c. as typical L. corallozdes fully coincides with f. australis in the sense here taken, according to Specimens kindly communicated to me. Typically developed spe- cimens of this form appear to be scarce with us. I have seen but some few ones, but others partly approaching f. australis partly f. norvegica have more often been met with. As such an inter- mediate form I regard the specimens figured by Kjellman l. c. pl. 5, fig. 9—10, however, most nearly related to f. norvegica. Cp. pl. 16, fig. 24—31. The figures 24—25 represent the present form from Haugesund, fig. 26 a somewhat differing specimen from Storfosen near Bejan, fig. 27—30 British specimens (from Cumbrae) and fig. 31 a French specimen (from Morlaix).
Of the form flabelligera 1 have not seen typically developed Norwegian specimens, but those represented on pl. 16, fig. 32—37 I got through the kindness of Dr. Bornet ,dragué a l’embouchure de la reviere de Morlaix (Finistere)“. It is analogous to the form aleicornis of L. tophiforme. The branches are rather irregularly divided, with very short axes, spreading almost in one plane, either subcylindrical or compressed, of about the same thickness as those of f. australis, with rounded or almost truncate ends. Some other specimens ,jeté a la cote de St. Malo (Ille-et-Vilaine)“ at least in “part belong to the same form, or forming transitions to f. australis.
The form subsimplex is closely connected with f. australis, distinguished by the entire or almost entire absence of lateral bran- ches, the whole frond being simple or nearly simple, and either Straight or angularly bent. Cp. pl. 16, fig. 38—42 (British speci- mens). Of this form I have not seen any characteristic Norwegian Specimen, either, but only transitions to it.
The species is as to the structure characterized by its rather small cells. They are in a longitudinal section of a branch 7—9
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p- long and 4—o p thick, and often slightly smaller in f. norvegica. than in the other forms.
I have examined hundreds of specimens from different tracts and seasons, collected in May to October and in January and March, but nearly all of them have been sterile, only a very few ones of f. norvegica and f. saxatilis bearing organs of propagation. I am, therefore, inclined to suppose, that the plant in all rather seldom develops these organs. The conceptacles of sporangia partly are scattered partly crowded in the upper part of the bran-
ches. They are slightly convex and very little prominent, the roof
frequently somewhat flattened in the central portion, 300—350 in diameter, most commonly about 300 », and in general a little larger in f. saxatils than in f. norvegica, intersected with rather numerous muciferous canals, of which I have numbered about 50. The sporangia are four-parted, in f. norvegica 100—130 p long and 35—45 y broad, in f. saxatilis frequently a little larger, or 110—140 p long and 40—55 broad. 1, however, have seen but few, especially in f. nmorvegica. Most of the sporangia in f. saxa- twas were only two-parted, but probably not fully developed, and here I also found bisporic together with tetrasporic overgrown ones.
The conceptacles of sporangia grow down into the frond, but in f. norvegica they are extremely scarce. I have examined nume- rous specimens without finding any trace of overgrown organs of that kind, but in others 1 found some few ones especially in the peripherical portion of a branch, never in any great number, and I occasionally met with overgrown conceptacles that had been filled with local formations of tissue, as in other species before mentioned. Once I even found a solitary sporangium in such a filled and overgrown conceptacle. In f. saxatils overgrown conceptacles sometimes are not uncommon, sometimes apparently wanting, and nearly always containing not escaped sporangia or such as have not been mature before they as well as the conceptacles grew down into the frond. On the other hand the whole roof appears now and then to fall away, and in such cases the conceptacles appa- rently not become overgrown, or the scars filled with local for- mations. In the other forms they have not been found.
Rew.
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What I suppose to be cystocarpic conceptacles have been found in very small numbers in a couple of specimens of f. norvegica,. in one of these together with some smaller and little developed conceptacles which, not unlikely, are those of antheridia. The for- mer are conical, low, 350—400 p in diameter at the base, and traversed by a canal about 20 » in diameter. I have not succeded in finding the carpospores.
Remark on the synonomy. The Lithothamnia that Gunnerus records under the name of Apora polymorpha among others pro- bably includes the present species too. Thus the figure on pl. 15, fig. 2 1. c. much resembles ZL. coralloides f. saxatilis. It seems. also to be probable, that the form delineated by Johnson l.c. pl. 24, fig. 5 is referrible to this species, and not unlikely identic with or nearly related to f. flabelligera. Whether on the other hand the two species described by Philippi 1. c. really are identic with L. coralloides is impossible to know without having access to the Original specimens, but they at least appear to be nearly related to it, L. gracile perhaps according with f. flabelligera and L. rubrum nearly connected with f. australis.
Mentioning L. norvegicum in Contrib. Il, p. 7 I also referred to it specimens, which, as remarked, I now consider partly belong to L. apiculatum f. patula partly constitute a separate species, the below described L. divergens. On the other hand I have lost the specimens recorded under the same name in Contrib. I, p. 6 from Mehavn in East-Finmarken, and I am not sure whether they belonged to the present species in the sense here taken. So far as I now remember it was not typical f. norvegica, but rather a form of L. apiculatwm. Therefore, I do not adopt this locality in the present paper.
ftelation to other species. Cp. under L. apiculatwm, L. gra- cilescens and L. divergens.
Habitat. The species lives in the upper as well as the lower part of the sublitoral region, with us descending to a depth of about 15 fathom, but often also to be found only in 5—6 fathoms water, seldom, however, farther up. On the British coast it occurs on a depth of 6—10 fathom. Cp. Batt. 1.c. It prefers harder
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bottom and somewhat sheltered places, especially appearing in sounds and fjords. Some specimens bearing conceptacles of sporangia and in part apparently ripe sporangia have been taken in June and July, and a couple of others with cystocarpic conceptacles in June.
Occurrence. Its most northerly and certainly known locality is Skorpen in Kveenangen, scarce (f. norvegica and f. saxatilis); Lodingen in Nordland; Herg in Helgeland (Schreiner); Frgien, scarce (f. norvegica); Storfosen near Bejan, scattered and apparently scarce (f. norvegica, f. saxatilis, f. australis); at different places in the Trondhjem Fjord, as Inderden, Tautra, Holmberget, Rotvold, Byberget. Roberg, Skjern and Bejan, mostly local and sometimes scarce sometimes abundant (f. norvegica, f. saxatilis); Sulen in Sognefjord (Boye); Haugesund (Wittrock) local but abundant (f. norvegica, f. australis); Mandal (Wille); and Nesodden in the Christiania Fjord (Schreiner).
Geogr. Distribution. Britain (Batters); France (Crouan, Bornet).
Lithothamnion divergens Fosl. mscr.
L. fronde libera in fundo jacente, roseo-flavescente, irregula- riter ramosa; ramis e centro solido, exiguo, vel axi primario egre- dientibus, omnino liberis vel inferne plus minus coalitis, divergen- tibus, flexuosis, teretibus, subeequalibus vel apicem versus attenuatis, 1.8—2.2 mm. crassis, apicibus rotundatis; conceptaculis sporangiferis convexiusculis, a superficie visis diametro 300—350 p; sporangiis quaternas(?) sporas foventibus, circa 120 » longis, 40 m crassis. ‘Tab. 16, fig. 48—50.
Syn. Lithothamnion norvegicum f. distans Fosl. Contrib. II, p. 7; ex parte.
Description of the species. The more or less irregular frond is in its longest diameter frequently about 2.5—4.5 cm. long. It always develops itself freely on the bottom. The colour is in dried specimens yellowish, or yellowish pink, towards the tip of the branches often somewhat darker, with a violaceous tinge. The solid central mass is insignificant, or forming a somewhat elongated
69
main-axis, from which the more or less spreading and sparsely divided branches frequently issue in all directions. The branches never are straight, but more or less curved, or angularly bent, terete, either nearly equal in thickness, generally 1.s—2.2 mm., or often rather attenuating towards the tip, with rounded ends, or now and then somewhat rounded-thickened ends. ‘They partly are free everywhere partly in more densely branched specimens more or less anastomosing below, but upwards always spreading. PI. 16, fig. 43—50. The surface of the frond sometimes is smooth sometimes and more frequently finely rugged and squamellate.
With regard to the structure this plant is in general coarser than the preceding species and most nearly agreeing with that of L. fruticulosum. In a longitudinal section of a branch the inner cells of the cup-shaped layers of tissue are 8—12 yp long, fre- quently about 8—10 p, and 6—7 + thick.
The conceptacles of sporangia are crowded in the upper part of the branches without any order, convex, but little prominent, rather reminding one of those in certain forms of L. fruticulosum, but frequently larger, seen from the surface 300—350 or occasio- nally up to 400 » in diameter and often not distinctly marked. The roof is rather thick and intersected with about 30 muciferous canals. The sporangia most probably are tetrasporic, but I have not seen any with distinct partition, about 120 » long and 40 p broad. However, I have seen but a very few. The conceptacles finally grow down into the frond. Overgrown ones sometimes are scarce sometimes rather numerous, chiefly in the peripherical por- tion of a branch, but they are on the other hand often apparently wanting. I have not seen conceptacles of cystocarps.
ftemark on the synonomy. Most of the specimens recorded l. c. under the name of L. norvegicum f. distams belong to the present species. I then had not the advantage of examining more thouroughly a greater number of specimens of the different forms. L. norvegicum was a little known plant, of which only sterile specimens were known, and as this together with the forms now separated often closely approach each other in habit, I considered
them to belong to one and the same species. 6%
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Relation to other species. Among the species of Lithotham- nion that I know ZL. divergens exhibits the greatest resemblance on the one side to L. fruticulosum f. curvirostra and on the other side to L. coralloides, forming an intermediate "species between these two. It is separated from the former especially by its more spreading and less attenuating branches and larger conceptacles of sporangia. Sometimes it much resembles certain forms of L. co- ralloides in habit, particularly intermediate ones between f. norve- gica and f. australis, but disinguishes itself from these by its in general coarser branches and coarser structure, and also with re- ference to the conceptacles of sporangia. Occasionally it also reminds one of ZL. tophiforme in habit, but is separated by essen- tial characteristics.
Habitat. This species occurs on a depth of 3—5 fathom in company with other species, as L. apiculatum and L. coralloides. A few of the specimens collected in the former half of September were provided with conceptacles of sporangia, most of which ap- parently not fully developed.
Occurrence. Hitherto only found at Skorpen in Kveenangen, north of Troms6, scattered and scarce.
Lithothamnion flabellatum Rosenv.
Grénl. Havalg. p. 772.
f. Granw Fosl. mscr.
f. fronde initio affixa, crustam tenuissimam formante, tuberculis vel ramis instructa, demum crusta evanida, fronde libera in fundo jacente, decomposito subdichotome ramosa; ramis teretibus vel sub- compressis, 2 mm. crassis, subattenuatis, apicibus plerumque ro- tundatis; conceptaculis sporangiferis convexiusculis, parum promi- nentibus, a superficie visis diametro 350 4; sporangiis binas sporas foventibus, 140—180 p» longis, 45—60 p latis. “Tab. 17, fig. 1—7, allo, YO. ster, AP.
f. Rosenvinegii Fosl. mscr.
Descr. et Fig. Lithothamnion flabellatum Rosenvy, |. c. et fig. 1—2._
Syn. Lithothamnion soriferum Rosenv. |. c. p. 772; ex parte sec. spec.
Remark on the species. The plant that Rosenvinge l. c.
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describes under the above name is in my opinion the most extreme form of a species, which in some respects rather differs in its development from most other Lithothamnia, so far as these are hitherto known. I have, at least, not been able to draw any limit between this form, which I propose to name f. Rosenvingi, and the above f. Gran, and it probably includes more forms, the latter perhaps taken in too wide a sense.
Description of the form of the species. The form Gran is at first fastened to shells or smaller stones, forming a very thin crust scarcely up to 0.5 mm. in thickness and closely adherent to the substratum. The peripherical portion of this crust is thinner than the internal, feebly zonated, with a whitish brim in specimens not fully encompassing the object, to which it is fastened. Small excrescences appear at an early stage of development, at first in the central portion, later over the whole or nearly the whole crust. At this stage it very much resembles younger individuals of L. colliculosum. Afterwards the excrescences arise into erect, straight or somewhat bent knobs or short branches, which are either simple, bifid or trifid above, and at length getting more branched in a rather irregular subdichotomous manner, in old individuals with branch-systems of at least three orders, with rather short axes. ee b/, fies 17, pl. 22) fie. Lo yAtithe same time the crust by and by disappears, the plant loosens itself from the substratum and lies free on the bottom, still plainly showing that it has been attacked at first, though not in old and more driven specimens. The branches are in older specimens more or less spreading and seldom straight, terete or slightly compressed, either nearly cylin- drical or, more frequently, slightly attenuating towards the apex, with rounded or occasionally obtuse ends, about 2 mm. thick, partly less partly a little more. They are frequently a little ana- stomosed below, and the surface partly is nearly smooth, occasio- nally with short, concentric strice, partly rather uneven on account of numerous local, scaly thickenings. The crust, so far as I have seen, never increases in thickness after the branches are developed, but if much attacked by animals in a younger stage a new crust here and there is formed upon the older, even over short knobs,
72
but especially between the knobs or short branches of younger specimens so as to cover the animals. This is, however, seldom, and in typically developed specimens not too much attacked I al- — ways found only the primary crust. If the crust by and by fully encompasses the object, or this is not of very small size, the plant appears to loosen itself in a later stage of development, sometimes even, not till the branches are much developed, or the plant appa- | rently is nearly full-grown. On the other hand it at length always loosens itself from the substratum; at first a part of the crust disappears or loosens and by and by the whole crust of parts of it together with some branch-system, so that more loosened indi- viduals arise from one fastened. These continue their growth and form at length irregular or subspherical masses, whose longest diameter gets up to about 7 cm. PI. 17, fig.6—7. The branches especially of loosened individuals often bear wart-like processes or short branchlets, which in the upper part occasionally may be rather crowded.
I do not know whether the plant also develops freely on the bottom. However, I have seen some younger specimens apparently freely developed and probably belonging to the same form.
An American specimen kindly sent me by Mr. Collins in habit stands between the specimens figured pl. 17, fig. 1—2, and it most probably belongs to f. Granz, but it is sterile and, there- fore, the determination not quite certain. The crust is very thin, partly disappeared and the plant nearly loosened from the object, a small stone, which it apparently has nearly encompassed. Col- lins’ collection B. ,Eagle Island, Maine. In pools at dead low- water.“ The specimen on the other hand somewhat reminds one of certain forms of L. fruticulosum. Cp. Hauck, Meeresalg. t. 5, fig. 4. However, in overgrown conceptacles I only found bi- sporic sporangia, but they were smaller than in the named form.
As remarked above I consider f. Rosenvingw to be the most extreme form of the species, characterized by its fan-shaped rami- fication and more or less compressed branches, analogous to J. tophiforme f. alcicornis, but on the other hand showing the most close affinity to f. Granw. A Greenlandic specimen kindly com-
4 we | 7) Ne
73
municated to me by Mr. Kolderup Rosenvinge nearly accords with fig. 1 on pl. 17, but smaller, and two others and younger also are so nearly agreeing with f. Granw, that they in my opi- nion must be referred to this form, with not or very slightly com- pressed knobs or branches. The crust is in the specimens that I have seen as thick or slightly thicker than in f. Granw, but Ro- senvinge mentions thicker crusts, however, not being sure whether they belong to the same form. Judging from these younger spe- cimens the present form apparently also loosens itself from the substratum, as they, being removed from the substratum, appear to have been but loosely attached. Typical specimens of this form have not been found with us, but only transitions to it.
With reference to the structure both the forms accord with one another. The branches show in a longitudinal section pretty regular cup-shaped layers of tissue, with the inner cells about 10—12 p» long and 5—8 vp thick.
The form Granw develops sporangia at a rather young stage, even before the branches are particularly developed. The concep- tacles only occur in the upper part of the knobs or branches and especially just below the apices, never in the crust. They are partly somewhat scattered partly and more frequently densely crowded, often so densely that the roofs become angular, or more or less confluent, in this respect rather accordidg with those of L. tophiforme, seen from the surface about 350 yp in diameter, sometimes less sometimes a little more, convex but little prominent, and now and then somewhat flattened especially in a younger state. The roof is traversed by about 30 muciferous canals. I have exa- mined several sporangia, all of which were bisporic and most of them apparently mature. They are rather straight or only a little bent, 140—180 p» long and 45—60 p broad.
The conceptacles of sporangia in f. Rosenvingw are stated by Rosenvinge l. c. to be only about 250 p» in diameter. I found some few in the above mentioned specimens which are 300—350 vin dlameter seen from the surface, but perhaps they are fre- quently smaller, or Rosenvinges measures may be from median
74
sections, sometimes showing less diameter than from the surface or the roof.
The conceptacles of cystocarps and antheridia are not yet known in any of the forms.
In both the forms the conceptacles of sporangia finally grow down into the frond. Overgrown ones are partly rather numerous, partly very few in number, sometimes even not to be found. Only the central portion of the roof gets dissolved, not seldom though the whole roof and then it partly leaves a nearly cup-shaped partly a deeper scar. Such scars become effaced by local formations of tissue, which, if the scars are not too shallow, rather often are covered by a new thickening layer of the frond and to be seen on a section.
Remark on the synonomy. Among some Greenlandic speci- mens from Julianehaab referred by Rosenvinge to L. soriferum (L. tophiforme) is a couple provided with conceptacles of sporangia. These in my opinion really belong to the present species and are closely related to f. Granw. I found overgrown conceptacles of sporangia or such ones filled with new-formed tissue, which is never due to L. tophiforme. In the superficial conceptacles, coin- ciding with those of the present species, I also found some few bisporic sporangia, which appeared to be mature. Besides, the specimens differ from ZL. tophiforme by a little thinner branches, shorter axes and somewhat uneven surface, but on the other hand the limits are in this respect often difficult to draw. A couple of others | suppose to be identic with the last named species.
elation to other species. With regard to the sporangia the present plant is most nearly related to LZ. glaciale, but otherwise it is quite different and cannot be confounded with this species except young individuals. It in some respects shows greater affinity to the following species, L. collaculosum. On the other hand it may without closer examination be confounded with certain forms of L. fruticuloswm, as f. curvirostra. However, it is most easily confounded with L. tophiforme, and sterile specimens sometimes are difficult to distinguish from smaller and thinner forms of the latter, although typically developed or fertile specimens are sepa-
79
rated both in structure, the sporangia and other essential charac- teristics.
Habitat. With us the plant grows in the upper part of the sublitoral region, on a depth of 3—8 fathoms. It apparently pre- fers protected places, in somewhat exposed localities descending farther down than in the former. On the Greenlandic coast it descends to a depth of 16 fathom. It bears sporangia in July, August, September and December.
Occurrence. Mehayn in East-Finmarken, Bergsfjord in West- Finmarken, scarce; Skorpen in Kvenangen, apparently rare; Rissen in the Trondhjem Fjord, rare; Drébak (Gran) and Nesodden (Schreiner) in the Christiania Fjord, apparently pretty plentiful.
Geogr. Distribution. Greenland (Rosenvinge); the Atlantic coast of North America (Collins).
Lithothamnion colliculosum Fosl.
Contrib. Il, p. 8.
f. densa Fosl. mscr.
f. crusta 0.5—1.5 mm. crassa; tuberculis usque ad 4 mm. altis, 1—2 mm. crassis, dense dispositis. Fig. Lithothamnion colliculosum Fosl. 1. c. t. 3, fig. 1 et tab. nostr. 17, fig. 8—10.
f. laxa Fosl. mscr.
f. crusta usque 3 mm. crassa; tuberculis tenuioribus, usque ad 2 mm. altis, laxe dispositis. Tab. 17, fig. il.
-f. rosea (Batt.) Fosl. mscr.
Descr. Lithothamnion roseum Batt. in Grevillea, vol. 22, p. 20. Fig. ; colliculosum f. rosea tab. nostr. 17, fig. 12—16.
Syn. Lithothamnion fasciculatum Farl. New Engl. Alg. p. 182; ex parte sec. spec. e, colliculosum Batt. in Grevillea, vol. 21, p. 23; Journ. of Bot. 1892, p. 8; saltem ex parte sec. spec.
Remark on the form of the species. The plant recorded by Batters |. c. under the name of L. rosewm is supposed by him perhaps to be the tetrasporic form of L. colliculosum. It is in fact so closely related to this species, that it in my opinion cannot be considered more than a denominated form, or not unlikely being
76
the typical form of the species. It even is partly included in the form of L. colliculosum mentioned in Contrib. 1. c. However, most of the specimens then gathered belong to the form that I have named f. densa. Others show transition to f. rosea, or being most nearly related to this form, of which I have later collected specimens that fully accord with British ones.
The form densa is characterized by its frequently thin crust which apparently seldom attains a thickness of 1.5 mm. It bears numerous and densely crowded knobs up to 4mm. high, frequently about 2 mm., by a thickness of 1—2 mm. These knobs are cy- lindrical or slightly tapering, or enlarged towards the tip, simple, or now and then towards the apex provided with one or two wart-like processes, frequently with obtuse apices. Pi. 17, fig. 8—10. In a younger stage the edges of adjacent crusts stumbling each other generally raise themselves against each other, forming more or tess elevated ridges. Cp. Contrib. II, pl. 3, fig. 1. These ridges rather seldom are to be seen in fully developed or older individuals, then being covered with knobs. The plant is often accompanied by other species, especially J. Strémfelta, which it, not seldom, by and by covers, and is fastened to stones or occasionally shells.
Two specimens from Spitzbergen kindly communicated to me by Conservator Sparre Schneider fully accord with Norwegian specimens of this form. They are dredged between Amsterdam- oderne and Norskderne by Capt. Nils Johnsen of Tromso.
A form apparently nearly related to the latter is f. daxa, but on the other hand I have been in doubt whether it might not per- haps be regarded a separate species. I have seen only a solitary specimen bearing a couple of not fully developed conceptacles of sporangia, and this is an American specimen. Pl. 17, fig. 11. Collins’ collection D., Rockport, Mass. However, I have Nor- Wegian specimens which closely resemble the latter in habit, but they are sterile. This form rather differs in habit from f. densa, and is characterized by its thicker crust, up to 3 mm., but appa- rently somewhat varying in this respect, as parts of one and the same specimen may be only 1 mm. in thickness, and now and then a new crust partly is formed upon the primary. The crust
7g)
bears more or less scattered knobs, which in general are thinner than in f. densa, up to about 1.5 mm. thick, but frequently less, and up to about 2 mm. high, subcylindrical, with rounded or oc- casionally obtuse apices. The colour appears to be a darker pink than in the named form, judging from dried specimens. This form requires closer examination of larger materials than I have at my disposal.
The form rosea distinguishes itself by its thicker knobs, about 2—3 mm., which are not so densely crowded as in f. densa, cylindrical, cylindric-conical or occasionally upwards thickened, in the Norvegian specimens not exceeding 5 mm. in height, but in British until 8 mm. according to Batters 1c. In most of the specimens that I have seen the knobs are simple, in others occa- sionally on the point of dividing, or carrying a small wart-like process, but Batters remarks that they also are bifid or trifid above. The crust is as thick or thicker than in f. densa. PI. 17, fig. 12—13 represents Norwegian specimens, fig. 15—16 British, and fig. 14 an American specimen from Rockport, Mass. (Collins’ collection F.).
The above quoted forms accord with each other as to the structure. The knobs show in a longitudinal section more or less regular cup-shaped layers of tissue, with the inner cells frequently longer in proportion to the thickness than those in a section of the upper thickening-layers of the crust, 8—12 » long and 5—8 p. thick, with rather thin walls.
The conceptacles of sporangia in f. densa are scattered or somewhat crowded in or between the knobs, seen from the sur- face 300—350 yp in diameter, very little prominent and as a rule rather flattened. The roof is intersected with 30—40 muciferous canals. The sporangia are two-parted, much varying in shape and size, convex-concave and frequently with the rounded or now and then rather attenuating ends somewhat bent together, occa- sionally nearly half-moon shaped, and large in proportion to the height of the conceptacles, in general about 180—220 yp long and 60—100 » broad, or more. I have, however, seen but few con- ceptacles and sporangia of this form.
78
In the above quoted specimen of f. daxa I found only two conceptacles in the crust, which are probably not fully developed, hardly perceptibly raised above the surface of the frond and much flattened, and of about the same diameter as in the preceding form. Some sporangia found in overgrown conceptacles were about 180 p. long and 60—90 p broad.
In f. rosea the named conceptacles are frequently rather den- sely crowded in the crust and knobs, the roofs occasionally con- fluent or nearly confluent, also here about 300—350 p in diameter, and partly much partly less flattened. In a British specimen kindly sent me by Mr. Batters I found them not or scarcely raised above the surface of the frond, indistinct and much flattened, but they were probably not fully developed, although the sporangia appeared to be mature. In another British specimen from the same locality they fully accord with those in Norwegian specimens, distinctly marked, slightly prominent and more or less flattened. In the above quoted Ame- rican specimen of this form (pl. 17, fig. 14) the conceptacles are of the same size, but much flattened and in part nearly disc-shaped, though very little prominent. The sporangia are of about the same size as in f. densa, or a little smaller. Cp. Batt. 1. c.
The above named conceptacles finally grow down into the frond. Overgrown ones sometimes are numerous sometimes very few in number, or apparently even wanting, which not unlikely may be. connected with the fact, that the cystocarpic and antheri- dian conceptacles appear not to occur in the same individuals as those bearing sporangia. However, sometimes the whole roof falls away and leaves a rather shallow scar, and now and then I found such scars covered with a new, local formation of tissue; the con- ceptacles being densely crowded this new formation even stretched over more ones.
Cystocarpic conceptacles have with certainty only been found in f. densa. They are scattered or crowded over the crust or knobs without any order, conical, about 500—600 p in diameter at the base, with a single orifice, and a little above the middle or towards the apex nearly always more or less constricted, the upper portion partly acute partly rather blunt. This portion or a part
79
of it easily falls away, or perhaps always towards maturity, and then the conceptacles are depressed-conical or nearly hemispherical. Later the whole roof disappears, leaving a cup-shaped scar with somewhat elevated edges, as in most other species. They are in a median vertical section inwards about 400 » in diameter at the base, 200 » high and the upper portion of the roof also about 200 » high, the canal intersecting this portion 50——60 yp in dia- meter except towards the tip, where it is thinner. —These measures are, however, from the largest conceptacles. The frequently appear to be lower. The carpospores are broadly cuneate, occasionally elliptical or elongated obovate, 120—160 p long and 50—70 p broad in the broadest part.+)
The conceptacles of antheridia are very numerous in some of the specimens collected, scattered or crowded especially between the knobs, and appear in the same individuals bearing conceptacles of cystocarps. They are of the same shape as the last named organs, but smaller, about 200—300 yp in diameter at the base and traversed by a canal at the tip. The spermatia are very much varying in shape, however, apparently most frequently rounded- angular and much compressed, about 50—60 p in diameter.
Remark on the synonomy. Prof. Farlow has had the kind- ness to send me two specimens of his L. fasciculatum. Another one is mentioned under L. fruticuloswm. These specimens I without any doubt refer to the present species, and represent a form closely related to f. densa. It only differs by its in part a little thicker crust, and the numerous knobs are more or less anastomosing below and above more often furnished with wart-like processes than in Norwegian specimens. The conceptacles of sporangia ac- cord with those of the named form. One of the specimens is accompanied by and partly anastomosed with L. compactwm.
The plant that Mr. Batters records 1. c. as L. colliculosum at least in part appears to belong to this species, according to
1) The shape and size quoted in Contrib. II, p. 10 partly refers to the sper- matia partly depending thereon, that the carpospores have not been removed from the conceptacle and thereby mostly not seen fully from the side. They really are much thinner than broad, frequently somewhat convex-concave, and in the conceptacles especially the upper portion more or less bent.
80
specimens kindly communicated to me. One of these, fastened to: a fragment of a shell, coincides well in habit with f. rosea, and is provided with conceptacles of sporangia also similar to this form, the roof intersected with about 40 canals, but I have not seen the sporangia. A couple of other specimens fastened to or encom- passing small stones partly nearly approach f. densa in habit partly and especially one of them nearly destitute of knobs may not un- likely belong to another species, perhaps being a young L. wmeru- stans. I have not succeeded in finding organs of propagation. However, Batters remarks!) that ,the tetraspores are formed in prominent hemispherical or conical conceptacles with a single naked orifice“. If so really is the case, this form is quite different from the present species and most probably belongs to an undescribed one. I never met with any species in which the conceptacles of sporangia are conical, resembling those common to the superficial cystocarpic ones, with a single orfice.
Felation to other species. This plant is more nearly related to L. glaciale than the preceding, but is, however, plainly sepa- rated, except sometimes in a sterile stage from young individuals of that species. Young individuals much resemble young ones of L. flabellatum f. Granu, and f. rosea even in an older stage some- times rather approaches younger and attached individuals of the latter. On the other hand, especially f. rosea encompassing stones, or forms standing between this and f. densa on the one side, and L. fruticulosum f. intermedia on the other side sometimes are difficult to distinguish without closer examination. Besides f. rosea now and: then reminds one in habit of L. polymorphum f. tuberculata, but it is. separated from this even as to the colour, if they are not too bleached.
Habitat. At the first place I found this species (Skorpen in Kveenangen) it grew on a depth of 10—15 fathom. Later I met with it in more shallow water, 5—10 fathom on the coast of Fin- marken, but on the whole it appears to descend farther down along the northern part of the coast than in more southern tracts, or in exposed localities. It prefers sheltered places. In the Trondhjem Fjord I have taken it on a depth of only 1—2 fathom. On the
1) Grevillea, Vol. 22, p. 20.
81
British coast it even occurs in the litoral region, here, however, only in deep pools, which also sometimes seems to be the case on the Atlantic coast of North America, but apparently never laid dry, as for inst. often is the case with L. polymorphum.. Cp. Batters l.c. On the northern Norwegian coast it has been found sparingly provided with sporangia, but more richly with apparently ripe carpospores and spermatia in July, the former half of August and September, and on the southern coast in July and August. On the British coast it bears sporangia in February and August. Thus it appears as if Z. colliculosum develops reproductive organs nearly all the year, although in this as well as in most other species the greatest number of the gathered specimens have been sterile.+)
Occurrence. Found at Kjelmé (f. densa) and Mehavn (f. rosea) in East-Finmarken, scattered and very scarce; Kistrand (f. densa), Kvalsund (f. rosea) and Sopnes in West-Finmarken; Skorpen in Troms6 Amt (chiefly f. densa), local but abundant; and at several places in the Trondhjem Fjord (f. densa, and f. laxa?), as Vanvik, Rissen and Kongensvold, scattered and very scarce.
Geogr. Distribution. Spitzbergen; Britain (Batters); the At- lantic coast of North America (Farlow, Collins).?)
Lithothamnion varians Fosl. mscr.
L. fronde crustacea, plus minusve lobata, crustis superimpositis demum sat crassa, tuberculis striisque brevibus instructa; concepta- culis_ sporangiferis convexiusculis, at parum prominentibus, a super- ficie visis diametro 300—350 p»; sporangiis binas(?) sporas foven- tibus, 100O—130 p» longis, 25—35 p latis; conceptaculis cystocarpi- feris conicis, subapiculatis, diametro circa 500 p.
f. verrucosa Fosl. mscr. f. crusta irregulariter lobata, tuberculis usque ad 2 mm. altis, 0.5—2 mm. crassis, dense dispositis. Tab. 18, fig. 1—5.
1) After this was in the hands of the printer I met with a form of the species at Ytterden in the Trondhjem Fjord, growing in a rock-pool at low-water mark, which partly coincides with f. rosea partly somewhat approaches the above mentioned North American.
2) Cp. the remarks under L. Strémfeltii as to L. Lenormandt Gobi from the White Sea, which probably also includes the present species.
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f. wrregularis Fosl. mscr.
f. tuberculis fere hemisphericis vel irregularibus, plus minusve laxe dispositis. Tab. 18, fig. 6—9.
Syn. Lithothamnion polymorphum Kjellm. N. Ish, Algfl. p. 134 (102); ex parte.
sec. Spec. ab auct. determ. Me 3 Kleen, Nordl. Alg. p. 11; ex parte? A 3 Fosl. Contrib. I, p. 9.
Description of the species. As remarked below under L. polymorphum 1 consider the present plant an independent species. It forms incrustations on rocks. The form of the crust partly depends on that of the substratum, to which it clings closely and at first firmly, but when older at least often is easily separated from it. In f. verrucosa the crust puts forth more or less clumsy protuberances or lobes, or such are formed by covering up extra- neous objects, and bearing, like the rest of the crust, numerous wartlike knobs up to about 2 mm. high and 0.5—2 mm. thick, with in general blunt apices. Pl. 18, fig. 1—5. In the form 7rre- gularis the crust is more or less irregular, and it is furnished with less numerous or few wart-like knobs, but more often smaller or larger subhemispherical or irregular processes. Pl. 18, fig. 5—9. Upon the primary crust new crusts are formed partly clinging to the subjacent one partly rather elevated and here and there free, or covering extraneous objects, or new, local crusts are formed so as to cover the numerous animals frequently living on or pene- trating the plant, and the marginal portion of these new forma- tions may sometimes be more or less free, or they form lamels, or ridges, or in all very irregular processes. Pl. 18, fig. 7 shows a specimen with in part small lamels. The crust attains a thick- ness of up to nearly 1 cm., frequently, however, less. Old indi- viduais occasionally are to be found nearly free on the bottom, or become loosened by external causes. Such loosened individuals continue their growth and new formations are partly formed on the lower side turned towards the bottom, which, however, is also the case in fastened but nearly free individuals. Younger speci- mens are feebly shining, older ones often finely rugged on the surface. The plant is furnished with short and very fine striz in
83
the crust as well as the knobs, but they are more or less indistinct and partly wanting in old specimens.
The colour is much fugitive. I have not noted that of fresh specimens, but dried ones partly are yellowish-white partly yellowish- brown and occasionally with a purplish tinge.
The structure is rather varying, aS in most other Lithothamnia. However, the cells of the inner layers of tissue are in a longitu- dinal section of a knob frequently ionger in proportion to the thickness than for inst. in L. polymorphum, and the walls appa- rently thinner, about 10—17 p» long and 6—10 p thick in the Specimens that I have examined.
The organs of propagation are as a rule very scarce and apparently seldom attain fully development. They are often attacked by animals, and in most of the conceptacles of sporangia that | have examined I did not succeed in finding spores, or I met with small animals or animal substance fully filling the cavity. The named conceptacles are irregularly scattered over the crust or knobs and never so numerous as in L. polymorphum, very nearly related to those of L. glaciale in appearance as well as development, though less distinctly marked, convex but very little prominent, and seen from the surface 300—350 y» in diameter, sometimes a little more sometimes less. The roof is intersected with 30—40 canals, which are crowded in the central portion of the roof. These canals are jarger than those in LZ. glaciale. The central portion often gets somewhat depressed when nearly dissolved, and then it looks, in a certain stage, as if the conceptacles were surrounded by an annular border, as in L. glaciale. Most of the certainly few sporangia that I have seen were bisporic, about 100—130 p» long and 25—35 p broad, but probably attaining larger size, nearly linear, or a little broader in the middle than towards the ends. However, in another specimen certainly somewhat differing from typical f. wregularis in habit, but most probably belonging to this form I found a conceptacle containing irregularly two- three- and four-parted sporangia. It may, therefore, be, that the sporangia have not been fully developed and mature ones in fact are tetrasporic.
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In a specimen from Borgever in Lofoten partly according with f. verrucosa partly furnished with some crowded, short and rather coarse branches reminding one of those in certain forms of L. glaciale | found well developed and apparently mature bisporic sporangia about 180 » long and 80 » broad. The part of the plant agreeing with the precent species was sterile. It may be that spores of LZ. glaciale have germinated on the named form of LI. varians, or both are grown together, though any limit between the crusts of the two supposed species is not to be detected, and the crust in all most nearly resembles that of the last named species. :
The named conceptacles finally grow down into the frond, but overgrown ones appear seldom to be found in any great number.
In one of my specimens of f. verrucosa | found a few con- ceptacles of cystocarps. Pl. 18, fig. 5. They are conical, often rather low, 450—500 p in diameter at the base, with a rather acute tip and traversed by a single orifice, on the one side ap- proaching those of L. apiculatum in appearance, but not so abruptly passing into this tip as in that species, and on the other side rather more resembling those in L. colliculoswm, but lower and so far as | have seen never constricted farther down, as often is the case in the last named species. This tip easily falls away and then the conceptacles look depressed-conical or subhemispherical. I have not succeeded in finding the spores.
Some few other conceptacles on the same individual and ap- parently similar in shape probably are those of antheridia. The greater part of the roof is in most of them fallen away, and al- ways the uppermost part. They, however, seem to have been rather low, and are about 200—250 p in diameter at the base.
I do not know which of the quoted forms might be concidered
the typical form of the species. They certainly are not well de-_
fined, although a limit frequently may be drawn, and they are often even considerably differing, and in my opinion ought to be regarded as denominated forms. Along the coast of Finmarken most of the specimens gathered belong to f. wregularis or forms
pe
85
which are most nearly related to this, but also specimens fully according with typical f. verrucosa were apparently not uncommon. The best developed individuals of the latter I met with at Balstad in Lofoten. However, as I formerly regarded the species identical with ZL. polymorphum I did not take any greater notice of it at the different places.
Remark on the synonomy. This species is included in L. polymorphum recorded by Kjellman 1. c., according to specimens determined by him. All the specimens that I now possess from East-Finmarken referred to under that name in Contrib. |. c. also belong to L. varians, except, perhaps, a specimen from Berlevaag. Still the plant mentioned by Kleen 1. c. under the name of L. polymorphum, not unlikely, in part includes the present species.
Relation to other species. The plant rather approaches smaller individuals of L. glaciale, and it, in some respects, appears to form an intermediate link between this species and L. polymorphum, although the conceptacles of sporangia as well as the sporangia themselves are different in both the named species. On the one side it shows great affinity to the former, and is not always easily to be distinguished, as remarked under this, even the conceptacles of sporangia nearly approaching one another. But on the other side it occasionally assumes forms, especially such ones growing on a plain substratum in somewhat sheltered localities, which in a Sterile state are very difficult or nearly impossible to separate from the latter. It probably is. most closely related to L. glaciale, but its nearest relationship cannot be made out before the organs of propagation are better known.
Habitat. On the coast of Finmarken it frequently lives in the upper part of the sublitoral region, on a depth of about 2—5 fathom, but it also descends farther down, to about 10 fathoms water, and on the other hand it also occurs in rock-pools in the lowest part of the litoral region. Farther to the south I only met with it in the sublitoral zone. It prefers exposed localities, but also appearing in somewhat sheltered places. The plant is nearly always much attacked by animals, which it, if possible, by and by covers in its existence struggle, being rich in cavities produced
bo Te
/
86
by boring-muscles, which particularly destroy the lower part of the crust, and always in very numerous passages made by worms. It grows over younger individuals of Mytilus, shells of Balanidee, tubes of Serpula and numerous other animals fastened to or living on it. It also serves as a substratum for Alaria, Laminaria and other algz, often widely extending over the rocks, and, not seldom, growing over the root and the lowest part of the stem of those large algze. Specimens bearing conceptacles of sporangia have been taken in June, July, August and September, but in very small numbers and few of them containing sporangia. A solitary speci- men collected in the later half of September was, as above men- tioned, provided with some few conceptacles of cystocarps and probably also antheridia.
Occurrence. I here only record the localities from which I have specimens left, viz. Havningberg and Berlevaag in East- Finmarken, Honningsvaag, Havésund, Gjesver and Ingo in West- Finmarken. A specimen from Kjelvik, picked up from a depth of about 15 fathom, perhaps also belongs to the same species. Besides it has been gathered at Skorpen in Kveenangen, and at Balstad and Borgeveer in Lofoten.
Geogr. Distribution. Some specimens from Greenland that I have seen, determined by Kjellman as L. polymorphum, not unlikely, at least in part, belong to this species. Cp. Kjellm. l.c.
Lithothamnion polymorphum (L.) Aresch.
in J. Ag. Spec. Alg. 2, p. 524; Millepora polymorpha L. Syst. Nat. p. 1285; ex parte. Descr. Lithothamnion polymorphum Strémf. Algveg. Isl. p. 19, t. 1, fig. 1—3. Hxsice. : $ Aresch. Alg. Scand. exsicc. No. 302.
f. tuberculata Fosl. mscr.
f. crusta tenuiore; tuberculis 2— 3 mm. altis, 2—5 mm. crassis, obtusis vel truncatis plus minusve dense dispositis. Tab 17, fig. 7-9,
f. valida Fosl. mscr.
f. crusta crassiore; tuberculis fere hemisphericis, diametro 9—20 mm., altitudine 2—6 mm. Tab. 17, fig. 20—21.
87
f. papillata Fosl. mscr.
f. crusta tenuiore, sublevi vel tuberculis minutis instructa. Maps. fie. 22-23.
Syn. Millepora polymorpha Mohr, Isl. Naturh. p. 141; ex parte.
Spongites crustacea Ktitz. Spec. Alg. p. 689; Tab. Phyc. 19, t. 97? Lithothamnion purpureum Cr. Fl. Finist. p. 150; sec. spec. , polymorphum Kleen, Nordl. Alg. p. 11; ex parte. - Aresch, Obs. Phyc. 3, p. 5; ex parte. 5 Hauck, Meeresalg. p. 271; ex parte. ‘ = Kjellm. N. Ish. Algfl. p. 184 (102); ex parte. 5 Batt. Mar. Alg. Berw. p. 139; sec. spec. ; excl. syn.
Remark on the limits of the species. Some forms formerly referred to this species were removed by Kjellman 1. c. It was taken in the same sense by me in Contrib. I, most of the speci- mens there referred to kindly determined by Kjellman and partly recorded by him |. c. However, regarding the plant distributed by Areschoug in Alg. Scand. exsicc. No. 302 as the type, 1 am now of opinion, that the species must still be limited and a form removed from it, which in fact appears to be rather more nearly related to L. glaciale. This I consider an independent species, the before mentioned L. varians. I here record the present species as defined by Strémfelt |. c. in regard to the vegetative parts, his specimens, as he remarks, also compared with Areschoug’s type specimen, and the below quoted shape and development of the organs of propagation.
Femark on the form of the species. This species seems to be less varying than several other Lithothamnia, although there is a rather considerable difference between the most extreme forms. It perhaps includes more than the above quoted orles. They are, however, not well defined, as transitions often appear to occur. I do not know which of them might be considered the typical form, nor have I seen any great number of specimens, as the plant has been rather scarce in the tracts where I have collected Litho- thamnia myself.
The form tuberculata is characterized by its rather thin crust, about 1—3 mm. in thickness, which bears more or less numerous
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knobs, that frequently are about 2—3 mm. high and 2—5 mm. thick, either thickened towards the tip, with obtuse or truncate ends, or occasionally forming wart-like, subconical or subhemis- pherical processes. New crusts are formed, one upon the other, which cling more or less closely to the older one and its knobs, and thereby also the knobs become thicker, but not always stretched over the tip of the latter, or here the edges now and then form somewhat irregular excrescences by trumbling each other. Pl. 17, fig. 17-19. Especially in younger crusts a smaller or greater part of the peripherical portion often is free, and this portion is more or less distinctly zonated, with a whitish brim, and the down- wards turned part of such a free portion frequently forms rather distinct concentric ridges. This also now and then is due to new crusts overlapping extraneous objects.
In f. valida the crust is thicker than in the preceding, up to 5 mm. or more, with larger and subhemispherical processes, which in general are 5—20 mm. in diameter and 2—6 mm. high. PI. 17, fig. 20—21.. This form reminds one much in habit of L. loculosum Kjellm. Beringh. Algfl. p. 21, t. 1, fig. 1—2. It often grows over shells of Balanidee and Mytilus, and the new crusts are rather closely united to one another, if not covering extraneous objects.
The form papillata appears to be less independent than any of the other forms, and often passing into the one or other, but, on the other hand, in its most extreme form it is rather differing. The crust is of about the same thickness as in f. twberculata, partly, however, nearly even, partly more or less uneven and provided with small processes, particularly in a younger stage with concentric zonated peripherical portion and whitish brim. Pl. 17, fig. 22—23. The surface of the frond is in younger individuals of this as well as the other forms rather smooth and often even shining. Magnifying shows, however, the surface to be uneven in consequence of concentric and radiating striz. These striz are not, or seldom, to be seen in older individuals, and in such ones the surface never is quite smooth.
On a radial section the cells of the upper thickening layers
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are rectangular, occasionally nearly squarish, about 10—14 p long and 6—8 p thick, with most often rather thick walls.
The conceptacles of sporangia, which I also found in Are- schoug’s above mentioned type, are more or less densely crowded over the whole frond without any order. I have not seen younger, but fully or nearly fully developed, or emptied ones. They are always immersed, seen from the surface depressed-globular or oblong, not cup-shaped, as in the below mentioned conceptacles, about 1OO—150 » in diameter, at least towards maturity surrounded by an annular or oblong border, partly rather indistinct, but visible by its a little lighter colour, partly distinct, but not or very slightly raised above the surface of the frond, including this border 200— 300 » in diameter. The roof is intersected with 20—30 muciferous and rather coarse canals, which towards maturity often are about 8—10 p» in diameter. By and by the roof gets nearly dissolved, the surrounding parts continue their growth and the conceptacles become overgrown. Occasionally the whole roof as well as the greater part of the border falls away, leaving a rather deep hole. The tetrasporic sporangia are in general 90—110 p» long and 25— AO or 45 p» broad, by a thickness of about 4/;—1/s of the breadth.
Overgrown conceptacles frequently are numerous, spherical or flattened-spherical, about 200—300 p in diameter, and now and then having been filled with local formations of tissue, probably corresponding with the mentioned falling away of the roof and border.
The conceptacles of cystocarps and antheridia appear to occur in other individuals than those bearing sporangia. Once I have seen them in an individual growing on the same substratum as, and in part confluent with another individual bearing sporangia. However, I am not sure whether the below described organs in- clude the one or other, or, as I am most inclined to suppose, both the named ones. I found them in two small specimens from Mandal and a couple of others from Helgoland, the former kindly sent me by Prof. Wille and the latter by Dr. Kuckuck.
In the named specimens from Mandal the conceptacles are from the surface of the frond at first visible as globular points
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which are imperceptible to the naked eye, 150—250 p in diameter. These points are slightly lighter than the surrounding parts, in the middle intersected with a single and rather indistinct canal, and the periphery forming a more or less light and very narrow annular border, not, however, raised above the surface of the frond. By and by the roof becomes sitghtly convex, seldom nearly hemisphe- rical or depressed-conical, rather thick, but in all very little pro- minent, of the same diameter as above quoted, with the orifice more distinct, but, so far as I have seen, not yet any spores for- med. Later the central portion of the roof gets thinly decorticated, but the conceptacles apparently not yet fully developed, nor did I find any distinct spores in the, however, very few conceptacles that I have seen in this state of development.
In the specimens from Helgoland I found some few concep- tacles very nearly resembling the named convex ones, and in others a smaller or greater part of the central portion decorticated, seen from the surface apparently by and by assuming a cup-shaped or depressed-oblong form, with not or very slightly elevated edges, successively depressed towards the centre, and the not much de- pressed central portion traversed by a single canal. Conceptacles in the last named state were numerous and appeared to be fully developed, at least some of them containing apparently mature spermatia, and others not unlikely carpospores, the former flattened and rounded or rounded-angulate, about 60 p» in diameter, the latter broadiy cuneate or oblong, but in all rather irregular, about 70 » long and 40—50 p broad. At maturity the orifice becomes larger, a smaller or greater part of the roof gets dissolved, or the whole roof falls away, leaving a rather deep hole.
From the rather scanty materials at my disposal, with the conceptacles in the specimens from Mandal in one and the same state of development, and so also in those from Helgoland, I have not been able to decide with certainty whether the first named really bear cystocarpic conceptacles in development, or both these and the antheridian ones. And 1 am not sure whether the last named specimens only were provided with spermatia, and if so, the latter are extremely varying, or if in fact are both the named
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organs, so that the convex conceptacles are cystocarpic ones in development. There is a slight difference between the convex con- ceptacles in the specimens from Mandal and the convex in those from Helgoland, as the latter appear frequentiy to be even less prominent and, especially those cup-shaped, in general a little larger than the former, although I, on the other hand, have not seen any true limit between the convex, in part decorticated, and the cup-shaped and fully. developed conceptacles.
There can be but little doubt that the here mentioned speci- mens belong to one and the same species, or to the present one.
Also these conceptacles apparently grow down into the frond, but are on the other hand often effaced by local formations of tissue. In one specimen with all the conceptacles emptied I found numerous such formations forming even disc-shaped, light and slightly projecting processes, which I, however, have occasionally seen also in other species.
Remark on the synonomy. Most of the authors from the former century did not refer crust-like Lithothamnia to this species, or all the forms known were apprehended as one and the same species, L. polymorphum. Among these probably was Linné, Gunnerus, Bsper, Hillis et Solander, Momr, and others. The latter refers 1. c. to Apora polymorpha Gunn. in Act. Nidros. 4, p. 70, which includes the forms mentioned under L. boreale, L. fruticulosum and L. coralloides, and he adds: ,I1 Fidru-Maalet treeffes den almindelig, men under en anden SkikKelse, nemlig ikke anderledes end en kalk, der har bekledt Stene, Snekker 9g Skaller, oftest kurlakred, uden Grene eller Knorter“. Here probably is in- cluded the present species, as well as L. circumscriptum and L. Stromfeltu. Also in the former half of this century the species often has been taken nearly in the same sense (cp. Johnston and Kiitzing 1. c.), or it has been very differently understood, until Areshoug defined it as a true crust-like plant, but later, and even by Areschoug himself, it has been the general practice to refer all or nearly all such forms to the present species. Cp. tagelim, 1. c:
Of L. purpureum Cr. I have seen 4 small fragments from
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Crouan’s collection in Museum d'Histoire Naturelle. One of these is provided with newly emptied conceptacles of sporangia coinci- ding with those of the species in question, and Crouan quotes the sporangia to be tetrasporic, and it in all accords well with L. polymorphum. It is only about 1.5 mm. thick, but overgrown conceptacles are visible from the side of the fragment. The roofs of the emptied conceptacles are fully dissolved, but not any part of the border, the holes 150—180 » in diameter, and including the border the conceptacles have been 200—300 y in diameter Seen from the surface. Two of the other fragments destitute of conceptacles perhaps or probably also are referrible to the same species. The fourth on the other hand seems to be somewhat. differing, but it is too small and fragmentary to be determined, as it only forms a part of the peripherical portion of af larger specimen.
Felation to other species. As remarked under L. varians these two species may easily be confounded in a sterile stage. So also in regard to the following species, L. imerustans. They, are, however, distinguished by characters quoted under the latter. The species on the other hand sometimes approaches in habit cer- tain forms of L. papillosum Zanard.
A Specimen that 1 got from Dr Bornet, gathered ane ee Croisic (Loire Inférieure)“, rather resembles in habit L. papdllosum Zanard. in Hauck, Meeresale. t. 2, fig. 4, with smaller or larger processes. I, however, found some few conceptacles of spo- rangia, which fully accord with those in L. polymorphum, and, no doubt, being a form of this species most nearly related to f. papillata. Overgrown conceptacles are numerous, but I have not seen the sporangia.
A British specimen gathered at Swanage by Mr. Batters is nearly related to the latter in habit, however, with more numerous, a little larger and more irregular knobs. It not unlikely is also a form of L. polymorphum, but it is sterile and, therefore, the deter- mination not certain.
Of L. papillosum Mad. A. Weber van Bosse kindly sent me 3 specimens from Hauck’s herbarium for examination. Two of these fully coincide with Hauck’s description 1. c., and it probably
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is a well defined species. They are about 4—6 mm. thick. Upon the primary crust new crusts are formed, sometimes closely united to one another, sometimes and more often, in one and the same specimen, rather loosely connected, with in part visible interwalls, or covering extraneous objects. Together with the wart-like and small prominences small lamels often are formed, with the edges free and bent downwards, or gripe over and older prominence, or at length form hollow prominences. These lamels are frequently concentric zonated. The conceptacles grow down into the frond. They are in a median section about 100 » high and 200—250 in diameter. I have not seen superficial conceptacles of sporangia, nor do the sporangia appear to be Known. I, however, found some few other superficial conceptacles, which apparently are cy- stocarpic ones, and probably those mentioned by Hauck l. c. p. 272. They are nearly subhemispherical, with a single orifice and about 300—400 p in diameter. The third specimen rather differs from the other two. It is of about the same thickness as these, but the frond appears to be composed of minute lamels more or less densely united. Seen from the surface these lamels are very small and horizontally extended, seldom slightly raised, giving the surface a rugged and squamellate appearance. It is sterile, and I have not examined the structure, nor do I know whether it really is a form of L. papillosum, or, more probably, belongs to another Species, not unlikely even of the subgenus Lithophyllwim. It grows together with a very small fragment of typical L. papilloswm. Habitat. On the northern part of the coast the plant lives in rockpools, or on nearly perpendicular rocks in the lower part of the litoral region. It also occurs a little below extreme low-water mark, to about 1 fathom, but I do not know whether it descends farther down in the sublitoral region. On the south-western coast I met with it in 2—-3 fathoms water, as at Hvitingso near Hauge- sund, and in the Christiania-Fjord it has been taken on a depth of about 5 fathom. It appears in sheltered places as well as in rather exposed localities, and it apparently develops organs of pro- pagation nearly all the year at least in more southern waters. Thus it is found near Troms6 with ripe sporangia in the middle of June
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and with conceptacles (of sporangia?) in development in the former half of September. On the southern coast it bears reproductive organs, especially sporangia, in July and December, partly mature partly in development. Summer- and winter-specimens from Helgo- land are partly furnished with sporangia partly with spermatia (and carpospores?). On the coast of Britain it develops reprodiictive organs in February and on the coast of France in May, but pro- bably also at other seasons of the year.
Occurrence. In the sense here taken the species has not with certainty been found farther to the north than Honningsvaag in West-Finmarken, and here apparently rare; Skorpen in Kveenangen, local and scarce (f. twberculata); Lyngé near Troms6, local but pretty plentiful (f. valéda); the coast of Nordland, common, accor- ding to Kleen I. c.; Sulen in Sogn (Boye); Hvitingso; Mandal (Wille); and Nesodden in the Christiania-Fjord, a solitary specimen (Schreiner). It probably is more commonly dispersed along the western and south-western coast.
Geogr. Distribution. The Bahusian coast of Sweden (Are- schoug); Iceland (Stré6mtelt); Britain (Batters); Helgoland (Kuckuck); France (Crouan, Bornet). The form quoted by Hauck |. c. from the Adriatic Sea very likely is ZL. wmerustans Phil. Cp. under this species.
Lithothamnion incrustans (Phil.) Fosl. mscr. Lithophyllum incrustans Phil. in Wiegm. Arch. p. 388; Solms Laub. Corall. p. 16.
f. depressa (Crn.) Fosl. mscr. Lithothamnion depressum Crn. Fl. Finist. p. 151. Descr. Lithophyllum incrustans Solms Laub. 1. c. Fug. Lithothamnion incrustans f. depressa tab. nostr. 18, fig. 1O—11.
f. Harveyt Fosl. mscr. Descr. et Fig. Melobesia polymorpha Harv. Phye. Brit. pl. 345, fig. Lithothamnion incrustans f. Harveyi tab. nostr. 18, fig. 12—15.
Syn. Nullipora polymorpha Johnst. Brit. Spong. and Lithoph. p. 238; ex parte; pl) 205 fis. 2-3 Melobesia polymorpha Harv. Man. p. 108; ex parte. Spongites confluens Kitz. Spec. Alg. p. 698; Tab. Phyc. 19, t. 97; Aresch in J. As. Spec: Ale. 25 ip) 519?
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Syn. Spongites incrustans liitz. Spec. Alg p, 698.
racemosa Ktitz. Phyc. gen. 386; Phyc. germ. p. 296; Spec. Ale. p. 698? Cfr. Tab. Phye. 19, p. 30.
Lithophyllum incrustans Aresch in J. Ag. Spec. Alg. 2. p. 519.
”
Lithothamnion crassum Unger, Leithakalk p.. 21, t. 5, fig. 9?
f polymorphum Crn. FI. Finist. p. 151.
> x Le Jol. Liste Alg. Cherb. p. 151; saltem eX parte.
ts 3 Rosan. Melob. p. 99; saltem ex parte.
Fs = Hauck, Meeresalg. p. 27]; saltem ex parte.
Remark on the determination of the species. I have not the advantage to decide with certainty what Philippi has meant by his L. incrustans. He refers to Corallina cretacewm lichenoides mite Corllsp ot t. 27, tic. d. Dione of which is probably not a Lithothamnion, the other not unlikely represents the species in question, although the figure does not give any good idea of the plant. Solms Laubach l.c. declares L. imerustans in its typical development to be easily recognized from the nearly allied L. po- lymorphum Aresch., but it is on the other hand not quite evident whether it really may be the same plant that I apprehend as L. merustans. Thus he remarks, that ,die Conceptacula sind ausser- lich nicht sichtbar“ and that the surface is often sprinkled ,,mit nadelstichartigen Léchern“, which by Ktitzing is quoted as a character of his Spongites confluens, the latter being considered by Solms Laubach identical with L. incrustans, and these holes he states to be ,nur die Miindungen zahlreicher, von Thieren ge- bohrter Gange“. In this respect the plant in the sense here taken quite differs from that of Solms Laubach. The conceptacles of sporangia are, as below mentioned, visible from the surface of the frond just as small pin-holes, but they are, on the other hand, particularly when emptied, easily confounded with passages made by worms, which certainly are often to be found in this as well as in all or nearly all other species. He records as a well marked character, that LZ. merustans distinguishes itself by the colour of a fracture of the frond.’ ,Auf dem Querbruch ist er schmutzig- weiss .... Normal entwickelte Individuen beider Arten eleichen sich vollkommen, lassen sich aber in frischen Zustand sofort an
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der Farbe des Querbruchs unterscheiden, welcher namlich hier (L. polymorphum) nicht triibweiss, sondern schén gelb erscheint*. I have not seen fresh specimens of L. mmecrustans, but judging from L. polymorphum and dried specimens of both, this character is, in my opinion, of less value, as the colour of the surface as well as that of the fracture is also rather varying and often depends on the locality where the plants grow and relations connected with this. However, there can be but little doubt, that the species is, in the sense here taken, identic with that considered by Solms- Laubach to be ZL. mecerustans Phil. He refers to an Adriatic specimen, that he got from Dr. Hauck under the name of Z. polymorphum. Also of this form Mad. A. Weber van Bosse kindly sent me two specimens from Hauck’s herbarium for exa- mination, which are mentioned below. If not, the name L. de- pressum Crn. has the priority.
Remark on the form and addition to the description of the species. Of L. depressum Crn. { have seen three authentic but small fragments from the collection in Museum d Histoire Naturelle, all of which are provided with conceptacles of sporangia, and the one also with those of cystocarps. The crust is about 1—2 mm. thick, and the surface is partly nearly even, smooth and somewhat shining, partly irregular, with some few, small and irreguler ex- crescences. The conceptacles of sporangia are irregularly scattered or crowded over the whole frond, seen from the surface strikingly reminding one of small and shallow pin-holes, about 50—80O p in diameter. They at first appear as indistinct depressed-circular points. Later the deepenings get a little larger, the central part deepest, darker and more distinct, the bottom of which forms a part of the roof of the Conceptacle. The surrounding part is also slightly depressed and gradually passing into the surface of the frond. I have not seen more than a single canal traversing the centre of the roof, which is to be found also in younger conceptacles, about 15—20p. in diameter. Towards maturity this canal becomes larger, or at length the greater part of the roof falls away, leaving a hole about 80—120 » in diameter, sometimes a little smaller sometimes larger. These holes much resemble passages made by
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worms. Crouan |. c. quotes the sporangia to be bisporic. Ho- wever, this may probably depend thereon, that he has examined not fully developed ones. Judging from a solitary conceptacle examined they appear in fact to be tetrasporic. I also found some bisporic, but neither the former nor the latter appeared to be ma- ture. The cystocarpic conceptacles are convex or nearly hemis- pherical, 150—200 yp in diameter, most frequently very little pro- minent and furnished with a rather coarse orifice, in appearance rather resembling a certain stage of those mentioned under L. polymorphum. 1 have not seen the spores.
A specimen that I got from Dr. Bornet under the name of L. polymorphum cum tetrasporis“, gathered at Cherbourg, is nearly related to the above mentioned in habit. The crust is about 2 mm. thick, the surface rather irregular, with subhemispherical or irregular but small processes, smooth and rather shining. PI. 18, fig. 10. Seen from the surface the conceptacles of sporangia form in a younger stage very small, shallow depressed-circular points about 20—30 y in diameter, owing to the dark bottom, a part of the roof, looking as deeper holes, with not or scarcely not depressed edges. Later the edges or a slightly larger part of the surrounding portion than in Crouan’s specimens get depressed, and thereby the points are more easily perceptible and even look a little larger than in the latter, but still gradually passing into the surface of the frond. Also the central portion by and by becomes a little larger, as a part of the edges get dissolved, though frequently smaller than in the named specimens, or not more than about 50 /- in diameter, but probably not yet fully developed.
Another but smaller and younger specimen ,,cum disporis“ that I also got from Dr. Bornet under the same name and from the same place nearly accords in habit with the former, but partly with an indistinct whitish brim. It bears some few concep- tacles of sporangia nearly coinciding with the above mentioned and most developed ones, but the edges less depressed. I also found but bisporic sporangia, abouth 120 » long and 50 p broad, and some of them even with an apparently fully developed wall, but they were probably not mature. As before mentioned the parti-
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tion of the sporangia in immersed conceptacles apparently takes. place in a more slow succession and, therefore, the middle wall may perhaps be even fully developed before the other walls are founded. , The specimen also bears conceptacles of cystocarps in development.
The named specimens from the Adriatic Sea (Hauck’s coll. No. 72) belongs to the same series of forms, and so also most probably that represented in Hauck, Meeresale. t. 1, fig. 5. The other figure (4) not unlikely is identic with the below mentioned f. Harveyt. The one specimen has a rather even and smooth surface, with a couple of smaller and rather clumsy protuberances. In the other some individuals originally have fastened themselves to one and the same substratum, in their farther growth anasto- mosing, and the edges trumbling each other form coarse ridges. Otherwise it is partly even and smooth partly with some few irre- gular processes. In both I found some few conceptacles of spo- rangia fully according with those in L. depresswm Crn., seen from the surface 60—80 p in diameter. In a few others the whole roof has by some reason disappeared, the emptied conceptacle for- ming a hole about 200 p in diameter.
Another and younger specimen from Hauck’s herbarium, ga- thered at Miramar and labelled L. Lenormandi nearly covers an individual perhaps being the latter, which specimen probably also belongs to the same series of forms as the above mentioned. It is richly provided with in part even confluent cystocarpic concep- tacles, that very nearly accord with those mentioned under L. de- pressum Crn., about 150—200 yp in diameter.
The here mentioned specimens without any doubt belong to one and the same species, L. depressum Crn., which I adopt as a form of L. merustans Phil., very likely being the typical form of this species. This form is, besides, as to the reproductive or- gans, characterized by its crust either being in part even, or bea- ring more or less numerous subhemispherical or irregular, but fre- quently small processes. ‘The peripherical portion is in general and especially in older individuals not much thinner than the internal, never, so far as I have seen concentric zonated and not even in
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younger specimens with any distinct whitish brim. Old specimens appear to be more vaulted, which probably sometimes also is the case in younger, as Solms Laubach remarks l.c. ,In der Jugend ist er kreisfOrmig und in Folge des in der Mitte rasch voranschrei- tenden Dickenwachsthums ziemlich stark convex“. The crust at- tains a thickness of at least | cm. New crusts formed upon the primary one are closely united to each other, and the limits are difficult to detect, except when covering extraneous objects, which, however, apparently not often infest this form. The surface is frequently smooth, more seldom with local, scaly thickenings or other local new formations, partly rather shining partly not. The four-parted sporangia, of which I have seen but few, appear to be about 100—120 p» long and 30—5SO p broad. Overgrown con- ceptacles sometimes are numerous sometimes very few, almost Spherical and about 200 p» in diameter. Some specimens gathered at Mandal on the south coast, also bearing conceptacles of spo- rangia, most of which are emptied and the whole roof having dis- appeared, partly accord with this form (cp. pl. 18, fig. 11) partly form transitions to f. Harvey.
The plant recorded by Harvey |. c. under the name of Melo- besia polymorpha also has been one of the doubtful forms, which by Areschoug as well as some recent authors is referred to L. polymorphum. As before remarked there is no authentic specimen of Harveys Lithothamnia in existence. I got, however, some spe- cimens from Mr. Batters, gathered at Cumbrae and considered by him to be identic with Harveys plant, which without any doubt really is the case However, Harvey referred all the crust- like forms known to him to the same species, as he remarks him- self, and among these probably also the true L. polymorphum. Cp. Phyc. Brit. and Man. |. c. But, on the other hand, the figures in Phyc. Brit. as well as the description of the reproductive organs refer to the form in question. He describes the conceptacles such: ,Ceramidia minute, dot-like, sunk deeply in the outher layers of cells, extremely numerous and often punctuating over the whole surface of fertile fronds as if they had been closely marked with pin-holes“. There can be no doubt that this refers to the con-
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ceptacles of sporangia and agrees perfectly with the specimens that I have seen. In this respect Harvey's plant fully coinsides with the above quoted f. depressa, only the conceptacles frequently a little larger. The point-like depeenings are, in the named specimens, at first 40—50 p in diameter, in a more advanced state getting larger, about 70—80 yp. in diameter, and, so far as I have seen, always with a single orifice, which towards maturity becomes larger, or the whole bottom, a part of the roof, as well as the lower part of the depressed edges of these depenings get dissolved, especially in dead specimens even the whole roof, and then for- ming distinct holes about 200—300 yp in diameter. I found nume- rous sporangia, but at least most of them appeared not to be fully developed, unparted or bisporic and among the latter some few with apparently a fully developed wall, as in the above mentioned French specimen of f. depressa. I, however, also found a couple of tetrasporic ones and two others with indistinst partition of the one or both just formed cells. I, therefore, consider mature and normaly developed sporangia to be tetrasporic. They are very much varying in shape and size.. Sometimes I found them 120— 150 » long and even up to 65 yp broad, sometimes and apparently in the same state of development only about 90 » long and 30—40 py broad. Overgrown conceptacles partly are very numerous partly few. In one of the specimens bearing conceptacles of sporangia I also found a couple of other conceptacles, which probably are those of cystocarps. They nearly agree in shape with those in f. depressa, but are a little larger, or up to 250 p» in diameter at the base. ; This form, which I propose to name f. Harvey2, can hardly be considered a separate species. It is nearly connected with f. depressa, and especially the above mentioned specimens from Man- dal shov complete transition. On the other hand it is, in its most extreme form, much differing, and a specimen from the west coast probably belonging to the present form even somewhat approaches L. crispatum Hauck |. c. t. 2, fig. 3 in habit, and Mr. Batters informs me, that it often comes near J. expanswm in appearance. It seems to be extremely varying, the primary crust often nearly
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disappearing, and the more or less anastomosing and iregular knobs now and then divided in a very irregular manner, or bearing irregular processes. Pl. 18, fig. 12—15, which represents British specimens. It is nearly always much attacked by animals, new formations are formed so as to cover these as well as other extra- neous objects, the edges often being free, or the overlapping flaps nearly in contact with each other bend downwards and form a deepening over the overlapping object, which, however, also may be a knob or a short branch, or not closed at the summit, that sometimes may be more or less compressed or wavy, and in all assuming peculiar forms, most of which probably are raised in its struggle for existence, as specimens not much attacked by animals more or less approach f. depressa also in habit.
Besides the above mentioned specimen from the west coast | have seen another fromthe same locality (Sulen in Sogn), that most probably belongs to f. Harvey2, but it is sterile and the lower or older parts nearly destroyed, the upper and younger ones co- vering tubes of Serpula, shells and other objects.
A British specimen frona Chapman’s Porl. Dorset, referrec by Batters to the same form, rather reminds one of certain forms of L. polymorphum and especially f. tuberculata in habit. The erust is about 2 mm. thick, with rather densely crowded and in part anastomosing knobs up to 7 mm. high and 5 mm. in dia- meter, but more or less irregular in shape, and here and there with some wart-like processes. It on the other hand seems to be nearly related to f. Harveyt and not unlikely belonging to this, but it is sterile and cannot, therefore, be determined with certainty.
As to the structure the species appears often to be rather varying. In the form depressa | frequently found the cells of the upper thickening layers to be about 1O—12 » long and 5—6 p thick on a radial section, and pretty uniform, but especially in f. Har- wey? the named cells sometimes are of about the same size some- times much larger even in one and the same specimen. Here I found them up to 18 p long and 9 » broad, nearly always elongated,
with rather thin walls. Occasionally the cell-rows are in vertical ; yes
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direction of the frond so loosely connected, that they after decalci- fying are easily separated by pressure.
With reference to colour it also appears to be subject to much variation. Crouan quotes the colour in f. depressa to be ,rosée“. The named fragments that I have seen are much faded, partly, however, with a faint purplish tinge. The specimen from Dr. Bornet’s collection with tetrasporic sporangia (pl. 18, fig. 10) is yellowish-brown and partly with a purplish tinge. Another speci- men from Cherbourg is feebly wine-coloured. Solms Laubach remarks |. c., that the colour ,schwankt zwischen tribroth und braunlichviolet; an Uppig wachsenden Exemplaren ist seine Ober- flache blaulich bereift*. In f. Harveyt the colour of living speci- mens is according to Mr. Batters ,a purplish pink very much like that of L. polymorphum but fainter and more fugitive*. Dried specimens of both forms often closely resemble each other in colour.
Remark on the synonomy. Besides the above mentioned sy- nonymes is to be remarked, that L. polymorphum Crn. no doubt. also belongs to the present species and stands nearest to f. Harveyt.. I have seen three authentic but fragmentary specimens, which are up to 1 cm. in thickness, with rather coarse and irregular processes. The conceptacles of sporangia accord with those of the present species, and the sporangia are tetrasporic, of about the same size as the above quoted smaller ones in f. Harvey.
So also with regard to L. polymorphwm Le Jol:, of which I have seen a smaller specimen (Herb. Le Jol. No. 1745). It is. about | mm. thick, confluent crusts form ridges, but otherwise being nearly even and smooth, with conceptacles of sporangia and cystocarps in development, and most probably identic with f. de- pressa. In an overgrown conceptacle I found tetrasporic sporangia. Whether it, however, is identic with the form distributed in Alg. mar. Cherb. No. 11 is unknown to me.
As mentioned under ZL. fruticulosum and L. crassum John- stons Null. polymorpha probably includes both these species as. well’as the) present.” (Phus soll 25) fig. 2—3 1. c. represent forms, — that seem to be most nearly related to f. Harveyi, the one, fig: 2, however, perhaps being a form of L. crasswm.
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Relation to other species. This plant in some respects corre- sponds with the northern L. varians, the form Harvey? nearly connected in habit with certain forms of that Species, but it is in fact