FRERE h = rss eee SERGE Zi 2e 5 HE See 3 | EHORMMEEMPE ORPIEE FOR EDVCATION FOR SCIENCE LIBRARY OF THE AMERICAN MUSEUM OF NATURAL HISTORY / Bound: JA.M.N. ks CAR Lo DENE UM ED DET KONGELIGE DANSKE VIDENSKABERNES SELSKABS SKRIFTER SYVENDE RÆKKE NATURVIDENSKABELIG 0G MATHEMATISK AFDELING SYVENDE BIND MED 2 KORT OG 8 TAVLER KØBENHAVN HOVEDKOMMISSIONÆR: ANDR. FRED. HØST & SØN, KGL. HOF-BOGHANDEL BIANCO LUNOS BOGTRYKKERI A/S 1909—31 In nr Au THE MARINE ALGÆ OF DENMARK CONTRIBUTIONS TO THEIR NATURAL HISTORY VOL. I RHODOPHYCEZÆ BY L. KOLDERUP ROSENVINGE WITH TWO CHARTS AND EIGTH PLATES D. Kar. DANSKE VIDENSK. SELSK. SKRIFTER, 7. RÆKKE, NATURVIDENSK. OG MATHEM. AFD., VII. 1—-{ KOBENHAVN HOVEDKOMMISSIONÆR : ANDR. FRED. HØST & SON, KGL. HOF-BOGHANDEL BIANCO LUNOS BOGTRYKKERI A/S 1909—31 THE MARINE ALGÆ OF DENMARK CONTRIBUTIONS TO THEIR NATURAL HISTORY "PART I INTRODUCTION. RHODOPHYCEEI. (BANGIALES AND NEMALIONALES) BY L. KOLDERUP ROSENVINGE WITH TWO CHARTS AND TWO PLATES D. Kar. DANSKE VIDENSK. SELSK. SKRIFTER, 7. RÆKKE, NATURVIDENSK. OG MATHEM. AFD. VII. 1 +--+ KOBENHAVN BIANCO LUNOS BOGTRYKKERI 1909 HE CNE LANTA TNA MN PTA VARA PREFACE. The study of the marine Algæ engaged my interest at an early period. Originally certain morphological, cytological and physiological questions were the objects of my studies, but later the plan to procure a general view of the Algæ found in the Danish waters gradually developed. In 1890 I began to make syste- matic collections in the Danish waters and continued during the following years, especially in 1891—95, when I became able to make extensive dredgings in all the Danish waters inside Skagen (Kattegat to Baltic) by means of official support during 4 years (from “Kommunitetet”) and permission from the ministry to sail with the fishery control-steamers S.S. “Havernen” and S. S. “Falken” and the fishery in- spection-ship, the gunboat “Hauch”. During the following years I have as occa- sion offered continued these collections partly onboard the Biological Station’s S. S. “Sallingsund”, especially on a cruise round Bornholm in 1901, the life-saving steamer S.S. “Vesterhavet” and the lightship transport S.S. “Nordsgen” in 1905 in the North Sea, the deep-sea research-ship S. S. “Thor” in the Skagerak, Kattegat and the Sound in 1907, a former revenue-cutter “Ragna” in private possession in 1904—1906 and partly in fishing boats, especially at different places on the north- western coast of Jutland. The reason why my work has extended over such a long period is chiefly, that different works regarding Greenland’s flora, vegetation and marine Algæ, have during a series of years taken up so much of my time that until 1898 I was mostly obliged to content myself with collecting material, while the working up of this could not begin until after that time. Another cause of the slow progress of the work is the abundance of the material collected, and lastly the scope of my work was gradually somewhat enlarged. From the beginning the aim of my investigations was, not only to state what species are found in the Danish waters, but to elucidate their extension here and also their variation and if possible their dependence on the external conditions. While working with the single species my investigations came more and more to have to do with morphology and the de- velopmental history, and I saw how desirable it would be for the task I had undertaken if I could contribute as much as possible to the elucidation of the natural history of the separate species on the whole in Danish waters; I have also expressed this in the title of my work. I feel quite well, that I have not given 1" 4 nearly so much as I could have wished in this direction, and I am by no means blind to the defects in my work just in this respect. But it is also quite clear to me, that if I do not wish to postpone the publication of my work until an uncertain future period, thus running the risk of never getting it finished, I must have it published, even if my investigations are not complete on many points. On account of the extent of the work I have decided to have it published in small portions, to begin with the Rhodophyceæ. Of this family the well-known specialist, the conservator Mr. M. FosLiE, several years ago undertook to determine the Melobesiee and Mag. sc. Mr. HENNING E. PETERSEN undertook to work up the genus Ceramium. Mr. Fosie has already given the preliminary results of his work in several publications, but they will be dealt with in more detail in the present memoir. Mr. PETERSEN’s work on the genus Ceramium was really destined to be embodied as a part of the same, but as it was finished before mine and was of considerable extent it was preferred to have it published separately!. Besides the two mentioned groups of red Algæ a large portion of the blue-green Alge I have collected was worked up by Dr. Joxs. SCHMIDT in 1899°. It may also be mentioned here, that mainly on the basis of my own collections and investiga- tions I have been able to enumerate not a small number of species, which have not been known before in the Danish waters, in my work on the Algæ in Rostrup’s Guide to the Danish flora’. My thanks are due to many persons, who during the many years that have passed since I began my investigations have rendered me valuable assistance in different ways. I would here mention especially the different captains, the late fisheries supervisor Mr. A. Brocn, Commander P. Grove, the former fisheries super- visor Mr. HOLSTEIN, the present fisheries supervisor Mr. W. Larsen, Captain RosEn- KILDE, the retired Captain C. TROLLE; further the director of the Danish Biological Station Dr. C. G. Jon. PETERSEN and Dr. JoHs. Scamipr; also Dr. F. Borcesen, Dr. TH. Mortensen, Dr. C. H. OSTENFELD, Mag. A. OTTERSTROM, Mag. Ove PAULSEN and Mag. Henn. PETERSEN, who haye placed their collections of Danish marine Algæ at my disposal. I desire here also to express my best thanks to the Directors of the Carlsberg Fund for the assistance they have given to defray various expenses in connection with the publication of this work, especially the charts and photographs of plants. + HENNING E. PETERSEN, Danske Arter af Slægten Ceramium (Roth) Lynepye. K. D. Vidensk. Selsk. Skr. 7. R. 5. B. No. 2 1908. 2 Jous. Scaminr, Danmarks blaagronne Alger (Cyanophyceae Daniae) |. Hormogoneae. Botanisk Tidsskrift Bd. 22. ° E. Rosrrup, Vejledning i den danske Flora.»Anden Del. Blomsterlose Planter. København 1904. INTRODUCTION. Earlier sources of our knowledge of Denmark’s marine Algæ. W hen on searching for the oldest statements in the literature on the Danish marine Alge, we come upon ÖEDER’s Enumeratio plantarum Flore Danice', we might expect to find important information there, as the work deals specially with the “Cryptanthere” i. e. the cryptogams. A considerable number of species of the genera Conferva, Ulva and Fucus are certainly mentioned there, but these are not known to occur inside the boundaries of the Danish kingdom. As the - author, according to his own statement, had not studied the lower plants very closely, he contents himself with giving a good many North-European species, which he supposes might be found here. This paper therefore does not contain any more information about the Danish marine Algz than that found in “Flora Danica”, to which work reference is made for all the species figured there. OEDER has certainly mentioned not a small number of species in this monumental pictor- ial work, which began to appear in 1761, but they are almost all from Norway and Iceland or without indication of the locality. Only two species are noted from Denmark, namely Tab. 166, Fucus siliquosus (1763) [Halidrys siliquosus (L.) Lgb.] and Tab. 393, Fucus fastigiatus (1768) [Furcellaria fastigiata (Huds.) Lamx.]. In the parts of the same work edited by O. Fr. Mürrer (1775—1782) only a few marine Alge from Denmark were mentioned (Tab. 763, Ulva prolifera | Entero- morpha prolifera (Müll.) J. Ag.]; Tab. 771, 2, Conferva Linum |Chelomorpha Linum (Müll.) Kütz.]; Tab. 821, Fucus Filum [Chorda Filum (L.) Stackh.]; Tab. 882 Conferva flexuosa [Cladophora sp.|; Tab. 889, Ulva Linza |Enteromorpha Linza (L.) J. Ag.]), and none at all in the parts edited by Martin Var. At the end of the 18th century information was thus present about only a very small number of species of marine Algæ found on the coasts of Denmark. In 1803 ScHuMACHER® gives 26 species of Algæ from the coast of Sealand. A considerable proportion of these are however so insufficiently described that 1G. €. OEDER, Enumeratio plantarum Flore Danicæ. Cryptantheræ. Hafniæ 1770. ? Icones Flore Danicæ. Hafniæ 1761—1883 (Edit.: Orper, ©. F. MÜLLER, M. VAHL, HORNEMANN, LIEBMAN, JOH. LANGE). 3) C. F. SCHUMACHER, Enumeratio plantarum in partibus Sællandiæ septentrionalis et orientalis. Pars posterior, Hafniz 1803. 6 they cannot be identified. Besides three species formerly known as Danish, the following may be mentioned: Enteromorpha intestinalis (L.) Link (Conferva int. Schum.), Cladophora rupestris (L.) Kütz. (Conferva rup. Schum.), Chordaria flagelli- formis (Müll.) Ag. (Ceramium longissimum Schum.), Ahnfeltia plicata (Huds.) Fr. (Ceram. plicatum Schum.), Fucus serratus (L.), Fucus vesiculosus L. and Rivularia atra Roth (Linckia hemispherica Schum.). Further Lynepye believed that he was able to identify Elachista fucicola (Vell.) Fr. (Conferva ferruginea Schum.) and Chondrus crispus (L.) Lgb. (Fucus ceranoides Schum.)!. No further information on Denmark's marine Algæ appears in the 2nd edition of Hornemann’s “Plantelære”? published 3 years later. Only 11 species, all referred to the genus Fucus, are noted, but not a single one is expressly mentioned as found in Denmark. It was only in the 2nd decade of the 19th century that a more exact study of the Algæ was begun in this country, first by N. Horman Bane, the owner of Hofmansgave on the north coast of Fyen, and at his instigation also by H.C. LYNGBYE, private tutor at Hofmansgave from 1812—1817. The publisher at that time of Flora Danica, HoRNEMANN, who was in close connection with these two investi- gators of Algæ, included in this work during the years 1813—1818 25 species of marine Alge from Denmark, mostly until then unknown in its flora; the number of the species was by this addition more than doubled, but a decisive change was not accomplished until the publication of LyNGBYE's hydrophytology’. This work was originally written in 1817 as an essay to which the University had awarded a prize in the previous year, but it was enlarged so much later that the Algz from Holstein, the Feroes, Iceland, Greenland and also partly from Norway all came to be included in it. On the whole 323 species are mentioned here, for Denmark about 100 species with 12 varieties of marine Algæ; Denmark thus rose at once to the level of the countries, in which the algal flora was relatively well investigated. This work holds a good place as one of the main works among the earlier descriptive phycologies by reason of its careful descriptions of species and its numerous good figures. With regard to Denmark it is essentially based upon numerous collections by Horman Bang and by LyNGBye at Hofmansgave and upon studies of the latter at the same place, in less measure upon collections in the Sound, while other lo- calities are very incompletely represented. Consequently it deals relatively exhaus- tively with the algal flora of the north coast of Fyen, while it gives very little 1 Among these species Ceramium cartilagineum (l. c. p. 112) must also be mentioned. LyNGByE who had the opportunity to examine SCHUMACHER’s specimen, found between Amager and Sjælland, dis- covered that it really belonged to Fucus cartilagineus Turner (= Gelidium cartilagineum (Turn.) Gaill.) a species, the native place of which is at the Cape of Good Hope, and he found that, in regard to the epiphytic animals it also agreed with samples of this species from that place, consequently he was right in concluding that it in some way, e.g. by a ship, had been transported from its original, far- off home (LynGByE Hydr. p. 56). 2 J. W. Hornemann, Forsøg til en dansk oekonomisk Plantelere. Kjøbenhavn 1806. 3 H. C. LyNGBYE, Tentamen Hydrophytologiæ Danicæ. Hafniæ 1819. information about the distribution of the species within the Danish area. As LYNGBYE's work will be cited in the following pages when dealing with the single species, its importance to the knowledge of the Danish marine algal flora need not be more closely explained here. During the following years several Danish marine Algz were included in the parts of Flora Danica published by HORNEMANN, without anything essentially new being given in addition to what is found in LyNGByE’s work. A greater increase in the number of Danish species appears in the 3rd edition of HorNEMANN’s “Plantelere”!, the number here reaching 127. The real increase was however far from being so great. Thus, two of the species mentioned belong to the animal kingdom (Alcyonidium diaphanum and flavescens); some seem to have been included by mistake as found in Denmark, as they have not been discovered here by others and no Danish specimens are known (Spherococcus ciliatus, S. laci- niatus, Zonaria dichotoma). Several of the new species are scarcely sufficiently distinct from others found earlier, e. g. several Hutchinsia-species, Vaucheria litorea Ag. (V. clavata Lgb.) etc. But even after these reductions, a number of real additions remain of which the most important are: Calothrix fasciculata Ag. Halymenia palmata Ag. (Rhodymenia pal- Rivularia pellucida Ag. mata) Bryopsis plumosa Ag. Rhodomela dentata Ag. (Odonthalia den- Ectocarpus tomentosus Ag. tata Lgb.) Zonaria deusta Ag. (Ralfsia verrucosa) Callithamnion roseum Ag. Chordaria divaricata Ag. Ptilota plumosa Ag. (Plumaria elegans) Bangia atropurpurea Ag. (B. fuscopurpurea) Halymenia edulis Ag. (Dilsea edulis) Two years later LIEBMAN? made some new additions to the Danish marine algal flora. A great part of these species were however not really new in the flora; thus his Laminaria latifolia is only a form of L. saccharina, Asperococcus echinatus = Scytosiphon Lomentaria, Punctaria cespitosa = Phyllitis Fascia, Sphacelaria cœspitula not identical with LYNGBYE's species of that name but perhaps only small specimens of Sphacelaria cirrosa, Polysiphonia lepadicola — P. urceolata. — New to the flora are however at all events Callithamnion pyramidatum Liebm. = C. fruticulosum J. Ag. and Lyngbya lutescens Liebm. = L. lutea (Ag.) Gom., and probably Ptilota plu- mosa. His Dictyota dichotoma is also new, but however, as the specimens prove, is Taonia atomaria; but this Atlantic species cannot have grown on the coasts of Den- mark, but must probably have been transported by a ship. A smaller contribution to the flora was given by ØRSTED in 1841 in an ac- count of an excursion to an alluvial deposit at Hofmansgave”, where some blue- 1 J. W. HORNEMANN, Dansk oeconomisk Plantelære 3. Udg. 2. Del. 1837. ? F. LIEBMAN, Bemærkninger og Tillæg til den danske Algeflora. Kroyer’s Naturhist. Tidsskrift 2. Bd. 5. Hefte, 1839. 3 A. S. ØRSTED, Beretning om en Excursion til „Trindelen“, en Alluvialdannelse i Odensefjord. Kroyer’s Naturhistorisk Tidsskrift 3. Bd. 1841, p. 552. 8 green Algæ were especially mentioned, amongst others a new species Spirulina subsalsa. Orstev’s dissertation’, published three years later, in which the distribution of the marine Algæ in the Sound is discussed, is of greater importance. In this paper, which deals with the geographical, geological, botanical and zoological con- ditions of the Sound, all the species of Algæ are mentioned, which were found there by the author, but the single species are not described in detail, which is the rea- son why it is not always possible to know the meaning of a name given by the author. A number of species, considered by him as new, are however described in the comments under the text, but mostly so briefly and incompletely, that the plant cannot be recognised; and the result has been, that none of the genera and species, given by ØRSTED, have been maintained. Some of them have later been published in Flora Danica. The systematic value of the paper in thus very small, but its importance for our subject lies in this that it is based upon systematic investigations by means of dredgings, with the result, that for the first time the Alsæ are not only discussed in regard to their horizontal distribution but also in regard to their vertical. It cannot be determined what new species have been added to the flora by ØRSTED's work without examining his specimens. Already several years before the appearance of OrsTED’s work, LyNGBYE in 1836 had written a treatise of a somewhat kindred character, but, on account of special conditions, it was not published before 18807. In floristic regard it is not of so much importance in enriching the flora, as in its being based upon investi- gations in the southernmost part of the Kattegat off Gilleleje, a region not investi- gated before, and especially by its containing more exact data on the distribution of the Algz in relation to the depth. Neither his nor ØRSTED's divisions into re- gions of depth need be mentioned here. Since ØRSTED's work there has not until the end of the 19th century appea- red any noteworthy, floristic or systematic contribution to the Danish literature on the Danish marine Algæ. In Flora Danica marine Algæ from Denmark were included up to 1861, but very few new species were added beyond those mentioned by Lıesman and ØRSTED. Helminthocladia purpurea*, found by Miss CAROLINE ROSENBERG, is perhaps the most interesting addition. During the same period pub- lications which partly deal with the algal flora in Danish territory have appeared À. S. ØrsTED, De regionibus marinis, elementa topographiæ, historiconaturalis freti Øresund. Hauniæ 1844. * H. C. LYNGBYE, Rariora Codana (Opusculi posthumi pars). Vidensk. Meddelelser fra den naturh. Foren. i Kjøbenhavn, 1879—80, p. 215. ° In “Nomenclator Flore Danice” published by Jou. LANGE in 1881 a systematic summary, pre- pared by myself, was given of all the Algæ mentioned in this work with data on their occurrence. This general summary, which in regard to the determination of the species, is essentially based upon the references available in the literature and consequently in part out of date, comprises the following Danish marine Algæ: 47 Rhodopyceæ, of which two are however incorrectly named as Danish, 38 Pheophycee (1 incorrectly named Danish), 18 Chlorophyceæ and 7 Cyanophyceæ. By accident the Cha- raceæ were omitted in this work. 9 in the neighbouring countries. Bornholm’s algal flora has thus been investigated, in connection with that of the inner Baltic, by Krok! who gave valuable information regarding this region, not investigated until then. During the years 1870—1875 two expeditions were made from Kiel respectively to the Baltic and to the North Sea, on which occasions some dredgings were also made in the Danish waters, mostly in the Great Bell, and reports on these have been given by P. MaGnus”. By these dredgings the existence of Algæ at great depths was determined in the Great Belt, among which were some species not found before in the Danish waters (Antitham- mion Plumula, Chylocladia clavellosa (Lomentaria clavellosa), some Lithothamion-species and the new species Callithamnion (Rhodochorton) membranaceum Magn.). The marine Algæ have not in general been included in the Danish local floræ, or only the most obvious mentioned en passant; in J. P. JAcoBSEN’s list of the plants? found in Læsø and Anholt only some few species of marine Algæ from each of these islands have also been mentioned. Corrın’s work on the marine fauna" of the Limfjord contains some remarks about the flora of this fjord, in which some of the most important species in the composition of the flora are mentioned, partly from the information given by J. P. JacoBsen. The number of the species stated is however also here too small to be of any importance in flo- ristic regard. One of the species mentioned, Rhodomenia mamillosa (Gigartina ma- millosa (Good. et Woodw.) J. Ag.) is however of interest, as it had not previously been found on the coasts of Denmark. For two smaller groups however we find special contributions in the literature. The Characee, which in this country have not usually been studied in connection with the other Algæ, were included in two editions af LANGE's manual’ and were later exhaustively studied by P. NIELSEN, especially in South West Sealand". In 1880 I published a preliminary report on the submarine Vaucheria-species, the number of the known Danish species being thereby augmented‘. Collections employed for the present work. My work is naturally mostly based upon my own collections, but it need hardly be said that I have also employed all the marine Algæ accessible to me 1 Th. ©. B. N. Krox, Algfloran i inre Östersjön och Bottniska viken. Öfversigt af K. Vet. Akad. Förhandl. 1869. ? P. MAGNUS, Botanische Untersuchungen der Pommerania-Expedition vom 3. bis 24. August. Aus dem Bericht über die Expedition.... Pommerania. Kiel 1873. P. Macnus, Die botanischen Ergebnisse der Nordseefahrt vom 21. Juli bis 9. Septbr. 1872. Il. Jahresber. der Kommission z. Unters. d. deutsch. Meere in Kiel. Berlin 1874. 3 J. P. JACOBSEN, Fortegnelse over de paa Læsø og Anholt i 1870 fundne Planter. Botan. Tids- skrift. 11. Bind 1879. ‘ Jonas Corrın, Om Limfjordens marine Fauna. Kjøbenhavn 1884. > Jon. LANGE, Haandbog i den danske Flora. 2. edition 1859, 3. edition 1864. % P. NIELSEN, Exsiccatsamling af Characeer, navnlig fra Danmark. 1869. Idem, Sydvestsjællands Vegetation. Botanisk Tidsskrift 2. R. 2. Bd. 1873. 7 Botanisk Tidsskrift Bd. 12, p. 11. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. rm 10 whieh have been collected in Danish waters by others in earlier and more re- cent times. Other collections. LyNGBYE's herbarium of Algæ, kept in the Botanical Mu- seum of Copenhagen, is of the greatest importance for the study of the Danish marine Algæ, as it contains the original specimens of LYNGBYE's Hydrophytology. The specimens in this herbarium have not been particularly well prepared, but they are furnished with exact indications of the place and time of collecting; most of them originate from the neighbourhood of Hofmansgave on Fyen. The Botanical Museum’s Danish herbarium contains a considerable number of specimens of marine Algæ. The majority of these come however, like LYNGBYE’s herbarium, from the neighbourhood of Hofmansgave and have been collected mainly by Horman Bang and Miss CAROLINE ROSENBERG. The latter, who passed the greater part of her life (+1902) at Hofmansgave, has from there during a long series of years sent a large number of carefully prepared specimens of marine Alge, many of which have come to be housed in the Botanical Museum’s herbarium. As they have been collected at different seasons, they provide a good material for following the development of the single species during the course of the year. Further, spe- cimens are also present from HORNEMANN, LIEBMAN and ØRSTED, by which the determinations of the latter can be controlled, and also from J.VaHr, C. M. POULSEN, Jou. LANGE, CHR. THOMSEN (mostly from Samsø), J. P. JACOBSEN (mostly from the Limfjord), E. Rostrup, C. RascH and others. Since I began my systematic collections, some material collected by others has further been left to me. Dr. TH. MORTENSEN has thus placed at my disposal a valuable collection principally from the Limfjord procured at different seasons in 1894—95; and Dr. F. BorGesen has permitted me to examine the Algæ dredged on two expeditions with the fishery-inspection ship S. S. “Guldborgsund” in 1897 and in 1898 in the Skagerak, Kattegat and the Baltic. Smaller collections have been given me by Dr. C. H. OsTENFELD, Mr. A. OTTERSTROM, Mag. OVE PAULSEN and Mag. HENNING E. PETERSEN. My own collections. I began my first collections of Danish marine Algz already towards the end of the seventies, but it was not until 1890 that I made extensive and systematic collections and they were carried on most energetically during the years 1891—1895, whilst later they have been continued almost every year though less extensively. My aim has been to make as uniform an investi- gation of the Danish waters as possible and also, as far as possible, to investigate them at different seasons; for that purpose I have made dredgings at more than 700 different places and besides made collections at numerous harbours and at other places close to the land; I have made these collections during all the months of the year, chiefly however during May—September. The dredgings have almost all been made by means of a triangular dredge with sharp steel teeth (Reinke’s model), more rarely with a quadrangular dredge without teeth or with seine. The greater part of the material has been preserved as herbarium specimens, of which I possess 11 ca. 8000 samples, averaging at the least twice as many specimens. I have also preserved several hundreds of specimens in alcohol or formalin and likewise a considerable number of samples of stones and the like with incrusted Algæ. Neither the conditions nor time have as a rule permitted a more exact examination of the collected material at the place investigated; the aim was to keep or at least to note all the species present at the single dredging localities. I have however, during longer stays at some places on the Danish coasts, been able to make closer microscopical examination of fresh material. The main portion of my investigations is however based upon preserved material. Remarks on the Danish waters. As the present work does not intend to give a complete account of the floristic conditions nor of all the algal communities, the natural conditions of the Danish waters need not be described in detail here, but only the most important points, which may serve as a guide for understanding the distribution of the separale species and their biological conditions. The boundaries of the region. These are partly determined by the poli- tical limits. Thus, my investigations extend southward in the North Sea to the boundary towards Slesvig, and east of Jutland as far as a line drawn between the German and Danish territories thus to the boundary of the region investigated by REINKE!. I have made dredgings in the North Sea as far out as the lightship on Horns Reef and the eastern side of the Jutland Reef ca. 24 miles from land, in the Skagerak ordinarily only to 4 miles from the land except north of Vend- syssel where the distance is greater. In the Kattegat my investigations have extended to the eastern channel and the grounds in and near it, and in the Sound to the deep channel east of Hveen in order to obtain the flora belonging to the salt under-current there. The waters surrounding Bornholm constitute a special region, which is however connected with the waters east of Mgen by some few scattered dredgings. The conditions of depth. A general view of these is obtained from the charts, which show that a deep channel (the eastern channel) passes from the Skagerak southward through the eastern Kattegat, while the water in the western part of this sea is relatively shallow. Narrower channels lead further from the eastern channel through the Sound and the Belts, of which that through the Great Belt is the most important. At Gjedser-—Darsserort this channel meets with a barrier, the maximum depth over which is 18 meters, whilst a similar barrier, which has a maximum depth of only 8 M., occurs at Saltholm and forms the southern boundary of the deep channel through the Sound. South of Schonen the depth increases in the Baltic, but becomes specially considerable north and east of Bornholm. For the rest, reference may be made to the charts. 1 J. REINKE, Algenflora der westlichen Ostsee deutschen Antheils. 1889 12 The nature of the bottom. The most important kinds occurring in the Danish waters, are (1) stony bottom, (2) sand-bottom and gravel-bottom, (3) mixed bottom consisting of a mixture of sand and clay or mud and (4) soft bottom con- sisting of clay or mud. To these may be added (5) rocky bottom and (6) compact clay (tertiary or glacial). I shall not endeavour here to describe more closely the distribution of these kinds of bottom, as the nature of the bottom is very variable from place to place. With regard to the Kattegat reference may be made to C. G. Jou. PETERSEN’S chart!. For the rest some information is given below in the list of my dredgings; it may however be remarked, that I have chiefly dredged at places with stony bottom. The rule is, that sand-bottom is connected with shal- lower water, soft bottom with the deeper and mixed bottom with the intermediate depths. The stones are mostly found in shallow water and on reefs, which are for a great part noted on the charts. There are grounds, however, the surface of which is exclusively or predominantly sand, e. g. Horns Reef, Anholt’s N. W. Reef and Gjedser Reef, which is the reason, why they are not overgrown with Algæ. The extent of the true stone-reefs, the surface of which consists only of stones, is relatively small; on the larger banks and flats stony bottom is ordinarily inter- mixed with gravel, sand or even clay. In deep channels with strong current stony bottom is often found, which is kept clean by the current. Rocky bottom is found at several places near Bornholm, but elsewhere is scarcely known with certainty; it occurs perhaps at some places in the Skagerak near Hanstholm and Bulbjerg. On the other hand, firm glacial clay occurs at many places in the Skagerak and firm tertiary clay at all events in the Little Belt. The salinity and temperature of the sea-water. As these conditions are of the greatest importance in understanding the distribution of the species, the conditions which are of special importance for our subject may briefly be dis- cussed here; for the rest, reference may be made to the hydrographical works mentioned below’. In consequence of the fact that the salinity in the North Sea is more than 32/0, while in the true Baltic (east of Gjedser—Darsserort) it is or- dinarily less than 10°/0, the greater part of the Danish waters is a mixed region with complicated and variable hydrographical conditions, the most important mo- ment in which is that the heavy North Sea water from the Skagerak penetrates along the bottom through the deep channel in the eastern Kattegat and further as ! C. G. Jon. PETERSEN, Kanonbaaden Hauchs Togter, 1898, Kort III. * MARTIN KNUDSEN, Havets Naturlere. Hydrografi med særligt Hensyn til de danske Farvande. Skrifter udg. af Kommissionen for Havundersogelser. Nr. 2. København 1905. De internationale Havundersogelser 1902-1907. Skrifter udg. af Kom. f. Havundersog. Nr. 4. 1908. J. P. JACOBSEN, Mittelwerte von Temperatur und Salzgehalt, bearbeitet nach hydrographischen Beobachtungen in Dan. Gewässern 1880—1907. Meddel. fra Komm. for Havundersogelser Ser. Hydro- grafi. Bind I, Nr. 10. 1908. Nautical-meteorological Annual 1902—1906, published by the Danish Meteorological Institute. I am much obliged to Mr. J. P. Jacossen for placing at my disposal some unpublished lists with hydrographical averages. I am much indebted to Mr. MARTIN KNUDSEN and Mr. J. P. JACOBSEN for various pieces of information regarding the hydrography of the Danish waters. 15 a bottom-current through the channels in the Sound and the Belts, especially the Great Belt, while a surface-current streams out from the Baltic in an opposite direction. On account of the rotation of the earth this northward so-called Baltic Current is forced eastward and consequently remains on the eastern side of the Kattegat along the Swedish coast, and for the same reason the north-going surface- water moves more rapidly in the Sound than through the Belts. Vice versà the salt bottom-current is forced westward. The boundary between the two water-layers is very distinct in summer, while the transition is uniform in winter. The salinity does not vary much in the North Sea. At the lightship on Horns Reef the conditions in the years 1880—94! were: Temperature Salinity Mean minimum Mean max. Mean minimum Mean max. O0 M..... 2,2° (Febr.) 15,8° (Aug) | 32,7 "100 33,2 0/00 23 - .... 36° (March) 15,5° (Sept) | 33,1 0/00 33,7 loo The numbers are the averages of the monthly means; the variations are thus a little greater than indicated by the numbers. Along the coast a narrow and not very deep margin occurs with a somewhat lower salinity. The conditions in the part of the Skagerak which lies nearest Jutland are essentially like the corresponding part of the North Sea, the water mainly strea- ming from the North Sea towards the Swedish coast. In the waters inside the Skaw (Skagen), at every place where the depth is considerable, an upper, relatively not very salt layer, the temperature of which almost constantly follows that of the air, can be distinguished from a deeper layer with salter water and with special conditions as to temperature. With regard to the surface water, the highest temperature of the year is commonly observed in the beginning of August and is in the greater part of the waters on an average 16°, while the lowest temperature of the year, which on an average is 2°, is or- dinarily observed in the middle of February. In fjords and bays, where the renew- al of the water is not considerable, the maximal temperature is however higher and falls in July, and the minimal temperature is lower in winter. In the deeper and salter water-layers both the maximal temperature and the minimal temperature occur later than at the surface, and the maximum temperature is lower than at the surface, the minimum temperature higher. The differences from the surface are various but are essentially regulated by the depth. With regard to the hydrography of the Limfjord only some few observations are available. In this shallow water there is only a small difference between the surface and the deeper water-layers. The water in the western part is most like that of the North Sea, the eastern part like the surface-water of the Kattegat. It is only for Oddesund and Aalborg that continuous observations on the surface- water are available. In 1902—1906 the salinity at Oddesund was on an average \ Meteorologisk Aarbog for 1896. 14 29,3% (the monthly mean was 26,3—82,4° 00); at Aalborg it was during the same period on an average 23,5"/00 (18,4—27,7°/o0). At the same time the monthly mean temperature at Oddesund alternated between -—-0,2° (Febr.) and 18,5° (July). At Aal- borg it alternated between —1,4° and 18,3°. The conditions characteristic of the Limfjord are: a relatively high salinity, especially in the western part, a higher summer temperature than in the open waters and the absence of a salter under- layer with smaller alternations in the temperature. In the northern Kattegat, north of Læsø, an active exchange takes place between the surface-current and the under-current, which is. the reason why the salinity decreases considerably in both from north to south. As a rule the salinity of the water streaming in at Skagen is between 30 and 35°00, and the salinity of the surface-water is ordinarily more than 25°. According to J. P. JACOBSEN the result of daily observations for 1880—1905 shows, that the temperature and salinity at Skagens Reef vary on an average in the following manner; Temperature Salinity 0 M......... 2,5°—16,2° (mean 8,8°) 27,3—31,4 202) ees Gages 3° —15° 32,3—33,8 SEI er: 4° —13,9° (mean 8,2°) 33,3—34,5 At Læsø Trindel the salinity, according to the charts in J. P. JACOBSEN’s paper, is: at 0 M. 23—27°/o0, at 10 M. 28—29°%oo, at 20 M. 31—32 9/00. In the eastern Kattegat the salinity of the surface water gradually de- creases southward; not nearly so great an exchange however occurs here as in the northern Kattegat. At Anholt’s Knob the salinity is at 0 M. 19—230/6, at 10 M. 23—250/0, at 20 M. 29—31" co and at the same place the temperature alternates at the surface between 1,6° (mid. Febr.) and 17° (ca. 1. Aug.) at a depth of 28 M. between 4,2° and 13,5°, at a depth of 40 M. between 4° and 11,5°. In the western Kattegat (Km.), which is only of small depth, the salt bottom water is absent, except in Læsø Channel. At the lightship in Læsø Channel in 1880—94 the averages were: Temperature Salinity mean minim. mean max. mean minim. mean max. OM........ 2,2° (Febr.) 16,1° (July) 2239100. 27,80/ou DAN 3,4° (March) 13,9° (Aug., Sept.) 32.2 oo 33,9 2/00 The salt water coming through the Læsø Channel causes on mixing the water in this region to become relatively saline, especially to the north and along the coast of Jutland. In the greater part of the region the salinity at the bottom is however not more than 2500. In the Southern Kattegat and the waters east of Samsø the salinity at the surface is fairly uniform. In this area there is, especially in summer at a depth of 10—20 M., a very distinct limit between an upper layer, which has ca. 20°00 15 salinity, and an under layer, which has 28—32°/0. Where the depth is greater the salinity is even higher. At Schultz’s Grund it increases during the summer months, when it is greatest, up to 32—33°/oo at a depth of 26M. During the winter months the salinity at the bottom is less (at Schultz’s Grund ca. 29—80°/o0), while at the same time the surface salinity increases on account of the intermixing. The maximal temperature at the bottom is relatively low, lower than it is both north and south of the region. The mean temperature of the bottom-waters for the year is 7°. Ac- cording to J. P. JACOBSEN (1. c.) the conditions at Schultz’s Grund are the following: 0 M. 10 M. 20 M. 26 M. Salinity Salinity Salinity | Salinity 16—21,6 900 19,9— 23,3 °/00 27,8—31,5 [00 29,1 — 32,9 oo Temperature Temperature | Temperature Temperature 1,5° (Febr.) —17° (Aug.) | 2° (Febr.) —16,5° (Aug.)| 3,3°(Mch.)—13°(Aug,) | 3,8° (Mch.)—12° (Aug.) In the area between Samso, Jutland and Fyen the depths are mostly not more than 20 M. The salinity at the surface increases considerably towards the Jutland coast, where it is greater than in the adjacent regions, which is caused by the salt bottom-water here being nearer the surface and mixed with the surface- water. On account of this also the surface waters maximum temperature is here 1° lower than in the Kattegat. At a depth of 20 M. the salinity is 25—30° 00, the temperature 2,5—13,5. To illustrate the conditions in the Isefjord the following averages for the surface-water at Rorvig, near the mouth, and at Frederikssund, half way up Ros- kildefjord, during the years 1902—1906 may be given: Salinity mean temperature in February (the coldest month) July (the warmest month) Bones 19,4 0/00 06009 018) 17,3° (16,1--18,7) Frederikssund... 1500 0,4° (+ 0,6— + 1,9) 18,0° (16,6—19,7) In the Great Belt the salinity of the surface-water is very variable. Thus, at Sprogø it varies between 10°/oo and 20°/oo. The highest salinity is found at the coast of Fyen. A salt bottom-water is found here, but the boundary between this and the surface-water is here not so distinct as in the Kattegat. At a depth of 20—25 M. the temperature alternates between 3° and 13°, at the same depth the maximum salinity is reached in July and is 27 °/oo. The following averages for 1895—1902 illustrate the conditions (manuscript lists). The western part of the Great Belt; 55°18’ N.L. 10°54’ E. L. Temperature Salinity Min. Max. Min. Max. UM See 2,2(March) 16,6 (Aug.) 13,4°/00 18,3 15 - ...... 292 (March) 13,9 (Sept) Wiel 24,3 DNA ENT. 2,4 (March) 13,2 (Sept.) 18,7 - 27,6 16 In the Little Belt there is only a small difference between the salinity at the surface and in deep water; it is about 20° or a little less. The temperature at the surface is comparatively low in summer (during 1902—1906 on an average 13.7° in June, in July 15,2°, in Aug. 15,1°), comparatively high in winter (during the same period 2,5° in January, 1,7° in Febr.). There is generally a strong cur- rent, especially in the narrowest part of the Belt. In the Sound a salt bottom layer is found as far as Saltholm Tærskel, some- times however passing it. The salinity greatly deereases southward in the upper layers. The salinity of the bottom-layer also deereases southward; north of Hveen it is 25—28%Y% at a depth of 20M. In deep hollows the salinity may be 30—32° 0 and here the temperature in winter is constant for a long time. The following numbers found at the lightship on Lappegrunden are very instructive. Average of 1883—94 (Meteorol. Aarbog): Temperature Salinity Min. Max. Min. Max. OM. 2225226552 1,0° (Febr.) 17,0° (July) 12,0 %/00 16,7 “/00 1 1 En RE ET 3.1° (March) 15,7° (Aug.) 21,0 - 26,2 - AO ee EEE 4,1° (March) 11,5° (Sept.) 28,3 - 32,8 - DE ie Wea ater 2 3,5° (April) 11,3° (Oct.) Day alee Dies North of Saltholm (1880 — 1907): Salinity 0 M. 10—13"/00, 10 M. 13—16 oo. In the western Baltic there is also, at any rate in the summer, a contrast between the surface-water and the salt bottom-water, but as a considerable mixing occurs the surface-water west of Fehmarn is comparatively salt, 11—18°o, and has a somewhat lower temperature in summer than in the true Baltic. The salt bottom-water has its maximal salinity in July and August, when it is ca. 20° 00 at a depth of 20M. In the area between Fehmarn and Gjedser—Dars—Terskelen the salinity decreases considerably in the upper water-layers eastwards. The salinity also decreases somewhat in the bottom-water (ca. 15—20° 0 at a depth of 20 M.). At the lightship on Gjedser Reef the average salinity was in 1880—94: OM. ...... 8,7—12,8%o0 Bie ee 98—136 - its RE ag In the Baltic round Møen, from Gjedser to Sweden, the salinity and tem- perature are fairly uniform from surface to bottom. At Moen the salinity at the surface is on an average ca. 8°00, at a depth of 20 M. 8—10°%oo. From this place the salinity increases both at the surface and at the bottom towards the two en- trances, the Gjedser—Dars—Terskel and the Drogden Tærskel. To illustrate the hydrography of the Baltic round Bornholm it may be mentioned that the salinity of the surface-water at Christiansø in 1902—1906 was on 17 an average 6,7 °/00 (the monthly means varying between 5,5 and 8,8°/oo). A salter bottom-water is found here, but only at a rather considerable depth. At a station north of Bornholm, 55°26' N.L. 14°46' E. L., the salinity of the surface-water is ca. 7—8"/oo, of the bottom-water ca. 13-—15°/00. The boundary lies at a depth of about 60 M. The salinity however increases somewhat above this boundary, as will be seen from the following numbers found by the international investigations during the years 1903—1907 (Bulletin trimestriel). North of Bornholm 55°26' N. L., 14°46’ E.L. The salinity were at depths of: 0—30M.... 8°/oo 40 - ... 7,32—11,560/00 50 - ... 7,38—11,94 - 60 - ... 10,61—14,89 - The currents in the Danish waters are complicated and variable; they de- pend not only on the above-mentioned exchange between the waters of the North Sea and the Baltic, but also on the wind, in a less degree on the tide and of course on the configuration of the coast and the bottom. When the wind is strong it determines the strength and direction of the surface currents. Thus, with westerly winds salt surface-water streams from the Skagerak into the Kattegat, and from the Kattegat a northerly current brings relatively salt water in through the Sound and the Great Belt. Easterly winds produce the contrary effect. A sudden change in the direction of the wind often causes a strong current, especially in the narrow belts and sounds. There is on the whole almost always a more or less strong cur- rent in the latter, e. g. in the Little Belt, in the Sound at Helsingør, sometimes as strong as in a river. That currents can be produced by the tide is not only seen at the most southerly part of the Jutland west coast, south of Skallingen, but also at some single places inside Skagen, for instance in the bay inside Korsør and in some of the Sounds in the Smaaland Sea, where the current, at any rate during calm conditions of the weather, regularly changes with the tide (every 6 hours). The height of the water-level at the Danish coast is only in a small degree dependent on the tide. This is only at the southern part of the Danish North Sea coast of a fairly considerable magnitude. North of Thyborgn channel and in the waters inside Skagen its greatest height is only at some few places 1 foot or a little more, at other places it is only some few inches, and at Bornholm there is no tide at all. According to “the Danish Pilot”! the following heights occur: The North Sea and Skagerak Waters inside Skagen mean high-water above mean low-water the mean height of the spring-tide ESbDjensas.s ea... 5 feet Frederikshavn .. 1 foot Nordby (Fang)...... 4 — 9inches Aarhus......... (inches Blaavands Huk ..... 5 — Eredericia -:2-.. » — 11 Nynunder Gabs 3 — Korsør aides ois < » — 1 — ' Den danske Lods; 4. edit. 1893, p. 29. D. K. D. Vidensk, Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 3 The North Sea and Skagerak mean high-water above mean low-water Waters inside Skagen the mean height of the spring-tide Thyborøn channel .. 1 foot 6 inches Slipshayn....... 1 foot ASSEr in. kk URL 1 — 1 — Helsinger....... , — »o inches Sleep cuccueceoc l'US Copenhagen OT Skagen. IHRER 1 — , — The figures for the places inside Skagen are so small that they are often neutralized by the change of level caused by the winds. The wind’s influence on the height of the water-level is at many places very distinct and well known. Thus, westerly winds cause a high level of the water in the Kattegat on account of the influx of water from the Skagerak, while easterly winds cause a low level of the water. With the variable winds, so pronounced in our country, the changes in the level of the sea are also very variable; but as certain directions of the wind are predominant at certain seasons, others at other seasons, the average height of the water-level is also different at different periods of the year. From Apam PAULSEN a general summary is given here of the average deviations of the water- level at three different places on the Danish coasts from the height of the mean -water-level during the twelve months of the year, calculated as the averages of observations made during the years 1889—1902!. The annual variation of the height of the water-level. Station | Jan. | Febr. March April | May | June | July | Aug. | Sept. | Oct. | Nov. | Dec. | em | cm em | em | cm | em | cm em | em | em | em | cm Hirshals.......... |—0,3'|—4,6 | 88 | 10,8] 10722 | 512 | 72 | ss | 66 | 37 664) Frederikshayn .... 1,2 4,7 —7,4 11,6 9,6 | —3,2 | 3,9 | 5,5 6,6 6,7 | 5,3 | 7,3(5) Eredericia tete 0,6 2,1 4,5 | — 6,6| — 54 —2,6 | 13 | 28 | 51 | 60 | 34 | 2,6(2) The numbers in parenthesis for December indicate the annual mean-height of the water during this month, when the extraordinary. mean-height for December 1898 is left out of consideration. It appears from this, that the lowest water-level at all three places is in April, and it is in agreement with this, that easterly winds according to simultaneous observations are most predominant in April. This condition is of the greatest im- portance to the upper littoral vegetation, and it is the reason why an upper belt of vegetation, which has grown perfectly well during the course of the winter, is killed every spring. Division of the Danish waters. To facilitate the summary over the di- stribution of the Algæ, I have not only maintained the ordinary divisions, but have also made further subdivisions in the Kattegat and Baltic. These will be found ! ADAM PAULSEN, Meddelelser om det danske meteorologiske Instituts Vandstandsmaalinger. (Ac- count of the measurements of the height of the sea-level, carried out by the Danish Meteorolog. Insti- tute). Nautisk-Meteorologisk Aarbog 1906, København 1907, 19 on the present chart, and the boundaries are more exactly indicated below. The limits between the waters are for the most part those commonly accepted (see e. 9. “The Danish Pilot”); I have however moved the boundary between the Kattegal and the Sound a little to the south-east for the purpose of including the Ostindie- farer Grund and Soborghoved Grund, and I have moved the southern boundary of the Sound up to the southern point of Amager, as a distinct biological boundary is found nearly at this place. North Sea. Ns. Boundary towards the Skagerak: Hanstholm point. Skagerak. Sk. The boundary towards the Kattegat is a line from Skagen to the Paternoster rocks at Marstrand. The northern part of the Kattegat. Kn. The boundary to the south is a line from Sæby to Læsø north-west Reef, the north coast of Læsø, and a line from the east point of Læsø due east. The eastern part of the Kattegat. Ke. The boundary to the west is marked by the Kobber Grund and a line from its south point to the east point of Anholt and thence to Gilbjerg Hoved on Sealand; the boundary towards the Sound is a line from Nakkehoved to the point of Kullen. The central part ofthe Kattegat. Km. The boundary to the south is a line from the south point of Anholt to Fornæs Point. The southern part of the Kattegat. Ks. The boundary to the south-west! is a line from the end of the Sjællands Odde to Hjelm. 3° 20 The Samso area. Sa The boundary towards the Little Belt is a line from Æbelø to Bjornsknude and towards the Great Belt a line from Fyens Hoved to Refsnæs Point. The Little Belt (Lillebælt). Lb. The boundary to the south is a line from Pels Huk on Als to Vejsnæs on Æro, and towards the South Fyen waters a line from Hornenæs to Skjoldnæs. The South Fyen waters (Sydfynske ®gaard). Sf. The boundary towards the Great Belt is a line between Turø Reef and Næs Hoved on Langeland. The Great Belt (Storebælt). Sb. The boundary to the south is a line between Gulstav at Langeland and Kappel church on Lolland, towards the Smaaland Sea a line from Korsør passing Egholm, Agerse, Omø and the south-westerly Omø Staal Grund to the eastern point at Onse Vig in Lolland. The Smaaland Sea. Sm. The boundary towards the Baltic off Grønsund is a line round Tolken, towards the Baltic off the Bogestrom a line round the sand shallows to the Bogestrem buoy. The Sound (Øresund) Su. The boundary towards the Baltic off Grønsund is a line from the south point of Amager eastward. The western Baltic. Bw. To a line between Gjedser and Darsserort. The Baltic round Mgen. Bm. To a line from the north end of Rügen northward. The Baltic round Bornholm. Bb. The waters surrounding Bornholm. Remarks on the dredging localities. I have considered it useful to make a list of all the localities where I have dredged and to give information about the depth, the nature of the bottom and the vegetation at each. They are also indicated on the accompanying charts by signs, illustrating the vegetation. By means of this it will be possible in the fol- lowing to give a detailed account of the occurrence of the single species in the Danish waters without too great prolixity, and, by means of the list and the charts, to contribute perhaps to the characterization of the separate waters with regard to the vegetation, even if the dredging localities are not so near each other, that they can serve as base for a chart showing the distribution of the vegetation. To obtain this, much more numerous observations than I have been able to make are ne- cessary. The Danish waters are so complicated, and the nature of the bottom often so variable from place to place, that it is not possible, from the dredging at one place to draw conclusions as to the conditions at another close by. It may also be remembered, that the aim of my investigations was not so much to de- termine, to what extent the bottom was overgrown, as to study the distribution and the mode of occurrence of the single species. That is why I have usually preferred to dredge at places where I could expect the bottom to be overgrown. If the result has nevertheless been, that so great a number of the dredging lo- calities have proved to be without vegetation, the reason is, that a relatively large part of the bottom in the Danish waters is not overgrown, especially in the more open waters. This is especially the case with regard to the North Sea, which is quite without vegetation except at some few places in the most northern part of the region referred to here. In the Skagerak the greater parl of the bottom is also quite without vegetation, even on stony bottom Algæ are often lacking. Here and there some small overgrown plots are however found, but it is only at some few places that a more abundant vegetation is found, especially near the land, e. g. at Hirshals and Bragerne. Also in the other waters large tracts are without vege- tation, especially the soft bottom, which in the Kattegat and the Baltic extends over wide areas in the greater depths. A main rule is, that the total quantity of the vegetation is generally the greater the more sheltered the place is. It must however be remembered, that in the more sheltered waters we have the Zostera, which grows on sand bottom or on mud bottom more or less mixed with sand', while the algal vegetation is found on stony bottom. The last applies not only to bottom exclusively or predominantly consisting of stones but also to sand bottom or soft bottom with scattered stones. On the last mentioned kind of bottom there is commonly, according to the con- ditions, scattered algal vegetation or Zostera vegetation with Algæ, which is indi- cated on the charts by a special sign. But also on true stony bottom scattered algal vegetation is often found especially in deeper water. In such cases the lo- cality is however indicated on the charts with the same sign as those with unin- terrupted algal vegetation. Only when the vegetation is practically lacking, but where however some few scattered specimens of Algæ were found, is the locality indicated with ©. It is important to distinguish between Algæ grown on the dredging locality and those found loose’. In some cases where such Algæ occur they have been brought by chance from another locality, in other cases they appear in large quantities and always at the same place, where they keep living for a long time. Such collections of loose Algæ are found e. g. at some places near Anholt and near Moen; they are given a special sign. Of a different nature is a number of more or less transformed loose forms of different algal species connected with the Zostera vegetation; probably they have been carried into this vegetation after having been torn loose, but when there have been kept among the Zostera plants and have gone on living perhaps for a long time, propagating by division, while reproduction by spores has ceased and the appearance has become more or less transformed’. 1 C. H. OSTENFELD, Aalegræssets (Zostera marina’s) Væxtforhold og Udbredelse i vore Farvande. Beretn. fra den danske biologiske Station. XVI. 1908. (Report from the Danish Biological Station. XVI.) ? Such a distinction has not been made in C. G. Jos. PETERSEN, “Kanonbaaden Hauchs Togter” where the signs indicating the Zostera, Laminaria and some other higher Algæ in the Kattegat are given on the Atlas, Plate III (1893). In some single cases at any rate, plants are here noted as growing at localities, where according to my experience the bottom is quite without vegetation. > The largest and perhaps the best known is Ascophyllum nodosum f. scorpioides; of others may also be mentioned: Phyllophora Brodiei, membranifolia and rubens, Ahnfellia plicata, Polysiphonia nigrescens and violacea, Cladostephus verticillatus, Halopteris filicina and scoparia, Sphacelaria cirrosa etc. 22 In the following list of the dredging localities are indicated for each locality the most common and predominant species, which above all others contributed to the characterization of the vegetation, the most important first, the less predominant in parenthesis. With regard to the indication of the locality it must be remarked that the bearings are always by compass. Besides the localities mentioned in the list, I have also made collections at many harbour-piers, stone-reefs and at other places near the land, which are for the most part indicated by a mark on the charts together with the name of the place concerned. In the list the localities are arranged for the North Sea from south to north, for the Skagerak and the Limfjord from west to east, for the rest of the waters generally from north to south, or from without inwards, in the Baltic however essentially from west to east. In the Samsø region the area east of Samsø is distinguished from that west of this island. The same method as in the lists will be kept in the following pages. To facilitate the orientation the detailed list is supplemented by a chrono- logically arranged summary of the dredging localities with indications of the waters where they are situated. List of stations arranged according to the different waters. North Sea. (Ns) aH. °/s1905. Vyl light-ship N.W. by W.1: W., 6 miles. — 20 meters. — Fine grey sand with shells. — No vegetation (at the same station Dr. A.C. JoHansen took, in 1903, several fresh Laminaria together with Halidrys and Furcellaria in trawl, but it was uncertain whether they were growing on that spot). aL. ‘05. Vyl light-ship S.E. */2 S., 6'/s miles. — 25 meters. — Coarse sand with small pebbles. — No vegetation. al. °/s 05. Vyl light-ship S.W.1/s W., 6s miles. — 9,5 meters. — Firm coarse sand (with small pebbles). — No vegetation. aK. ‘C5. A little more south than al. — 8 meters. — Coarse sand with pebbles. — No vegetation. aQ. */s05. A tract immediately N. of the light-buoy at the south end of Slugen (Horns Reef). — 7,5 to 19 meters. — We searched here with grapnel for a wreck and dredged several times, but only bare sand without vegetation was found; the shells were without Algæ. aN. */s05. Horns Reef light-ship N.W. ls W., a good 6 miles. — About 23 meters. — Sand with small pebbles. — No vegetation. aM. */s 05. Horns Reef light-ship N.W. by W.1/: W., 7 miles. — 16,5 to 18 meters. — Coarse sand with a few small pebbles. — No vegetation. aM *.*/s05. A little more to the south. — 22,5 meters. — Coarse sand. — No vegetation. — 24,5 meters. — Sand, pebbles. — No vegetation. aR. “ls 05. Double broom at Søren Bovbjergs Knob S.E. by E.2/s E. 1/4 miles. — 13 meters. — Sand. — No vegetation. 23 aS. “8 05. The light buoy at the north end of Slugen W.N.W 4 W. 3 miles. 9,5 meters. — Sand. — No veg. (loose Fucus vesiculosus). aP. °/s 05. Horns Reef light-ship W.°’lı N. a good 64/2 miles. — 11,5 meters. — Sand. — No vegetation. aQ. Is 05. 1 mile E. of Horns Reef light-ship. — 30 meters. Partly sand, partly stony bottom. — No vegetation. aB. °; 05. Off Harboøre; Bovbjerg light-house S$. 1/1 W., 61}: miles. — 24,5 meters. — Sand, thereafter stones. — No vegetation. aA. %|7 05. Thyborøn beacon E. "2 N., ca. 10 miles. — 22 to 25,5 meters. — Coarse sand. — No vegetation. ZZ. |; 05. Thyborøn beacon S.E. by E., 5 miles, 4 miles off land. — 24,5 meters. — Sand. No vegetation. aC. *|; 05. Thyborøn beacon S.E. by S.!l»S., 3 miles. — 21 meters. — Sand, firm clay. — No vegetation. ZR. °*105. Lodbjerg light-house E. “/s N., 10°}; miles, near the 15 meter shallow. — 28 meters. — Sand. — No vegetation. aF. Ys 05. Thyborøn beacon S.E.!E., 141}: miles. — 31 meters. — Sand with small pebbles to coarse gravel with pebbles. — Vegetation very poor to rather rich: Eelocarpus sili- culosus, Brongniartella, Chorda Filum and Ch. tomentosa.... ZQ. */; 06. Jutland Reef; Lodbjerg light-house E. by S., 26!/» miles. — 24,5 meters. — Gravel with small and partly a little larger pebbles. — In two dredgings Chorda Filum, (Lami- naria saccharina and hyperborea (?), fragment ...); in one dredging Phyllophora mem- branifolia a. 0. aG. ‘ls 05. Thyborøn beacon S.E.!l» E., 19/2 miles. — 38 meters. — Eclocarpus siliculosus. aD. 7/7 05. Lodbjerg light-house S.E.°lıS., ca. 4!/2 miles. — 23,5 meters. — Stones. — a) Eclo- carpus siliculosus, Desmarestia viridis, Flustra foliacea with Derbesia a.o. — b) Ectocarpus, Desmarestia aculeata. aE. *7/; 05. Lodbjerg light-house S. by W. "> W., 7/s miles. — 16 meters. — Sand. — Some few Ectocarpus and Brongniartella. (The dredge foul). XR. */s 00. Off Orhage (by Klitmøller), at most 1 mile off land. — 11 to 13 meters. — Stones. — Cystoclonium, Delesseria sangvinea, Spermothamnion. Vegetation scare, partly wanting. Skagerak. (Sk) YT. 7/3 02. N. and W. of Helshage (Hanstholm). 1) N. of the point. — 5,5 to 7,5 meters. — Stones. — Very few Algæ (Delesseria sangvinea, Phyllophora membranifolia). 2) A little farther from land. — 9 to 11 meters. — Stones. — Very few Algæ (Phyllophora membranifolia). 3) A shallow about off the light-house. — About 5,5 meters. — Stones. — Richer vege- tation (Dilsea edulis, Laminaria hyperborea). 4) Farther from land. — About 15 meters. — Stones. — Very scarce Algæ (Deless. sangvinea). 5) Another shallow farther S. — About 13 meters. — Stones. — Richer vegetation: La- minaria saccharina, Polyides. 6) From 5) landward. — 7 to 11,5 meters. — Stones. — Much the same species as in 5) but scarcer, further Laminaria hyperborea. 24 YU. 5k 02. At Roshage (Hanstholm), near land. 1) Immediately E. of Roshage, on a dry rock near land, the bottom in a depth of 2 meters. — Polysiphonia Brodiei (at the upper level), Polys. nigrescens, species of Ceramium .... 2) Eastside of Roshage, near land. — About 2 meters. — Stones. — Abundant vegetation: Spermothamnion Turneri, (Chondrus, Corallina off). 3) Inside the rock (1). — 1,5 meters. — Stones. — Rich vegetation: Chorda Filum, Cera- mium rubrum. ... i 4) Off Roshage and from thence along the shore towards the landing-place. — 2 to 2,5 meters. — Ceramium rubrum, Cystoclonium, Polysiphonia; in some places Laminaria digitata; on the W. shore Gracilaria confervoides. YM. “/; 02. The W. and S. part of Bragerne (a bank). — 2,5 meters. — Stones — 1) Floridee, rather scarce (Rhodomela, Polysiphonia violacea var. fibrillosa, Corallina off). — 2) The same Algæ and Laminaria hyperborea). YM* 1], 02. Bragerne. — 1 to 2 meters. — Stones. — Mesogloia, Ceramium fruticulosum, Lami- naria digitata and saccharina, Fucus serratus, Cystoclonium, Corallina off. — 1 meter: Laminaria, Punctaria, Spongomorpha. YN. !0/5 02. Immediately inside Bragerne. — 4,5 meters. — Stones. — Fucus serratus, Lami- naria digitata. YN!. 2% 02. A little nearer to land. — 6,5 meters. — Stones. — Chorda Filum, Brongniartella. YN?. 20/5 02. S.E. of Bragerne. — 10,5 meters. — Stones. — Laminaria hyperborea, Chorda Filum, Phylloph. Brodiæi, rubens, Spermothamnion, Corallina offic. YN®. 12%: 02. S.E. of Bragerne, near land, towards Sandnæshage. — About 2 meters. — Sand and boulders. — Almost no Algæ (Polysiphonia elongata). SZ. “Js 94. About 2 miles N.W. of Løkken. — Stones. — No vegetation. SY. “94. About 1 mile N. of Løkken. — ca.13 meters. — Stones. — Scarce vegetation, mostly Cystoclonium, Rhodomela and Spermothamnion. ZK°—*. >15 04 Off Lønstrup. 0) W. side of Mellemgrund, 1,5 miles from land. — 7,5 to 9,5 meters. — Stones. — Hali- drys, Cystoclonium. 1) N. end of Stenrimmen, 2 miles from land. — ca. 7,5 to 9,5 meters. — Laminaria digi- lata, saccharina, Halidrys; Floridee, mostly Corallina office. Furcellaria. 2) E. end of Mellemgrund. — 7,5 to 9,5 meters. — Stones. — Laminaria hyperborea, Halidrys, Floridec. Mellemgrund. — 13 to 15 meters. — Stones. — Some few Halidrys and single Floridew. 4) Gronne Grund 1 mile from land. — 9,5 to 11,5 meters. — Stones. — Halidrys, Florideæ, particularly Cystoclonium, Phyllophora membranifol., further Laminaria hyperborea and saccharina. 5) Palen, abreast of Rubjergknude light-house, 1 mile from land. — ca. 11 meters. — Stones. — Veg. as in 4). 6) Shallow off the landing-place. — 11 to 13 meters. — Firm clay with stones. — Phyllo- phora membranif., Furcellaria, Laminaria. ) E. end of Rimmen, abreast of Rubjersknude lisht-house, about 4 miles from land. — 17 to 19 meters. — Stones. — Halidrys, Laminaria sacchar. and hyperborea. — Later, clay with pebbles and scarce Algæ, mostly Heterosiphonia coccinea. = 25 8) A little more S. — Sand without vegetation. 9) Stenrimmen, about 4 miles from land. — 13 meters. — Stones. — Few Algæ: Halidrys. single Floridew. 10) Mellemgrund, something more than 2 miles from land. — 11,5 meters. — Stones. — Halidrys, Laminaria hyperb., Cystoclonium. 11) Graagrund, off Maarup church, about 1,5 miles from land. — 9,5 meters. — Stones. — Rather scarce vegetation: Halidrys, (Lomenlaria clavellosa, Cysloclonium). 12) Kongshoj Grund, off Maarup church, 1 mile from land. — 8.5 meters. — Stones. — Cystoclonium, (Polyides, Deless. sangvin., Halidrys). 13) Near land, immediately N. of the landing-place. — 1 meter. — Stones, clay; Mytilus, acorn-shells. — Various Florideæ, as species of Polysiphonia, Gracilaria confervoides. YL. !/s 01. Hirshals light-house S.E. 2,5 miles (Pullen). — 13 meters and something more. — Stones. — Halidrys with Floride. YL’. 18 01. Hirshals light-house S.E. 1,5 miles. — Stones. — A few specimens of Brongni- artella byss. 2/:02. Hirshals light-house S.E., ca. 1 mile (the church between the hills). — Stones. — Flu- stra foliacea with various small Algæ, Delesseria sangvinea scarce Halidrys, Cystoclonium). 2175.02. N. and W. end of Bredegrund, N.W. of Hirshals. — ca. 11 meters. — Stones. — Few Algæ (Halidrys, Cystoclonium, Laminaria hyperborea). >1,02. Within Bredegrund. — 19 meters. — Stones. — One specimen of Halidrys. 2]; 02. The channel within the stony shallows N.W. of Hirshals. — 19 meters. — Clay. — No vegetation. YK. 101. Hirshals light-house in S.S.E. 2 miles (the church on the brook). — 14 meters. — Stones. — Cystoclonium, Brongniartella, Laminaria digitata. — 15 meters. — Flustra foliacea with few Algæ. XO. °/s 99. Mollesrund by Hirshals, ca. "> mile from land. — 11 to 15 meters. — Stones. — Laminaria hyperborea and Halidrys, (Laminaria saccharina). *1/, 02. Off the brick-works at Hirshals, near land. — 6,5 meters. — Sand with stones. — Rhodomela, Polysiphonia nigrescens. 21/5 02. Off the marine hotel at Hirshals. — 4,5 meters. — Stones. — Polyides. VJ. 26 95. Off Hirshals, W. of the mole. — 4,5 meters. — Stones alternating with sand. — On the stones Polyides and Furcellaria. bD. */; 07. 13 miles N.N.W.!/2 N. of Hirshals; 57°46’ N., 9°44’ E. — 32 meters. — Soft bottom. — No vegetation. bC. */; 07. Hirshals light-house S.1/}: W. 12 miles. — 45 meters. — Soft bottom, ooze. — No vegetation. bE. */; 07. 6 miles N.E. by N. of Hirshals. — 23 meters. — Coarse sand. — No vegetation. bF. °/; 07. Skagbanken; 9 miles N.E. by E. of Hirshals. — 16,5 meters. — Sand. — No vegetation. bB. 5}: 07. Skagens light-house E. 10 miles; Lat. N. 57°41°5, Long. E. 10°20’. — 24 meters. — Stones and sand. — No vegetation. bG. °/: 07. Northside of Skagens Gren, N.N.W. of Skagens light-house. — 5,5 to 17 meters. — Sand. — Few loose Algæ. 51,03. Between Gammel Skagen and the Siren, within the first shoal. — Small pebbles. — Chorda Filum, Polysiphonia nigrescens. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 4 bG. ZS. ZN. ZN. EN. M. I ZU. 26 51,03. Between first and second shoal. — 3,5 to 4,5 meters. — Small pebbles. — Polysiphonia nigrescens, Ceramium rubrum. 151,03. Between Gammel Skagen and Hojens light-house; between first and second shoal. — 3,5 to 5,5 meters. — Small stones. — Few Algæ, mostly species of Polysiphonia, (acorn- shells and young Mytilus). Limfjord. (Lf) %/; 05. Under the land at Kobberod. — 2 to 4 meters. — Stones. — Fucus serratus. %/7 05. In the middle of Nissum Bredning; the broom for Mullerne E. 2,5 miles. — 5 meters. — Soft bottom. — Cladophora gracilis. (Ciona canina in abundance). — A little farther N.; the broom E. by S.!/> S. 2,5 miles. — (Small shells, Ophioglypha albida, often infested by a Dactylococcus). 24/8 93. Between Gellerodde and Inderron near Lemvig. — 3 to 3,5 meters. — Sand with spots of loose Furcellaria, (Cladophora, Phyllophora Brodici). 9 90. Søndre Ron near Lemvig. — 1 meter. — Stones. — Fucus vesicul., here and there Zostera. 2:05. W. of the N. end of Ronnen near Lem Vig. — 3 meters. — Stones. — Fucus vesicul. — Thereafter (northward) 4 meters — sand with Ciona canina and Fucus serratus. LX. */s 93. Ronnen, a reef near Lem Vig. — Uppermost Fucus vesicul.; — 2 to 4 meters Fucus serratus; — 4 to 5,5 meters broad-leaved Zostera. ZT. > 05. Off Osterbol. — about 4 meters. — Zostera, and a little farther out loose Fur- cellaria and Cladophora gracilis in great quantities. XV. 1/6 01. N. of Ronnen by Lem Vig. — Oysters, Furcellaria. XX. 12/6 01. Midway between XV and Mullerne. — 5,5 meters. — Furcellaria, (Cladophora gracilis). LZ. */s 93 Off Rajens Odde. — 4 meters. — Clay-mud with a few stones. — No vegetation. ZX. °% 05. Immediately E. of the broom at Mullerne. — 6,5 meters. — Soft bottom. — Cla- dophora gracilis. ZY. **|; 05. Nearer to land. — 4,5 meters. — Stones and soft bottom. — Zostera, Fucus serratus. XY. 601. Near Mullerne. — 6,5 meters. — Soft bottom with stones. — Fucus serratus, (spa- ringly Zostera). MA. **/s 93. Off Jestrup. — 5 meters. — Stones. — Scarcely any vegetation, only single spe- cimens of Fucus serratus, Chorda Filum and Desmarestia aculeata. LY. */s 93. Off Nissum Huk. — 5,5 meters. — Clay-mud mixed with sand, with stones and oysters. — No plants. LU. */s 93. Off Kamstrup Ron. — Scarcely 7,5 meters. — Clay-mud without plants (a few Cladophora gracilis). XU. 2/6 01. Immediately W. of Oddesund-Nord. — 4 meters. — Sand with single stones. — MB. MD. ME. Fucus serratus, (Halidrys). %/8 93. S.W. of Oddesund-Nord. — 6,5 meters. — At first bare sand, then clay-mud with single Floridez and, rather abundantly, loose Cladophora gracilis. */s 95. Studemilen, right opposite Doverodde. — Thick Zostera vegetation everywhere; up on the bank also stones with Fucus vesiculosus. “Is 93. Off Skjoldborg (Thy), near the shoal. — 7,5 meters. — Soft bottom without vege- tation. 27 ME. “ls 93. Sundby Stengrund, at the N. side of Mors. — Stones. — Chorda Filum. MG. *7/s 93. Stony reef by Hanklit. — Fucus vesiculosus, covered with Melobesia, Lithophyllum pustulatum and Laurencia pinnatifida. — Outside the reef Zostera. MH. */3 93. Bank off Skrandrup, Thisted Bredning. — Stones. — Fucus vesiculosus, (Chorda Filum, Corallina offic.). I. So 90. Venø Bugt, off Nørskov, Venø. — 3,5 meters. — Stony bottom with Zoslera, (few Algæ, Phyllophora membranifol.). K. le 90. Venø Bugt, off Nørskov, Venø, N. of Venø Tap. — 4,5 to 5,5 meters. — Furcellaria and Phylloph. membranif. L. So 90. Venø Bugt, Nygaards Hage. — 3,5 meters. — Stones. — Zostera, (Furcellaria, Phyllo- phora membranif.). XT. 1) 01. South side of Jegindø Tap. — 4,5 meters. — Clay. — Zostera, (loose Furcellaria). MC. “8/3 93. Jegindø Tap, immediately W. of the broom. — 6,5 meters. — Clay-mud without veg. MC!. */s 93. East side of Jegindø. — From shallow water to 4 meters depth Zostera, farther out clay-mud without vegetation. H. SJ 90. Kaas Bredning, off Sillerslev, Mors. — 7,5 meters (?). — Clay-mud without vegetation. XN. "1 99. Sallingsund, immediately S. of Glyngøre. — 4 to 9 (?) meters. — Stones, oysters. — Chorda Filum, Fucus vesiculosus. XM. "3/7 99 and 2/6 06. Off Snabe. — 4 to 5,5 meters. — Zostera and stones with Fucus vesi- culosus, Chorda Filum etc. XY". % 01. Vodstrup Hage (Skælholm) near Nykøbing. — Stones. — Fucus vesic., Rhodomela, Furcellaria (loose). LT. ”/s 93. Immediately outside the broom at Vodstrup Hage. — Ca. 5,5 meters. — Firm bottom with Zostera, (Polysiphonia nigrescens). LS. */s 93. Off Alsted (Arnakke), Mors. — 5 meters. — Clay-mud with dead shells. — Floridee, particularly Polysiphonia nigrescens. LS! — Nearer to land. — 1 to 3 meters. — Stones with Fucus vesiculosus; in some places also Zostera; farther out clay-mud with scarce Floridew. aT. *#/6 06. Outer part of Draaby Vig, off Alsted church. — 4 to 5,5 meters. — Soft bottom with Zostera and Furcellaria; in other places stones and oysters but few Algæ, farther out, 7,5 meters — soft bottom with shells, without vegetation. MF. */s 93. Løgstør Bredning, off Ejerslev. — From land to 4 meters depth clayey sand with Zostera; in shallow water stones with Fucus vesiculosus. MK. */s 93. Holmtunge Hage. — Stony reef with Fucus vesiculosus, here and there Zostera. LQ. “/s 93. Lendrup Ron. — Stones. — Fucus vesiculosus, (Fucus serralus, Laurencia pinnatifida). LR. */s 93 E. of Livø. — 6,5 meters. — Soft bottom. -- Zostera. F. *J9 90. Skive Fjord, North side of Lundø Hage. — Ca. 5,5 meters. — Soft bottom. — No vegetation. Ft. — On the bank. — 3 meters. — Zostera, (a few loose Furcellaria and Phyllophora Brodii). G. ‘lo 90. Off Skive. — 3,5 meters. — Zostera (a few loose Furcellaria). — On bare bottom loose clumps of Furcellaria, (Phyllophora Brodiwi, Cladophora gracilis). E. 4/9 90. Louns Bredning, W. of Trangmanden. — 5,5 meters. — Soft bottom. — Loose Alsæ: Cladophora gracilis, (Rhodomela, Phyllophora Brodiwi etc.). Et. — A little farther northwards. — Same depth and bottom, similar vegetation. 4 28 ML. 2“/x 93. Outside the broom near Klitgaard in Gjøl Bredning. — Thick broad-leaved Zoslera vegetation with Melobesia Lejolisit and some Ceramium rubrum. Kattegat, Northern part. (Kn) bH. °% 07. 8 miles S.E. by E. ‘LE. of Skagen. — 30 meters. — Soft bottom. — No vegetation. FG. #%/:92. Herthas Flak. — 19 to 22,5 meters. — Stones, gravel. — Laminaria saccharina, Desmarestia aculeata, (Deless. sangvin., Cystoclonium). XI. 2%}: 96. Herthas Flak. — 20 to 22,5 meters. -- Gravel and stones. — Lamin. sacch., Desmar. acul., Deless. sangv., Ceram. rubrum, Callithamnion corymbosum, Sporochnus. (Vege- tation spread). — 1/7 05. — 20,5 to 24,5 meters. — The bottom alternately clay-mud and gravel with single stones; on these some few incrusting Algæ, for the rest nearly no vegetation (repeated dredgings). bI. */; 07. S.E. of Herthas Flak; 11 miles S.E. !4 S. of Skagen. — 26,5 meters. — Clay-mud. — No plants. IZ. |; 93. Skagens light-house N.N.W.4/sW.a good 7 miles. — About 24,5 meters. — No vege- tation (seine). IY. "1; 93. Hirsholm light-house S.W. by S. a good 5 miles. — 22,5 meters. — Clay-mud. — No vegetation. KA. "5/5; 93. Hirsholm light-house S. by E. ‘2 E. a good 5 miles. — 13 meters. — Fine sand. — scarce Zostera (seine). TV. 1/10 04. Krageskovs Rev, northern shoal. — Stones and sand. — 5 meters. — Abundant vegetation: Halidrys, Fucus serratus, Laminaria sacch., Furcellaria, (Corallina off). KC. 1/5 93. Krageskovs Rev, southern shoal. — 4 to 5,5 meters. — Stones. — Abundant vege- tation: Halidrys, Fucus serratus, Laminaria digitata. KB. "5/5 93. Off Snedkergaarde. — 4,5 meters. — Fine bare sand with only a few spots most probably of Zostera. TX. ho 94. Inside the broom N. of Græsholm (Hirsholmene). — 7,5 to 9,5 meters. — Stones. — Dense vegetation: Halidrys, Fucus serratus, Laminaria hyperborea. — 5195 and *4/; 95. Same vegetation; of predominant species further Laminaria digitata and saccharina, Furcellaria. YR. °1 02. Naamands Rev N. of Græsholm. — Stones. — Halidrys, Laminaria digitata. XK. ! 99. N.E. of Græsholm. — 7,5 to 11,5 meters. — Stones. — Laminaria hyperborea.... YS!. 21/7 02. E. of the broom N. of Gresholm. — Ca. 9 meters (?). — Soft bottom. — No vegetation. YS°. 3/7 02. The broom N. of Græsholm W.S.W. ca. 1 mile. — 15 meters. — Clay-mud with snails etc. — On the snail-shells some Algæ (Antithamnion, Polysiphonia atrorubescens, P. elongata a. o.). YX. 17 04. E. of the broom at N.E. reef by Hirsholm. — 22,5 to 28 meters. — Soft bottom. — On molluse shells: Polysiphonia atrorubescens, P. elongata a. 0. Algæ. TU. 10 94 and */1 95. At the broom at N.E. reef by Hirsholm. — ca. 9,5 meters. — Sand and stones. — Laminaria saccharina, (Desmareslia aculeata, Laminaria hyperborea). — 1704. Same place, but within the broom. — 7,5 to 9,5 meters. — Stones. — Laminaria hyperborea, L. sacchar., Furcellaria a. 0, Florideæ. TU. NF. IE NE. YQ. NT: NG. 29 111,04. Outer side of the same reef. — 95 to 11,5 meters. Soft bottom and gravel (?, - Sticlyosiphon, Striaria a. 0. 21/9 93. Immediately outside the harbour of Hirsholm. — 4 meters. — Sand. — Zostera. 210 94. The bank S. of Hirsholm. — 7,5 meters. — Sand and single stones. — Scattered Zoslera. 21,93. Off Lerbæk. — 5,5 meters. — Gravel. — Zoslera. 251, 02. E. side of Kolpen. — 2 to 5,5 meters. — Stones. — Abundant algal vegetation: Fucus vesicul., F. serratus, Chorda Filum, Halidrys, Laminaria sacchar., L. digit.... 1. 21a 95. E. of Deget. — 4 to 5,5 meters. — Stones. — Halidrys, Fucus serr., Florideæ, (La- minaria hyperb.). . %/9 92. Outside Busserev near Frederikshavn. — 3 meters and more. — Stones. — Fucus serratus, Halidrys, (Laminaria digitata). . 1, 95. Marens Rev. — 4,5 to 5,5 meters. — Stones. — Halidrys, (Laminaria digit., sacchar., Fuc. serr.). . 17 9%. The beacon buoy at Marens Rev W. by S. ca. 1 mile. — 15 meters. — Clay-mud with snails (Turritella, Aporrhais.). — On the shells Polysiphonia atrorubescens. . ‘I; 99: The buoy at Marens Rev W. by N. a good 1,5 miles. — 19 to 20,5 meters. — Clay- mud. On Aporrhais and Turritella: Polysiphonia atrorubescens, Sticlyosiphon lortilis, Antithamnion, Sphacelaria. . 12/2 92. Borrebjergs Rev, near the triple broom. — 4 to 7,5 meters. — Sand. — Zoslera. . */7 02. Outside Laurs Rev. — Stones. — Halidrys (with Eelocarpus). . #/: 02. Borrebjergs Rev. — Stones. — Halidrys, (Laminaria digitata and sacchar.). . 1: 02. Laurs Rey. — Stones. — Halidrys, Lamin. digit., hyperb. and sacchar. . 1: 95. Between Borrebjergs Rev and Laurs Rev. — No vegetation. 20, 02. 1 mile S.E. of Laurs Rev. — Soft bottom. — Dead Zostera-leaves. 13/7 05. In the deep channel N.W. of Læsø. — Soft bottom. — No Algæ. . #18 91. Off Sæby. — 7 meters. — Firm clayey sand. — In spots Zostera. . J) 94. Nordre Ronners light-house S.E. by S. 2,6 miles. — 13 meters. — Sand without vegetation. 3/7 95. Nordre Ronners light-house S. scarcely 2,5 miles. — 9,5 meters. — Sand. — Zostera, Fucus serratus, Florideæ, (Laminaria sacchar.). - 3 95. Nordre Ronners light-house S. scarcely 2 miles. — 11,5 meters. — No plants. “6/9 94. Nordre Ronners light-house E.S.E. scarcely 1,5 miles. — 12,5 meters. — Firm clay with stones. — Laminaria sacchar., Desmarestia acul. a. 0. (vegetation not abundant). . lo 94. Nordre Ronners light-house E. by N.4/4N. 11}: miles. — 7,5 meters. — Stones. — Rich vegetation: Fucus serratus and Floridew. — Nearer to the reef. — 4 to 5,5 meters. — Sand with stones. — Alternately sand without vegetation or with scarce Zostera, or stony bottom with various Algæ. °/ 94. Nordre Ronners light-house E. by N. 22/5 miles. — 9,5 meters. — Sand. — Zoslera. . %/, 93. At the beacon-buoy at Nordvestrevet, Læsø. — 11,5 to 22,5 meters. — Sand to sandy clay-mud. — No vegetation. . 5: 05. The broom N.E. of Nordre Ronner S. 2 E. 1 mile. — 11,5 meters. Sand with stones. — Zostera, Halidrys, (scarce Fucus serratus). 1/9 93. N. of Nordre Ronner. — 4 meters. — Stones. — Abundant vegetation: Halidrys, Fucus serratus, (Laminaria digitata, Fucus vesiculosus). UC. 5h 95. At the broom N.E. of Nordre Renner. — ca. 9.5 meters. — Stones. — Halidrys, Fucus serratus, (Florideæ, Laminaria digitala). VU. %: 95. Nordre Ronners light-house S.W. by W.‘/: W. 25 miles. — 15 meters. — Stones. — Halidrys, Cruoria. GL. “ 92. 4/2 mile E. of the broem at Nordre Ronner. — 9.5 meters. — Sand without veg- etation. GN. %/s 92. Anchoring ground at the E. side of Nordre Ronner. — Ca.4to5 meters. — Stones. — Fucus serratus, (Halidrys, Laminaria digitata and sacchar.). UB. */: 95. Nordre Ronners light-house W.N.W. 2/5 to 32 miles. — Here and there stones. — Halidrys, Fucus serratus, Florideæ mostly Furcellaria and Corallina, (Zostera). TH. */s 94. Nordre Ronners lisht-house W.N_W._:/: N. a good 3 miles. — 105 meters. — Sand. — Fucus serratus, (Floridee, Zostera). ZL. *!; 05. 3 miles S.E. by E. of Nordre Ronner. — 6,5 meters. — Sand with stones. — Fucus serratus, (Fuc. vesiculosus, Halidrys). ZL:. — Near the preceding. — 95 meters. — Similar vegetation but moreover Zostera and Desmareslia acul. ZL. — Near the preceding. — 11,5 meters. — Stones. — Similar vegetation, in abundance Farcellaria and Corallina off. TN. “: 94 Trindelen light-ship E.S.E. 5'/s miles. — 12 meters. — Sand. — No vegetation. NH. “/s 93. Trindelen light-ship E. 5‘/: miles. — 15 meters. — Gravel. — Almost no vegetation. ZM. =1, 05. Ca. 4/2 miles E.°/: N. of Nordre Renner. — 15 meters. — Gravel and small pebbles. — Almost no Algæ. IX. */; 93. Trindelen light-ship N.E.°/sE. 4 miles. — ca. 19 meters (in the channel). — Des- marestia acul., Laminaria sacch., (Halidrys). GM. %/4 92. At Engelskmands Banke. — Ca. 55 meters. — Stones. — Fucus serratus. Chorda Filum, Florideæ (Phyllophora). — */; 95. Stony reef by Jegens Odde. — 2 to 4 meters. — Fucus serraius with Polysiphonia violacea, Halidrys. — On a dry rock particularly Chordaria flagelliformis, Ahnfeltia, Spermothamnion, Chondrus. TG. “ls % Syrodde Pynt (Læsø) S.S.E. 1'!!: miles. — 9,5 meters. — Sand. — Halidrys, Fucus serratus, Floridee, mostly Furcellaria, (Zostera). TO. “is 94. Tonneberg Banke; Trindelen light-ship S. %/- miles. — 18 meters. — Stones. — Laminaria saccharina (large specimens) and Florideæ. TP. “|; 94. Tonneberg Banke; Trindelen light-ship S.S.W.+/z W. 21: miles. — 16 meters. — Sand (?) with stones. — Floridee, Halidrys, Laminaria saccharina. ZA. “I: 0£ Tonneberg Banke; Trindelen light-ship S.W. by S. 2 miles. — 12 to 18 meters. — Stones. — Desmareslia aculeata, Halidrys, Brongniariella, Fucus serraius, later Lami- naria sacchar. YZ. “I: 0& Kummel Banke: Trindelen light-ship S:W. by W-. Siz W. 3/4 miles. — 38 meters. — Clay. — No Algæ. NK. */s 93. Kummel Banke. — 28 to 30 meters. — Grayel. — No vegetation: ZB. “I: 04 Trindelens light-ship W. by S.*/:S. 214 miles. — 28 to 30 meters. — Gravel, shells. — Lithothamnion calcareum, Corallina offic. Furcellaria, Rhodomela. FF. *|; 92. Double broom at Trindelen S. by W.:: W. |: mile. — 15 meters. — Stones. — Halidrys, Laminaria sacchar., (Floridec). 31 FE. "/; 92. Trindelen, immediately E. of the double broom. — 9,5 to 11,5 meters. — Stones. — Fucus serratus, (Laminaria, Furcellaria). NI. “193. Trindelen. — 9,5 to 10,5 meters. — Stones. — Halidrys, Fucus serratus, Floridew@: abundant vegetation. TQ. *l 94. At Trindelen light-ship. — Stones, mostly rather small. — Incrusting Algæ, e. gr. Lithoderma, Cruoriella Dubyi, (other Algæ scarce). TR. “le 9. Trindelen light-ship N.W. 11/41 miles. — 23,5 meters. — Stones. — Incrusting Algze e. gr. Lithoderma, Cruoria pellita, Aglaozonia..., (Desmareslia acul., Laminaria sacch.). IV. "5 93. Triple broom S. of Trindelen E. by S. ‘lz mile. — Ca. 11 meters. — Sand. — No vegetation. VV. */; 95. E. of the triple broom S. of Trindelen. — 32 to 36 meters. — Clay-mud (?). — No vegetation. VX. 37 95. Bochers Banke. — 29 meters. — Gravel. — Almost no Algæ (scarce Laminaria sacch., Desmarestia acul., Odonthalia). Kattegat, eastern part. (Ke) FD. |; 92. E. of Flyndergrund, E. of Læsø, Lat. N. 51°1625”, Long. E. 11915”. — 95 to 11,5 meters. — Dark sand. — In spots Zostera. FC. */; 92. E. of Flyndergrund, Lat. N. 57°16'10”, Long. E. 11°166”. — 17 to 18 meters. — Soft bottom. — Molluscs with single Algæ. FB. “: 92. E. of Flyndergrund, Lat. N. 57°1545”, Long. E. 11°18’. — 30 to 36 meters. — No vegetation. EY. ©: 92. Kobbergrundens light-ship E. by S. /; mile. — 13 meters. — Fine sand. — No plants. ZH. */: 04. North end of Groves Flak; Kobbergrundens light-ship W.!/2S. 6%/s miles (?). — 32 meters. — Soft bottom, partly firm clay, also pebbles. — Scarce vegetation: Lami- naria sacch., single Delesseria sinuosa. ZI. */; 04 North end of Groves Flak; Kobbergrundens light-ship W. 4*/s miles. — 26,5 meters. — Stones and gravel, shells. — Almost no Algæ. EX. 22, 92. Groves Flak, Lat. N. 57°730”, Long. E. 11931'40”. — 26,5 meters. — Sand. — Scarce algal vegetation. VZ. 51:95. Groves Flak, Lat. N. 57°618”, Long. E. 11°32’40”. — 24,5 meters. — Gravel and stones. — Incrusting Algæ: Cruoria pellita, Cruoriella Dubyi (Lamin. sacch. overgrown with Mem- branipora, Desmarestia aculeata). IR. */; 93. Groves Flak; Kobbergrundens light-ship N.W. by W. a good 8 miles. — 24.5 meters. — Stones. — Cruoria pellita, (Desmarestia acul.). IS. #/; 93. Groves Flak; Kobbergrundens lightship N.W. a good 7 miles. — 22,5 meters. — Sand. — Desmarestia aculeata, (Laminaria sacch.). IT. /; 98. Groves Flak, S.W. border; Kobbergrundens light-ship N.W. "> N. 7 miles. — 24,5 meters. — Desmarestia acul., Deless. sangvin. (traw)). IU. "21; 93. Same place. — 30 to 38 meters (seine). — Desmarestia acul., (Delesseria sangvin.). EV. 2/; 92. South end of Groves Flak, Lat. N. 57°450’ , Long. E. 11°35’. — 22,5 meters. — Stones. — Laminaria sacch., (Lamin. digit., Desmarestia acul. and viridis, Florideæ.). IL. 1; 93. Fladen, Nidingen N.E.'/2N.a good 4 miles. — 24,5 meters. — Stones and gravel. — Lithothamnia, (Laminaria sacchar., digit., Desmareslia aculeata). 32 IL]. "1; 93. Fladen, Nidingen N.E. 42/; miles. — 28 meters. — Gravel and stones. — Litho- thamnia, (Laminari®, Odonthalia). IM. "2; 93. Fladen, Lat. N. 57°12'50’, Long. E. 11°47. — 16 meters. — Gravel. — Halidrys, Des- marestia acul., Laminaria sacch. ZG. 8h: 04. Fladens light-ship S.E. by S. a good 2 miles. — 18 meters. — Stones. — Halidrys, Florideæ, Laminaria hyperb., Desmar. acul., Corallina off. VY. 5/: 95. Fladen, Lat. N. 57°11’22”, Long. E. 11°44. — 18 meters. — Sand with stones. — Vege- tation not abundant: Halidrys, Desmarestia acul., Polysiphonia elongala. IN. 2/5 93. Fladen, Lat. N. 57°11’10”, Long. E. 11°45’. — 15 meters. — Gravel, stones, — Fucus serralus, Halidrys, Desmar. acul. IO. 2/5: 93. Fladen, Lat. N. 57°10'40”, Long. E. 11°44’40”..— 10,5 to 11,5 meters. — Stones. — Fucus serratus, Halidrys. ZF. *8|; 04. Fladens light-ship S. by E. a good mile: — 22,5 meters. — Stones. — The three species of Laminaria, particularly L. digitata, various Floridee. LE. */; 04. Immediately W. of Fladens light-ship. — 26,5 meters. — Stones. — Laminaria digit., sacch., Fucus serratus, a few Floride. ZE!. **/; 04. Fladens light-ship S.E. by E. ‘le mile. — 19 meters. — Stones. — Laminarie 3 species, various Florideæ e. gr. Odonthalia. — — Fladens light-ship S.E. by E: 1/3 mile. — 15 meters. — Stones. — Floridew, mostly Furcellaria, Halidrys, Fucus serratus. IP. 2/: 93. W. side of Fladen, Lat. N: 57°10’, Long. E. 11°41 20”. — Ca. 21 meters. — Stones. — Desmarestia acul., (Lamin. sacchar., Lithothamnia, Halidrys). IQ. 21:93. W. side of Fladen, Lat. N. 57°9'30”, Long. E. 11°41’40”. — 21,5 to 30 meters. — Stones. — Laminaria sacch. — — — 30 to 38 meters. (seine). — Incrusting Algæ, Desmarestia aculeata. XA. */; 95. Kobbergrundens light-ship N. by W. > W. a good 61}> miles. — 13 meters. — Gravel with stones, shells. — Scarce vegetation: Halidrys, Chorda Filum, various Floridec. IK. "I; 93. Lille Middelgrund, the beacon S.W. by W. 1?/s miles. — 17 to 19 meters. — Gravel. — Lithothamnia. II. /: 93. Lille Middelgrund, the beacon S.E. by S.1l2 S. 5/6 mile. — 14 meters. — Stones. — Fucus serratus, (Furcellaria). EU. "2, 92. Lille Middelgrund, Lat. N. 56°5628’, Long. E. 11°51'52°. — 14 meters. — Gravel with stones. — Corallina offic., (Halidrys, Chorda Filum, Lithothamnion Lenormandi). ET. "2, 92. Lille Middelgrund, Lat. N. 56°56'25°, Long. E. 11°5240”. — 12 meters. — Stones, gravel. — Fucus serratus. ES. "217 92. S.W. of Lille Middelgrund. — 24,5 meters. — Coarse brown sand. — No vegetation (1 specimen of Laminaria sacchar.). IH. "|; 93. The beacon at Lille Middelgrund N.W. by N.!» N. a good 4 miles. — 20 to 28 meters. — Stones and gravel. — Lithothamnia, (Laminaria sacchar., Desmarestia acul.). IG. '%5 93. The beacon at Lille Middelgrund N.W.‘/s N. 6 miles. — 36 meters. — Sand and clay-mud. — No vegetation. ER. ©1192. Fyrbanken, the beacon at Anholt Knob S. by W 154 miles. — 28 meters. — Sand with stones. — Scarce algal vegetation, (mostly Desmarestia viridis). EQ. ©1792. At the beacon at Anholt Knob. — 9,5 to 16 meters. — Scarce algal vegetation. IF. 2}; 93. Rode Banke, the beacon at Anholt Knob N.W. by W. 1}: W. 8 miles. — 31 meters. — Red clayey sand. — No vegetation. IE. "I, 93. Near Rode Banke, Anholt Knobs light-ship N.W. 7 miles. — 34 to 36 meters. — No vegetation. RU. !/s 94. Tylo light-house E.S.E.!l» E. scarcely 9 miles. — 26,5 meters. — Clay-mud. — Scarce Floridee. RV. !/s 94. Tylo light-house S.E. "> S. 54/2 miles. — 20,5 meters. — Stones. — Nearly no Algæ. RT. "Is 94. Store Middelgrund, Lat. N. 56°37,5°, Long. E. 12°4,5. — 24,5 meters. — Sand. — No vegetation. ID. 15 93. Store Middelgrund, Lat. N. 569345', Long. E. 12°5,5. — 19 meters. — Stones. — Corallina offic. IC. "|; 93. Store Middelgrund, Lat. N. 56°33'20”, Long. E. 12°5'10”. — 10,5 meters. — Stones. — Fucus serratus, (Furcellaria). IB. 2/: 93. Store Middelgrund, Lat. N. 56°33’, Long. E. 12°5. — 11,5 to 13 meters. — Fucus ser- ratus, Halidrys, Furcellaria, Laminaria digitata. IA. "|; 93. Store Middelgrund, Lat. N. 56°32'50", Long. E. 12°5 20”. — 11,5 to 13,5 meters (trawl). — Fucus serratus. — 22107. Nearly in the same place. — Stones with incrusting Algæ, Cruoria pellita, Litho- thamnia, and Delesseria sangvinea, Desmarestia acul., D. viridis, Corallina offic. HX. "1; 93. Store Middelgrund, south side, Lat. N. 56°3230”, Long. E 12°3’40”. — 17 meters. - Stones. — Fucus serratus, Halidrys, Corallina offic. HY. /5 93. Store Middelgrund, south side, Lat. N. 56932207, Long. E. 12°5'20°. — 15 meters. — Reddish gravel. — Fucus serratus. | HZ. "I; 93. Store Middelgrund, south side, Lat. N. 56°32’, Long. E. 12°5 40”. — 25,5 meters. — Few Algæ. GI. I, 92. Ostindiefarer Grund. — 4 to 8,5 meters. — Stones. — 4,5 meters: Halidrys, Lami- naria digitata, Fucus serratus, Floridew. — 4 to 7,5 meters: Florideæ, mostly Phyllophora membranifolia, Furcellaria, (Fucus serratus). OO. "|; 94. Søborghoved Grund. — 8,5 meters. — Stones. — Fucus serratus, Halidrys, Phylloph. membranif., (Phylloph. Brodiæi, Lithothamnia, Corallina off., Laminaria digit., sacchar.). Kattegat, central Part. (Km) TT. 410 94. W. of Dvalegrunde, Læsø Rendes light-ship S.E. ‘2 E. 2?/s miles. — 7,5 meters. — Coarse sand. — Zostera. FI. "|; 92. Dvalegrund, by the double broom. — 4,5 meters. — Sand with shells. — No Algæ. BO. */s 91. By the broom at Stensnæs. — 5,5 meters. — Sand. — Narrow-leaved Zostera. BN. #8 91. Asaa W. by N., the broom at Stensnæs N.N.E. — Ca. 9,5 meters. — Sandy clay- mud. — Scarce vegetation: Halidrys, (Polysiphonia nigresc.). TS. 1h10 94. Off Hov, Lat. N. 57°21/, Long. E. 10°27’. — 7,5 meters. — Clayey sand with few stones. — Zostera, Halidrys, Corallina offic. VQ. */7 95. Svitringen, Lat. N. 57°, Long. E. 10°35’. — 11,5 meters. — Sand. — Scarce Zostera. VS. 2, 95. Læsø Rende, Ryggen, the light-ship S.W. 14/2 S. 2%/4 miles. — 18 meters. — Sand. — No vegetation. KE. 155 9. By the broom at Sondre Ronners Flak. — 7,5 meters. — Sand without vegetation. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 5 En VR. 7); 95. Læsø Rendes light-ship N.W. by N.!ls N. 3%/4 miles. — 20,5 meters. — Soft bottom without vegetation. XF. 4; 95. Sondre Ronners beacon E.N.E. 4 miles. — 8,5 meters. — Sand with few stones. — Zostera with Fucus serratus, (Ahnfellia, Corallina offie., Cystoclonium). KE. %/; 93. Læsø Rendes light-ship N.W. by N.1/:N. a good 14 miles. — 6,5 meters. — Sand with pebbles. — Fucus serratus, very broad, (Fuc. vesiculosus, Zostera). XE. °/- 95. Near the broom at Silderon. — Mostly 2 to 4 meters. — Sand. — Zostera, (Fucus serratus). FA. #/; 92. E.S.E. of Hornfiskeron, S. side of Læsø. — Within 1/2 meter line bare sand, out- side this line Zostera-vegetation. EZ. 2}: 92. W. of Mellemflak, S. of Læsø. — 4 meters. — Sand. — Zoslera. YY. “/; 04. From the broom at the N. end of Kobbergrund northwards. — 4,5 meters. — First bare sand, later single stones with Fucus serratus. ZC. °° 04. The broom at the N. end of Kobbergrund N.E. 1,5 miles. — 4 to 45 meters. — Sand. — Zostera in spots, with various Algæ, Fucus serratus. ZC}. “|; 04. Inside Kobbergrund. — 5 meters. — Sand. — Chorda Filum, Spermatochnus. ZD. “|; 04. Kobbergrundens light-ship E.S.E. 4 miles. — 7,5 meters. — Sand. — Zostera with Fucus serratus, large, broad plants. XD. I; 95. The broom at Sildergn, N.5%/: W. nearly 8 miles. — 9,5 meters. — Sand. — Zostera (with Fucus serratus). XB. */; 95. Kobbergrundens light-ship N.°lı E. 8°] miles. — 12 meters. — Stones. — Fucus ser- ratus, Furcellaria a. 0. Floridee. BM. */s 91. The broom at Muldbjerg Grund W.?/s N. a good 2 miles. — 8,5 meters. — Sand (?) with stones. — Zostera and Halidrys. VP. 7/; 95. The broom at Muldbjerg Grund N.N.W. 1/3 N. 51/2 miles. — 7,5 meters. — Fine sand. — Scarce Zostera. BL. */s 91. Mariager Fjord S.W. by W.#/s W., Muldbjergene N.W.*/s N. — 9,5 meters. — Sand. — Zostera. VO. 7/7 95. Off Stevn in Mariager Fjord. — Mud with Mytilus, scarce Ceramium rubrum. VN. 1:95. The buoy at the mouth of Randers Fjord N.W. 31/3 miles. — 8,5 meters. — Sand. — Loose Furcellaria in abundance, very scarce Zostera. VM. "|; 95. The buoy at Tangen N.E.°/: E. 47/4 miles. — 8 meters. — Sand. — Loose Furcel- laria in abundance. BK. */s 91. By the buoy at Tangen. — 7 meters. — Coarse sand with stones. — Zostera, rather narrow-leaved with broad Fucus serratus, (Furcellaria). VL. ! 9. The buoy at Tangen N.N.W. 51}: miles. — 10,5 meters. — Sand. — Dead Zostera- leaves, loose Furcellaria. NC. “93. E. of Tangen, Fornæs light-house S.1/: W. 7 miles. — 8,5 meters. — Sand with stones. — Fucus serratus, Laminaria digitata, Furcellaria, Corallina offic. BI. */s 91. Gjerrild Flak; Fornæs light-house S. by E.1/;E. a good 6 miles. — 7,5 meters. — Sand with sparse spots of Zostera, (Furcellaria). BH. */s 91. Off Gjerrild Klint, !/; mile from land. — 7,5 meters. — Bare sand with spots of vegetation: Zostera and Furcellaria, (Fucus serratus.) VK. 1:95. Fornæs light-house S.1/: W. 2?/; miles. — 12 meters. — Pebbles. — A clump of Halidrys. VK" FK. gi FL. FM. FN. ND. HT. HU. XC. bK. bL. KF" KF?. KG. HV. RQ. FO. NB. BB: NA. KH. MZ. 35 . Ar 95, "Is mile W. by N. of VK. — 10,5 meters. — Sand and pebbles. — No vegetation. 15/1, 92. Aalborg Bugt, Lat. N. 56°56,5', Long. E. 10°45,5°. — 12 to 13 meters. — Sand. — No vegetation. 15/, 92. Lat. N. 56°56,5', Long. E. 10°46,8°. — 9,5 meters. Sand, alternately bare and cov- ered with Zostera. 15], 92. The buoy at Tangen W. by S.4/2S. a good 8 miles. — 13 meters. — Sand, shells. — No vegetation, only single specimens of Corallina offic. 151; 92, Fornees light-house S. 1/2 W. nearly 14 miles. — 12 meters. — Sand with stones. — Halidrys. 1/9 93. Fornæs light-house S. by W. 1}: W. 11%: miles. — 11,5 to 13 meters. — Sand with single stones. — Very scarce vegetation: Lithothamnion, Halidrys. 25 93. Fornæs light-house S.W.°/s W. 7 miles. — 16 meters. — Sand and pebbles. — No vegetation. 3/5 93. Fornæs light-house S.W. by W.1/4 W. nearly 13 miles. — 17 meters. — Sand with stones. — No vegetation. 517 95. The double broom at the end of Anholt Nordvest Rev S.S.E. 1}: E. 11 miles. — 11,5 meters. — Gravel with stones. — Halidrys. 2/7 07. 15 miles N.W. by W. 14/2 W. of Anholt light-house. — 15 meters. — Stones. — Very few Algee (Polysiphonia elong., Desmarestia viridis.). 2/, 07. 13 miles W. by N. 1/4 N. of Anholt light-house. — 19 meters. — Sand. — No vegetation. 16/; 93. Anholt Nordvest Rev, 2 miles of the broom. On the reef and on both sides of it bare sand. 16/; 93. N. of Anholt, E. of Nordvest Rev. — Ca. 8 to 13 meters. — Bare sand, here and there spots of loose Furcellaria partly mixed with Polyides. 18, 93. W. of the double broom by Ronnelobet by Anholt. — 4,5 meters. — Sand with stones. — Fucus serratus. 3/5 93. Anholt light-house N.E. by E.”/6 E. T1}: miles. — 5,5 to 7,5 meters. — Sand. — No vegetation. Kattegat, southern part. (Ks) 51/7 94. Fornæs light-house W.1/4S. 1 mile. — 17 meters. — Coarse sand. — Almost no vegetation. 15/7 92. Off Havknude. — 5,5 to 6,5 meters. — Sand. — Very scarce vegetation (Fucus ser- ratus, Floridee). 1819 93. Havknudeflak. — 7,5 to 8,5 meters. — Sand with stones. — Vegetation in spots: Furcellaria, (Fucus serratus, Brongniartella, Zostera). 15], 92. Jessens Grund, by the buoy. — 4 meters. — Stones. — Fucus serratus, (Laminaria digitata, Florideæ, Halidrys). 18/9 93. Hjelm light-house S.W. by S.4/4S. 541 miles. — 17 to 18 meters. — Fine gravel. — No plants. 1,93. The broom at Jessens Grund N.N.W.1/1 W. 34/2 miles. — 18 meters. — Stones. — No vegetation. 18/9 93. Hjelm light-house S. by E. 2 miles. — 10,5 to 13 meters. — Gravel (?) with stones. — Chorda Filum, (Corallina offic.). BG. EP: ZN. RS. RR. ZO. EO. EN. EM. OP. EK. EJ. HQ. BANS 21/8 91. 1!/s miles N. by E. 1/2 E. (?) of Hjelm light-house. — 38 meters. — No vegetation. 2; 92, Pakhusbugt by Anholt. — 19 meters. — Sand. — Loose Furcellaria. 197; 05. Anholt light-house N.E. "> N. 12 miles. — Gravel and sand. — No vegetation. 11, 94. Fornes light-house W.'/»S. 15 miles. — 20,5 meters (?). — No vegetation. 11: 94. Fornæs light-house W. "/> S. 7 miles. — 17 meters (?. — No vegetation. 10), 05. Lat. N. 56°28'15’”, Long. E. 11°231/s‘. — 15 meters. — No vegetation. 11; 92. The light-house S. by E. 9,1 miles. — 26,5 meters. — Clay-mud with shells. — No vegetation, on Modiola some few Lithothamnia and Antithamnion plumula. . 5 93. Briseis Grund. — 7,5 to 13 meters. — Stones. — Fucus serratus, Furcellaria, (Hali- drys, Laminaria digitata). ; . 1: 94. Near Briseis Grund, Lat. N. 56°185, Long. E. 11°17,7. — 20,5 meters. — Stones (gravel?). — No vegetation. . 12, 94. Hastens Grund, the buoy S.W. by W. 1°/s miles. — 13 to 14 meters. — Gravel and stones. — Fucus serratus. . 1:94 Hastens Grund, the buoy S.W.!/S. 1 mile. — 16 meters. — Gravel. — Fucus ser- ratus, (Halidrys). . 1,94. Hastens Grund, the buoy N.W. by W. ’/s mile. — 9,5 meters. — Stones. — Lami- naria digitata, Halidrys. . 194 Schultz’s Grund, the buoy S.W. !/s mile — Sand with stones. — 9,5 meters. — Abundant vegetation: Halidrys, Laminaria digitata, (Fucus serratus, Furcellaria, scarce Zostera). 7. 12494. The beacon on Sjællands Rev S.E.1/: E. 12/3; miles. — 17 to 19 meters. — Sand. — No vegetation. . #494 W. of the beacon on Sjællands Rev. — 9,5 meters. — Stones. — No vegetation. . 21, 94. Nearer land. — ca. 4 meters. — Stones. — Fucus serratus. - 1792. Sjællands Rev, E. side of Mellemrevet. — A good 4 meters. — Stones. — Fucus serratus, (Furcellaria a. 0. Floridee). . 4); 92. Sjællands Rev, in the Snekkelob. — 8 meters. — Stones. — Fucus serratus, (Floridec.) . "1194. E. of Lille Lysegrund, Hesselo light-house S.E. by S.1/:S. 81/5 miles. — 20,5 meters. — Sand. — No vegetation. . “49% S.W. side of Lille Lysegrund. — 17 to 18 meters. — Brown Sand. -— No vegetation. - "I: 92. N. of Lysegrund, 2?/s miles N.W. "> W. of the buoy. — 20,5 meters. — Clayey sand. — No vegetation. “1:92 Lysegrund, '/2 mile N. of the 2 meters shallow. — 14 meters. — Stones. — Scarce Lithoderma, otherwise no Algæ. — 17 meters: Polysiphonia violacea, Ectocarpus. 4), 92. Lysegrund, '/s mile N. of the 2 feet shallow. — Ca. 9,5 meters. — Stones. — Fucus serratus, (F. vesiculosus, Furcellaria). 121, 94. Lysegrund, near the 2 meters shallow. — 6 meters. — Stones and gravel. — Fucus serratus, Halidrys, Laminaria digitata. 11), 92. W. side of Lysegrund. — 14 meters. — Sand. — No vegetation. uj; 92 Lysegrund, near the triple broom. — 4 to 5,5 meters. — Stones. — Fucus serratus, (Fucus vesiculosus, Floridee). ‘Is 93. E. side of Lysegrund. — Ca. 9,5 meters. — Sand. — Single clumps of Fucus serratus (and F. vesiculosus). 37 HP. 5: 93. S. E. of Lysegrund, 4!» miles N.W. by W. !/s W. of Hesselo light-house. — 25,5 meters. — Furcellaria, (Fucus serratus). RO. 31/7 94. W. of Hesselo. — 20,5 meters. — Sandy clay-mud. — Desmarestia viridis, otherwise no plants. HR. 5/: 93. S. of Hesselo. — 19 meters. — Soft bottom. — No vegetation. RN. “4/7 94. By the Sydostrev by Hesselg. — 21,5 meters. — Gravel. — Desmarestia viridis, otherwise no plants. B. "I 90. Hesselo light-house N.W. ‘4/3 N. a good 3 miles. — 24,5 to 32 meters. — Soft bottom. - No vegetation. A. "|; 90. Hesselo light-house N.W. 5/4 N. nearly 4 miles. — 28 meters. — Soft bottom. — Loose Dilsea edulis, shells of Cyprina, Aporrhais a. o. with Lithothamnia and boring Algæ. C. 7, 90. 5 miles N. of the buoy at Grønne Revle. — Ca.19 to 22,5 meters (?). — No vegetation (only some few Desmarestia viridis on Buccinum and loose Dilsea edulis). GH. 2}; 92. Lat. N. 5691/40”, Long. E. 11°301/>. — 19 meters. — Clay-mud. — No vegetation. aU. ®/s 06. Lumbsaas mill S. 32° W. 2 miles. — 13 meters. — Sand with few stones. — Fur- cellaria, (Zostera, Fuc. serratus, Polyides, Ectocarpus). — Another dredging: Larger stones with Furcellaria, Fuc. serratus, Laminaria digitata. D. "I, 90. 1 mile N. of the buoy at Grønne Revle. — 11,5 meters. — Stones. — Abundant vege- tation: Fucus serratus, Furcellaria, (Zostera, Phylloph. Brodiei, Laminaria digit., Polyides, Ahnfeltia . . .). HO. */5 93. Hesselo light-house W. by N. "4 N. 12 miles. — 22,5 meters. — Clay-mud with - stones. — Lithothamnia. RM. ‘1/7 94. Off Raageleje, Lat. N. 56°10'10”, Long. E. 12°51/o’. — 19 meters. — Sand. — No ve- getation. RL. °°; 94. The buoy at Ostindiefarer Grund S.E. by E. 21} miles. — 15 meters. — Floridew, particularly Cystoclonium, Furcellaria, Phyllophora, Chondrus, (Laminaria digitata, L. saccharina, Fucus serratus). EJ. I; 92. Isefjord, midway between Korshage and Spodsbjerg. — Ca. 4,5 meters. — Sand almost without vegetation. EH. "|, 92. Off Lynæs, ls mile W. of the broom. — 4,5 meters. — Sand with pebbles. — Chorda Filum, (Zostera, Rhodomela, Polysiphonia elongata and nigresc.). NL. %l9 93. 15/6 miles W. 7/2 S. of Lynæs. — 4 meters. — Sand with Zostera. NM. %l 93. Roskilde Fjord off Nordskov, Kulhus mill W."/3 N. 1°/4 miles. — 7,5 meters. Mud: with broad-leaved Zostera. PQ. 31594. E. of Bogenæs in Roskilde Fjord. — 3 meters. — Stones. — Zostera, Mylilus, Polysiph. nigresc., Phylloph. Brodiei. PQ: 3/5 94. Between Bogenæs and Boserup. — Stones. — Zostera, Potamogelon pectinalus, Polysiphonia, Ceramium, Spirulina versicolor. Samsø area. (Sa) KK. 1:93. Klorgrund, S. of Hjelm. — 6,5 to 8,5 meters. — Stones. — Fucus serratus, Hali- drys, (Fucus vesic.). KI. 17:93. Hjelm light-house N. "> W. 24/2 miles. — 13 meters. — Stones. — Lithothamnion norvegicum, Corallina offic. 38 KL. "i/s 93. Bjarkes Grund, S.W. of Hjelm. — 5,5 to 7,5 meters. — Stones. — Halidrys, Lami- naria digilala, Fucus serratus. KM. "I; 93 Hjelm light-house E. by N.*/s N. a good 3!» miles. — 9,5 to 17 meters. — Stones. — Halidrys, Fucus serratus, (Laminariæ . ….). PJ. 21, 94. Ebeltoft Vig, Ellemands Bjerg S.W.3°/s miles. — 13 meters. — Clay-mud with stones. — Scarce Floridew. FR. 16/7 92. Near Pikkelgrund in Ebeltoft Vig. — 5,5 meters. — Soft bottom. — Dead Zostera- leaves, loose Algæ. FQ. “|; 92. E. side of Ebeltoft Vig. — 8 meters. — Soft bottom. — Broad-leaved Zostera and Chorda Filum, (loose Algæ). MY. 15/9 93. Sletterhage light-house N.W. by N. 3/41 miles. -- 9,5 to 14 meters. — Sand with stones. — Halidrys, (Laminaria sacch., L. digit., Fuc. serratus, Corallina off). FT. '% 92. Klepperne, at the N. end of Samsø, inside the double broom. — 5,5 meters. — Halidrys, (Laminaria digitata, Florideæ, in particular Cystoclonium). PH. ”|, 94. Lindholms Dyb W. of Vejrg, 41s mile S. of the double broom. — 20,5 meters. — Mud with stones. — Lithothamnion norvegicum and Cruoria pellita. FS. 1%, 92. Vejro Sund, N. of Bosserne. — 4 to 19 meters, (dredging up the slope). — Stones. — Abundant vegetation: Fuc. serratus, (Fuc. vesic., Lamin. digit., L. sacch., Chorda Filum, Halidrys, Floridee). PG. **/, 94. The beacon on Hatter Rey E. by S. */4S. 12/s miles. — 7,5 to 8,5 meters. — Stones. — Laminaria digitata, (Lam. sacch., Florideæ, Zostera). OZ. 1194. W. of Gniben, Sjællands Odde point in E.*/sS. l/s miles. — 14 meters. — Sand without vegetation. PA. "14 94. Near Albatros, on the W. side of Sjællands Odde. — Ca. 7,5 meters. — Stones. — Furcellaria, (Laminaria, Fucus serratus). GD. *"I7 92. 11} miles N.E. by N. of Sejerø light-house. — 11,5 to 14 meters. — Stones. — Fucus serratus, (Laminaria digit., Florideæ in particular Furcellaria, Delesseria sangvin., sinuosa, scarce Zostera. GE. *"/7 92. Sejerø light-house S.W. by S. 1 mile. — 7,5 to 9,5 meters. — Stones. — Halidrys, (Zostera, Fuc. serratus, Lamin. digit., Florideæ, in particular Furcellaria). PB. 194. Sejerø Bugt, Sejerø light-house N.W. by W. 2/3 W. nearly 7 miles. — 14 meters. — Clay-mud without plants. , PC. 2211 94. Between Sejerø and Ordrups Nes, the point of Ordrups Nes E.S.E. nearly 2 miles. — 4 meters. — Stones. — Fucus serratus, Laminaria digitata, Floridee. YV. 2/6 04. The light-buoy at Hatterbarn N. 21}> miles. — 15 meters. — Stones. — Florideæ, in particular Furcellaria, Delesseria sinuosa, sangvin., Polysiph. elongata, and Laminaria digit. and sacchar. PD. "1194. S. of Sejerø, Lat. N. 55°48’, Long. E. 11°5. — Ca. 13 meters 9%). — Sand without vegetation. PE. “194. Refsnæs light-house S. by E. 2 E. 1!Jı miles. — 23,5 meters. — Clay-mud, gravel and pebbles. — Laminaria digitata, Desmarestia acul. PF. *4194 The light-buoy at Refsnes S.E. by E. a good half mile. — 18 to 20,5 meters. — ? with stones. — Scarce vegetation: Florideæ, in particular Delesseria sinuosa, and Des- marestia acul, 39 MP. Jo 93. Falske Bolsax. — 11,5 to 13 (to 19) meters. — Stones. — Laminaria sacchar., Flo- rideæ, (Laminaria digit., Fucus serratus). DK. "21592. Bolsaxen, N.E. of the broom. — 15 to 15 meters. Stones. — Halidrys, Lami- naria digil., (Desmar. acul., Floridee). AH". ¥/s 91. Lillegrund by Fyens Hoved, by the northernmost broom. — 9,5 meters. — Stones. PK. AS. BD. MX. FX. MV. BC. MU. Abundant algal vegetation: Furcellaria, Fuc. serratus, Lamin. sacchar. . 2/3 91. Same reef, by the middelmost buoy. — 7,5 meters. — Stones. — Fucus, (Laminaria digitata, Furcellaria). 21/8 91. Of Sletterhage, ca.*/2 mile. — 14 meters. — Stones. — Lithothamnion norvegicum, (Corallina offic., Cruoria, Brongniartella). 4/591. Off Sletterhage, ca.*/s mile. — 10 meters. — Stones. — Halidrys, (Corallina of]. Lithothamnion spp., Chorda Filum). . 181, 92. S. side of Begtrup Vig. — 5,5 meters. — Dead Zoslera-leaves, living Zoslera, Chorda Filum. . 5 98. Sletterhage light-house S.E.*/4S. 5 miles. — 15 meters. — Sandy clay-mud with small pebbles. — No vegetation. . #8 91. S.W. of Skodshoved, nearly 1 mile. — 4 meters. — Sand. — Fucus serratus and vesiculosus, (Halidrys, Zostera). . %l4 94. Aarhus Bugt, Ryes Flak. — 4,5 meters. — Small pebbles and gravel. — Spots of Zostera, Fucus vesiculosus, Fuc. serratus, Halidrys. . 18/8 91. W.N.W. of Skodshoved, ”/s mile of land. — 17 meters. — Clay-mud without veg. . 3/494. Kalo Vig, Skodshoved S. by E. 1 mile. — 5,5 to 11,5 meters. — No vegetation. . 88 91. Off the entrance to Knebelvig. — 9,5 meters. — Mud. — Zostera in spots. . 3/494. Kalø Vig, Skodshoved point S.W. 2°}: miles. — 5,5 to 11,5 miles (?) — Zostera. . 31494. Kalo Vig, by Kalo. — 9,5 meters. — Mud without vegetation. 23/, 94. E. side of Wulffs Flak. — 9,5 to 13 meters. — Clayey sand. — Fucus serr., Des- marestia acul., Lithothamnion glaciale, Corallina off. a. 0. Floridee. . 8/7 92. E. side of Hesbjerg Grund. — 6,5 meters. — Sand with small pebbles. — Zostera, (Fucus vesic., Halidrys, Furcellaria). 211, 94. E. side of Norsminde Flak, the broom in S. "> mile. — 5,5 meters and some more. — Sand with stones. — Zosiera with Chelopteris a.o., Rhodomela, Fucus vesic. and serr., (Halidrys, Corallina off.). 18/8 91. W. side of Meilgrund. — 4 to 5,5 meters. — Zostera with Fuc. serratus, (Halidrys, Ahnfeltia). 21/8 91. Tune light-house S. ?/s E. 3 miles. — 15 meters. — Sandy clay-mud. — Scarce vege- tation, mostly Polysiphonia elongata forma. 18/9 93. N. side of Tung Rey. — 7,5 to 11,5 meters. — Sand. — Zostera. 18/, 92. Off Dyngby Hage, Tunø light-house E.S.E. 51} miles. — 6 meters. — Sand. — Floride®, in particular Furcellaria, (Zostera, loose Halidrys). 189 93. Kirkegrund S.W. of Tung. — 7,5 to 9,5 meters. — Zostera with scarce Florideæ, mostly Furcellaria. 21/8 91. Abreast of Hoy Ron, the broom N.E.!sE. "|, mile. — 5,5 meters. — Sand and mud with stones. — Dense Zostera-vegetation (with Fuc. vesic. and Furcellaria). 18/9 98. Abreast of Søby Rev, Kolse Nak point S.W. by W. 1/6 W. 3'l2 miles. — 6,5 to 7,5 meters. — Dense broad-leaved Zostera. BB. “91. By the buoy at Sogrund. — 3 to 4 meters. — Sandy mud with single stones. — Dense broad-leaved Zostera, (Fucus vesiculosus). AT. 7%. 91. Svanegrund. 4/2 mile E.S.E. of the broom at its S.E. side. — 45 meters. — Gravel and sand). — Fucus serratus, (Furcellaria, Halidrys). BA. /; 91. Skomagergrund, near the double broom. — 8.5 meters. — Soft bottom. — Dense broad-leaved Zostera-vegetation. MT. :°/s 93. Horsens Fjord. by the broom W. of Aldere. — 4 to 11,5 meters. — Broad-leaved Zostera with Laminaria saccharina and Chorda Filum. AZ. is 91. S. side of Sondergrund S. of Hjarnø. — 9.5 to 11,5 meters. — Mud. — Pure Zostera- vegetation. aV. °/s 06. Vestborg light-house E. by S. 51: miles. — 8,5 to 9,5 meters. — Sand. — 1) Broad- leaved Zostera, Halidrys, Lamin. sacchar., Fucus vesic. — 2) Zostera and dead Zostera- leaves. with many loose Algæ, in particular Ahnfeltia. AO. "|; 91. 1!/s miles SE. by E. of the S. point of Endelave. — 7.5 meters. — Zostera (Fucus serratus). MR. “93 Æbelø light-house W. by S. #2 S. nearly 8 miles. — Ca. 26 meters. — Soft bottom. — No vegetation. MQ. "Is 93. S. of Paludans Flak, Vestborg light-house N. "> E. 4 miles. — 11,5 meters. — Sand with stones. — Fucus serratus, Furcellaria, ‘Laminaria digit.. Corallina off. Halidrys, scarce Zostera). aX. °/s 06. At the south side of Endelave. — 45 meters. — Sand. — Zostera, in spots, with single Fucus vesic. and F. serratus: numerous loose Alsæ between the Zosiera, on the sand bottom. MS. “k: 93. S. of Klophagen, Æbelø light-house S.S.W. ls W. 5°: miles. — 15 meters. — Sandy mud with stones. — Florideæ, mostly Polys. nigresc., and Desmarestia acul., Chorda Filum. AY. #: 91. By the broom at Ashoved. — 95 to 11,5 meters. — Sand with stones. — Zostera, Fucus vesic., F. serrat., Furcellaria. FY. */; 92. 1 mile N.E. by E. of the point of Bjornsknude. — 5,5 meters: — Sand with stones. — Fucus vesiculosus, (F. serratus, Lamin. digit., Zostera, Halidrys). OA. Is 4. E. of the buoy N. of Æbelø. — 7,5 meters. — Zostera, (Fucus vesicul). AJ* "Is 91. By the N. side of Æbelø. — 4 meters. — Stones. — Fucus serrat., Furcellaria, Ahn- feltia, Lamin. digit. GB. |; 92. Æbelø light-house W. 3*/s miles. — 17 to 18 meters. — Soft bottom. — No vegetation. DJ. "Is 95. E. of Æbelø. — 7.5 meters. — Sand with stones. — Fuc. serratus, Furcellaria, (Fuc. vesicul.). t GC. I; 92. Æbelø light-house W. by N.'/s N. 61; miles. — 13 meters. — Sand with stones. — Desmar. aculeata. 'Floridee, dead leaves of Zostera). NZ. “Is 4. Off Torress, Fyns Hoved E. ‘lc S. 5°: miles. — 45 meters. — Fucus serratus, F. vesic., Furcellaria. aY. °/s 06. Fyns Hoved E.*/:N. #1: miles. — 8.5 to 9,5 meters. — Sand with stones. — Zosfera. Fucus vesicul., F. serratus. | aZ. “ls 06. Fyns Hoved E.*/: N. 542 miles. — 4 to 5,5 meters. — Sand with stones. — Fucus vesic. and serratus, (Zostera with loose Algæ). NY. “is 94 Off the entrance to Odense Fjord. — 6,5 meters. — Fucus serratus and vesicul. Floridee, in particular Furcellaria, and Zostera. 41 Little Belt. (Lb) X. 2/4 91. Near the double broom at Bjornsknude. — 9,5 meters. — Clayey sand. — Zostera, (Fuc. serralus, Furcellaria). GA. 2017 92. W.N.W. of Æbelø, 2!/s miles. — 18 meters. — Clay-mud. — No vegetation. AU. AM. EF EC 19/8 91. Vejle Fjord, off Barritskov, 1 mile off land. — 17 meters. — No vegetation. . 8/3 91. Vejle Fjord, off Rosenvold. — 19 meters. — Mud. — No vegetation. . 7 92. Near the triple broom at Kasser Odde. — 6,5 meters. — Sand with stones. — Fucus vesicul. and serratus, Halidrys, Furcellaria, Laminaria digit. . #/ 91. Trelde Nees N.W. by W. 4 miles. — 13 meters. — Sandy mud. — No vegetation. . 4/3 91. Stavrshoved W. by S. 1 mile. — 17 meters. — Soft bottom. — No vegetation. . M/s 91. W. side of Baaring Vig. — 7,5 meters. — Sand (?). — Furcellaria, Zostera. . "|, 92. Trelde Nees N.N.W. 3 miles. — 13 meters. — Mud with dead Zostera-leaves. — Few Floridee. . 2/5 94. Off Stavrshoved, ‘/s mile off land. — 9,5 to 11,5 meters. — Stones. — Laminaria saccharina a. 0. | 14/8 91. Sand bank N.E. of Fredericia. — 5,5 to 6,5 meters. — Bare sand. . #8 91. Off the N. end of the wall at Fredericia. — 4 to 5,5 meters. — Stones. — Fucus vesiculosus, (Fuc. serrat., Chorda Fil., Zostera). . 217 00. Lyngsodde S. by W.%/4 W. 1 mile. — Ca. 19 meters. — Stones. — Delesseria sang- vinea, Phylloph. membranifolia. . 2/3 94. E.N.E. of Middelfart. — 15 meters. — Clay with stones. — Laminaria digit., sacchar., (Floridee, in particular Phylloph. membranif. and Deless. sinuosa). . 1/7 00. Nearly the same place. — Ca. 19 meters. — Stones. — Laminaria sacch., Deless. sangv., Desmar. viridis, Phylloph. membranif. . 125 94. Between Middelfart and Kongebroen. — 15 to 19 meters. — Stones, and clay with pebbles. — Laminaria digit. and sacchar., Desmarestia acul. . 8/6 92. By the N.E. side of Feng Kalv. — Stones. — Laminariæ and Floridee. . 3/3 94. S. of Fænø Kalv. — 14 meters. — Soft bottom. — No vegetation. . 126 92%. Fænø Sund, S.E. of Hindsgavl. — Below the Zostera-zone stones with Florideæ and Laminarie. 1,21, 92. S. of Hindsgavl. — 9,5 to 11,5 meters. — Stones. — Laminariæ and Floridee. . 10/8 92. S. end of Feng Sund. — 13 meters. — Desmarestia acul., Ectocarp. silicul., Lami- narie, Floridee. . 11/6 92. Between Midskov and Feng. 1) and 2). In the middle of the Belt. — 54,5 to 56 meters. — Stones. — No attached Alsæ, but loose fresh Florideæ. 3) More westerly. — 34 meters. — Stones. — Fresh Algæ, uncertain whether attached. 4) More westerly. — 13 meters. — Stones. — Laminarie, Floridee, Desmarestia acul. 5) E. of 1). — 28 to 36 meters. — Clayey sand with dead shells. 6 and 7). More easterly. — 24,5 and 13 meters. — Sand with stones. — Desmarestia aculeata. 8) More easterly. — 11,5 meters. — Zostera, (Florideæ). . 1% 92. S. of Fæno. — Ca. 5,5 meters. — Zostera with single Fucus vesiculosus and Lami- naria digitata. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 6 OD. DH. OE. DG. OF. DF. DE. DD. DC. DB. CD. CE. DA. CF. DY. LG. DX. LE. CC. CZ. CB. CX. CY. CA. CG. BZ. CU: CV. — 2 = 5]; 94. S. of the broom at Stenderup Hage. — 17 meters. — Gravel. — Scarce vegetation (Phylloph. Brodiei, Furcellaria). u, 92, Near Flækojet, the broom at Stenderup Hage N.N.E. 1 mile. — 11,5 to 15 meters. — Stones (?). — Scarce Algæ (Desmarestia aculeala, Floridee). 23/, 94, At the N. side of Brandso. — 85 meters. — Zostera, (Furcellaria). 1}: 92, Off Ivernes. — 5,5 meters. — Sand with stones. — Zostera, (Fucus vesie., Floridee). 21, 94. Fyrrenden, Baago church E. by N. ‘is N. 1'/ miles. — 13 meters. — Mud with dead Zostera-leaves, scarce Floridee. 11}; 92. Remmen, E. of Baago. — 5,5 meters. — Sand (?) with a few stones. — Zostera. (Fucus vesic.). 10/, 92. By the broom at Thorg. — 5,5 meters. — Sand. — Zostera, (Ceramium Rosenvingii, Rhodomela). 10/; 92. N. side of Thoro Banke. — 7,5 meters. — Sand. — Fucus vesic., Zostera. 1:92. Aakrog Bugt, off Brunshus. — 5,5 meters. — Sand (?) with stones. — Fucus vesicul., (F. serratus, Furcellaria). 191, 92. Lillegrund, W. of Helnæs, near the buoy. — 7,5 meters. — Stones. — Furcellaria, (Fuc. serratus ...). i 21/8 91. Helnæs Hoved Flak. — 4 meters. — Sand with stones. — Zostera, (Fuc. vesiculosus). 4/9 91. S. of Helnæs Hoved Flak. — 26,5 meters. — Mud. — No vegetation. 10, 92. Off Bøjgden. — 5,5 meters. — Stones. — Fucus vesiculosus and serratus. 22/591. Near the broom W. of Lyø. — 15 meters and some less. — Florideæ, (scarce Zostera). 4]; 92. W. side of Skjoldnæs, Ærø. — 7,5 to 9,5 meters. — Bare sand with spots of Zostera (rather small and narrow-leaved). #1: 93. Off Vidsø, Ærø, "4 mile of land. — 8 to 10,5 meters. — Sand with a few stones. — Zostera, (Fucus vesiculosus). 14], 92. Vodrups Flak. — 13 meters. — Sand with stones. — Floridee, in particular Fur- cellaria, Deless. sinuosa, (Fucus serratus, Laminaria digit.). ‘|, 93. Vodrups Flak. — 9,5 meters. — Sand. — Zostera, Fucus serratus, (Furcellaria). The South Fyen Waters (Sydfyenske Øgaard). (Sf) 2/9 91. S. side of Hornenæs. — 7,5 meters. — Sand with stones. — Zostera, Furcellaria, Fucus vesiculosus and serratus. 19/5 92. E. of CC. — 9,5 to 15 meters. — Soft bottom. — Few Algæ (Phyllophora Brodiæi). #/9 91. Near the N. side of Lyø Rev. — Ca. 21 meters (9). — Mud. — No vegetation. 15 32. Between the N. end of Lyø and Knollen. — 19 meters. — Mud. — No vegetation. 7/5 92. Near CX. but nearer to Lyø. — 20 meters. — Mud with dead leaves of Zostera. — No vegetation. #9 91. Faaborg Fjord, W. of the broom at Højen. — Dense vegetation of broad-leaved Zostera. “ls 91. S. end of Skrams Flak. — 6,5 meters. — Sand with stones. — Zostera with Fucus serratus and vesiculosus, (Polys. nigrescens, Furcellaria). #19 91. W. of Svelmø. — 15 meters. — Mud, dead Zostera-leaves. — No vegetation. °l; 92. Near the buoy at Flæskholms Flak, N. of Drejø. — 5,5 meters. — Zostera. %s 92. Billes Grunde, N. of Ærø, the most eastern bank. — 5,5 meters. — Sand with stones. — Fucus vesic. and serratus, Florideæ: Phyllophora Brodiæi, Ceramium Rosenvingii. _43 UX. 21; 95. Skjoldnzes light-house S.%/4 W. “1 mile. — 9,5 meters. — First sand with Zostera, farther out stones with Laminaria digit, Furcellaria a. o. Floride. UV. 25]; 95. Skjoldnæs light-house N.W.?!s W. nearly 5 miles. — 13 meters. — Stones. — Flo- rideæ: Furcellaria, Deless. sangvinea..., (Fucus serratus). DZ. “Js 92. Egholms Flak, near the buoy at the N. end of Mørke Dyb. — 5,5 meters. — Zostera. V. 18/9 90. At the W. side of Birkholm. — 4 to 7,5 meters. — Zostera with Fucus vesic., F. ser- ratus, Chorda Filum. U. 18/0 90. Same place, nearer to land. — 1 to 2 meters. — Fucus vesic., Chorda Filum. CT. °%s5 92. The bank W. of Knudedyb W. of Taasinge. — 2 meters. — Stones. — Fucus vesicul. and serratus. Outside the stones: Zostera. BY. ‘8/9 91. Svendborgsund, W. of the pier at Taasinge. — 7,5 meters. — Stones. — Floridew, (Laminaria sacchar.). BX. 1 91. E. of Svendborg, near Taasinge. — 5,5 meters. — Sandy mud, dead Zostera-leaves, with scarce Floridee. EB. #/: 92. Near the broom at Stenodde, E. side of Taasinge. — 7,5 meters. — Mud. — Zostera. EA. 5]; 92. Near the buoy on Middelgrund at the N. end of the Rudkøbing channel. — 5,5 meters. — Zostera. Great Belt. (Sb) MO. 9 93. Refsnæs light-house N.W. '/s W. 3 miles. — 19 meters. — Clay-mud with stones. — No vegetation. DL. "Is 92. S. side of Refsnæs, 1!/» miles from the light-house. — 6,5 to 7,5 meters. — Bare sand with patches of Fucus serratus. MN. #93. The broom at Asnæs S.W.‘/s W. a good 3 miles. — 10,5 to 11,5 meters. — Fine sand with stones. — Zostera, Fuc. serratus, Laminaria digit. GT. 11 92. ‘ls mile N. of the broom at Asnæs. —- 7,5 meters and probably more. — Stones. — Florideæ, in particular Furcellaria, (Deless. sangv., Del. sinuosa). DM. ”/s 92. Asnæs Rev, inside the broom. — 6,5 meters. — Shells. — Scarce Algæ (Desmar. aculeata, Chorda tomentosa). GU. °/1 92. The broom at Asnæs N.W.':N. 2 miles. — 19 meters. — Stones. — Laminaria sacch., Desmar. acul., Deless. sangv. GS. ?/11 92. N. side of Lysegrunde S. of Asnæs. — 9 meters (?). — Sand with stones. — Zostera, Fucus serratus. LK. 6/: 93. Elefantgrund. — 6,5 to 11,5 meters. — Stones. — Fucus serralus, Laminaria digi- tata, Floridee, in particular Furcellaria. AG. ®/s 91. By the broom at Klæpen W. of Romsø. — 4 meters. — Sand with vegetation in spots of Furcellaria, (Fuc. vesicul., F. serratus). LM. ®/s 93. By the S. side of Romsø. — 4 to 5,5 meters. — Sand with stones. — Fucus vesic., F. serratus, Halidrys, (Lamin. digit., Furcellaria). GV. 9/1 92. By the buoy S.E. of Romsø. — Stones. -- Furcellaria, (Halidrys, Laminaria sacch., Fuc. vesic.). 3 LN. 5:93. Off the E. side of Stavreshoved. — 5,5 meters. — Stones. — Fucus vesicul., F. serral., Halidrys, Lamin. digit. — Also sand with Zostera. LP. "”|s 93. Off the S.E. side of Stavreshoved. — 2 to 4 meters. — Stones. — Fucus vesicul., (F. serratus). 6 AF. “91 Mollegrund S. of Stavreshoved. — 8 meters. — Sandy mud with dead Zostera- leaves. — Furcellaria, Phylloph. Brodiei, Polys. nigresc. LL. 2/s 93. Ronnen off Broløkke by Kerteminde. — 4 to 5,5 meters. — Stones. — Fucus vesicul., (Halidrys, Furcellaria). AE. “js 91. Off the slope at Lundsgaard. — 7,5 to 9,5 meters. — Clayey sand. — Zostera, (Fur- cellaria). LO. "Is 91. Of the valley S. of Lundsgaard. — Ca. 55 meters. — Sand with stones. — Fucus vesicul., (Halidrys, Furcellaria, Spermatochnus). É AD. "191. Of Risingehoved, ca. ‘l: mile off land. — 13 meters. — Clay-mud with dead shells. — Very sparse vegetation on tubes of Annelids a. o. MM. “93 The buoy at Elefantgrund N. by W.‘/s W. 3 miles. — 19 to 20,5 meters. — Soft bottom. — No vegetation. GR. °/:: 92. Musholm Havn. — 4 meters. — Zosiera. GO. “lu 92. W. side of Slettings Grund. — 7 meters. — Zosiera, (Fucus vesic., F. serratus). NU. =/: 94 Off the Strandskov by Bogense, ‘/: mile of land. — 11,5 meters. — Sand () with a few stones. — Furcellaria. AA. °/s91. Sprogø light-house S.E. 51: miles. — Ca. 26,5 meters. — Clay-mud. — Nearly no vegetation (Brongniartella, Polys. nigrescens, Ectocarpus). Z. ls 91. Off Skagbo Huse. Sprogø light-house S.E. by E. 4/s E. 5 miles. — 19 meters. — Sandy mud. — Scarce veg.: Desmar. acul., Polys. nigr. GX. "In 92. Sprogø light-house S.E. 3 miles. — More than 21 meters. — Clay-mud. — No veg. AB. °/s91. Off the S. end of Teglgaardsskov by Nyborg, :/: mile of land. — 7,5 meters. — Sand with stones. — Fucus vesicul., F. serr., Zostera, scarce Floridee. AC. "Is 91. Knudshoved light-house S.W. 7/2 S. */z mile. — 17 meters. — ? with small pebbles. — Searce veg. of Florideæ (Polys. nigresc. and Brongniartella) and Desmarestia acul. GY. “/:: 92. W. side of Gjellegrund S. of Sprogø. — 5.5 meters. — Sand with stones. — Zostera, (Fac. serratus). NO. =: 94 E. of Gjellegrund. Sprogø light-house NW. by NN. 1°: miles. — 13 meters. — Sand (?) with stones. — Florideæ and Chetomorpha Melagonium, (Zostera). GP. */:: 92. Near the light-buoy at Halskov Rev. — 9,5 to 11,5 meters. — Stones. — Laminaria digitata, Delesseria three species. NR. =/: 94 Immediately N.W. of the entrance to Korsør harbour, between the double broom and the buoy. — Stones. — Fucus vesiculosus. 5 NP. =: 9£ Is mile W.+/:S. of the broom at Badstue Rey. — 9.5 meters. — Sand with stones and Mytilus. — Polysiph. elong. a. o. NQ. =I: 4. Badstue Rev. — 4 to 5,5 meters. — Sand with stones. — Zostera, Mytilus with a few Floridee, in particular Rhodomela. NN. =: 94 Sprogø light-house N.E.*/. E. 31]: miles. — 19 meters. — Florideæ (Delesseria sangv., D. sinuosa, Rhodomela). NT. “: 94 Knudshoved light-house W. by N. ©- mile. — 19 meters. — Clay-mud or sand. — No vegetation. NS. =]; % Between Slipshavn and Knudshoved, */: mile of land. — 5,5 meters. — Sand with stones. — Fucus vesicul., F. serrat., Florideæ, Zostera. BS. Is 91. W. side of Palesrund. — 7,5 meters. — Mud. — Zostera, (Furcellaria). 45 LJ. 5: 93 E. of Palegrund. — 16 meters. — Soft bottom with dead Zostera-leaves and some loose Florideæ. XS. %/10 00. By Kloverhage, Knudshoved light-house N.E. */s N. 2% miles, and a little more north. — 5,5 to 7,5 meters. — Mostly Zostera, here and there stones with Furcellaria. Phylloph. Brod., Polys. nigresc. BT. 75/9 91. S. of Kloverhage. — 7,5 meters. — Sandy mud. — Dense Zostera-vegetation. Y. 1/4 90. By the broom at Stokkebæk Flak. — 45 meters. — Sand with stones. — Fucus vesicul., F. serratus. — ‘4 mile S. of the broom. — 7,5 meters. — Zoslera. BU. “lo 91. Off Lundeborg. — 5,5 meters. — Mud. — Dense broad-leaved Zoslera-vegetation. CJ. 3/9 91. 4s mile S.S.W. of the entrance to the Stoense channel. — 5,5 meters. — Zoslera. BV. 5/8 91. Of the S. side of Elsehoved. — 6 meters. — Dense, pure Zostera-vegetation. UU. “Ils 95. Snøde Rev. — 4 to 4,5 meters. — Dense Zoslera-vegetation. X. 1%, 90. 2 miles N.E. of the broom at Turg Rev. — 11 meters. — Clay-mud. — Broad-leaved Zostera, no Algæ. LH. °*/; 93. S. of Egeløkke Rev, off Bøstrup. — 8,5 to 10,5 meters. — Soft bottom with stones. — Zostera, (Furcellaria). CH. “Jo 91. 14/3 miles E.N.E. '/s E. of the broom at Turg Rev. — 11,5 meters. — Mud with dead Zostera-leaves. — No vegetation. bA. "/s 06. Sprogø light-house N.N.W. 4 miles. — 22,5 to 23,5 meters. — Sand. — No vegetation. UE. *°/5 95. By the buoy at Vresens Puller. — 6,5 to 7,5 meters. — Zostera (with stones on which Fuc. vesic., F. serratus, Lamin. digit., Furcellaria a. 0. Florideæ). UF. 21]; 95. N. point of Langeland S.W. by W.?2/s W. 21} miles. — 8,5 meters. — Sand and stones. — Zostera, Fucus serratus, Florideæ, (Laminaria digitata). DN. 1/5 92. Vengeance Grund. — 11,5 to 12 meters. — Stones. — Floridee with Laminaria digitata, Fucus serratus and Halidrys. DO. */; 92. Langelandsgre, W. side of Omg. — 4 to 5,5 meters. — Zostera-vegetation and stones with Fucus vesiculosus. UG. >”; 95. Langelandsbelt, abreast of Osterhuse, the point by Hov N. by W. 'l4 W. 2! miles. — 33 meters. — ? with stones. — Some few loose Alge. UH. */:5 95. Tranekær lisht-house S.W. by W. 44/2 miles. — 19 to 21,5 meters. — Stones. — Lamin. digit., Delesseria sangvin. T. 17/9 90. 4l2 mile N.W. of the buoy at Staalgrunden. — 4 to 5,5 meters. — Sand with stones. — Zostera with a few Fucus vesicul., Chorda Filum a. o. UT. */5 95. Tranekær light-house E. by N.1/3 N. 2?/s miles. — 19 meters. — Coarse sand with stones. — Delesseria sangvin. a. 0. Floridee, Laminaria sacch. and digit. UK. 7/5 95. Abreast of Tranekær light-house, 1/2 miles. — 12 meters. — Gravel (?) with some stones. — Desmarestia acul., (Phylloph. Brodici). DP. */; 92. The broom at Onsevig S.W. "> W. a good 1 mile. — 6,5 meters. — Sand with some stones. — Zostera with some Fucus vesic. UI. */: 95. The broom at Onsevig S. a good 1/2 mile. — 7,5 meters. — Zostera, (Florideæ in particular Furcellaria, Rhodomela). DQ. "15 92. N.W. of Nakskov Fjord, Taars ferry outer light-house S.E. 3/2 E. 21}; miles. - 5,5 meters. — Sandy clay-mud. — Zosiera, (with Florideæ; numerous shells). US. 2215 95. Gillebjerg N.W.7/4 W., Taars light-house E. — Ca. 45 meters. — Stones. — Scarce Delesseria sinuosa and sangvinea. 46 US. 2/5 95. Gillebjerg N.W. "2 W., Taars light-house E. — 20 meters. — Stones. — Laminaria digitata and sacch., Deless. sangvinea. DR. “/; 92. Near the buoy at Albu Triller. — 8,5 meters. — Zostera, (with Florideæ),. DS. “1; 92. The buoy at Albu Triller N.E. by E. 11 E. 2 miles. — 11,5 meters. — Sand (9). — No vegetation. DT. “5 92. Off Magleby on Langeland, */s mile of land. — 7,5 to 9,5 meters. — Sand. — Zostera. LB. “/; 93. Kjelsnor light-house W. nearly 4 miles. — 17 meters. — Mud with stones. — Flo- rideæ, mostly Delesseria sangvin., (Laminaria digitata). UR. 2}; 95. S. of Albuen, Kappel church E.?/4 N., Fakkebjerg light-house W.!ls N. — 7,5 meters. — ? with stones. — Rather dense Zosiera-vegetation, (Mytilus, various Floridew, some Fucus serratus). Smaaland Sea. (Sm) GZ. 1/11 92. 11/2 miles N. of the N. end of Egholm. — 6,5 meters. — Sand with stones. — Zostera, (Fucus serratus, F. vesicul.). HA. 1/1 92. Agerso Sund, the broom off the channel to Skelskor Nor S. E.1/s E. a good 1 mile. — 11,5 meters. — Stones. — Florideæ, (Polysiphonia, Delesseria). VB. 7/5 95. E. side of Omø Tofte. — 5,5 meters. — Sand with Mytilus, among which various Algæ, mostly Furcellaria and Ceram. rubrum. HB. 14/11 92. S. end of Agerso Sund, Helleholm light-house N.W. by W.:/s W. 3 miles. — 8,5 meters. — Stones and Mytilus. — Rhodomela and Polysiph. nigresc., (Zostera). VC. °”J; 95. Venegrund, inside the buoy. — 4 to 5,5 meters. — Sand with stones. — Zostera, not dense, various Algæ, Mytilus. HC. "I 92. By the broom at Knudshoved Odde. — 11,5 meters. — Zostera. — Florideæ (Polys. nigrescens). CK. */9 91. 2 miles S. by E.:E. of the buoy at Staalgrund. — 9,5 meters. — Sand (?) with stones. — Furcellaria, (Phyllophora membranif., Ph. Brodici, Polys. nigresc.). CL. ?Is 91. In the middle of Raagø Sund. — 5,5 meters. — Dense veg. of broad-leaved Zostera. CM. #9 91. By the broom at Kragenæs. — 4,5 meters. — Dense broad-leayed Zostera. S. 1/9 90. By the W. side of Fejø. — 5,5 meters. — Zostera. CN. *5/9 91. N.E. of Middelgrund at the E. end of Fejø. — 4,5 meters. — Zostera, (Fuc. serratus, Furcellaria). HD. "Ji 92. Knudskov Rev. — 4,5 meters. — Fucus vesicul., (Zostera). CQ. Is 91. 14 miles N.E. by E.4/sE. of the broom at Kogrund. — 4,5 meters. — Sand with a few stones. — Zostera, (Fucus vesicul.). Q. "ls 90. N. of Vesterskovsflak. — 7,5 meters. — Sand. — Zostera. P. 1/9 90. Between Kogrund and Suderg, 11 mile S.E. by E. of the broom inside of Kogrund. — 3 meters. — Dense Zostera-vegetation with scarce Fucus. CO. “ls 91. By the broom at Vigsø Skal. — Ca. 6 meters. — Zostera. CP. **/9 91. By the broom at Guldborg. — 4 meters. — Zostera. O. "Is 90. Off Guldborg. — 5,5 meters. — Mud without vegetation. N. “la 90. Guldborgsund, off Vennerslund. — 1 to 2 feet: Polysiphonia violacea f. aculeata a. o. scattered. — 2 feet: Potamogelon pectinatus and Zannichellia pedicellata. — 3 feet: Sper- malochnus paradoxus, Fucus serratus a. 0. — 3 to 4 feet and outwards: Zostera. at CR. 2/9 91. By the beacon at the W. end of Stor Strom. — 4,5 meters. — Broad-leaved Zostera. HE. "Ji 92. W. end of Masnedsund, near the beacon. — 4 to 5,5 meters (?). — Sand. — Pure Zostera-vegetation. KP. ”]z 93. S.E. of Masnedø, between Kalvestrom and Fergestrom. — Ca. 3 meters. — Zostera, with scattered Fucus vesic. HF. ””/ 92. W. of Faro, about */s mile of land. — 12 meters. — Mud with stones and dead Zostera-leaves. — Very scarce Florideæ. R. 2/9 90. Off Petersveerft, near land. — Ca. 2 meters. — Zostera. R!. 16/9 90. Off Sprove, Møen, right opposite Lange. — From 1,3 meters outwards Zostera. - In the channel mud without vegetation. HJ. li: 92. Bredemands Hage by the S. side of Bogø. — 6,5 meters. — Zostera, dead and probably also growing, (scarce Florideæ). KQ. */; 93. Grønsund, off the N. end of Østerskov. — 4 meters. — Bare sand. — 3,5 meters: Zostera. The Sound. (Su) RX. !/s 94. Outside of Mollegrund off Höganäs. — 15 meters. — Clay-mud with stones. — No vegetation. BQ. "Io 91. Off Ellekilde. — 5,5 meters. — Stones. — Fucus vesic., Fuc. serratus, (Furcellaria a. o. Florideæ). BR. “Ilo 91. Off Odinshej. — 9,5 to 11,5 meters. — Zostera-vegetation. CS. 1/5 92. Off Aalsgaarde. — 4 to 5,5 meters. — Stones. — (Fucus vesiculosus, F. serratus, and Floridee. GK. "Is 92. Off Hellebæk. — Between first and second shoal. — Stones. — Fucus serratus, (F. vesicul., Furcellaria). ON. "I, 94. E. side of Lappegrund. — 6,5 to 9,5 meters. — Coarse sand with pebbles. — No vegetation. HN. 81; 93. @retvisten, E. side, Kronborg light-house S.W.*/;S. 2 miles. — 17 to 19 meters. — No vegetation. HM. 5: 93. @retvisten, Kronborg S.W. Is S. 18/5 miles. — 24,5 to 28 meters. — Clay-mud. — (A stone with a young Lithothamnion, one spec. of Delesseria sangvinea). HL. 4/5 93. @retvisten, Kronborg S.W.!4S. 11/4 mile. — 41,5 meters. — Soft bottom (?). — No vegetation. OK. I, 94. Disken, Lat. N. 56°0,3’, Long. E. 12°38,5°. — 7,5 meters. — Bare sand. OM. "I, 94. W. side of Disken, Lat. N. 56°0,2’, Long. E. 12°38’. — Sand. — No vegetation (Mytilus). OL. 17/494. E. side of Disken, Lat. N. 56°0', Long. E. 12°31,7. — 14 to 16 meters. — Sand. — No vegetation. PX. 2], 94. Off Tibberup. — 8,5 meters. — Sandy mud with a few small pebbles. — Dense vegetation of Zostera, (with Fucus vesiculosus, Rhodomela, Polysiph. nigrescens). TD. Io 94. Hveens revolving light S. 1/2 W. 21/2 miles. — 20,5 meters. — No vegetation (seine). OI. 1741 94. Nivaa Flak, off Nivaa. — 6,5 meters. — Rhodomela (seine). HK. 5:93. Off the N.W. end of Hveen. — 17 meters. — Clay-mud. — No vegetation. — 9,5 to 21,5 meters: In part clay-mud. — A few Algæ (Polysiph. nigresc., Ceramium rubrum, Delesseria sinuosa). TC. EVE OH. BN? PZ. TE: = TES ro ER BES QA. Eu 19/9 94. Hveens revolving light N. 1/2 W. > mile. — 17 meters. — Clay-mud (9. — No vege- tation (seine). 231, 94. N. end of Lous’s Flak, Hveens revolving light E. by N. 1/2 N. 3 miles. — 10 meters. — Fine sand. — Zostera. 17), 94. Vedbæk W.S.W. 4/4 S. 1 mile. — 9,5 to 10,5 meters. — Sandy clay-mud with a few stones. — Floridee, in particular Furcellaria and Rhodomela, (Laminaria sacchar.). 23) 94. E. of Hveen, Haken light-house S.‘/2 W. 1 mile. — 40,5 meters. — Clay-mud. — No vegetation. 23), 94. Near the E. side of Hveen, Haken light-house S. by E.!;E. 1 mile. — 10,5 to 19 meters. — Stones, from 12 meters upwards. — Floridee, Laminaria sacchar. 35], 94. W. of Staffans Flak, Haken light-house N.N.W.!ıN. a good 1,5 mile. — 22,5 to 30 meters. — Clay-mud with stones. — No plants. — The channel between Hveen and Landskrona. — 45 meters. — Clay-mud. — No plants. 35), 94. Staffans Flak. — 12 to 13 meters. — Stones. — Laminaria sacch., Floridee, in particular Furcellaria, (Chorda Filum). 25; M4. Immediately S. of Staffans Flak. — 28 to 32 meters. — Clay-mud and stones. — No plants. 23), 94. S.W. border of Staffans Flak. — 14 to 18 meters. — Laminaria digitata, Floridee, Phymatolithon polymorphum. 23), 94. By the buoy at Pilhaken, off Landskrona. — 24,5 to 39,5 meters. — No vegetation. . 3), 94. S. of the same buoy. — 16 meters. — Coarse sand, almost without vegetation, (a few Desmarestia viridis and Ectocarpus). + I. I; 07. S. of Hveen, 1 mile W.S.W.!/ıS. of the whistle buoy at Pilhaken. — 22,5 meters. — Stones. — Abundant vegetation: Laminaria digilala, L. sacchar., Florideæ, in particular Delesseria sinuosa and sangvinea. E. of Lous Flak, Lat. N. 55°51,6’, Long. E. 12°41,5°. — 13 meters. — Clay-mud. — A few Algæ. Lous Flak, Lat. N. 55°51,5, Long. E. 12°38’. — 12 meters. — Sandy clay-mud. — Clado- phora gracilis. . #/; 07. — Off Vedbæk, Lat. N. 55°51’, Long. E. 12°36,5. — 13 meters. — Abundant vegetation of Alge and Zostera; of Algæ mostly Ectocarpus, Furcellaria, Polysiphonia elong. and nigrescens, Rhodomela. . 57 94. Off Eremitagen, */s mile of land. — 7,5 meters. — Sand and mud. — Zostera and Furcellaria (probably loose). . 2]: 94. By the broom at Taarbæk Rev. — Stones. — Abundant vegetation: Fucus serratus, Furcellaria, Polysiph. nigrescens, Chorda Filum, Zostera. . #1 94. Taarbæk Rev, nearly 1 mile W. of the broom. — 6 meters. — Sand with stones. — Florideæ, in particular Furcellaria and Rhodomela, Fuc. serratus. . 21/, 94. The broom at Taarbæk Rey N.W: by W. 2/3 W. 21/6 miles. — 12 meters. — No vege- tation. . 1/9 94. The harbour of Skovshoved W.S.W. 1}: mile. — 5,5 meters. — Sand (?) with stones. — Furcellaria, Zostera, (Chorda Filum). . Ms 94. Near the harbour of Skovshoved. — 4,5 meters. — Sand. — Zostera. . 21/7 94. Off Charlottenlund, the broom at Taarbæk Rey N.E. 1/2 N. 21/3 miles. — 5,5 meters. — Sand with stones. — Abundant vegetation: Zostera, Ectocarpus, Chorda Filum, Furcellaria. 49 KO!. 8:93 Off the fort of Charlottenlund. — 3 meters. — Stones. — Chorda Filum, Cla- dophora. KO. 15 93. A little farther out. — 7 meters. — Stones. — Fucus serratus, Laminaria sacch., Furcellaria, Zostera. OG", 1:94 Between Trekroner and Middelgrund. — Ca. 9,5 meters (9). — Desmarestia acul., Delesseria sinuosa and alata, Chætopteris. RI. 1 9. S. end of Middelgrund, between the beacon and the triple broom. — 5 meters. — Gravel with stones. — Chorda Filum, (scarce Zoslera). QE. *"/; 94. Nordre Rose. — 10,5 meters. — Gravel and stones. — No plants. — 5 to ca. 10 meters: Stones. — Zostera, Chorda Filum, (Mytilus). RH. %/; 94. S. end of Knollen. — 9,5 meters. — Stones. — Laminaria sacchar., Floridew, mostly Polysiphonia violacea, broad-leaved Zostera. QC. I 94. E. side of Saltholms Flak, */s mile E.%/s S. of the broom. — 6 meters. — Sand (?) with stones. — Dense vegetation of Fucus vesiculosus, F. serralus, Furcellaria a. 0. Flo- rideæ, Chorda Filum. QD. */; 94. E. of the N. end of Saltholm, 1 mile S.S.W. 1/2 S. of the beacon. — 5,5 meters. — Sand (?) with stones. — Dense vegetation of Fucus serralus, Furcellaria, Polysiph. ni- grescens, Zostera. SA. */s 94. Flinterenden; ‘1 mile S. of the buoy at N. Flint. — 10,5 meters. — Stones and black mud. — Broad-leaved Zostera, Laminaria sacchar., (Dictyosiphon, Laminaria digit.). SB. */s 94. Flinterenden; °/s mile S.W. of Oscargrund light-ship. — 8,5 meters. — Stones. — Fucus serratus, (Florideæ, Dictyosiphon foeniculaceus). PR. "Js 94. Off Dragør. — 7,5 to 9,5 meters. — Hard bottom with stones. — Florideæ: Rho- domela, Polysiph. nigrescens, Furcellaria and Zostera. PR!. */; 94. About the same place but farther out. — Ca. 7,5 meters. — Zoslera and the same Algee as in PR. Baltic, Western Part. (Bw) VA. *|5 95. Vejsnæs Nakke E. 1/3 N. — 26,5 meters. — Sand and pebbles. — No vegetation. DV. "I; 92. S. of Marstal, Fakkebjerg light-house S. E. #4 E. nearly 7 miles. — 9,5 to 11,5 meters. — Sand with pebbles. — Zostera, Fucus serralus, Furcellaria. LE. "|, 93. N. side of Vejsnæs Flak. — 9,5 meters. — Sand. — Zostera, (Fucus serratus, Floridec). UY. “|; 95. Vejsnes Flak. — 9,5 meters. — Bare sand with a few stones, on which Fucus vesiculosus and F. serratus, (and some Floridee). UY! >95. S. side of Vejsnæs Flak. — 18 meters. — Sandy clay-mud. — Loose Furcellaria, Laminaria digitata. UZ. °°/5 95. In the channel E. of Vejsnæs Flak. — 34 meters. — Clayey sand with small stones. — No vegetation. LD. ‘I 93. Fakkebjerg light-house E.S.E. 1/4 E. 64 miles. — 20,5 to 22,5 meters. — Clay-mud without vegetation (Ophiure). DU. "1; 92. Off Dimesodde S. of Bagnkop, '/s mile of land. 11 meters. — Stones. — Fur- cellaria, (Fucus serratus, Laminaria digilala ...). LC. "I 93. S. of the buoy at Gulstav. — 11,5 meters. — Stones. — Floridew, mostly Furcellaria, Fucus serratus, Halidrys, Laminaria digit.). D. K. D, Vidensk. Selsk, Skr., 7. Række, naturvidensk. og mathem, Afd. VII. 1. 50 UL. 24,95. Femerbelt; Øjet, Markelsdorf Huk S.‘kE. 7 miles. — 20 meters. — Gravel with stones. — Abundant vegetation: Laminaria digitata, L. saccharina, Floridee. LA. I; 93. Kappel church N. by W. */4 W., W. end of Vesterskov N.!lı W. — 7,5 meters. — Sand with some stones. — Zoslera, Floridew, (Fucus vesiculosus). UQ. #1: 95. Tillitse church N.E., Kappel church N. by W.1/: W. — 12 meters. — Gravel and stones. — Mytilus with Polysiphonia nigrescens and a few other Floride«. UP. 2}; 95. Off Kramnisse Gab, 11/4 miles of land. — 8,5 meters. — Sand with stones. — Some Zostera, scarce Furcellaria and Fucus serratus, (Mytilus). KZ. I; 93. Immediately outside Kramnisse Gab. — 7,5 meters. — Zoslera, Fucus serratus, Fur- cellaria. KY. :1- 98. Olstrup church E.N.E. 6 miles. — 12,5 meters. — Gravel and stones, Mytilus. — Florideæ, in particular Ceramium and Polysiph. nigrescens, (dead Zostera-leaves). KX. 31, 93 Olenburg Huk S.W. by W. ‘1 W. a good 6 miles. — 26,5 meters (?). — Mud. — A few Floridew on stones. KV. */; 9. S. of Nysted, the buoy N.E. by N. "> mile. — 5,5 meters. — Sand. — Zostera in large patches, Floride. KU. I; 93. Schonheyders Pulle. — 6,5 meters. — Stones. — Fucus serratus, Florideæ, (Lami- naria digitata). — 1595. — 7 meters. — Small pebbles or coarse gravel, in great measure without vege- tation, with however patches of Fucus serratus and a few Floridee and some Zostera, (Mytilus). KT. >; 9. Gjedser Rev, near the inmost broom. — 8,5 meters. — Stones. — Fucus serralus, Florideæ, in particular Ceramium Rosenvingii. UO. “|; 95. Gjedser Rev, Trindelen. — 5,5 to 7 meters. — Sand, gravel. — No vegetation. UN. */; 95. Gjedser Rev, Yderknoben. — 5,5 to 9,5 meters. — Sand and coarse gravel without vegetation. UN. Is 95. Gjedser Rev, by “Varsko”. — 9,5 meters. — Sand without vegetation. UM!. *|; 95. Near Gjedser Reys light-ship. — 19 meters. — Sand without vegetation. UM. °/; 95. Kadetrenden; Gjedser Revs light-ship N.W. 14/, miles. — 245 to 25,5 meters. — Small pebbles. — No vegetation, (a few Hildenbrandtia a. o.). Baltic, Part around Mgen. (Bm) QF. I; 94. W. of Lille Grund by Flinterenden, Drogdens light-ship N. by W.11 W. nearly 3 miles. — 9,5 meters (?). — Stones. — Zostera, Fucus serratus, broad, Ectocarpus, (Mylilus). RG. */; 94. Falsterbo light-house S.S.E. 6 miles. — Sand, stones. — Fucus serratus, Floridew, (the Algæ probably in part loose). QG. #1: 94. Abreast of Bredgrund, "> mile N.E.il»E. of the broom at Virago Grund. — 7,5 meters. — Stones. — Fucus serratus, F. vesiculosus. QM. “I; 94. N. of Juels Grund, harbour of Kage W. 51/2 miles. — 6,5 to 7,5 meters. — Sand with stones. — Abundant vegetation of Fucus vesiculosus, Polysiph. nigrescens a o. Floridew, Zostera. QL. *l; 9. S. of Juels Grund. — 11,5 meters. — No vegetation. OR. *1, 94. Off Køge Sohuse. — 9,5 meters. — Fine sand. — Zostera. QN. */; 94. Off Køge Sohuse, %/, mile of land. — 6,5 meters. — Stones. — Fucus serralus, (with Floridew). QI. > 94. Køge Bugt, 7 miles due N. of Stevns light-house. — 16 meters (seine). — Floridea, Laminariw. QO. “I; 94. Køge Sonakke N.W. 11 W. 1,3 miles. — 4,5 to 5,5 meters. — Stones. — Fucus vesi- culosus, Floridew. QP. “|; 94. Kalkgrund, at the N. end of Stevns Klint. — 3 to 4 meters. — Limestones. — Fucus vesiculosus and F. serralus, (Ceram. rubrum, Chorda Filum). VF. */; 95. Off Mandehoved, Stevns. — 4 to 9,5 meters. — Limestones. — Rather abundant vegetation: Fucus vesiculosus and F. serralus, (Polys. nigrescens). QJ. I; 94. 6 miles due W. of Falsterbo light-house. — 16 meters. — Fine sand. — No vegetation. QH. "1: 94. Falsterbo light-house N.E. "> E. 21}; miles. — Ca. 7,5 meters. — Sand. — Zoslera, Fucus vesiculosus a. o. SC. */s 94. Falsterbo light-ship S.E. 1/2 S. 21}: miles. — 9,5 meters. — Fine Sand. — No vegetation. VE. =]; 95. Stevns light-house N.E.*/2 E. 1/s miles. — 15 meters. — Gravel, small pebbles. — No vegetation. QQ. */; 94. Of Rødvig. — 6,5 to 7,5 meters. — Stones. — Fucus vesiculosus, (F. serratus). VD. */; 95. Near the whistle buoy at the entrance to Bogestrommen. — 7,5 meters. — Sand with stones. — Fucus vesiculosus, F. serratus... . RA. */; 9. Hollænder Grund. — 5,5 meters. — Stones. — Fucus vesiculosus, Spermatochnus. RB. */;: 94. Inside Hollænder Grund. — 4,5 meters. — Sand and gravel with stones. — Fucus vesiculosus, Zoslera; the vegetation here and there wanting. QR. */7 94. "Gyldenløves Flak. — 7,5 meters. — Gravel with stones. — Fucus vesiculosus. SD. ?Is 9. Stevns light-house N. by W. 1/4 W. nearly 15 miles. — 23,5 meters. — Sand. — Loose Floridee in abundance, in particular Furcellaria, Delesseria sangvinea, D. alata, Rhodo- mela, Polysiphonia nigrescens. QS. */; 94. The Møen cliff S.S.W. 7 miles. — 20,5 meters. — Gravel and small stones. — Floridew. in particular Rhodomela, Delesseria sangvinea, D. alata, for the most part loose, (many Mytilus). VG. 15 95. N. of the Moen cliff, abreast of Hellehavns Nakke, %/4 mile of land. — 17 meters. — Gravel and stones. — Mylilus with various Floridee. RC. *8/; 94. Inside “Danneskiold” near the Møen cliff. — 7,5 meters. — Stones. — Fucus vesi- culosus. QZ. > 94. Abreast of Moen light-house. — Ca. 7,5 meters. — Stones. — Fucus vesiculosus, F. serratus, a great many loose Rhodymenia palmata. QY. #/: 94. S. side of Bjelkes Flak. — 10,5 meters. — Stones. — Fucus serratus. VH. */; 95. S. side of Böchers Grund. — 8,5 to 10,5 meters. — Sand and stones. — Fucus ser- ratus and F. vesiculosus. VI. >; 95. Off Hjelm, Møen, near land. — 5,5 to 6,5 meters. — Gravel with stones. — Fucus serratus and vesiculosus, (Rhodomela, Polysiph. nigrescens). HG. "/1 92. Præstebjergs Rev, N. of the broom. — 7 meters. — Stones. — Fucus vesiculosus and serralus. HH. ””/ 92. The broom at Præstebjergs Rey N.W. by W. a good 2 miles. — 17 meters. — Clay-mud. — No vegetation. KR. ©: 93 By Korselitze Grund. — 7,5 meters. — Sand with stones. — Fucus vesiculosus, F. serratus, Floridee. KS. bo. QV. QX QU SE. QT. bP. YI. 2-93. E. of Falster. off Ulfslev: Gjedser light-ship S-S-W.%/: W. 11/2 miles. — 9,5 to 11,5 meters. — Gravel and stones, Fucus vesicul. and serratus, Florideæ, in particular Rho- domela and Polys. nigrescens. 1). 07. Lat. N. 54°37’, Long. E. 12°25 (Mag. O. Pausen). — 15 meters (trawl). — Laminaria sacchar.. Desmarestia acul., various Florideæ. 2%). 94. Lat. N. 54°436, Long. E. 12°2%8,5. — 17 meters. — Sand. — No vegetation. |, M. Lat. N. 54°49,7’, Long. E. 122284. — 20,5 meters. — Fine sand. — No vegetation. |. 94. Lat. N. 54°46,6', Long. E. 12°34°/;. — 16 meters. — Fine sand. — No vegetation. 2/,94. Lat. N. 55°4, Long. E. 12°47’. — 28 meters. — Clay-mud without vegetation. 25). 94. Moen light-house W. by N. 10*/s miles. — 54 meters. — Clay-mud with fine sand. — No vegetation. 1.07. E. side of Kriegers Flak, Lat. N. 55°3, Long. E. 13°5 (2) (Mag. O. Paursen). — Ca. 1 YH. RD. SK. SE WE: YG. 15 (18%) meters. — Rhodomela, Ceramium striclum, Desmareslia viridis a. 0. . 3%, 94 Lat. N. 55°10’, Long. E. 13°15. — 37,5 meters. — Sand and clay-mud, a few small stones. — No vegetation. Baltic, Part around Bornholm. (Bb) . 507 94. Lat. N. 55210. Long. E. 14°. — Ca. 40 meters. — No vegetation. . 5 9. Adler Grund, 4/2 mile S. of the light-ship. — Ca. 10,5 meters. — Sand with stones. — Furcellaria, Ceramium vertebrale. _ 5/3 94. Adler Grund, 1°]: miles S. by E. ‘J, E. of the light-ship. — Stones. — 10,5 meters. — Furcellaria, Ceramium vertebrale. . 71s 94. Rønne Banke, Lat. N. 54°54’. Long. E. 14°33’. — 245 meters. — Hard sand with stones. — Scarce vegetation, in particular Rhodomela and Eclocarpus lilloralis. . ils 94. W. side of Rønne Banke, Lat. N. 54°55°1/, Long. E. 14°33’. — 18 meters. — Stones. — Mytilus; a few Florideæ and Eclocarpus littoralis. "Is 94. W. side of Rønne Banke, Lat. N. 54°581/;/, Long. E. 14232113. — 19 meters. — Stones, gravel. — Sphacelaria racemosa. .°/s94. Rønne Banke. Lat. N. 54°594/s’, Long. E. 14°45'/s’. — Stones. — Slictyosiphon, Ceramium. . "Is 94. Rønne Banke. Lat. N. 55217, Long. E. 14°41%/s’. — 15 to 16 meters. — Gravel and stones. — Floridee, in particular Rhodomela and Eclocarpus. 101. Port of Rønne E. by N. 2%: miles. — 33 meters. — No vegetation. uj, 01. Port of Rønne E.N.E. 1: miles. — 245 meters. — Stones. — Incrusting Algæ (Hildenbrandtia, Lithoderma). a few arbuscular Floridea. 27/, 94. Hvidmzhrn, S. of Rønne. — 9.5 meters. — Stones. — Fucus vesiculosus. (F. serratus). Sis 94. Rønne Banke: Hojbratterne, */s mile S. of the broom. — 11,5 meters. — Gravel and stones. — Fucus serratus, F. vesicul., (Furcellaria with Ceramium). ‘js 94. Rønne Banke, Lat. N. 55°*/2’, Long. E. 14°4781/. — 13 meters. — Gravel. — No vege- tation. 11; 01. Inside Arnager Rev. — 5,5 meters. — Fucus serratus and vesiculosus, (scarce Zostera). NE: 117 01. Arnager Rev, a good mile of the port. — 7 meters. — Limestone. — Fucus vesi- culosus a. 0. 1:01. Off @lenaa, */s mile of land. — 10,5 meters. — Stones or rock. — Polysiph. nigres- cens, Furcellaria, (Fucus serratus). 09 SN. f/s 94. Davids Banke. — 15 to 17 meters. — Fucus serralus, (Eelocarpus). — — — — 24,5 to 28 meters. — Stones. — Laminaria saccharina. 7A, ie Oil, — — N.W. side of the bank. — 29 meters. — Stones. — Red and brown Algæ, no Laminariw. NZ — Davids Banke — 12 to 22,5 meters. — Stones. — Fucus serralus (and some Floride). GRE 15 meters. — Stones. — Fucus serralus with red and brown Algæ. XZ‘, — — — 19 to 20,5 meters. — Laminaria saccharina in abundance, Fucus serralus. XZ5. 57 O1. Hammer Odde S.E. by E. 7 miles. — 41 to 43 meters. — Firm clay with a few small stones. — No plants. SM. ls 94. N. of Hammeren, Lat. N. 55°18,8’, Long. E. 14°46’. — 24,5 meters. — Sand. — No vegetation. SL. °» 94. Off Allinge. — Ca. 5,5 to 11,5 meters. — Rock and stones. — Fucus vesiculosus, Ceramium rubrum, C. vertebrale, Sphacelaria racemosa. SO. 5/8 94. Off Gudhjem. — 5,5 to 11,5 meters. — Rocky ground. — Floridee, in particular Ceramium rubrum f. ballica, C. vertebrale, Phyllophora membranifol., Ph. Brodiwi, Fur- cellaria, Dielyosiphon, Fucus serratus. SP. ls 94. 44 mile N. by W.!l»W. of Mollenakke by Svaneke. — 28 meters. — Gravel. — No vegetation. SQ. °/s 94. Close S. of Broens Rev. — 9 meters. — Rocky ground. — Fucus serralus, (very few Florideæ). YD. °7 01. The double broom at Salthammer Rev W.14S. 1 mile. — 19 meters. — Stones. - Abundant vegetation of red and brown Algæ: Eelocarpus littoralis, Delesseria sangvinea, Rhodomela, Polysiphonia elongata var. a. 0. YC. 5: 01. The double broom at Salthammer Rev N.W. 3/4 N. ll miles. — 24,5 meters. — Rather rich vegetation of Ectocarpus lillor., Rhodomela, Polysiph. clongata var. a. 0. YA. fir 01. Dueodde light-house W. 55/1 miles. — 37,5 meters. — Rhodomela, Sphacelaria race- mosa, Furcellaria, Deless. sinuosa. YB. 5: 01. Dueodde light-house W. 6 miles. — 43,5 to 45 meters. — Stones. — No plants. SY. ‘is 94. Nordvestgrund by Christiansø. — 30 to 32 meters. — Rocky ground. — No vegetation. SX. °/s 94. That by Christiansø. — 0 to ca.15 meters. — Abundant vegetation. List of stations arranged chronologically, with indication of the waters where they are situated. July 1890. A—D Ks. | Aug. 1891. AI—AN Lb. Sept. 1891. BS—BV Sb. SED ERE EST os | Sa Eg ae LYSE = N—S Sm REP PAT AR | D =, CD CHE m. T Sb. = — AY—BF | Sa. => en CG St. == UV | Sf — — BG ao | à CHCl nse: D, 7 X—Y Sh | — — BH-BO | Km | — — CK-CR Sm Aug. 1891. Z—AG Sb. — = BP Kn. | May 1892, CS Su. = = AH—AT Sa. Sept. — BQ—BR Su. — = CT —CZ St. 54 DA—DI May 1892. — — DJ—DK — — DL—DT — = DU—DV — — DX—DY = — DZ—EB June — EC—EG July — EH—EP = = EQ—EY — — EZ—FA — — FB—FD = = FE—FH - — FJ—FN = = FO—FP = = FQ—FY = = FZ—GA = = GB—GE = = GF—GH = = GI Aug — GK Sept. — GL—GO Nov. — GP—GY = = GZ—HF = = HG—HH = = HI May 1893 HK—HN = = HO—HS = = HT—HY = = HX—IU == IV—KD = = KE—KG = = KH = = KI—KN June — KO July — KP—KQ = = KR—KS = = KT—LA = = LB — — LC-LE — — LF—LG — — LH-LK Aug. — LL—LP = = LQ—ML Sept. 1893. Jan. 1894 March — © MM—MN MO—MY MZ—NB NC—ND NE—NK NL_NM NN—NU NV_NX NY—OA OB—OF OG—ON 00-0Y OZ—PP PQ—PQ: PR—PR: PS—QE QF—RC RD—RF RG RH—RK RL-RQ RR—RS RT—RV RX—SB SC—SE SF--SX SY-SZ TA TE TG—TR S00 TU—TY TZ—UD UE-UK UL—UQ UR—UU UV-UX UY—VA VB—VC VD—VF VG VI VJ VK—VK: Sk. July 1895, Aug. — July 1896 July 1899 Aug: — July 1900. Aug. — Oct — June 1901. July — Aug. — July 1902. Aug. — June 1904. July — Aug. — June 1906. NE — July 1907. VL—VS VT—VX VY—XA XB—XF XG XH—XI XK—XL XM—XN XO XP—XQ XR XS XT—XY XZ—YI YK—YL YM—YN YO—YS MAb YU NV YX WA YZ—ZB ZC—ZD ZE—ZI ZK ZL—ZM ZN—ZO ZP ZQ—ZR ZS—ZY ZZ—aE aF—aS aT aU aV—aZ bA bBB—bG bH—bI bK—bL bM—bN bO—bP Rhodophycee. A. Protofloridee. I. Bangiales. Fam. 1. Bangiaceæ. J. AGARDH (1883), Till Algernes Systematik. Tredje afd. VI. Ulvaceæ. Lunds Univ. Årsskrift Tom. XIX. G. BERTHOLD (1881), Zur Kenntniss der Siphoneen und Bangiaceen. Mittheil d. zoolog. Station zu Neapel, II. — (1882), Die Bangiaceen des Golfes von Neapel. Leipzig. H. Hus (1902), An Account of the species of Porphyra found on the Pacific coast of North America. Proc. Calif. Acad. sc. 3. ser. vol. II No. 6, San Francisco. H. Kyrın (1907), Studien über die Algenflora der schwedischen Westküste. Upsala. Fr. OLTMANNS (1904), Morphologie und Biologie der Algen, I, p. 529—534. Fr. Scumirz (1894), Kleinere Beiträge zur Kentniss der Florideen. V. La Nuova Notarisia, Ser. V, p. 717. (1896), Bangiaceen. Engler-Prantl, Natürl. Pflanzenfam. I, 2, p. 307— 316. With regard to the natural history of the Bangiaceæ reference may be made to the above-quoted works of BERTHOLD, SCHMITZ and OLTMANNS; I wish only to make some remarks on the spores produced asexually. BERTHOLD named them “neutral spores”, a name in my opinion but little applicable, as these spores cannot be said to be more neutral than the carpospores. Scumirz named them monospores as they are produced by the whole contents of a cell, but the carpospores were given by him the same name, and consequently this was not a name peculiar to the spores produced asexually. Besides, it seems to me more reasonable to compare the cell, which after division produces a number of spores, with the tetrasporangium in the Florideæ, than to compare the daughter-cell the contents of which become a spore with the monosporangium of Chantransia, for the fact is that the spores in the tetrasporangium are also separated by cell-walls. If the term monospore might be used within this family, it must be for the cases where one spore only is produced by each originally vegetative mother-cell (e. g. Gonio- trichum, Erythrotrichia). When more than one spore are produced by a mother- cell, it might be desirable to give them the same designation as the tetraspores of the Floridew, but against that we have the fact that the number of spores is nol fixed and may be reduced to one. In order to avoid a long designation the spores produced without sexual process may be named gonidia. According to their mode of development the family may be divided into the following sections 56 1. Bangiee. Gonidia arising by division (or also without division) from an originally vegetative mother-cell. Frond fi fon see cee 2 ne Te Ce Bangia. Frond flatts qa See EE CL Ge OC EL LES Porphyra. 2. Erythrotrichiee. Gonidia arising in special monosporangia, cut off by a curved wall in a vegetative cell. EronderecEstilrfo rr me RE re EE PT EC LS Erythrotrichia. Frond first cushon-like, thereafter vesicular, ruptured and ex- panded in a monostromatic plane ......................... Porphyropsis. Frond consisting of creeping branched filaments, more or less CON MAN TO AMOTCSROTAUMNEC ChSEe EM eee po oc Erythrocladia. (Frond a monostromatie parenchymatous dise................ Erythropeltis). 3. Goniotrichieæ. Gonidia arising without cell-division. Gonidiannaked 5575 S80: CARR REP N ARTE CPR Goniotrichum. GonidiasproyadedSwilhzeellwalleegee pe cri ES SER ae Asterocylis. Bangia Lyngb. emend. 1. Bangia fusco-purpurea (Dillw.) Lyngb. LYNGBYE Hydr. p. 83, tab. 24 C; Harvey Phye. Brit. pl. 96; REINKE in Pringsh. Jahrb. 9. Bd. p. 274 tab. 12; BERTHOLD (1882) fig. 12—14; Kyrın (1907) p. 107. Conferva fusco-purpurea Dillw. Brit. Conf. pl. 92. Bangia atro-purpurea (Roth) /, fusco-purpurea (Dillw.) Ag. Syst. p. 76; Fl. Dan. tab. 1841; J. Agardh (1883) p. 36. In 1806 Rorx described (Catal. bot. III p. 208), under the name of Conferva atro-purpurea, a filamentous Alga found in a water-mill at Bremen; it was referred to the genus Bangia by LYNGBYE and was found in similar localities at many other places in Europe. Three years later, DirLwyn described a somewhat similar species, B. fusco-purpurea, first found on the British shores, and largely distributed on the Atlantic and Mediterranean shores. The resemblance between the two species, however, was so great, that LYNGBYE referred Rorn’s species as a variety to B. fusco-purpurea, while C. AGARDH conversely regarded B. atro-purpurea as the main species and B. fusco-purpurea as variety. The latter view was also maintained by J. AGARDH, who, however, expressly distinguished the freshwater form from the marine form while the older AGARDH only took the colour into consideration. I shall not enter on the question of the relation of these species, but like most of the marine phycologists record the marine species under Dittwyn’s name. The distri- bution of the species on the Danish shores does not favour the supposition ofa gradual transition to the freshwater form, as it does not occur in water of low salinity. The plant is at first a filament consisting of a single row of cells, and fixed at the base by rhizines, which grow downwards from the lower cells in the common outer-wall (REINKE |. c. fig. 1). In this form the plant can attain a con- siderable size, but sooner or later longitudinal walls occur, which have a more or less radial position and which divide the articles into wedge-shaped cells. 57 According to BERTHOLD (Il. €. p. 9), the first stage in the formation of the “neutral spores” or gonidia begins with the protoplasmic body increasing in mass, while at the same time shining globules occur, which are soluble in water and are slained brown by iodine, more rarely minute starch-grains, and the pyrenoid ‘ occupies the centre of the cell. During the first stages of these changes one or two divisions take place and then the cell-bodies are set free as spores. BERTHOLD does not indicate, if these divisions are only anticline or if they can also be pe- ricline. According to Scumirz (1896 p. 311), these spores can also arise without division from the whole of the contents of a vegetative cell. The first dividing wall of the fertilized carpogonium is, according to BERTHOLD (l.c. p.16), parallel with the surface of the thread, while the following are radial, and we thus have as result eight carpospores in vigorous threads. These though of very variable size are smaller than the gonidia, and differ from the latter, according to BERTHOLD, by containing minute granules of starch and a smaller and less lobed chromatophore; they show amoeboid movements though slower than those of the other spores. It will be understood from the above, that it is not always easy to decide if we have to do with gonidia or with carpospores, especially in examining dried specimens, and when the direct traces (e.g. canal) of the fecundation process have disappeared. — Male filaments I have met with rather seldom, though at different seasons, but most frequently and best developed in spring. While the formation of spermatia ordinarily takes place very uniformly, all cells in the same part of the thread being in the same stage of development, some threads collected in July at Frederikshavn showed a more irregular disposition, the antheridia being inter- mingled with cells which were little or not at all divided, and which undoubtedly would not reach to the production of spermatia. They could not be supposed to be carpogonia as there were no spermatia attached outside them and they showed no periclinal walls. BERTHOLD states also, that the species is dioecious “mit we- nigen Ausnahmen”. Female filaments with attached spermatia I have met with in February, April and May, and I have also several times been able to see the fine fertilization tube, though it seems to disappear rapidly along with the spermatia. In fig. 1 some fertilization tubes are still visible after the disappearance of the spermatia. The carpogonia may appear in thin threads, which are only divided by a few longi- tudinal walls, as well as in thicker filaments the articles of which consist of several cells (fig. 1). Fig. 2 A and B show transverse sections of female filaments which, seen from the side, showed spermatia attached to the surface. The cells, which have been divided by periclinal walls, must be supposed to be fertilized carpogonia. How many cells belong to the individual cystocarps in fig. 3 B is difficult to decide; it seems that vegetative periclinal divisions have also taken place, either before or after fertilization. I have only seldom seen carpospores containing starch-grains, e. g. in specimens collected at Hirshals in April, showing distinctly the process of D. K. D. Vidensk, Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 8 fertilization (fig. 1). nQ JC In dried specimens I could not see distinet starch-grains, but only indistinetly limited spots giving blue-violet colour with iodine. Gonidia seem to occur much more frequently than the carpospores on our coasts, as I have met with the species at all seasons and most frequently with Fig. 1. Bangia fusco-purpurea. Frag- ment of female filament with fertilization tubes and a few spermatia still adhering. 390 : 1. spores, which must be regarded as gonidia. These spores may arise in very thin threads whose articles show only one longi- tudinal wall, but their origin can also take place in thick threads with numerous longitudinal walls. As a rule two or four spores are produced by each mother-cell; most frequently I found no starch in these spores, but in a few cases I obser- ved numerous very small starch-grains in spores which were undoubtedly gonidia (Thyborøn and Skagen, July). In May I saw the spores escape from threads recently collected at Hirs- hals, a process that took place very rapidly; amoeboid move- ments I did not observe, but the chromatophore showed alter- ations of form. In one spore it had taken a globular form and was sharply defined; shortly afterwards it became angular and seemed about to take the ordinary stellate shape, but it soon took again the rounded form. In other cases these spores showed the amoeboid movements. This species occurs at ordinary high-water mark and higher, so that it is frequently out of the water and even dried up and in great measure only wetted by the spray of the waves. It is therefore easy to understand why it is not commoner than it is at the Danish shores, where the tide is mostly insignificant; in unfavourable periods with continual low water and calm, dry weather it would be in danger and would be killed at all the places, where it is not protected by special conditions against desiccation of long duration. At Frederikshavn it grows chiefly on the outer sides of the moles, where with a westerly wind the level of the sea is pro- portionally high, while with an easterly wind the level is low but the mole ordinarily washed by the waves. The most dangerous condition for the Bangia vegetation is a fairly long period of easterly winds with the wind so light, that this vegetation is not reached by the waves, especially when the weather at the same time is bright and dry. Its occurrence Fig. 2. Bangia fusco-purpurea. Transverse sections of female threads with eystocarpia. 200: 1. is therefore very different, not only at various seasons, but also in different years. In winter it is very abundant, but the critical period of the spring will every year kill a greater or smaller part of it and on the duration and intensity of this period depends to what degree that will take place. In summer for example it occurs at -purpurea, growing on Phyl- Bangia fusco ug. A lilis zosterifolia, mole at Hirshals, nal. size. Phot., Fig. 3. Specimens collected at Middelfart (Kongebro) Bungia fusco-purpurea. After photograph, natural size. March 1894. s 60 Frederikshavn in some years only in small quantities, while in others it forms extensive growths especially on the outer side of the south mole, as in the be- ginning of August 1902. In the Little Belt it completely disappears in summer, at all events in certain years (e. g. 1901), while in spring it is often abundant and luxuriant. In March 1894 it was so well developed there, that I have never found it better developed on the Danish shores; the threads attained a length of 14—15 cm and were above thick and curled (fig.3). In April 1904 I searched for it in vain at the same place. This is the most southern locality known on the Danish shores. Localities. Ns: Thyborøn, groin No. 58. — Sk: Hirshals, on the mole and on a boulder on the shore, observed in the months April to August, may occur abundantly still in July. Has also been found growing on Phyllitis zosterifolia (fig. 4). Greatest length of the threads observed here ca. 7 cm. — Lf: Harbour of Lemvig (2); Thisted; Glyngøre. — Kn: Harbour of Skagen: Busserev by Frederikshavn (April and July); harbour of Frederikshavn. — Ke: Harbour of Gilleleje. Febr. and May, ca. 1 cm long. — Lb: Harbour of Fredericia (Hofm. Bang. !); harbour of Middelfart, stone-slope west of the harbour, March and April, Kongebro. Bangia pumila Aresch. (DARBISHIRE, Ueber Bangia pumila Aresch., eine ende- mische Alge der östlichen Ostsee. Wiss. Meeresuntersuchungen, N.F. 3.Bd., Abt. Kiel 1898, S. 25) which according to DARBISHIRE is readily distinguished from B. fusco-purpurea as well as from the fresh-water B. atro-purpurea, and which, as far as known, is endemic in the Baltic, has not been met with hitherto in the Danish shores, though I have sought for it, particularly on the shores of Bornholm. It differs from B. fusco-purpurea in particular in that the articulation of the frond is still distinct in the older frond, which is divided by longitudinal walls, and through smaller cystocarps. As it has been found at Swinemünde and at Dantzig, there is reason to believe that it may also be found on the Danish Baltic coasts. According to KyLix (1907 p.109), however, this species has been found by ARESCHOUG not in the Baltic but “in den innersten Buchien von Göteborg”. This author regards it as being not a distinct species but probably only feebly developed specimens of B. fusco-purpurea. Porphyra Agardh. 1. Porphyra umbiliealis (L.) J.Ag. (Plate I and II fig. 1—3.) J. Agardh (1883) p. 66. ir laciniata (Lightf) Ag: Thuret in Le Jolis Liste des Alg. mar. de Cherbourg 1864, p. 99, Janczewski, Études anat. sur les Porphyra. Ann. sc. nat. Ve ser., t 17 1873, p. 241, pl. 19 fig. 25—26; Thuret et Bornet, Études phycologiques, 1878, pl. 31, p. 58. f. linearis (Grev.) Harv. P. linearis Greville, Alge britannicæ 1830 p. 170 tab. 18; Kützing Tabulæ phycologicæ XIX tab. 79: J. Agardh, Lc. p. 71; Le Jolis Algues marines de Cherbourg No. 96; Kylin (1907) p. 111. Ulva purpurea 5, elongata Lyngb. Hydr. p. 29. h P. vulgaris forma, Harvey Phycologia Britannica pl. 211, fig. 2-3; Thuret in Le Jolis Liste p. 99. P. hiemalis Kylin, (1907) p. 112 Taf. 3 fig. 2 f. vulgaris (Ag.) Thur. in Le Jol. Liste p.99. Ulva purpurea Roth Catalecta I p.209, Lyngb. Hydr. p. 29. 61 Porphyra vulgaris Agardh, Flora 1827 II p. 642, Icones Algar. tab. 28; Harv. Phye. brit. pl. 211; Aresch. Alg. Scand. exs. No. 261. f. laciniata (Lightf.) Thur. in Le Jolis Liste p. 99. Ulva umbilicalis Lyngb. Hydr. p. 28; Flor. Dan. tab. 1663. P. laciniata Ag. Syst. Algar. p.191, Icones Algar. pl.27; Harv. Phye. Brit. pl.92; Areschoug Alg. scand. exs. No. 116 and No. 260. P. laciniata var. umbilicalis Ag. Ic. Algar. tab. 26. ; With regard to the limitation of the species I agree with Taurer (in Le Joris Liste), but I follow J. AGARpH in adopting the specific name of LINNÉ, as it is the oldest and besides not less significant than Lignrroor’s name laciniata. As to the f. linearis, the views of authors have been divergent. It was Harvey (Phyc. Brit. pl. 211) who first showed, from observations in nature, that it is only a juvenile winter-form, which later passes over into the broader form, and this has been confirmed later by THurer and others. J. AGAnpu regards it however as a distinct species, emphasizing that it occurs not only in winter but also in spring. Kyrın follows this author but without discussion of his view. Having observed this form in nature in winter and spring, I cannot but come to the same result as Harvey and THURET. In winter this species is abundant on the moles at Frederikshavn, on the inner as well as the outer side, and it occurs then mainly in rather narrow forms, which pass gradually and evenly into specimens which correspond exactly with P. linearis Grey. While the latter is said to attain only a length of a few inches, specimens more than 20 cm. long but less than 1 cm. broad, for the rest fully typical, were commonly found. The largest specimen I have col- lected is without the basal portion but is notwithstanding 43 cm. long with a breadth of only 0,8 cm. The typical specimens of f. linearis have a well developed stipe, rounded base and the margin a little or not undulated. In some broader specimens the margin becomes more undulated, the base broader and cordate (Plate II fig. 1—3). Such specimens agree with Kyrın’s P. hiemalis; the only diffe- rence between this and P. linearis seems to me to be, after Kyrın’s description, besides the somewhat greater dimensions, the fact, that the sporocarps form long narrow sori. This I have also observed in some of the specimens mentioned here (Plate II fig. 1), but by no means in all, and on the other hand it occurs also in broad specimens of P. umbilicalis (Plate I fig. 3), and therefore it cannot be used as a distinguishing character between the forms of this species. These narrow forms occur in great quantity in winter on the moles of Fre- derikshavn, particularly on the outer side of the outer moles, at high level, and also on moles and groins on the west coast of Jutland. In spring, when easterly winds occasion low water, this fact in connection with the increasing dryness of the air and the strong sun will cause these Porphyra plants to a great extent lo die. The individuals surviving this critical season are those growing at a rather low level or in places which are protected by particular conditions against drying up during low water. In growing older the frond of these individuals increases more in breadth than in length, and the same frond may then pass in development 62 from f. linearis through f. vulgaris to f. laciniata (comp. Taurer in LE Joris Liste p.100). In f. vulgaris the longitudinal axis of the frond is much longer than the radii going outwards or downwards, but under the continued growth of the frond in transverse direction this difference diminishes and at last entirely disappears, the frond obtaining an approximately orbicular outline, at the same time becoming more or less laciniated and, on account of the continuous transverse growth, much radially folded (Plate I fig. 2). The point of attachment in this stage is only appa- rently, not really central and umbilicate, as supposed in the older descriptions and drawings (LINNÉ, Spec. plant. II 1763, and Dırrenıus, Hist. muscor. 1741, tab. 8). Though the f. linearis normally disappears in spring on the Danish shores, it can however be found much later in the year if rarely. Thus I have met with it on the outer side of the northern mole of Frederikshavn, near the entrance of the harbour, at a place where the sea is as a rule agitated, in July 1895 and September 1892. The specimens found in September were very well developed, up to 30 cm. long, 0,5 to 1,3 cm. broad, fully typical, only of a lighter colour than the specimens occurring in winter. These discoveries, however, may be very rare exceptions, for I have otherwise never found this form in summer at Frederikshavn, one of the best investigated localities in Denmark, as little as in any other locality. ARESCHOUG has also found it in August on the shore of Bohuslän (Phyc. scand. mar. p. 180). This species has been met with in all the months of the year, and it occurs at all seasons in fully developed specimens. It can probably attain an age of more than one year, but most of the specimens die, as said above, at a rather young age. It has been found fertile at all seasons, and then nearly always with sexual organs (or carpospores). While several authors state that the species is as a rule dioecious (THURET, BERTHOLD, Kyrın), I have found it most frequently monoecious on the Danish shores, at all events in summer. In winter only have I found the specimens generally dioecious, particularly f. linearis (Plate II fig. 2—3). In the spe- cimens met with in summer the frond is generally divided by a longitudinal limiting line into a male and a female portion, distinguishable thereby that the margin of the first is yellowish white, that of the second purple. The limiting line is most often re- markably straight; it is very distinct towards the margin, while downwards it be- comes indistinct and finally vanishes on reaching the sterile portion of the frond (Plate I fig.1). The male and female parts of the frond are in some cases of equal size, in others the male or the female is broadest. Even the narrow winter forms can be monoecious and show a well marked limiting line (Plate II fig. 1). According to Hus (1902, p.197), the sporocarpia and antheridia in Porphyra laciniala (umbili- calis), when they are developed in the same frond, “occur in patches very much as in P. perforata”. If that is really normal to the species of the Pacific coast, it must be supposed that it is a different species from the European P. umbilicalis. The decoloration of the developing antheridia generally takes place gradually from the margin inwards. Some few specimens from Helsingør showed however, at some distance from the margin, some lighter spots, reminding one of the an- 63 theridial spots in P. leucosticta. They were found to consist of antheridia earlier in their development than the surrounding antheridia, which were still in division. As first shown by BERTHOLD (1880 and 1882), the spermatia attach themselves to the female portions of the frond, and a fine fertilization canal is formed through the wall of the carpogonium-cell. These fertilization canals contain a thin strand of protoplasm, which is still to be seen a long time after the fertilization, while the exhausted spermatium quickly disappears. Their number is often remarkably great, much greater than that of the carpogonia (fig. 5 A—C). It is evidently a very common case that several fertilization tubes are intro- duced to one carpogonium. The fertilised carpogonium divides, as is well known, by a transverse wall; thereafter follow olten one or two further transverse walls, whereupon arises a 3- or 4- celled prismatie body wich there- after may be further divided by differently orientated walls (fig. 5 D, F). Such divisions result no doubt in cystocarps with numerous carpospores, while the typical case is regarded to be eight carpospores in two layers. Extraordinarily large cystocarps, containing a great num- ber of spores, were found in speci- mens collected in the harbour of Skagen dinvAprilishesrond ofiwhiehePrelgreswnlientn eyes Benson ne ERE Saen, was unusually thick, 90 to 1154 (fig. and, at a higher level, the fertilization tubes and in Aa spermatium ME TEE RS pean nie cies fig. 10. frond with cystocarps from the same locality, April. 230:1. F, in- completely divided cystocarp, Frederikshavn December. 500: 1. In anumber of specimens (52) collected in March on groins near Thyborøn, nearly all belonging to f. linearis. a few to f. laciniata, I found only cystocarps containing about 8 carpospores arranged in two layers, but in no case could spermatia or fertilization tubes be observed, and none of the plants contained antheridia. As the spores in all cases examined resulted from a division parallel to the frond, it may be supposed that we have here a case of apogamy, if it should not be found that the monospores can resull also from such divisions. The development of the cystocarps is as a rule uniformly progressive from the margin of the frond inward. Sometimes, however, the maturation takes place 64 more rapidly in some irregularly ramified spots than in the surrounding parts, and these spots appear therefore with a deeper red colour, as observed earlier by BERTHOLD (1882 p. 16). As mentioned above, this is to be found in broad as well as in narrow forms, and it cannot be used as distinctive character between them. The carpospores contain as a rule numerous minute starch-grains which are stained brown-violet with iodine. I have also found fertilised carpogonia containing starch before dividing, but on the other hand I have also seen carpospores with- out starch. The gonidia result, according to BERTHOLD, from one or two divisions per- pendicular to the plane of the frond, and the frond after these divisions is conse- quently one-layered as in the vegetative state. These spores seem to oceur much rarer on the Danish shores than the carpospores. I have not had occasion to observe this kind of fructification in fresh spe- cimens or in specimens preserved in alcohol; I have only met with a few herbarium specimens which seemed to contain gonidia. Thus, a specimen collected in the harbour of Seby in September was without sexual organs, rather uniformily rose-coloured, and consisted merely of a single layer of cells of the same size as the vegetative cells, but with richer, more granular plasmatic contents, which stained brown-violet to nearly dark with iodine, without however showing distinct starch-grains. Further, the cell-bodies were much disposed to leave the cell under the softening. The germinating plants are, as shown by THURET and BORNET (1878 p. 58), at first filiform, but at an early period longitudinal Fig. 6. divisions and rhizines arise. The apical cell is early divided by Rs a longitudinal wall, while the inferior part of the thallus is still growing on Nemalion filiform (fig. 6). Saas A cn. The species grows, on the Danish shores, about at ordinary water level, or at some distance above it, especially in winter, or a little under it, but hardly under the lower water-level. When occurring in the Fucus-zone, it grows only in the upper part of it. At Esbjerg it occurs only in the upper part of the littoral region. It thrives best where the salinity of the water is compara- tively high and the locality tolerably protected. It attains therefore its greatest size at Esbjerg and in the Limfjord, where it becomes more than 40 cm. long, while it is smaller on the more exposed groins and moles at Thyborøn and Hirshals. In the most southern localities in the seas within Skagen I found the following maximal sizes of the frond: in Little Belt (Middelfart) 24 cm., in Great Belt (Smor- stakken) 29 cm., in the Sound (Helsingør) 12 cm. Most of the Danish places for this species are moles; the natural habitats are emerging reefs and boulders near land. It grows also on wood, more seldom on Fucus; young specimens have been found growing on Nemalion multifidum. Conan OODUS QU DE, 65 Localities. Ns: Nordby, Fano (C. Rasch, abundantly in the Fucus-zone!); Esbjerg (Borgesen, on moles and embankments in the upper half of the littoral region!); groins by Thyboron (in spring chiefly f linearis, in summer only broader forms. — Sk: Hirshals (on the mole and on boulders on the shore, in spring f. linearis abundantly above high-water mark, in summer the species disappears entirely or almost entirely). — Lf: Harbours of Lemvig, Struer and Thisted; Aalborg, harbour and piers of bridge (!, Th. Mortensen and unknown collector in herb. C. Rosenberg); Nørre Sundby; Hals. — Kn: Harbour of Skagen; Busserey (with Bangia near high-water level, small specimens in April; harbour of Frederiks- havn (in winter f. linearis abundantly, mainly at high-water level, in summer only broader forms, as a rule in small quantity); harbour of Sæby. — Ks: Harbour of Grenaa. — Sa: Kyholm (upper Fucus- zone, with Ralfsia); Aarhus, harbour, and on boulders on the shore by Riis Skov. — Lh: Harbour of Bogense (!, Borgs.); Fredericia (Hofm. Bg., Joh. Lange,!); Strib; harbour of Middelfart (Hofm. Bg., C. Ro- senb.,!), Kongebro. — Sh: Harbour of Lohals; Smorstakken. — Su: Harbour of Helsingor. 2. Porphyra leucosticta Thuret. (Plate II fig. 4—13.) Thuret in Le Jolis, Alg. mar. de Cherb. 1864, p.100. Janczewski, Ann. se. nat. Ve ser. t. 17, 1873, p. 241 pl. 19 fig. 1—14. Berthold (1881) p.79. Id. (1882) Taf.1 Fig. 1—6. Porphyra atropurpurea Olivi in Saggi Accad. di Padova III. 1. 1791, teste De-Toni, Syll. Alg. IV. Sect. 1, p.17. Exsicc.: Crouan Alg. mar. du Finistère No. 397. Le Jolis Alg. mar. de Cherbourg No. 156. This species which has only been met with on our most northern shores, occurs there in its typical shape but does not attain a considerable size. The largest observed specimens are (in a dried state) 10—11 cm. long, only one specimen was UN - 16 cm. long. The longest fronds are lingulate, | à an, (8 \ Uy, A about 2—4 cm. broad, with rounded or more frequently cordate base, but very often the margins of the frond overlap each other below he baser, particularly in the broadest speci- Porphyra leucosticta. | sections of frond mens, in which the attachment may then with carpogonia: in 4 these are not fertilized, become apparently umbilicate. The frond is wre in Eines a Pe ae MINS generally entire, rarely a little lobed, the margin more or less undulated. The colour is as a rule a little more reddish than in P. umbilicalis, but the difference is not absolute; the two species can occur with exactly the same colour. The thickness of the frond I found to vary between 28 and 44 y. The specimens met with in April were all provided with sexual organs, in so far as they had attained a tolerable size. The antheridia formed the well known patches, running longitudinally in the upper part of the frond, 5—10 mm. long, 1—1,5 mm. broad. There are, however, also very small antheridial patches, originating in a group of very few mother-cells. The number of spermatia arising from each mother-cell is fairly often smaller than 64. As shown by JANCZEWSKI (1. c. p. 247), isolated cystocarps are often scattered among the antheridia. The carpogonia had very often produced a hyaline protuberance at each extremity, a state which, according to BERTHOLD, is due to the fact that the carpogonia have been obliged to wait a long time for fecundation. When all the carpogonia assume this form, the frond becomes papillose on both sides. Fig. 7 B shows a spermatium D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 9 66 attached to the top of a papilla, while the adjacent carpogonium has divided by a transverse wall after fecundation; the fertilization-canal of this carpogonium is yet to be seen below. The carpogonia produce 4 or 8 spores in two layers. This species seems to disappear during the summer. On July 22¢ 1905 on the moles of the harbour of Skagen I only found some very small specimens 1— 1,5 cm. high, being evidently the under part of specimens which had exhausted their spermatia and carpospores; there were namely still to be seen remnants of emptied antheridial sori and some few cystocarps containing 8 spores, while the upper border of the frond consisted of emptied cell-walls (Plate II fig. 9—13). In 1907 the species remained longer, perhaps in connection with the fact, that the summer was unusually cold with predominant westerly winds. On July 11% 1907 I found in the same locality rather large specimens, some of which showed antheridia, in part not emptied, and cystocarps. Other specimens did not show these organs and did not seem to have produced them earlier. In such a specimen the cells in the upper part of the frond had more granular contents than the vegetative cells, for which reason I am inclined to believe, that they were producing gonidia (Plate II fig. 8). These cells had a sharply limited lateral vacuole; they were not divided by walls parallel to the frond. Kyrın (1907 p. 110 Taf. 3 Fig. 1) has established a species nearly related to P. leucosticta under the name P. elongata (Aresch.) Kyrın (P. laciniata var. Areschoug Alg. Scand. exsicc. No. 117), which is distinguished by its elongated form of frond with uniform breadth, its thinner frond (25—33 y while it is said to be 33—40 u in P. leucosticta), and the smaller antheridial sori; it may be added that the author found it epiphytic and fructiferous in August. It appears to me, however, to be rather doubtful if it can really be regarded as a species distinct from P. leu- costicta; at all events, the alleged characters are hardly conclusive. As said above P. leucosticta has often a lingulate form (comp. PI. II fig. 4—8), and that is so also in specimens from the coasts of France. The thickness of the frond was found, in the Danish specimens of this species, to vary on both sides of the limit given by Kyrın (se above). That the sori of antheridia in the specimens of KyLiN reached only a size of 2 mm., while they attained a length of 10 mm. in the Danish spe- cimens, is scarcely sufficient for specific distinction. I have found no specimen on the Danish coasts fully agreeing with P. elongata Kyrın, the specimen most similar to it was 16 cm. long, 2 cm. broad, on the one side with a small lobe; it had a thickness of 28 », but the antheridial sori .were long. The plant grows on stones at the mean level of the sea. Localities. Sk: Hirshals, on the mole and: on a large boulder on the shore, April 1906. — Kn: Harbour of Skagen; it appeared contemporaneously with the construction of the harbour; it was detected by Mag. M. L. MORTENSEN, “/4 1905, on the moles commenced the preceding year and constructed, as far as known, exclusively of stones taken on land. Later, I have found it, on several visits in April and July, on the outer and inner sides of the moles, but only or principally near land. Erythrotrichia Areschoug. Phyceae Scandinavicae marinae 1850 p. 209. 1. Erythrotrichia carnea (Dillw.) J. Ag. J. Agardh (1883) p. 15. Conferva carnea Dillwyn, Brit. Conf. 1809 pl. 84. Conferva ceramicola Lyngb. Hydr. 1819 p. 144 tab. 48 D (teste specim.) Banyia ceramicola Chauvin. Rech. sur l’org. de plus. genr. d’Algues, Caen 1842, p. 33; Harvey, Phye. Brit. pl. 317: Hauck, Meeresalg. p. 22. Erythrotrichia ceramicola Aresch. l.c. p.210; Le Jolis (Thuret), Alg. mar. Cherb. p. 103 pl. Ill fig. 1—2!; Berthold (1882). This species is attached to the substratum not by means of a basal layer of cells, but only by the basal cell which gives off short ramified rhizines radiating in all directions on the surface of the substratum, while the other cells of the fila- ment produce no rhizines. In fig. 8 C the rhizines are rather irregular as the plant was attached to the border of a Porphyra thallus. At the base the filaments are a little thinner than higher up, but the outer cell-wall becomes by and by incrassated. The filaments often attain only a length of 0,5 cm., but where the plant thrives well it becomes at least 3 cm. long. The thickness of the filaments is 16—24 y, a little less at the base. The cells contain a star-shaped chromatophore with numerous narrow branches radiating in all directions, in particular downwards and upwards, and with a cen- tral pyrenoid. The nucleus is small and not always visible as it is often hidden behind the chromatophore or between its branches (fig. 8 D—F). The vegetative cells contain in general no starch; some specimens collected in Sallingsund, Lim- fjord, in July were however the exception in this respect, all cells containing nu- merous small starch grains staining blue-violet with iodine; yet the sterile cells showed not so many starch grains as the sporangia. The length of the cells in proportion to the breadth is rather variable. In specimens collected in January the cells were very short and their contents very dense; their length was always shorter than the breadth, often only a third, while in summer filaments are often met with, the cells of which are 3—4 times as long as broad and then with rather poor contents. Plants collected on Herthas Flak (Kn) in 19 meters depth in Sep- tember consisted of cells of about equal height and breadth. I have only seldom met with a few cells divided by longitudinal walls and they gave one rather the impression of being somewhat abnormal. BERTHOLD (l.c. p. 25) also found longitu- dinal divisions very seldom, while J. AGARDH (I. c. p. 14—15) thought that they were common in this species’. : This species has only non-sexual reproduction. The spore-mother cell is, as well known, cut off by an oblique wall at the upper end of a cell which is not different in form from the vegetative cells. Its formation begins with the nucleus 1 It may be doubtful, whether all that is referred to this species by this author, belongs really to it, as for inst. his Tab. I fig. 8, which represents a polysiphonous proliferous filament. oF 68 dividing into two, the one lying over the other at the one side of the cell. Then the chromatophore divides after a longitudinal plan into two of unequal size lying side by side (Fig. 8 D); the larger later moves upwards and is taken up in the spore together with the upper nucleus (Fig. 8 E, F). In the lower chromatophore the pyrenoid is very small and indistinct shortly after the division, while the upper contains a large and distinct pyrenoid; it is therefore probable that the original pyrenoid passes undivided over into the larger chromatophore, while a new pyrenoid is formed in the smaller. The fructiferous cells contain many small starch-grains which stain dark-violet with iodine; they are to be found in the sporangia as well as in their sister-cells. The sporangium is in general smaller than its sister-cell; when the mother-cell is very short, however, they à i can be of equal size or even larger. As shown by a THURET and BERTHOLD, the under-lying cell, after is the evacuation of the spore, expands and occupies = the place of the original mother-cell, and the pro- cess of spore-formation may be repeated. The plant has been found in almost all Danish waters excepted the Baltic, as a rule, however, only in small quantities and therefore not conspicuous. In greater quantity only found at Struer, in the Limfjord, (Sept. 1890) and in the harbour of Frede- rikshavn (particularly in August 1891 and July 1896). It is a summer Alga, nearly exclusively met with in the months July to September; it has how- ever also been collected in winter (Nov. and Jan.). It has been found fructiferous in all the months Fig. 8. named. It does not like much agitated water; it A ROE CTE on es hag dean found most frequently and in greatest and bases of plants attached to Porphyra. fo) 380:1. D—F, fructiferous cells; in D the quantity in harbours, on piers and the like, in chromatophore and the nucleus have re- 3 cently divided, in E and F the sporangiad Small depths, but it has been found down to 19 Gall! hes bean GH Gi Bl, meters. It is always epiphytic and has been found growing on a number of different Algæ, e. gr. Polysiphonia nigrescens and violacea, Ceramium rubrum, Brongniartella, Bryopsis, Porphyra umbilicalis and many others. Localities. Sk: SY, off Løkken, 13 meters. -- Lf: Harbour of Struer; Sallingsund, at Glyngøre and off Snabe, 4—6 meters: LS, off Arnakke, 7 meters; MI, off Ejerslev, 4 meters. — Kn: Herthas Flak, 19 meters, (Borgs.): harbour of Frederikshavn; Borrebjergs Rev; Nordre Ronner; GM, 6 meters. — Km: BL, 9,5 meters; BH, off Gjerrild Klint, 4 meters. — Ks: Holbæk Fjord. — Sa: Kalo Rev; Hofmansgave (Lyngbye, Hofm. Bg.). — Lb: Harbour of Middelfart. — Su: BQ, off Ellekilde, 5,5 meters; PZ, E. of Hveen. Porphyropsis gen. nov. Frons initio pulvinata parenchymatica, dein vesiculosa et ruptura in mem- branam monostromaticam expansa. Spore (gonidia), ut in Erythrotrichia, divisione obliqua in cellulis frondis gignuntur. Reproductio sexualis ignota. 69 1. Porphyropsis coccinea (J. Ag.). Porphyra coccinea J. Agardh, Novitiæ fl. Svec. 1836 p. 6 (without description); J. Areschoug, Phye. Scand. mar. 1850 p. 181 tab. I D; J. Agardh (1883) p.56; P. Kuckuck, Bemerk. z. mar. Algenveg. Helgoland II, 1897, p. 390 fig. 13, 14. This pretty little Alga, which has been referred till now to the genus Por- phyra, I have met with only at three places in the eastern Kattegat, at the two only in extremely small quantity. As its mode of fructification has been hitherto unknown, its systematic position has remained uncertain, as pointed out by Kuckuck, who showed that the chromatophore has no central pyrenoid as in the other spe- cies of Porphyra but that it forms a much divided parietal plate. It will be seen from the following that this plant also in other respects differs so much from the typical species of Porphyra, that it must be removed from this genus. Thus the development of the frond is quite different; whereas in P. umbilicalis this begins as a filament which early becomes leaf-like, being divided by longitudinal walls, in Porphyropsis coccinea the frond is at first cushion-like, parenchymatous and composed of more than one layer of cells. The frond increases in height and becomes globular and vesicular. Such a condition is to be seen in Fig. 9 A. As this and other similar plants were growing together with more advanced stages of this species and as they much resembled the lower, basal portions of the latter, I conclude that they belong really to the same species. The plant figured is nearly hemispherical with a lobed plane of attachment, in the margin of which the cells are somewhat elongated. The upper part of the frond consists of a layer of cells which are actively dividing by anticlinal walls; the growth caused by these divi- sions has caused a separation of this cell-layer from the cells lying within, and the continued growth must necessarily cause the plant to become more and more ve- sicular. A rupture of the vesicle must, however, take place at an early period, for small individuals occur with an irregularly lobed monostromatic frond tapering downwards and ending in a cushion-like, basal disc resembling the under part of fig. 9 A. In consequence of this development the young frond is usually more or less cup-shaped; in particular, the margins immediately above the basal cushion are most frequently bent inwards to the same side. The expanded frond projects from the one side of the basal cushion, the greater part of which is situated at the hol- low side of the young frond. On the side of the cushion opposite to the frond are often to be seen irregular projections representing the lower border of the split by which the monostromatic frond has arisen. The lap visible below on the left in fig. 9 C belongs undoubtedly to this category. The formation of the split itself I have unfortunately not observed; probably a transverse split is formed on the one side of the vesicular frond. The development here described is not entirely un- known; J. AGARDH (1883 p. 56) describes the young plants thus: “Hoc modo plan- tam nondum lineam altam fere hemisphæricam vidi, nempe lamina marginibus ila involuta ut media pars sursum spectaret, apice marginibusque ad ambilum hemi- sphærii decumbentibus (Tab. II fig. 41); dum dein eircumeirca increscil, sensim magis 70 erigilur et fil fere cucullatim involuta, marginibus sursum hiantibus (1. c. fig. 42)”. The celebrated author has not perceived that the leaf-like frond arises by splitting of a globular vesicle, but his fig. 41 seems to represent just the state where the split is formed. When the frond grows older, numerous rhizines are formed from the cells in the lowest part of the frond, which may result in the original basal cushion becoming less distinct; it is however always evident that the cells in the basal portion of the frond are situated in more than one plane. QUE værn W DS Sood X47) 1 (ce SD re za Q v Q 80 I Ww £ qs AUX 6 we) ) SO 6. ie) Cc he > | ) CSO Porphyropsis coccinea. A, young plant. still hemispherical. 550-1. B. more developed plant with expanded lamina and spore-mother cells scattered over the frond. 340:1. C. lower part of older plant: it was not plane. but the borders were curved somewhat backwards. 340:1. D, basal portion of frond showing the rhizines. 550:1. This plant offers an interesting analogy to the genus Monostroma among the Chlorophycee and the genus Omphalophyllum among the Phæophyceæ. In Porphyra naiadum Anderson the frond also begins according to Hus (1902, p. 212) as a parenchymatous cushion, but the later development is quite different from the above described, the cushion producing from its surface hair-like projections which, dividing in two directions, give rise to a monostromatic frond. The cell-divisions take place in some measure uniformly over the whole 71 monostromatie frond, more frequently however at the border, where the cells are therefore a little smaller and closer together. The intensive marginal growth results in the margin becoming much undulated. In fig. 9 C, which was drawn after a dried specimen, the cells are seen to be arranged in groups of two or four or a little more, rather distant from each other. As said above, the reproduction has hitherto been unknown in this species, and I have also searched in vain for any indication of a fruclification in several fully developed specimens. In other cases, however, I succeeded in finding a for- mation of spores corresponding lo that in Erythrotrichia; even in very small spec- imens it could be observed. Thus in fig. 9 B several cells are divided by an in- elined curved wall into a roundish cell filled with protoplasmie contents, the spore-mother cell, and a crescent-shaped sterile cell. The spore-mother cells are scattered without order over the whole frond; even marginal cells may produce them (fig. 9 B, at the summit). In fig. 10 is shown a small fragment of another, larger plant where most of the cells have produced spores. As I have only exa- mined the plant in preserved condition I cannot give any information of the be- ‚haviour of the sterile cell on the escape of the spore. The described fructification along with the peculiar develop- 4 ment of the frond justify the establishment of this plant as the 3 2 2 representative of a new genus. On account of the resemblance 6 © 1e in appearance to the genus Porphyra I have named it Porphyropsis; 09e & a diagnosis is given above. Only found in the eastern Kattegat in 20 to 25,5 meters depth, Fig. 10. epiphytic on various Alge. The largest specimens, 5 mm. high, AC en with much undulated margin, were met with at the end of July; rangia. 630:1. young plants were collected in May and July. Localities. Ke: Fladen, ZF, on stalks of Laminaria digilata, on Dilsea edulis and Rhodymenia palmata a.o.; Groves Flak, VZ, on Desmarestia aculeata; Lille Middelgrund, IK, on Odonthalia dentata. Erythrocladia gen. nov. Thallus horizontaliter expansus, e filis ramosis, aliis algis adfixis, radiatim egredientibus, initio inter se discretis, dein in discum tenuem unistratosum confluen- tibus, constans. Crescentia filorum apicalis. Sporangia eodem modo ac in genere Erythrotrichia in cellulis intercalaribus vel rarius terminalibus gignuntur. Generatio sexualis adhuc ignota!. 1 Barrers has in 1896 (Journ. of Botany Vol. 34) established a genus Colaconema, characterized by branched filaments living in the cell-walls of various Algæ and by monosporangia “formed from portions cither of the terminal cells of the principal axes, or of short swollen 1- or few-celled lateral branches, or even from a portion ofa cell in the continuity of the filament. The undifferentiated por- tions of the cells forming cup-like bases for the sporangia’. This genus was later placed by Barrens (Journ. of Bot. Vol. 40, 1902, Supplement p. 57) near to the genus Acrochætium (Chantransia) and one species was removed to this genus. The indicated mode of formation of the monosporangia suggests however that the genus may include forms belonging to the Erythrotrichieæ, and the sporangia arising SJ i) 1. Erythrocladia irregularis sp. nov. Thallus minutus, ambitu irregulari. Fila lateraliter ramosa, irregulariter ra- diantia, sæpe maxima pro parte inter se discreta. Rami plerumque in cellula sub- terminali nascuntur. Cellule plerumque oblongæ, long. 7—11 y, lat. 3,5 —5 y, chromatophorum unicum parietale, ut videtur pyrenoide instructum, continentes. Sporangia diametro c. 4 y. Scumitz has established a genus Erythropeltis (1896 p. 313), which in its re- production agrees with the genus Erythrotrichia but differs from it by the frond consisting only of a monostromatic disc with continuous border and with marginal growth. To this genus is only referred one species, E. discigera (Berth.) Schmitz!, and to the same species BATTERS has later referred a new variety, var. Flustre, (Journ. of Botany, Vol. 38, 1900 p. 376). The thallus is described in this as “orbi- cular, becoming confluent and irregular in outline’, and it must therefore be supposed that the irregularity only appears by the fusion of originally separate discs. In our plant, on the contrary, the frond consists of mutually separate filaments which only at a later stage are partly confluent, and it must therefore be referred to a new genus. The plant of which a diagnosis is given above was found in rather great, numbers on some specimens of Polysiphonia urceolata dredged off Hirshals in the Skagerak. It forms irregular spots of up to 100 » in diameter on the surface of the host-plant. It consists at first of branched filaments whose branches are mutu- ally enlirely separate. As shown in fig. 11 A the primary filament grows out in two opposite directions and gives off branches at both sides. These branches grow out and branch further, and in the more developed plant the filaments are there- fore radiating in all directions in the horizontal plane, and the filaments are then more or less fused together in the central part of the frond. The filaments show apical growth, and transverse walls appear only in the terminal cells, a natural consequence of the filaments being fixed to the substratum. The branches usually arise in the subterminal cell, sometimes also in cells nearer the centre of the frond, but the terminal cell is only very seldom ramified. The ramification is thus strongly monopodial. Not seldom a number of consecutive cells each give off a branch, now alternating, now secund. The outline of the plant is always more or less irregular, some filaments growing longer than others. The cells contain a single chromatophore, the form and structure of which I have not been able to determine with certainty, as I have only had dried speci- mens at my disposal. In several cases however it appeared to be undoubtedly parietal, and I often saw a body which I took to be a pyrenoid, though it was not very distinct (fig. 12). from a cell in the continuity of the branched filaments recall the genus Erythrocladia, but the plants need further examination. None of the described species can apparently be referred to the genus Erythrocladia. 7 The genus is founded on Erythrotrichia discigera Berth.; but, according to BERTHOLD (1882 p. 25), the dise in this species sometimes produces erect filaments, and it must therefore be supposed that Scumirz has taken the species in a more restricted sense than BERTHOLD. 73 The sporangia are cut off in the ordinary vegetative cells, in la}similar manner as in the genus Erythrotrichia, by a more or less oblique curved wall. The for- mation of sporangia takes place usually in the inner, intercalary cells, more rarely in the terminal cells. The orientation of the wall is not always the same; usually the sporangium is cut out at the proximal end of the cell, apparently very seldom at the distal end; but the wall is not seldom —@ooo— OSG longitudinal, particu- larly in short cells from which a branch is given off (fig. 12). The spores are in the fully deve- EL RS loped state nearly glo- Br > » bular, about 4 y in dia- 99009 © meter; they have more Q granular contents than SE the vegetative cells and Ae? Ya YEN I often show a distinct Fig. 11. parietal chromatophore Erythrocladia irregularis. A, young plant seen from above. B—D, more devel- oped plants with sporangia seen from above. E—I, plants in vertical section, (fig. 11 C, D, fig. 12). F—I, with sporangia. A—E 390:1. F—I 620:1. It is evident that the above described plant cannot be referred to the genus Erythropeltis on account of the structure of the frond. It differs further from E. discigera var. Flustre Batters by its much smaller spores, while the spores in Batters’ plant are about 9 # in diameter. Localities. Sk: Mollegrund off Hirshals, 11,5 to 15 meters, on Polysiphonia urceolata, August. 2. Erythrocladia subintegra sp. nov. Thallus minutus suborbicularis. Fila sat regu- lariter radiantia, plerumque fere ad apices latera- liter connata, cellulis terminalibus tamen inter se plus minus discretis. Ramificatio fit in cellulis ter- minalibus, sæpe dichotoma. Cellule plerumque cy- Fig. 12. lindricæ, lat. 3—4 (—5) x, long. 8—10,5 w. Sporangia Erythrocladia irregularis. Plant with spor- jn parte proximali aut distali cellularum orta dia- angia seen from above. 730: 1. metro €. 4 (—S) y. In company with the foregoing species I found some individuals of a species evidently nearly related to it, but showing however such differences that I think it best to consider it as a distinct species. It is more regular, more or less approa- ching to the orbicular form, and consists of more regularly radiating, closer to- gether and a little thinner threads (3—4 4), which are most often united almost to D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 10 _ 74 the extremity, the terminal cells, however, being usually more or less free, and the same being also sometimes the case with the cell next to the end-cell. The rami- fication takes place exclusively or principally in the end-cells, and it has usually the character of a dichotomy, the cell bifurcating with two equally developed bran- ches; the one branch, however, may sometimes be stronger than the other. The cell-walls of the filaments are thin and often not easily distinguishable. In the inner part of the cell-disc a granular substance is often to be seen in the middle of the walls; perhaps interstices between the filaments. The chromatophore seems to be of the same shape as in AMA A227 WRN ZA 2 5 a 3 : POLE the foregoing species, it is parietal, apparently mantle- ESM ET EE shaped, and seems to contain a pyrenoid; at all events FS. REISE a body of greater density is often visible in the middle of the cell. The cells are cylindrical or oblong or more irregular, usually 2—3 times as long as broad, if | in the inner part of the frond generally a little broader CON AAN than at the margin. i The sporangia are, as in E. irregularis, cut off in Erythrocladia subintegra. Frondgrow- the ordinary cells through a faintly curved wall, some- Så re UE pe ie times at the proximal, sometimes at the distal end of rangium is cut off. 650:1. the cell: they have a parietal, cupshaped chromato- phore and measure 4 y in diameter. This species shows more resemblance than the preceding to the genus Ery- thropeltis, from which it differs, however, by the margin of the frond consisting of separate filaments. If we supposed, that the distinction established between these two genera might prove not to be constant, there would be reason to compare Erythro- cladia subintegra with Erythropeltis discigera Schmitz. Such a comparison, however, is difficult to undertake, as the last-named species is imperfectly known, in particular on account of what is alluded to above (p.72) with regard to the limitation of the species. Using the magnification indicated by BERTHOLD I have calculated that the cells of his species are 5,5 to 7 » broad, thus considerably Fig. 14. broader than in E. subintegra, and in Erythropeltis disci- Æruthrocladia subintegra. Frond seen from above. A few sporangia gera var. Flustræ Batt., where the spores are much larger are visible. 630-1. than in our species, namely 9 » in diameter; the cells are also larger than in E. subintegra. It must therefore be supposed, that the spe- cies described here has not hitherto been observed, but I admit that it needs further investigation as well as the species of Erythropeltis and the relation between this genus and the genus Erythrocladia, and the relation between the genera Erythro- peltis and Erythrotrichia. The description given above refers only to the specimens mentioned as found 19 on Polysiphonia urceolata. Later I have found, on Flustra foliacea, some dises which I think must be referred to the same species; they differed in their slightly larger dimensions and in the margin being partly continuous, the filaments being united to the extremities. These discs were thus still more similar to Erythropeltis, but the filaments had always partly free endings. The filaments were 3,5—5 y thick, narrowest at the border, broadest in the middle of the frond. The spores were 4—5 y in diameter. Localities, Sk: Off Hirshals (XO and YK), 11,5 to 15 meters, August. Goniotrichum Kitz. 1. Goniotrichum elegans (Chauv.) Le Jolis. Le Jolis, Alg. mar. Cherb. p. 103; J. Agardh (1883) p.13; Berthold (1882) p.26; Hauck, Meeresalg. p. 518. Bangia elegans Chauvin, Mém. Soc. Linn. Norm. t. 6 (not seen); Rech. sur l’org. d. plus. genr. d’Algues, Caen 1842 p.33; Harvey Phyc. Brit. pl. 246. Ceramium ceramicola Fl. Dan. tab. 2207 fig. 2 (? not the description). This plant attains a length of at least 5 mm. in the Danish waters. The fila- ments are below up to 50 » thick, above they become gradually thinner and are at the summit only 15 » thick. The increase in thickness below is usually due only to the thickening of the gelatinous outer wall, the diameter of the cells not increasing, and the cells forming usually a single row. There may be, however, more than one cell at the same level. This was caused, in the cases examined by me, not by longitudinal division of the cells but by displacement of the cells, so that the growing axes became inclined, the cells dividing then as usually by walls perpendicular to the growing axis and becoming arranged in two irregular longitu- dinal rows, or even more than two cells may occur at the same level (fig. 15 E). The outer wall is usually uniform, limited outwards by a fine line. Sometimes, however, the cells are provided with a denser, special membrane. In the plant represented in fig.15 E a rather thick, dense cuticular-like outer-wall was visible in the lower part of the plant; the cells were here also provided with dense spe- cial membranes, and between these and the outer membrane a stratification was often visible. The ramification takes place in a manner reminding one of the so-called false branching of the Scytonematacew. The branches rise at a great distance from the end of the filament, a cell growing outward through the gelatinous wall, dividing by a wall perpendicular to the new direction of growth (fig. 15 B, C). The further growth results in the branch coming to form a direct continuation of the principal filament and often takes nearly the same direction as this, the upper part of the principal filament being more or less pushed aside and taking the appearance of a branch (fig. 16). The cell lying at the origin of the branches is divided by a transverse wall as well as all the other cells. New branches very often arise below the older; even in old filaments new branches may arise (fig. 15 A). 10° The cells are of rather variable length, usually about as long as broad or somewhat longer, up to 3 times as long, in the last case usually barrel-shaped. On the other hand they may be sometimes much shorter than broad, up to 3 to 4 times as broad as long (fig. 15 B); they are then proportionally broad, 9—12,5 y, being otherwise 6,5—10 broad. The cells contain, as is well known, a star-shaped chromatophore with a central pyrenoid.. The colour is lilac; in very light localities, however, it is faded, feebly yellowish or grayish. Such a pale yellowish specimen was placed in a glass-vessel filled with sea-water in a room with subdued light for some days. After 24 hours the colour was already somewhat reddish, and after © (9) | © 2] | 3 Loe | © ZS) | 9 = 8 © a C O ZO Bye la Oo C m) ie © I Ss Ee ee a 5 = ©) @ IE m) N 6% Oh D AV 6 RR = 5 À = | 8 O TE | À (an) S < & © re: 6 LG) < 7 ® AS 8 e 1S = à ol [6) Fig. 15. Fig. 16. Goniotrichum elegans. A, portion of the older part of a frond with young Goniotrichum elegans. After a living branch below the older. — Band C show the normal ramification; the plant from Sallingsund. 290 :1. cells partly very short. — D and E, the cells displaced, giving up the uni- serial arrangement; the cuticle in E very thick. — B and C from the Skage- rak, the others from Sallingsund. — All figures 190 :1. 3 days the plant had a decided lilac colour. When dying the cells assume a light blue-green colour. Concerning the reproduction I have made no observations. According to SCHMITZ (1894 p. 718 (14) and 1896 p. 314), monospores are produced by the or- dinary cells, the cell-content being condensed and liberated as a naked spore. I have not seen this spore-formation, but I have sometimes remarked, that single cells were wanting in the filaments, probably because they had been set free in the form of spores. The species has hitherto been found in the Skagerak, Limfjord and Kattegat, AI I but it is not improbable that it may have a somewhat larger distribution. The plant represented in Flora Danica tab. 2207 fig. 2, which is said to have been found by LYNGBYE in Odense Fjord, seems to judge from the figure to belong to this species; the description, however, belongs not to it but to Erylhrotrichia carnea. In LyYNGBYE's herbarium I have, from the locality in question, seen only the last- named species, not Goniotrichum, and it must therefore remain doubtful, if Gonio- trichum elegans really occurs in Odense Fjord. — It has been found growing on various species of Polysiphonia, on Rhodomela, Gloiosiphonia, Zostera and Flustra foliacea in depths of 2 to 15 meters; it has only been observed in summer (June to August). Localities. Sk: YK, N.W. of Hirshals, 15 m. — Lf: MH in Thisted Bredning; at several places in Sallingsund; LS, N. of Nykøbing. — Kn: Busserev at Frederikshavn; VT, N. of Læsø. — Km: BL, 9,5 m. — Sa: (Odense Fjord, Lyngbye?). Asterocytis Gobi. 1. Asterocytis ramosa (Thwaites) Gobi. C. Gobi in Arbeiten St. Petersb. Naturf. Gesellsch. Bd. X 1877 p. 85; Fr. Schmitz 1894 p. 717; id. 1896 p. 314; N. Wille, Algolog. Notizen, I—IV. Nyt Mag. f. Naturvid. Bd. 38, 1900 p. 7 Taf. I fig. 8—14. Hormospora ramosa Thwaites in Harv. Phye. Brit. pl. 213. Goniotrichum ramosum Hauck, Meeresalg. p.517, Batters, Mar. Alg. Berw. p. 13; Lakowitz, Algenfl. Dan- ziger Bucht 1907 p. 79. Goniotrichum simplex Lakowitz l.c. p. 80. The genus Asterocylis has been established by Gosı in his “Bericht über die im Sommer 1877 ausgeführte algologische Excursion” published in 1879 in “Arb. St. Petersb. Nat. Ges.” Bd. X. As this report has only been published in the Russian language, I give in the nole below a translation in German of that part of the re- port which treats of this genus, and which Professor Gogı has kindly communi- cated to me!. Later the genus and the species on which it was founded, A. ramosa (Thwaites) Gobi, has been mentioned by Scumirz (1894) who examined specimens of it from water of very low salinity at Greifswald and found that it had nearly the same mode of reproduction as the genus Goniotrichum, only with this difference that the monospores in the last-named are set free by the sporangial wall becom- ing mucilaginous, while in Asterocytis they escape through an opening in the 1 “Die sogenannte Hormospora ramosa Thwaites (Vid. Harvey, Phyc. Brit. Tab. 213; auch Raben- horst Fl. Eur. Alg. etc. Bd. III, p. 49) welche bis jetzt (als Pseudoparasit) nur an den Küsten Englands im Meerwasser angetroffen wurde, habe ich schon mehrere Male auf meinen früheren Excursionen im Finnischen Meerbusen (1872 u. 1873) gefunden und zwar auch immer nur auf anderen Meeresalgen auf- sitzend in Form einzelner einfacher oder schwach verzweigter Faden. — THWAITES, welcher zuerst diese Form beschrieb, (die im lebenden Zustande bis jetzt nur von SmirH beobachtet wurde), sah sie als zur Gattung Hormospora Brebisson gehörend an, mit welcher Gattung jedoch sie nichts Gemeinschaftliches hat sowohl in structureller Hinsicht, als auch in der Färbung ihres Zellinhaltes. Meiner Ansicht nach muss diese Alge als eine neue Gattung angesehen werden, für die ich provisorish den Namen Asferocylis (strahlende Zelle) vorschlage, mit dem einzigen bis jetzt bekannten Repräsentanten Asferocylis rumosa (Thwaites) mihi.” (l.c. p. 85—86). 78 unaltered sporangial membrane. In the treatise on the Bangiaceæ by the same author (1896), however, these characters are not mentioned; the author states only some less essential differences and declares that at least A. ramosa might possibly be referred to the genus Goniotrichum. In 1900 WırLE has given a more detailed description of an Alga which he had found at Mandal on the South coast of Nor- way, and which he refers to the same species. He gives a description of the sel- ting free of the spores which is in accordance with that of Schmitz in 1894, but apparently without knowing the treatise of Schmitz, and he recommends that the genus Asferocytis should be kept distinct from Goniotrichum, primarily on account of the blue-green colour, but also because the author supposes that it produces resting cells, akinetes. It seems further that we may add as a distinctive character, that Asterocytis ramosa grows in brackish water, as stated by several authors (Har- VEY, Hauck, SCHMITZ, BATTERS), while Go- niotrichum elegans needs water of higher salinity. 50000 SG I have found in several localities in the inner Danish waters a small Alga Q with blue-green cells, undoubtedly be- longing to this species. It occurred, N Ÿ (2) à however, as a rule in small individuals, © = 9 most frequently even unbranched, and @ © ® 0 in such cases agreeing with Goniotrichum \@ ON 2 simplex Lakowitz. Some of these speci- Uj EN (©) Q mens were short and only 9—11 v thick, Au ei, Gi A With vegetative cells 3—6 broad. Others ZA were longer and somewhat thicker be- ig. 17. Asterocytis ramosa (from Guldborgsund). A, filament with low, and the most Visorous Roc branch; in some cells the pyrenoid is shown. B—D,small with one or a few branches. Such spec- unbranched filaments with akinetes. 20:1. imens had often a thickness of 16 7 near the base, in a single case of 25 »; the vegetative cells were about of the same size as in the smaller specimens, or they might be up to 7,5 » broad. In the plants examined by Witte the cells were, to judge from his figures and the magnification indicated, not a little greater (8—11,5 » broad), and the plants were as a whole more vigorously developed. In the Danish specimens the cells are usually oblong or ellipsoidal, often ca. 2 times as long as broad, sometimes shorter, nearly globular. The chromatophore, as is well known, is star-shaped with a dis- tinct pyrenoid; this, however, is not always central in the cell, the chromatophore being often nearer to the one side of the cell (fig. 17 B). The occurrence of akinetes supposed by Write I have been fortunate enough to confirm with certainty. In nearly all my gatherings of this species there was found a number of filaments, the cells of which were for the most part transformed 79 into spores, being provided with a thick firm wail, of a much denser consistency than the gelatinous wall of the vegetative filaments. The akinetes are only sur- rounded by a thin common membrane, much thinner than the wall of the vege- tative cells, and it is thus beyond doubt that the walls of the akinetes have risen by transformation of the innermost layers of the original gelatinous wall, and these cells thus agree completely with the conception of akinetes by Witte. In some cases the akinetes are close together, in others they are separated. They are partly ellipsoidal or oblong, partly globular, measuring 8,5 to 10,5 » in transverse diameter, up to 15 » in length. In fig. 17 C a free akinete is to be seen and two emptied cells which have contained an akinete. As shown in fig. 17 C and D, the formation of akinetes may take place in very small plants. As mentioned above, I have no doubt but that the specimens from the Danish waters really belong to Asferocytis ramosa, though it seems that the species does not attain in these waters the same dimensions as e.g. on the Norwegian coasts. The frequently occurring unbranched individuals do not represent a distinct species but only a reduced form, f. simplex (Lak.). The species has been found with certainty in some places in the Smaaland Waters and in the Baltic, but is probably widely distributed in brackish water. I have formerly noted it from Holbæk Fjord and from Kertinge Vig, but omitted to keep the specimens. It has been found in shallow water near land, fixed on Poly- siphonia violacea and nigrescens and Ceramium, only in summer (July to September). Localities. Ks: (Holbæk Fjord). — Sb: Kertinge Vig by Kerteminde. — Sm: Kragevig; off Petersværft; Guldborgsund, near Vennerslund. — Bh: Rønne, the reef S. of the town. B. Floridee. ll. Nemalionales. J. AGARDH, Species genera et ordines Algarum, Vol. II, pars II, Lundæ 1851—52; Vol. III, 1876. E. Borner, Deux Chantransia corymbifera Thuret. Acrochætium et Chantransia. Bull. soc. bot. France, tome LI, Sess. extr. 1904 p. XIV—XXIII, pl. I. É. Borner et G. THuRET, Recherches sur la fécondation des Floridées. Annales des sc. nat. 5e série, VII, 1867. — —, Notes algologiques. Fasc. I. Paris 1876. F. BORGESEN, Marine Algæ. Botany of the Ferées. Part II. Copenhagen 1902. F.S.Corrıns, Acrochaetium and Chantransia in North America. Rhodora, Oct. 1906. É. de Janczewskı, Note sur le développement du cystocarpe dans les Floridées. Mémoires de la Soc. d. sc. nat. de Cherbourg. Vol. XX. 1877. H. KyLin, Zur Kenntnis einiger schwedischer Chantransia-Arten. Botaniska Studier tillagnade F. R. Kjell- man. Uppsala 1906 p. 113—126. —, Studien über die Algenflora der schwedischen Westküste. Upsala 1907. G. Murray and Erne S. Barton, On the Structure and Systematic Position of Chantransia. Journ. Linn. Soc. Vol. 28. 1891. C. NÄGELı, Beiträge zur Morphologie und Systematik der Ceramiaceae. Sitzungsber. d. Akad. d. Wiss. München 1861. p. 401—415. 80 F. Ozrmanxs, Morphologie und Biologie der Algen. |, Jena 1904, II 1905. F. Scamirz und P. HAuPTFLEIScH, Helminthocladiaceæ. Engler u. Prantl, Naturl. Pflanzenfam. |, 2, 1896 p. 327. F. Scumitz, Untersuchungen über die Befruchtung der Florideen. Sitzungsber. d. Akad. Wiss. Berlin 1883. G. Taurer in Le Jouis, Liste des Algues marines de Cherbourg. Cherbourg 1864, p. 104. Fam. Helminthocladiacee. Tribe Chantransieæ. Chantransia (D.C.). As shown by THURET (1864 p.104), Erıas Fries was the first to define the genus Chantransia in such a manner that it had a natural limitation, and one could clearly see what plants it comprised. It was better characterized in 1864 by THURET who emphasized the fact that it has no tetrasporangia but only mono- sporangia. He mentioned at the same time the antheridia of Ch. corymbifera, and in 1576 (Notes alg. I p.16) he described in conjunction with Bornet the sexual re- production in this species, and the genus came thus to comprise species with and without sexual reproduction (comp. Murray and BARTON (1891)). In 1904, however, BorNET has proposed to separate the species with sexual reproduction from those bearing only sporangia, the first being kept in the genus Chantransia, while the others are referred to the genus Acrochetium Nægeli (1861), which might otherwise be regarded as synonymous with Chantransia. I do not make this distinction in what follows, as I have arrived at the view that it would not lead to a natural classification of the species. In several cases there is great resemblance and pro- bably also relationship between species with and without sexual reproduction, as e. g. between Chantransia hallandica and baltica, Ch. efflorescens and Ch. pectinata, Ch. Thuretii and Ch. Daviesii, and on the other hand the sexual species are mutu- ally very different. That is also evident from BORNET's paper (1904) in which the species are divided after the differences in the basal portion of the frond, while in every group distinction is made between the asexual species, referred to Acroche- tium, and the sexual ones, referred to Chaniransia. There is in reality no other difference whatever between the two genera than that of the presence or absence of sexual reproduction. It would, in my opinion, be equally justifiable to remove from other genera of Florideæ all the species in which only tetrasporangia are known. Undoubtedly, sexual organs will later be found in some of the species hitherto known as only asexual, as I have succeeded in detecting them in Ch. hal- landica, where Kyrın had only described monosporangia, but on the other hand there is no doubt that many species are really devoid of sexual organs. The great number of species described below will certainly appear surprising to many phycologists: it is the result of a careful search through a large material of Alge. Many of ihem are very small and inconspicuous and need careful exa- mination for determination. It is therefore not to be wondered at that they have been overlooked or perhaps so incompletely described that it is impossible to re- cognize them. 81 As two-thirds of the species described below are new, and as I have several new observations on most of the formerly described species, it might be useful to make here some general remarks on the genus Chantransia, based on the obser- vations communicated below. As shown by Borner (1904), the structure and development of the basal por- tion of the frond within the genus Chantransia offers considerable differences which can be used in subdividing the genus. I fully agree with this excellent phycologist who by his small but important paper has largely contributed to the classification of this genus. If my classification does not always coincide with that of Dr. Borner, it depends on the fact that I have not found representatives for all the subdivisions of Bornet in the Danish waters, and that I have found new species which do not fall under these groups. I may now give an account of the types found by me. In some species the germinating spore is a globular or hemispherical basal cell which keeps its form and divides only on branching. This cell is fastened to the substratum by a cementing substance staining intensely blue by Mayer’s Hæ- malum'. In some cases it gives off only free filaments (first group), in others it also produces endophytic filaments from its under side (BoRNET’s second group, of which no representative is mentioned below). In Ch. efflorescens (fig. 61) and Ch. Thuretii (figs. 30, 31) the hemispherical basal cell gives off an erect filament and several radiating, creeping, epiphytic filaments which later unite to a pseudoparen- chymatous disc giving off a number of erect filaments. During this development the original basal cell becomes indistinguishable amongst the other cells of the basal disc. I believe that the basal part of the frond probably develops in a similar manner in some other species, the germination of which has not been observed (Ch. attenuata, stricta, Daviesii). In a small group of species (Ch. polyblasta (fig. 43) and Ch. humilis (fig. 44)), to which may be added the partly endophytic species Ch. Dumontie (fig. 52) and Ch. cytophaga (fig. 50), the germinating spore is divided before ramification by a vertical wall into two cells of equal size each growing out in a creeping filament, which branches and forms a filamentous basal structure; in the central part of this the filaments may later fuse together, while a large number of relatively short erect filaments are given off from their upper side. In Ch. virgatula (incl. secundata) the germinating spore is usually divided by 3 excen- tric walls into 4 cells forming a parenchymatous disc, which for some time keeps this character during continued divisions of the cells, while later on some of the marginal cells may grow out into creeping filaments (figs. 37—41). In Ch. leptonema the development begins in the same manner, but the parenchymatous stage is very short, the disc at an early stage growing out into long creeping filaments (fig. 48). In Ch. Macula the basal disc behaves in a somewhat similar manner as in CA. vir- gatula, but the erect filaments are much reduced or wanting, the sporangia being 1 This substance attains an extraordinarily great development in Ch. microscopica var. collopoda Rosenv. (Deux. Mém. Alg. mar. Groenl., Medd. om Grenl. XX, 1898, p. 11). which, however, does not belong to Ch. miscroscopica Neg. but ought to be regarded as a distinct species, Ch. collopoda Rosenv. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk, og mathem. Afd. VII. 1. 11 82 situated directly on the basal dise or at the end of short unbranched erect filaments (fig. 42). An equally extreme reduction occurs in Ch. reducta, the frond of which consists of creeping filaments bearing sessile or short-stalked sporangia (fig. 49). In certain species the thallus is partly endophytic. In Ch. cylophaga the development begins as in Ch. polyblasta, and it is only when the plant has become multicellular that some of the cells in the creeping filaments produce short fila- ments from their underside, which penetrate into the cells of the host plant (Por- phyra umbilicalis), pushing aside the protoplasm and taking without doubt nutri- ment from it. This plant is thus a true parasite. The intracellular filaments or haustoria do not seem to penetrate from one cell into another but they may make their way again to the surface of the host plant (figs. 50, 51). In Ch. Dumontiæ the development begins in the same way but the endophytic filaments are intercellular and become much longer (fig. 52). These intercellular filaments are still more de- veloped in Ch. Nemalionis, where they form a widely extended system of branched threads, giving off free filaments at many points through the surface of the host (Nemalion), while creeping epiphytic filaments are wanting (figs. 53, 54). The ger- mination has not been observed in this species. Finally, there is a group of spe- cies the filaments of which are entirely endophytic. Ch. endozoica Darb. forms a transition to this group, the (endozoic) filaments sending out through the surface of the Alcyonidium it inhabits numerous short slightly branched sporangia-bearing filaments. In Ch. emergens only the solitary short-stalked sporangia are free (fig. 55), and in Ch.immersa and Ch. Polyidis the solitary sporangia are even more or less sunk in the host plant (figs. 56, 58, 60)". Most of the Chantransia are usually epiphytic and then not bound to parti- cular host plants; several species also occur on Hydroids and Bryozoa, further on Mollusc-shells, Ch. efflorescens even on stones. Probably other species may also sometimes grow on stones but have not been detected there on account of their small size. On the other hand, the endophytic species appear to occur only in one particular species of Algæ, or several nearly related. Thus, Ch. Dumontie has been found growing only in Dumontia filiformis, Ch. cytophaga only in Porphyra umbilicalis, Ch. corymbifera only in Helminthocladia, Ch. Nemalionis in Nemalion lu- bricum and multifidum, Ch. immersa in Polysiphonia nigrescens and violacea and in Rhodomela subfusca. The endozoic Ch. endozoica occurs only in Alcyonidium gelatinosum. The form of the chromatophore is of great systematic value as pointed out by Kyrın (1906, p.122). In the vast majority of Danish species the cells contain only one chromatophore, but these may again be divided into two groups. In a fairly large number of species the chromatophore has a central body lying in the 1 Rhodochorton Brebneri Batters (Journ. of Botany 1897 p.437 and 1900 Tab. 414 fig.17), which is endophytic in Gloiosiphonia capillaris, is evidently a Chantransia belonging to this group, to judge from the mode of growth, the hairs and the chromatophore; its name must therefore be Chantransia Brebneri (Batt.) Rosenv. The genus Colaconema Batters (see page 71 note) seems also to comprise spe- cies referable to the group of the endophytic Chantransie. 09 axis of the cell, usually in its upper part, and giving off a number of lobes in several directions towards the periphery of the cell. These lobes proceed further along the periphery of the cell and may together form a more or less interrupted cylindrical parietal layer. In the middle of the central body lies a pyrenoid, which is thus situated in the axis of the cell. This form of chromatophore shows a par- ticularly fine development in Ch. immersa, where the lobes are very long and di- stinct (fig. 57); but it must be confessed that in this species the pyrenoid is not always central (fig.57 B,C). In two species, Ch. Dumontiæ (fig. 52) and Ch. cytophaga (fig. 50), which also have stellate chromatophores, I have not been able to see any pyrenoid and must therefore suppose that it is wanting. In other species the chro- matophore is an entire or somewhat lobed parietal plate containing a pyrenoid which is thus excentric in the cell. The pyrenoid is always prominent in the interior of the cell, and it is sometimes so large that it reaches almost to the op- posite part of the chromatophore; when seen in profile, however, it is always easy to determine that it is parietal (figs. 30, 34, 54). Only in some species with very thin filaments it may be difficult to decide if the pyrenoid is axile or parietal, and transitions may perhaps occur. In Ch. Polyidis the chromatophore has a very pe- euliar structure, which I have unfortunately not been able to fully elueidate; it seems to be single but becoming very much branched (fig. 60). A third (or fourth) type of chromatophore occurs in Ch.efflorescens and pectinata, where each cell con- tains usually more than one spiral-shaped or more irregular band-like chromato- phores (figs. 64, 66). — In pyrenoids of Ch. immersa treated with picric acid an an- gular body, probably a crystalloid, was observed (fig. 57). The cells always contain a single nucleus lying almost in the central part of the cell, thus at a lower level than the pyrenoid. In some cases it is easily visible, even in the living state (fig. 30 C), in other it is concealed by the chromatophore; in Ch. immersa it is even sometimes found in a hollow in the mass of the chro- matophore (fig. 57). In nearly all the species hyaline, unicellular hairs occur at the ends of the filaments, which, when the filaments develop farther, are pushed aside, while the filament continues its way in the same direction as before, but really sympodially. This development has been pointed out by Kyrın (1906 and 1907) in some species, and I have found the same in all the species with hyaline hairs examined by me. The hair arises as the terminal cell of the filament, being however much narrower than the usual cells and containing no chromatophore but protoplasm and a nucleus. In the out-growing hair the protoplasm is collected towards the upper end of the cell and decreases in bulk on the lengthening of the hair. In some cases, how- ever, e. gr. Ch. rhipidandra, the hair is not pushed aside but retains its terminal po- sition, and the filament then makes a bend for each hair it produces, with the result that the sympodial nature of the filament becomes very evident (figs. 20, 21). But even in the cases where the hair is early shed, this process often causes a more or less pronounced obliquity of the upper end of the cell (fig. 18). The 11* 84 duration of the hairs is very different in the different species; thus they are vigo- rous and very persistent in Ch. virgatula, while in other species they only appear in the young plants or parts of the plant but soon fall off. They occur in the endophytic Ch. immersa (fig. 57) and Ch. Polyidis (fig. 60 B), while they are wanting in the equally endophytic Ch. emergens (fig. 55). The hairs appear very early in the young plants; it may even happen that the germinating spore produces a hair before giving off any other organ (Ch. gynandra). In Ch. Thuretii the above-men- tioned hairs seem to be wanting, but on the other hand the branches often taper into hair-like threads, the cells of which become long and discoloured and finally die, as in the hair-like organs of the Phæophyceæ (fig. 32 B). Similar hair-like or- gans occur in Ch. Daviesii (fig. 34 C). Sexual organs have been observed in 5 of the species mentioned below. Four of these are monoecious, Ch. rhipidandra only is dioecious. The carpogonium has nearly the same form in all species, being bottle-shaped with a trichogyne of about the same length as the ventral part. It is never borne at the end of a special carpogonic branch as in most other Floridez even the Ne- malieæ. In Ch. gynandra (fig. 18) and rhipidandra (fig. 20) the carpogonia are sessile and lateral on the main filaments. In the other species they are situated, usually laterally, on branched or unbranched branchlets, bearing often also antheridia or even sporangia (Ch. hallandica, figs. 21 A, E, 22 B; Ch. Thuretii, figs. 30, 31). In Ch. ef- florescens their position is very remarkable, intercalary carpogonia very often oc- curring besides others which are lateral (fig.62). In such cases the lowest cell in the short fertile branchlet develops into a carpogonium, sending out at its upper end a trichogyne upwards along the cell situated above the carpogonium. When the branchlet is two-celled, the upper cell is usually sterile and bears antheridia, but it may happen, though rarely, that two carpogonia are situated the one above the other (fig. 62 B). Intercalary carpogonia were hitherto unknown among the Florideæ; they were, however, also found in the here described Ch. gynandra where an antheridium is very often seated on the top of the carpogonium (fig. 18 H—K). The antheridia! are small roundish cells usually placed two or more together on the fertile branchlets. Only in extremely dwarfish plants of Ch. gynandra and Ch. hallandica they were found sitting directly on the main filaments, which con- sist indeed of only very few cells (figs. 18 D, 24 C). In the monoecious species an- theridia usually occur in the neigbourhood of the carpogonia, often very near, and in Ch. gynandra an antheridium is often, as already mentioned, placed directly on the carpogonium. After fertilization the ventral part of the carpogonium grows out and divides by a transverse wall, the trichogyne being pushed aside and later thrown off, and 1 The mother-cells of the spermatia, the spermatangia of SCHMITZ, may here in agreement with Orrtmanns (1904 p. 669) be named antheridia. Quite recently N. SvEDELIUs has entered a plea for the term spermatangium (Bau und Entwicklung der Florideengattung Martensia. K. Svenska Vetenskapsakad. Handlingar. Band 43 No.7. Uppsala 1908). 85 after further transverse divisions it becomes a 3- lo 5-celled filament giving rise lo a number of branches. The trichogyne or a small remnant of it may often be seen some time afterwards on the convex side of the second cell in the main fila- ment of the gonimoblast (figs. 18 C; 20 E,H; 62 E, F, H). Unfortunately, I have not been able to follow the development of the cystocarp in Ch. hallandica, where it seems to be somewhat different (figs. 21,22). In four of the five sexual species men- tioned the carpospores arise only in the terminal cells of the branched gonimoblast. In Ch. gynandra, rhipidandra and Thuretii the branches are numerous, the cystocarp capituliform; in Ch. hallandica the number of the branches and the carpospores is very low. Ch. efflorescens is also in this respect different from the other species, the carpospores arising not only in the terminal cell but also in one or two of the cells lying behind in the filaments of the cystocarp, thus seriately (fig. 63). Sporangia occur in all known species of Chantransia. For some time it was generally accepted that monosporangia only occur in this genus, the older state- ments of tetrasporangia by Harvey being supposed to be due to some error. In later years, however, tetrasporangia have been pointed out with certainty in some species by Scumitz and HAUPTFLEISCH (1896), BORGESEN (1903) and Kyrın (1906 and 1907), and I have been able not only to confirm these statements but also to find tetrasporangia in five other species, so that the occurrence of tetrasporangia is now established in eight of the species mentioned below (Ch. Thuretii, Daviesii, virgalula, polyblasta, cytophaga, Dumontiæ, efflorescens, pectinata). In Ch. Dumontiæ and poly- blasta tetrasporangia only have been met with, in the others also monosporangia. The division of the tetrasporangia is always cruciate, the first division being hori- zontal. Amoeboid movements of the monospores immediately after the liberation, similar to those described formerly for Helminthora divaricata, were observed in Ch. Thuretü (fig. 30). In most of the species provided with sex-organs sporangia occur in the sexual plants, in the monoecious species as well as in the dioecious Ch. rhipidandra. On the other hand, as the sex-organs are not present in all the plants, individuals bearing only sporangia will always be met with. In Ch.efflorescens only there is a sharp distinction between sexual plants and sporangia-bearing plants. This is perhaps connected with the fact that tetrasporangia occur in this species. As shown by Yamanoucxi! the tetrasporic plants of Polysiphonia violacea show double the number of chromosomes to that of the sexual plants, and a reduction in the number of chromosomes takes place by the formation of the tetraspores. If that is general for the Florideæ, a similar alternation of tetrasporic plants with sexual plants must be supposed to exist in Ch. efflorescens, and that is supported by the fact that the sporangia-bearing plants occur in the Danish waters chiefly in spring, the cystocarp- bearing plants in summer. In the sexual species with monosporangia such alter- nation of generations does not occur, and the reduction of chromosomes must be supposed to take place not in the sporangia but probably in the eystocarps, as in 1 S. Yamanouchı, The life-history of Polysiphonia violacea. Botanical Gazette Vol. XLII. 1906. 86 Nemalion'. Several questions connected with that just mentioned deserve a closer examination, thus, the cytological behaviour of the monosporangia of Ch. efflorescens in comparison with that of the tetrasporangia of the same species, further the nuclear division of the tetrasporangia in the non-sexual species. The following classification of the species is based in particular on the cha- racters of the basal part and of the chromatophore. Ch. efflorescens, however, which differs from the others in several characters, as mentioned above, is first separated as representing a particular sub-genus, Grania, named after the Norwegian investi- gator who first described its sex-organs, and to the same sub-genus is referred -Ch. pectinata, with similar chromatophores and probably related to it. Key to the Danish species of Chantransia. I. Subg. Euchantransia. One chromatophore, carpospores only in the last cell of the sporogenous filaments. 1. Frond epiphytic. 2. A single basal cell. Group I. 3. With sex-organs. 4. Antheridia situated on the carpogonia or on unicellular branchiletst®. 230.111. ONS AS) SU RARE 1. Ch. gynandra. 4. Antheridia never situated on the carpogonia. 5. Antheridia singly or two together, cystocarps with few carpospores; monoecious) EE EE CEE 3. Ch. hallandica. 5. Antheridia usually in flat triangular clusters, cysto- carps nearly globular with numerous carpospores; AIOE CLOUSLN TR: HANNO EER ER RSE ER 2. Ch. rhipidandra. 3. Without sex-organs. ANPyrenordiparieta lee RE See ee tae Cent ey tenn Sake 1. Ch. gynandra. 4. Pyrenoid axile. 5. Cells nearly cylindrical. 6. Filaments 9—11, thick, spor. 14—15 x 9—10y 2. Ch. rhipidandra. 6. Filaments at most 7 » thick. 7. Filaments 5—6, thick, sporangia 10 x 6—7y 3. Ch. hallandica. 7. Filaments 6—7 » thick, sporangia 12—16 x SALOPES N ER 4. Ch. baltica. 5. Cells roundish, frequently barrel-shaped ....... 5. Ch. moniliformis. 2. Basal layer multicellular. Group II. 3. Basal layer composed of filaments more or less fusing together into a pseudoparenchymatous disc. 4. Erect filaments well developed; pyrenoid parietal. 5. Erect filaments branched. 6. Branches scattered; monospores, rarely tetraspores. 7 Comp. J. J. WoLFE, Cytolog. Stud. on Nemalion, Ann. of Botany Vol. 18 Oct. 1904. 87 7. Sex-organs may occur; thickness of filaments usually less than 10 y, cells usually 5—8 diam. long, sporangia sessile or on unicellular branch- lets on the inner side of the branches ...... 6. Ch. Thuretii. 7. Without sex-organs; filaments 9—12,, thick, cells 2—4 diam. long; sporangia-bearing branchlets repeatedly branched, often in the axils ...... 7. Ch. Daviesit. 6. Branches partly opposite ..................... 8. Ch. attenuata. 5. Erect filaments unbranched, bearing only numerous sporangia-bearing branchlets, nearly from the base LOMUNCE LO Dirac tie ae iets RUN OU cs ie nie abe aU er NE 9. Ch. stricta. 4. Erect filaments numerous, rather short (up to 300 y) to very short or wanting; pyrenoid axile. 5. Erect filaments up to ca. 300 # long, branched. 6. Filaments 7—10y thick, sporangia tetrasporous 12. Ch. polyblasta. 6. Filaments 3—4 y thick, sporangia monosporous 14. Ch. leptonema. 5. Erect filaments up to ca. 60 4 long, usually unbranched, sporangia monosporous. 6. The cells of the creeping filaments give off 2—3 erect filaments bearing terminal and lateral spor- BA EH So ie d OS LOC CR APT BOLD 3 CET SOS CEC DUC cuban 13. Ch. humilis. 6. The cells of the creeping filaments bear one sessile orsstalkedEsporansiuml er Reel 15. Ch. reducta. 3. Basal layer first a parenchymatous disc, later growing out into radiating filaments; pyrenoid axile (Ch. leptonema). 4. Erect filaments 1—2 mm. long ..................... 10. Ch. virgatula. 4. Erect filaments very short or wanting; sporangia sessile on the basal disc or terminal on the erect filaments.. 11. Ch. Macula. 1. Frond partly or entirely endophytic or endozoic. Group III. 2. Vegetative part partly endophytic. 3. Epiphytic creeping filaments present. 4. Endophytic filaments intracellular ................ 16. Ch. cytophaga. 4. Endophytic filaments intercellular ................ 17. Ch. Dumontie. 3. Epiphytic creeping filaments wanting ................ 18. Ch. Nemalionis. 2. Vegetative part entirely endophytic or endozoic. 3. Vegetative filaments endozoic, giving off short free, spor- angia-bearing filaments ............................... 19. Ch. endozoica. 3. Filaments entirely endophytic. 4. Filaments creeping in the outer cell-wall of Polysiphonia; sporangia entirely free, short-stalked, single......... 20. Ch. emergens. 4. Filaments intercellular; sporangia partly or entirely immersed in the host. S'MChromatophonestellAle PAPE E LP EPP EEE EE aan: 21. Ch. immersa. 5. Chromatophore much divided ................... 22. Ch. Polyidis. II. Subg. Grania. Chromatophores ribbon-like, spiral-shaped, usually more than one; carpogonia often intercalary; carpospores seriate. Group IV. 1. Filaments usually 5—6 » thick; free descending filaments usually present; sporangia tetrasporous or monosporous, on alternate or opposite branchlets; sex-organs present .................... 23. Ch. efflorescens. 1. Filaments near the base 6—9 y (or thicker); free descending fila- ments usually wanting; sporangia or sporangia-bearing branchlets seriate on the inner side of the branches; sex-organs wanting 24. Ch. peclinata. Subgenus Euchantransia. Group I. Frond epiphytic with a single basal cell. 1. Chantransia gynandra sp. nov. = Thallus minutus. E cellula basali subglobosa, diametro 7,5—9 x, egrediunt fila 2—4 simplicia, ad circ. 200 „ alta, e cellulis diametro plerumque 2—3-plo long- ioribus, crassitudine 5—6 », superne nonnunquam leniter (ad 7 4) incrassatis, con- stantes. Ramuli nulli vel pauci, minuti, unicellulares. Chromatophorum parietale zonale, pyrenoide instructum, mediam partem cellulæ occupans. Pili hyalini ter- minales et laterales adsunt. Sporangia, antheridia et carpogonia in uno eodemque individuo occurrunt. Sporangia in filis lateralia sessilia solitaria vel in uno arti- culo duo approximata vel opposita, vel in ramulis terminalia monospora, ovata, long. 9,5—10 y, lat. 5—6 ». Carpogonia in filis lateralia. Antheridia ad apicem ramulorum solitaria vel sæpius gregaria vel carpogonio juxta trichogynum solitaria imposita, hemisphærica, oblique breviter ovata vel subconica, long. c. 2,5 4. Cysto- carpia Capitula irregularia e filis radiantibus longitudine vario constantia, carpo- sporis in cellulis ultimis, sporangiis similibus, formatis. This interesting species was found in abundance growing on some specimens of Ectocarpus confervoides dredged in the Northern Kattegat. The nearly globular basal-cell, which is fixed to the host by a very thin layer of a cementing substance, gives off a filament upward and usually two similar, though often shorter, fila- ments out to the sides. The filaments are either absolutely unbranched or bear, besides reproductive organs, only a few one-celled or rarely two-celled branchlets. The cells which are usually a little constricted at the transverse walls, contain a belt-shaped, rather narrow chromatophore containing a pyrenoid projecting inward. Hyaline hairs always occur; they are either terminal on the filaments and the branchlets or lateral. The hair situated at the top of the terminal cell is later pushed to the side, the terminal cell growing out beyond the insertion of the hair (fig. 18 K) which, after the next cell-division, comes to be situated at the upper end of the subterminal cell. Nearly all the lateral hairs have developed in this manner; it seems however that really lateral hairs may also sometimes occur. At all events two hairs may be found on one cell (fig. 18 G). Most of the hairs are early thrown off, leaving however a vestige in the outline of the cell, this being a little enlarged at the upper end. I have once seen a hair given off from a basal cell which had nol yet produced any filament. Most of the plants bear at the same time sporangia and both kinds of sexual organs, some plants, however, bear only sexual organs. The sporangia are sessile on the sides of the filaments or sometimes borne by the unicellular branchlets (fig. 18 A); they open by a split at the top (fig. 18 A, G). Fig. 18. Chantransia gynandra. A, plant with 3 branchlets, a cystocarp and sporangia. BD, upper end of filament with branchlets bearing antheridia. C, plant with two cystocarps and one sporangium. D, dwarfed plant with antheridia and one carpogonium; a spermatium is lying above. E, dwarfed plant (comp. text). Æ, two antheridia on a branchlet; a spermatium is situated immediately outside one of the antheridia. @, part of filament with a young cystocarp and two empty sporangia. H, plant with three carpogonia with epigynous antheridia, two young, the third in the fertilization stage. I and K. plants with young eyslocarps and epi- gynous antheridia. L, plant with carpogonium in fertilization stage. 630: 1, The carpogonia are situated on the sides of the filaments at various distances from the base; they are bottle-shaped, the trichogyne being of almost the same length as the ventral part. The antheridia are situated either on the carpogonia or on the ramuli; in the first case they are always solitary, in the latter there are D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem, Afd. VII. 1. 12 usually two or more crowded together. Only in the dwarfed plant represented in fig. 18 D have I seen the antheridia situated directly on the filament, but in this case the filament was only two-celled. The juvenile stages of the epigynous an- theridia show that these antheridia are really terminal, while the trichogyne rises as a lateral outgrowth from the subterminal carpogonium (fig. 18 E, H), a case hith- erto unknown among the Floridee. I have repeatedly, in material preserved in alcohol, observed a little globular body lying immediately outside an empty anthe- ridium or at a slight distance from it (fig. 18 F, D); as it agreed in size with the spermatia adhering to the trichogynes (fig. C, K, L), I have no doubt that they were really spermatia. Probably a spermatium is often transferred from an epigynous antheridium to the trichogyne of the supporting carpogonium. After fertilization the ventral part of the carpogonium grows out into a slightiy inwards curved fila- ment which becomes 3-celled. The trichogyne is pushed outward so that it be- comes situated on the convex side, on the second cell of the filament (fig. C). The two lowest cells give off several branches, while the uppermost cell produces a carpospore (fig. C). Possibly the primary filament of the gonimoblast may some- times consist of more than three cells. The lateral branches obtain a different length, some becoming relatively long, articulated, curved and branched, others remaining short and in part apparently unicellular, producing a carpospore without division. The mother-cells of the carpospores have about the same form and size as the sporangia. The trichogyne or the lowest part of it can be seen long after fertilization on the second cell of the main filament; even in mature cystocarps a slight remnant of it is sometimes to be seen, (fig. A). The emptied epigynous an- theridium is also often to be found some time after fertilization; it is then situated on the first cell of the main filament (fig. J, K). While the plants often attain a length of 200 », very reduced plants also occur, consisting of very few cells (fig. D, E). In the plant shown in fig. E there was only developed one filament consisting of one cell only, bearing a hair, a car- pogonium with epigynous antheridium and a lateral outgrowth the character of which could not be determined. The species differs from all more exactly described species of this group through the position of the sexual organs, the form of the cystocarps and the belt-shaped chromatophore. It may have been observed earlier, however, and pos- sibly some of the plants mentioned under the name of Callithamnion minutissimum have belonged to this species. ZANARDINT’s species of this name (Synops. Alg. mar. Adr. 1841 p.176; Hauck, Oesterr. bot. Zeitschr. 1878 Taf. II fig. 7—8), however, be- longs not to this group; and as to Sunr’s species (Kürzına Spec. alg. 1849 p. 640, Tab. phye. XI tab. 57), it is impossible to identify it from the description and figures. On the other hand, the specimens referred to that species by Crovan (Alg mar. du Finistère No. 114, Florule du Finistère p.134) show so much resemblance with the species here described, that they might probably be identical. This, however, cannot yet be decided with certainty as the specimens of Crovan bear no sexual 91 organs (Comp. Borner 1904 p. XIX). On the contrary, they bear abundant sporangia, in much greater number than in the Danish plants, very often two on each cell, 10—11 w long, 6-7 » broad, consequently nearly as in our plants, and of the same shape. The thickness of the filaments is the same (5,5—6 4), the basal cell is ca. 10 in diameter and the chromatophore is parietal, and finally Crovan’s plant grows on an Ectocarpus like the Danish plant. All these agreements suggest that Crouan’s plants are asexual individuals of Ch. gynandra. Locality. Kn: Tonneberg Banke, ZA, 12 to 18 meters, July. 2. Chantransia rhipidandra sp. nov. E cellula basali globosa vel rarius leviter depressa, diametro c. 14 (13—15) y, 2—3 fila erecta parce ramosa usque ad 350 y sallem alta, egrediunt. Rami sparsi simplices vel parce ramosi. Cellule (7,5—) 9—11 y late, diametro 2—3 (—4)-plo longiores, chromatophorum stelliforme, pyrenoide centrali, in parte superiore cellulæ sito, instructum, continentes. Fila primaria ramique apice plerumque pilo hyalino instructi. Sporangia in filis lateralia sessilia aut stipitata, stipite unicellulari, sparsa vel (rarius) opposita, sæpe seriata, monospora, ovata vel obovata, long. 14—18,5 y, lat. 9—10 y. Antheridia in ramulis, in una fere planitie ramosis, semiflabelliformibus ter- minalia, 6—6,5 » longa, 4—5 y crassa. Carpogonia in filis primariis vel in infima parte ramorum sessilia; cystocarpia subglobosa; carpospore in cellulis ultimis cystocarpii formats, eadem fere forma et magnitudine ac monosporæ. Antheridia et carpo- gonia in plantis distinctis, sporangia in plantis distinctis aut in plantis sexualibus. This species is distinct from all well-defined species with one basal cell. Thus, it differs from Ch. microscopica (Nægeli) (1861, p. 407 figs. 24, 25) by its globular basal cell! being much broader than the filaments and giving off 2 or 3 filaments, and by having longer cells. From Ch. hallandica it differs by its larger proportions, the position of the antheridia and the form of the cystocarpia etc., from Ch. micro- scopica var. pygmeea Kuckuck (Bemerk. Helg. II, p. 392 fig. 15) in the dimensions, the absence of endophytic filaments etc. Ch. unilateralis KsELLMAN (Algenfl. Jan Mayen, Arkiv f. Bot. Bd. 5 No. 14, 1906 p. 11) differs by having much thicker and more branched filaments and almost globular sporangia, and Ch. Alariæ Jonsson (Mar. Alg. Iceland. Bot. Tidsskr. vol. 24 p. 132) differs also by having much thicker and more branched filaments, and further by the branches being often opposite; both these species are devoid of sexual organs. From the short description given of Ch. microscopica BATTERS (Journ. of Bot. 1896 p. 9) it appears that this species can scarcely be identified with our species, for according to Barrers the antheridia form “very compact clusters at short intervals along the axes and branches”, and 1 NEGELI mentions and figures in Acrochætium microscopicum a basal disc, “von welcher es (nach Untersuchung an getrockneten Exemplaren) zweifelhaft bleibt, ob es eine niedergedrückte scheiben- förmige Zelle oder nur Verdickung der Membran ist (Fig. 24, 25)”. On examining the specimens of this species in RABENHORST's Die Algen Europas No. 1650, I have found that this basal dise is a cementing substance, occurring in all the species of this section. 12* 92 the cystocarpia are “clustered near the basal dise”, and according to Kuckuck (I. €.) the filaments are narrower (4,5—7 y) in BATTERS’ species than in Ch. rhipidandra. To the description given above the following remarks may be added. The basal cell is fastened to the surface of the host plant by a very distinct dise con- sisting of a cementing substance staining intensely blue in Mayer’s hæmalum. The sporangia are usually alternate or more or less regularly secund (fig. 19 on the left), seriate, as the plant generally has a tendency to unilateral ramification. When each cell bears two sporangia, they are usually, but not always, opposite, and several pairs of sporangia are then often superposed (fig. 19 to the right). When the sporangium is placed on a unicellular branchlet, this often bears also a hair; the hair IC being terminal, the sporangium is then lateral on SEG the branchlet (fig. 19). | ES The antheridia are placed in characteristic, flat, | Se à à) usually triangular clusters consisting of 2- to 5-celled “he branchlets branched only on the upper side; they Ar are produced in a number of one to three on all #28 the terminal cells of the cluster, and also singly by A py ( x) some of the other cells (fig. 20 A, B). U | cee The carpogonia are sessile on the upper part NAN VAT of the main filaments or on the lower part of the Wee branches; they are bottle-shaped, with a trichogyne Et LV of about the same length as the ventral part (fig. 20 NA D, c). After fertilization the carpogonium grows out Val in a three-celled filament which still bears the tri- a chogyne or a remnant of it on the second cell (fig. IR 20 E, H,t). A branch is now given off from the HU) lowest cell, the primary filament is further divided TED! so that it becomes 4- or 5-celled, and it gives off Fig. 19. more branches from the lower cells. In fig. 20 F, Chantransia rhipidandra. Two spore- the primary filament is seen to be 5-celled; the bearing plants. 300:1. uppermost cell produces a carpospore, the others, with exception of the subterminal cell, each bear two branches which are either unicellular and produce directly a carpospore or become 2- or 3-celled and produce a carpospore in the end-cell. The ripe cystocarpium is of somewhat irregular, nearly globular shape; its peripheral cells are swollen and each produce a carpo- spore (fig. 20 D). This species has only been found at Frederikshavn, where it was collected in August 1891 growing on Porphyra umbilicalis on the outer and the inner side of the moles. It grew on the flat side of the fronds, in some cases so abundantly that the frond of Porphyra had become dull and purplish. Locality. Kn: Frederikshavn. 93 3. Chantransia hallandica Kylin. H. Kylin (1906) p. 123. Ch. parvula Kylin (1906) p. 124. Kyrın in 1906 described two allied species, Ch. hallandica and Ch. parvula, differing from each other by the filaments being a little thinner, giving branches off at all sides and consisting of longer cells, further by the sporangia being often stalked and then usually placed two or three together in Ch. hallandica, while Ch. parvula is smaller, has shorter, a little thicker filaments with branches placed in one ortworows and usually sessile sporangia. In se- veral places in the Da- nish waters I have met with Chantransiæ agree- ing exactly with these two species, but I have also found specimens which were intermedi- ate in regard to one or more of the characters mentioned. As I have also found sexual or- gans, besides the spor- angia described by Ky- LIN, it will be necessary to mention these plants more closely. In the plants corre- Fig. 20. 3 Chantransia rhipidandra. A and B male plants, B also with sporangia, s. — C—I sponding to KyLin's Ch. portions of female plants. The carpogonia and the young cystocarpia made more D easily recognizable by shading; in C an unfertilized carpogonium and a young cy- hallandica, the basal cell PAT SE N STE VSSE AY Cg SES ESS i stocarp; in D carpogonia, c, and a ripe cystocarp; in a fertilized carpogonium. is (7,5—) 9—11 (14) u 3-celled, still with trichogyne, ¢; in Fa nearly ripe cystocarp after having been 0 5 5 subjected to pressure; in G an unripe eystocarp and two sporangia; in H a young in diameter, thick-wall- cyslocarp and an empty sporangium; in J a young eyslocarp. 300:1. ed; it gives off usually 3, at the most 4 erect filaments, (4—)5—6 y thick and consisting of cells usually 3—4 (—5) times as long as broad. Hyaline hairs are usually present. The origi- nally terminal hair is often pushed aside by the cell bearing it growing out sym- podially in the same direction as before, and the hair leaves then only a faint mark at the upper end of the cell which has produced it; but in other cases the hair retains it terminal position, and the filament, i.e. the branch, grows out in another direction (fig.21 E). Transitional cases are also found. The cells contain 94 a stellate chromatophore with central pyrenoid lying in the upper part of the cell, the strands radiating from the central body forming a more or less continuous pe- ripheral layer. As Kyrın (1906 fig. 8 G) represents Ihe pyrenoid as being some- times lateral, it may be remarked that I have always found il central. The sporangia are -lateralonthe filaments, sessile or stalked, i. e, situated on one-celled branchlets and then usually two on each stalk-cell. The branch- let may also be two- celled, the primary stalk-cell bearing, be- sides a terminal spor- angium, a lateral stalk- cell with a sporan- gium, Usually only one sporangium or sporangium - bearing branchlet is situated on each cell in the filaments. The spor- angia are ovate to oblong, (8,5—) 9,5—10,5 (—13) » long, (4—) 6—7 (—9) » broad. Many plants bear exclusively sporangia, but by searching, spe- cimens bearing also or exclusively sex-organs - are easily found, at all events in the Danish waters. In describing Fig. 21. the sexual organs I Chantransia hallandia a, typica, A, wasn sexual organs ame! sporangia, 385: 1. B, with yefer also to the plants sporangia, 385:1. C, with cystocarps, 300:1. D, fragment of plant bearing branchlets with antheridia and sporangia, 620:1. E, fragment of plant bearing a branchlet with belonging lo the var. carpogonium and antheridia, and an emptied sporangium. 620:1. A and C from AH", Bike Ge B, D, E from LC. brevior. The antheridia \ N \ LAV \ 95 are placed singly or in small groups of two or three at the end of shorter branches; they are round, 3 y long, 2,5 u broad. The carpogonia are situated on similar, rather short, usually 1- to 5-celled, branches as those bearing the antheridia, and they are often placed in the immediate vicinity of the antheridia (figs. 21 E, 22 B). I have not succeeded in follow- ing the development of the cy- stocarpia, especially the first stages. It seems that the tri- chogyne disappears very soon after fertilization. In fig. 21 E is shown a carpogonium imme- diately before fertilization, in fig. 23 another with adhering sper- matia, and in fig. 22 A and C abortive carpogonia are shown, but I have never seen a tricho- gyne on a carpogonium after the commencement of the divi- sions; it might perhaps have been on the place marked with * in fig. 22 D; the two spores situ- ated on each side of this must then be carpospores and the whole cell-complex a cystocar- pium. À very similar case is shown in fig. 23 B, and the plant shown in fig. 21 C bears undoub- tedly also two or three cysto- carps. The cystocarps are thus corymbiform and produce only a very small number of carpo- spores. Usually only two carpo- spores are present at the same time, but it is probable that others may develop after the first have been exhausted. The carpospores are somewhat larger Fig. 22. Chantransia hallandica 4, typica. A. fragment of plant with abortive carpogonia and sporangia. B, branchlet with antheridia and carpo- gonium. C, plant with abortive carpogonia and probably unripe cy- stocarps. D, eyslocarp, at * perhaps the place of the trichogyne, 50:1. AN plants from AH, than the sporangia, viz. 14—18 » long, 7—9 » broad. At some places, mostly in the northern Kattegat, specimens were met with which agreed in all essentials with those described above but differed in having shorter cells, about twice (11/2—3 times) as long as broad. The cells being, as in the main form, often a little enlarged at the upper end, they may differ somewhat 96 from the cylindric form (fig. 23 C). These plants are lower than the main form and usually branched from the base, while the main form is most often without Fig. 23. Chantransia hallandica ©. brevior. A and B from VT. A with sporangia. B with sexual organs and a cystocarp. — C and D from KC, C with sporangia. partly stalked, D with sporangia and antheridia. 390 : 1. branches below. In the specimens from VT the sporangia were almost al- ways sessile, alternate, se- cund or opposite (fig. 23 A), while in the speci- mens from KC they were often stalked (fig. 23 C). This form may be named f. brevior. The specimens just described are only slight- ly different from others agreeing with Kyrıns Ch. parvula. Fig. 25 shows such a specimen, the fila- ments of which are 5—7 u thick and the cells about twice as long as broad; the sporangia, however, were somewhat larger than indi- cated by Kyrın, namely (10—) 12—13 (—14) 4 long, cell was (10—) 12—13 (—15) » in diameter. Some specimens growing on the frond of Porphyra umbi- licalis on the mole of Frederikshavn (fig. 26) may also be referred here, though they were not strongly ramified in one plane; they bore numerous spor- angia, most often opposite, sometimes even three in one article. The axile chromatophore is very distinct in the figures which have been drawn after speci- mens preserved in alcohol. The last-named speci- mens as well as those from EM (fig. 25) were only provided with sporangia; on the other hand, spe- cimens from BH (fig. 24) had also sexual organs. Fig. 24 B fully agrees otherwise with Kyrın’s figures, while fig. 24 A might perhaps be better referred to f. brevior, but these plants grew side by side and were connected by transitional forms. A very re- duced plant provided with all kinds of organs of reproduction is shown in fig. 24 C. It seems not im- probable that the small cells shown in Kyrıy’s fig. 9h, i (1906) may have been antheridia. 6—8 (—9) x broad. The basal Fig. 24. Chantransia hallandica 7. paroula. From BH. A with longer cells and alternate spor- angia. B with sporangia and antheridia, C, dwarfed plant with sporangium and sexual organs. 390:1. 97 From what has been explained above it may be concluded that all the speci- mens mentioned must be referred to one species, Ch. hallandica, which may be divided into three forms not separable by distinct limits. a, typica. From the basal cell are given off usually three upright filaments which are branched on all sides, usually without branches below, 5—6 y thick. Cells ca. 4 times as long as broad. Sexual organs and spor- ‘angia present, often in the same plant, the sporangia usu- ally alternate, often stalked. P, brevior. Cells ca. 2 (1!/:—3) times as long as broad, primary filaments often branched from the base. For the rest as a. 7, parvula (Kylin). (Syn. Ch. parvula Kylin 1.c.). From the basal cell are given off up to 6 filaments which are (5—)6—7 y thick. Cells ca. 2 times as long as broad. Spor- angia almost always sessile, most frequently opposite. Sexual organs often wanting. The species has almost always been found epiphytic on LP Be i: À 2 4 Chantransia hallandica 7, par- Polysiphonia nigrescens and Pol. violacea. F. parvula has also vula. From EM. Plant with spor- been found on Porphyra umbilicalis. It has only been met Dee PE with in the summer months (May—August), in all cases with sporangia and usually also with sexual organs; ripe cystocarps have been met with in July and August. a and 8 have been found in depths of 4 to 15 meters, 7 in depths of 0 to 9,5 meters. Localities. Kn: Krageskovs Rev, KC, (2); Hirsholm, (@); Frederikshavn, (y); VT, N. of Nordre Ronner, (a and £); Trindelen, FF, 15 meters. — Ke: XA, 13 meters, (a). Km: VQ, Svitringen, (a); BH, off Gjerrild Klint, (7). Ks: EM, Lysegrund, (7). — Sa: BD, N. of Tuno; MQ, (2); AH!, N. of Fyens Hoved, (a). Lb: At Fæno, (a). — Sb: AB, W. of Sprogo, 7,5 meters (a). — Bw: LC, S. of Langeland, 11,5 meters, (a). Fig. 26. 4. Chantransia baltiea sp. nov. Chantransia hallandica ÿ, parvula. From Frederikshavn, grow- 3 ing on Porphyra umbilicalis. A, plant with sporangia. — B, E cellula basali globosa, diametro filament with partly emptied sporangia. — C, germinating 10,5—14 y, fila usque 6 subsimplicia, longitudine 400 » vel ultra, egrediunt. Cellulæ (5—) 6—7 (—9) » crassæ, in filis bene evolutis diametro 4—6 (—7)-plo lon- giores, chromatophorum axile, pyrenoide centrali instructum, in parte superiore cellule situm, continentes. Sporangia monospora ovata, 12—16 » longa, 8—10 4 lata, vulgo e. 14 longa, 104 lata, in filis primariis lateralia vel terminalia, sessilia vel stipitata, in stipite unicellulari singula, in articulis filorum sæpe bina, opposita, spore. — D and E, young plants, still sterile. 300:1. D. K. D. Vidensk. Selsk. Skr., 7. Reekke, naturvidensk. og mathem. Afd. VII. 1. 13 98 superne nonnunquam subsecunda. Organa sexualia desunt. Pili hyalini crebri, in ramulis sporangiferis terminales. This species which has been found only in two localities in the Baltic is cer- tainly nearly related to Ch. hallandica, but however so different from it, that I do not hesitate to set it up as a distinet species. It differs by the primary filaments Fig. 27. Chantransia ballica. (From QR). A, Band D, fully developed plants with sporangia, C young plant, seen from the side. 300:1. being more numerous, less bran- ched, somewhat thicker and con- sisting of somewhat longer cells, by the sporangia being larger, by the sporangial stalks bearing only one sporangium, and by the want of sexual organs. In some of the characters mentioned, the more numerous and thicker filaments, and the sporangia often opposite, it resembles Ch. hallandica f. par- vula, but it is very different from this by the long cells and the ) sporangia being often stalked. To complete the description given above, the following re- marks may be added. The basal cell is nearly globular, its plane of attachment being often smaller than its transverse section; it is rather thick-walled. The primary filaments bear usually no long branches but only sporangia- bearing branchlets. The most de- veloped primary filaments recall somewhat those of Ch. virgatula, but they are thinner and the branchlets bear only one spor- angium. The shorter filaments consist of shorter cells, 2—3 times as long as broad and often some- what enlarged above. In some specimens from SQ the longer filaments were up to 9 thick below, upward thinner, ca. 5 in diameter, the cells being up to 7 times as long as broad. The chromatophore reaches in the longer cells often only to the middle of the cell, the pyrenoid lies near the upper end of the cell. The spores contain a very distinct stellate chromatophore. I have never 99 seen a sporangial stalk bearing more than one sporangium, and a renewal of an emptied sporangium within the sporangial-wall from the stalk-cell has not been observed, but a new sporangium may sometimes be developed beside an emplied. Colourless hairs are always present; they are terminal or lateral, in the latter case, however, certainly always originally terminal. Localities. Bm: Gyldenløves Flak, QR, 7,5 meters, on Polysiphonia violacea, July. — Bh: SQ, S. of Broens Rey, 8,5 meters, on Polysiphonia elongata, August. 5. Chantransia moniliformis sp. noy. Thallus minutus cæspitulosus, 50—150 altus vel parum ultra (sine pilis). Cel- lula basalis singula subglobosa, fila 2—3 (vel plura?) erecta vel decumbentia et adscendentia, a basi ramosa, e cellulis plus minus inflatis constituta, emittens. Cel- lulæ diametro æquilongæ ad duplo longiores, plerumque fere sesquilongæ, subglobosz aut doliiformes vel in parte A NEN superiori incrassate, 7—10 , late, 7—14 longæ. Chro- c KY matophorum stelliforme, pyrenoide centrali instructum, Q\Sa | A 0.8 : 5 2 5 CR À in parte superiori cellule situm. Fila ramique, præci- I | a pue in statu juvenili, sæpe piligeri, pilis initio termi- | | | nalibus, dein evolutione sympodiali (pseudo-)lateralibus. ff \ Sporangia monospora sessilia, rarius pedicellata, late- | ralia, secundata vel opposita, ovata, 13,5—15 » longa, 7 a lata, post evacuationem- sæpe sporangio novo, e cellula subjacenti orta, repleta. Organa sexualia = Ki Alea ignota. Josh Al CE This small species is easily distinguishable from NLS the other species of this group by its short, more or Sp C less swollen cells, which in juvenile plants approach to the globular form, while in older plants they are cher nie ee: Sant hs almost barrel-shaped. The basal cell which is fixed to with hairs. 4 from Helsingør, Band C the host plant by a thin layer of cementing substance ne is scarcely different from the other cells in form. The displacement of the origi- nally terminal hairs is easily to be seen in the young plants (fig. 28 C); in older plants no hairs are to be found. In the plant represented in fig. 28 B the cell si- tuated beneath the upper terminal hair-cell had lengthened and become almost colourless, approaching thus to the character of a hair-cell; but this case appears to be very rare. The branches are mainly given off at the upper side of the de- cumbent or ascending principal filaments, and this holds good also of the sporangia which are often seriate on the upper side of the filaments. After the evacuation the sporangial wall is seen to be lamellate, but the acroscopic part of it is often dissolved (fig. 29 B). — On dried material I once saw a specimen with a blue-green colour; unfortunately I have not examined the species in the living state. 13* 100 This inconspicuous species has been found epiphylie on Polysiphonia violacea and nigrescens, infeompany with other species of Chantransia (virgatula, hallandica ete.), at several places but in small quanti- ties. It has been met with in May to Sep- tember, in depths from 1 to 11,5 meters, and was collected with sporangia in the same months. Localities. Kn: Krage- skovs Rey, KC. — Ks: D,N. of Isefjord, 11,5 meters. — Sa: AH!, N. of Fyens Hoved; MQ, S. of Samsø, 11,5 me- ters. — Su: Stone-slope at Helsingør (Kronborg). — Bw: LC, S. of Langeland, Chantransia moniliformis. Adult plants with?sporangia. A—C from Helsingør, Sep- 11,5 meters. — Bm: QR, tember, D from AH, In D full-grown sporangia, in B the sporangia have been emp- Gyldenløves Flak. tied and new sporangia are developing within their membranes. 390: 1. Group II. Frond epiphytic with a pluricellular basal layer. 6. Chantransia Thuretii (Born.) Kylin. Kylin (1907) p. 119. Chantransia efflorescens var. Thuretii Bornet (1904) p. XVI pl. I. a, amphicarpa nob. Of this species, which is quite distinct from Ch. efflorescens (J. Ag.), as shown by Kyrın, I have found specimens fully agreeing with Kyrın’s description and drawings. Such specimens, provided with monosporangia and sexual organs, were met with repeatedly in July near Frederikshavn. In some cases the sporangia and the sexual organs occur on different branches of the same plant, but as shown by Kyrın, the sporangia are often situated near the sexual organs, and all the three kinds of organs of reproduction may then occur very close together, as is seen in fig. 30 B, where the same cell bears a carpogonium and a sporangium, while a cluster of antheridia is situated on the next branchlet. Also in fig. 31 B, the spor- angium is siluated close to the carpogonium and in fig. 31 A a two-celled branchlet is seen to bear a carpogonium, an antheridium and a sporangium. When not occurring together with the sexual organs the sporangia are situated on the inner side of the branches near the base, usually 2 or 3 together on one-celled branchlets, or they are sessile at the same place; more rarely the branchlets are 2- or 3-celled. It may sometimes happen, that two sporangiferous branchlets are seated on the same cell, the one over the other (fig. 30 A). On maturation the spore leaves 101 the sporangium through a narrow opening at ils upper end. After liberation, which was observed in July, the spores took an ovoid form, thereafter they became glo- bular and then showed amoeboid movements. The germinaling spore forms an orbicular basal cell which gives off one up- right filament but for the rest remains unaltered for some time (fig. 30 D); later on it forms cells in the periphery which grow out in creeping filaments fusing together to a rather large-celled basal disc, which produces more upright filaments (fig. 31 C). The original basal cell is for some time distinguishable in the centre of the disc. As shown by Kyrın, no downwards growing filaments occur al the base of the upright filaments. However, N I have once observed two short vigorous | descending filaments given off very near the base of an upright filament, and each producing an upright filament on its convex side (fig. 31 D). The chromatophore, the form of which KyYLIN was not able to determine, is shown in fig. 30 which was drawn after living plants; it is a parietal plate, often with a lobed margin and with a large pyrenoid which is also parietal but much projecting inward in the cell. The nucleus often lies at the opposite side of the cell from the pyrenoid (fig. 30 B, C). Plants similar to those mentioned above were found at a locality in the Samsø Waters in September. They were, however, only provided with ripe cysto- carpia and bore no sporangia, perhaps to be explained by the sporangia accom- Fig. 30. plishing their development faster than an wk the cystocarps. sporangia and liberated spores. B, branch with branchlets Referring for the rest to, Kyzin’s Betvins aniherkin à eopogonium and sporangia; behind description, I may remark finally, that cell with chromatophore, pyrenoid p and nucleus, k. D, the filaments in my plants were 7,5— eh 9,5 y thick, that I have once observed a pair of opposite branches, that the spor- angia were 14—16(—17) long, 9—11,, broad, and that the carpospores were 19— 214 long, 11—12,5(—14)u broad. The main form has been found growing on Polysiphonia violacea, Ceramium rubrum, Cystoclonium and Dictyosiphon, with sexual organs and ripe carpospores and monospores in July, with ripe carpospores in September. Localities. Kn: Busserev by Frederikshavn, July. — Sa: MP, Falske Bolsax, 11-13 meters. 102 B; agama var. NOY. In the Danish waters plants only provided with sporangia are much more frequent than the above described sexual plants. As they greatly resemble these, I conclude that they belong to the same species; as they are different, however, not only by the want of sexual organs but also by somewhat larger sporangia they may be mentioned separately; and this will appear all the more legitimate when we remember the great likeness between the sporangia-bearing filaments of Ch. Thuretii and those of Ch. corymbifera Thur. (BorxET et THuRET 1876 pl. V), so that it is not excluded that the specimens mentioned here might represent a sep- arate species. As to the vegetative organs this form agrees with the sexual plants; the prin- cipal filaments, however, are as a rule a little thicker, namely 8—11 y in diameter. In some cases the thickness rea- ched 12 », and in some specimens from the North Sea (aF, fig. 32 F) it at tained even 132. On the other hand principal fila- ments only 7» thick may also occur. The cells are, as in the sexual plants, rather thick-walled; in Fig. 31. Chantransia Thuretii @, amphicarpa. From Busserev by Frederikshavn. A, the the lower part of the fila- branchlet bears a carpogonium. an antheridium and a sporangium. B, the branchlet bears a terminal carpogonium and a lateral emptied sporangium. C, ments they are proper lower part of a plant; above a branchlet with antheridia and a carpogonium. tionally short (seldom D, lower part of a ‘plant with two short descending filaments. A, B 50:1, B = C, D 350:1. ” however so short as in fig. 32 A), upward longer. The branches are somewhat thinner than the principal filaments and become thinner towards the apex. Sometimes they taper into very thin hair-like threads consisting of long, thin cells, the contents of which become colourless (fig. 32 B); this may also occur in a. Descending filaments at the base of the plants were not observed in typical specimens of this form. The chromatophores have the same shape as in the sexual plants. The sporangia have the same position and shape as in the sexual form but are somewhat larger. The length is usually 19—22 », but it may attain 24 „ and may sometimes be only 17,5 »; the breadth varies between 8 and 12 (7—13 yp). Only once have I seen a sporangium or a sporangium-bearing branchlet situated beneath another sporangium on thezsame cell (fig. 32 C, comp. fig. 30 A). In spec- imens collected towards the end of September in the Northern Kattegat (TP), 103 some peculiar crooked branchlets were observed, mostly rising from the sporangia- bearing branchlets, more rarely independently of these, and then usually given off from the lower end of the cells (fig. 33); in some cases they bear sporangia (fig. 33 A). Sometimes they occur in capitulum (fig. 33 B). These crooked filaments showed rich, coloured contents; they must without doubt be regarded as abnormal formations. Besides the monospor- angia tetrasporangia have also been met with, but only in one locality in the North Sea (aF, 31 meters) in August. The specimens bore numerous, typical monosporangia and in smaller number tetraspor- angia, having a similar position to the former. The number of tetraspor- angia on one hranchlet was frequently greater than usual, but that was also the fact for the mo- nosporangia in these spe- cimens. The tetrasporan- gia were almost globular, a little longer however than broad, 25—26 y long, 21—22 y broad (fig. 32 D). In one branchlet only one sort of sporangia occurred, but branchlets with mono- sporangia were found at a little distance from those great number on a branchlet, forming a short-stalked se os AE me on co CT EE ARS 1 — Fer nr man) Fig. 32. Chantransia Thuretii /7, agama. A—C from ZL‘, %5:1, A from the lower, B from the upper part of the plant. C, branch with sporangia, partly 2 on each cell. D, from aF. 345:1, branchlet with tetrasporangia. The pyrenoids have been drawn in some of the cells. with tetrasporangia on the same plant. Some plants bore only monosporous sporangia. Some specimens growing on Flustra foliacea dredged in the Skagerak N.W. of Hirshals in May (no. 7109) may be mentioned here, as they are somewhat different in the smaller size of the sporangia and the more irregular position of the spor- 104 angia-bearing branchlets. These were namely not restricted to the inner side of the branches but occurred on all sides of the filaments and at various distances from the base, and the sporangia were usually only 11—14 „ long, 7,5—8 » broad; one, however, was found to be 16 long, 9,5 ~ broad. The sporangia were for a great part emptied, and new were formed within the sporangial wall from the underlying cell. As these specimens agreed otherwise with the f agama, and as they were found only in very small number, I may content myself with just naming them here; it need only be pointed out that they showed short descending filaments near the base. Ch. Thuretii 8, agama occurs in depths of 2—31 meters. In the Limfjord it has been observed in depths of 2—7 meters, in the other waters only in depths greater than 9,5 meters. It has been found growing on 14 different species of Algæ, as species of Polysiphonia, stipes of Laminaria, Delesseria sangvinea, Gloiosiphonia, Desmarestia aculeata, Fucus serratus, further on Zostera- leaves and on Flustra foliacea. It has only been found in the months June to September, except the above named, somewhat aberrant specimens collected in May. Ripe sporangia have been met with in all the months named. Localities. Ns: aF, 31 meters. — Sk: ZK® off Lonstrup, 11— 13 met.; (? N.W. of Hirshals, 13—15 met., May, no. 7109). — Lf: ZU. 3 met., and XU, 4 met, in Nissum Bredning; MH in Thisted Bredning; off Gronnerup in Sallingsund, ca. 2 met.; LS and MI East of Mors. — Kn: Herthas Flak, 20— 22,5 met. (!, Borgs.); Frederikshavn; ZL? N. of Læsø, 9,5 met.; FF and TP, Trindelen, ca. 15 met. — Ke: Fladen, 22,5 met. — Ks: EM, Lysegrund. — Sa: MQ, S. of Samso, 11,5 met. — Lb: N. of Fano Kalv, 13 met. Fig. 33. 7. Chantransia Daviesii (Dillw.) Thur. Chantransia Thuretii /, agama. From T : : a. Tr = = ; HUR à i ; KYLIN 5 . 27. ee ET in LE Joris Liste p.106; Kyrın (1907) p. 117 fig. 27 branchlets rising mostly from the spor- Conferva Daviesii Dıuwyn, Brit. Conf. 1809 p. 73, pl. F (teste specim.). angiferous branchlets. 300:1. Callithamnion Daviesii Harvey, Phyc. Brit. pl.314; J, Acarpn Sp. III p. 8. Acrochetium Daviesii NÆGEL1 (1861) p.405; BorneT (1904) p. XXII. This species is as a rule easily recognizable by its fairly thick, thick-walled and short-celled filaments and by its fasciculated sporangia-bearing branchlets. It is undoubtedly nearest related to Ch. Thuretii which it may sometimes very closely resemble, while it is very different from Ch. virgatula with which it was formerly often confused. Although it was the first described of all the marine species of the genus, it is imperfectly known in some respects, for which reason a short descrip- tion of the Danish specimens may be given here. The basal part consists of branched creeping filaments which may become so densely interwoven that they form a continuous basal disc. When the plant is growing on an irregular surface, as e.g. the stalk of Laminaria hyperborea, the fila- ments are very irregularly curved and may grow over one another, and the basal part may thus become two or even three celis thick, as stated by Harvey G1BSON (Journ. of Bot. 1892 p. 104), but a real parenchymatous dise I have never seen. From the basal layer numerous erect filaments appear, forming 6 mm. high clusters. The filaments are usually 9—12 7 thick, but the thickness may vary from 8 to 13 y. The cells are usually 2—4 times as long as broad (more rarely 1—5 times). The cells contain a parietal chromato- phore with a well developed pyre- noid, very prominent in the inter- ior of the cell; sometimes the pyrenoid is so large that the part of the chromatophore in which it lies reaches nearly to the part of the same chromatophore on the opposite side of the cell (fig. 34 F). According to Kyrın (1907 p. 118) hairs rarely occur, a sporangia- bearing branchlet terminating in a hair instead of a sporangium. I have never seen unicellular hya- line hairs; on the other hand the fertile branchlets were often found tapering into very thin hair-like filaments, the cells of which be- come longer and thinner and de- coloured upwards (fig. 34 C), as in Ch. Thuretii. The sporangia are always sit- uated on branchlets which are more or less branched; the most vigorous are repeatedly branched and consist of at least 3 generations of branches, the youngest of which i one 3 : Fig. 34. 1S situated on the inner side of the Chantransia Daviesi. A and B, basal parts of plants growing on foregoing, so that the branchlet gets the stalk of Laminaria digitata seen from above and from the side. 0 C—E, erect filaments with sporangia-bearing branchlets. F, three the form of a fan-shaped fascicle. cells showing the chromatophore (December). A—E 300 :1, F 3%:1. These branchlets are mainly placed in the axils of the branches, on the inner side of their undermost cell, but they may also occur scattered on the sides of the principal filaments. In the first case one fascicle only is placed in each axil, especially when the branchlet is well de- veloped, but not rarely two less branched branchlets are placed the one over the other (fig. 34 D), and there is then a resemblance with Ch. Thuretii; typical sporan- gia-bearing fascicles are, however, always to be found on the same plants. I found D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 14 106. always only monosporangia, but Kyrın states (1907 p.118) that tetrasporangia may occur together with the monosporangia. The size of the sporangia was found to be somewhat different, the length varying from 11 to 19 y, the breadth from 8 to 10 u. It seems however that two groups of sporangia are distinguishable with re- gard to the size, the one being 11—14y long, 8—9 y broad, the other 15—19y long, 9—10 x broad, and one kind of sporangia is always only to be found on the same plant. As I have not found these differences of size connected with other differ- ences, I have not thought it necessary to distinguish the two kinds of individuals. It will be seen from the above that this species must be considered related to Ch. Thuretii; it differs from the asexual form of this particularly by somewhat thicker filaments, shorter cells and smaller sporangia being placed, at any rate in part, on repeatedly branched branchlets situated in the axils of the branches. The species occurs epiphytically on various Algæ, especially Laminariæ, on the stalks as well as on the blade, in particular on the borders of the segments of the digitate species; further it has been met with on Flustra foliacea and once on Littorina littorea. It has been collected in 1 to 23,5 meters depth. It is cer- tainly perennial or may be so. It has been found, in all cases with sporangia, in the months of May to December, in November and December in a great measure with empty sporangia. Localities. Ns: aD, 23,5 met. — Sk: N.W. of Hirshals, 11 to 15 met. — Kn: XK, TX and TU near Hirsholmene; Krageskovs Rev, 5 met.; port of Frederikshavn; Busserev; Borrebjergs Rev; TP, Tonneberg Banke, 16 met. — Ke: Lille Middelgrund, on Odonthalia, 17 to 19 met. — Sb: Kerteminde, 9,5 to 11,5 met., on Littorina littorea. 8. Chantransia attenuata sp. nov. Discus basalis bene evolutus, unistratosus, e filis repentibus confluentibus, cel- lulis fere isodiametricis, constructus. Fila erecta sat numerosa, parce ramosa, api- cem versus sensim attenuata, usque ad 550 y longa, basi 6,5—7 y, superne c. 5y crassa, cellulis inferioribus diametro c. duplo, superioribus 3—4-plo longioribus. Chromatophorum ut videtur unicum parietale, pyrenoide laterali instructum. Rami sparsi vel oppositi. Crescentia apicalis sæpe sistitur, formatione pili vel sporangii (?), et rami oppositi infra apicem extinctum egrediuntur. Monosporangia 7,5—9 u longa, 4,5—6 » lata, in ramulis unicellularibus solitaria vel bina, vel in ramulis majoribus plura sessilia, pedicellata et terminalia conferta. This species has only been met with once, growing on Desmarestia aculeata dredged in the Limfjord in August, and was then in a rather advanced stage of development. As moreover I have had only rather few dried specimens for exa- mination, my description is in some respects incomplete; the species seems, how- ever, to be distinct from all known species. The well developed basal layer resembles that of Ch. Thuretii. As the most striking character may be mentioned the frequent occurrence of opposite branches, which, however, were only found when the growth of the filament was stopped 107 seemingly by the formation of a terminal hyaline hair. The hair had usually dis- appeared, leaving only a faint scar, in some few cases it was still visible (fig. 35 B). The principal filaments consist in their lower part of short cells, about twice as long as broad; upwards the filaments become gradually somewhat thinner, and the cells at the same time longer. On the whole, the filaments are not much branched. Owing to the defective state of preservation of the material I have not been able to determine with certainty the forın of the chromato- phore. In some cases, however, I have seen that it is parietal, and I suppose it to be single and to have one parietal pyre- noid. The position of the sporangia is somewhat variable; they occur mostly in the upper part of the plant and are relatively often placed singly, more rarely two togeth- er on unicellular branchlets, or they are, though rarely, sessile on the fila- ments. Sometimes a greater number is placed on somewhat larger, often bran- ched branchlets, but Fig. 35. Chantransia attenuata. A, plant the basal layer of which is seen from the under face. 350:1. B and C, upper ends of filaments with sporangia. 560 : 1. ” such branchlets grade evenly to the long filaments. The sporangia-bearing branch- lets show usually no distinct arrangement on the filaments. The species is perhaps related to Ch. Thuretii; it differs from it by the op- posite branches and the small sporangia. Locality. Lf: MA in Nissum Bredning, 5 meters, on Desmarestia aculeata. 108 9. Chantransia stricta sp. nov. Discus basalis unistratosus e filis lateraliter confluentibus compositus. Fila erecta pauca e centro disci egredientia simplicia vel subsimplicia, stricta, usque ad 1 mm. et ultra longa, 6—7 crassa, ramulos sporangiferos per totam fere longitudi- nem gerentia; cellule 3—4,5 diametra longæ, chromatophorum parietale, pyrenoide instructum continentes. Ramuli sparsi, nonnunquam secundati, erecti, uni—bicellu- lares, monosporangia 2—3 gerentes, nonnunquam piliferi. Sporangia anguste ovata, (12—) 13—14 longa, (5—)6—7 y lata. r This species is characterized by its straight | erect filaments which are unbranched or bear- a ing at most a single branch of the same kind \ | as the principal filament. The direction of \ this is usually not at all influenced by the NE numerous lateral fertile branchlets, one of which is usually placed on nearly every one a of the cells from the base to the top. The > branchlets are situated on all sides of the filament, but not infrequenily a number of Ph 7 (i consecutive branchlets are placed on the same Ul! Fw side (fig. 36 C). Most of the branchlets are An LY unicellular and bear 2 sporangia, but two- QE? \ celled branchlets are also frequent, while such al] n .h) consisting of more than two cells are rare. In well developed filaments sessile sporangia Do) [|] do not usually occur, but they may be found [8 | in feebly developed filaments (fig. 36 A at left). 17 N Hairs are often met with at the end of the AN I branchlets and marks of decayed hairs are RS . 174 Rs visible. The sporangia are rela- IN rs tively narrow, twice as long as broad. As I SN j} have only had occasion to examine a small oo IV number of dried specimens, ! cannot give Fig. 36. any information on the development of the Chantransia stricta. A. lower part of a plant. B, frag- ment offthe middlemosi part, and C, the upper part basal layer. of the same plant. 30:1. As far as I can see, this species cannot be identified with any of the more exactly described species. The nameless spec- ies described by Rernscu (Conirib. ad Alg. et Fung. 1877 p.38 pl. XII fig. 1—2) which also has unbranched filaments, (setting aside the branchlets) differs among other things by its much smaller dimensions, shorter cells, less erect branchlets and more roundish sporangia. Only found in small quantity together with other species of Chantransia on Polysiphonia nigrescens in depths of 7,5 to 11,5 meters, in July and August. Localities. Km: BH off Gjerrild Klint. — Ks: D, N. of Isefjord. — Sa: AH‘ off Fyens Hoved. 109 10. Chantransia virgatula (Harv.) Thur. emend. I have for a long time been in doubt whether the forms mentioned under this species ought to be regarded as distinct species or as forms of one species. It is easy to point out within this group of forms some fairly different types, and I tried at first to carry out the first alternative, but I then repeatedly met individuals which might apparently with equal right be referred to one or other of the pre- sumed species. As the delimitation of the species seemed not to be facilitated by the establishment of new species embracing the intermediate forms nor by divi- sion otherwise of the forms, I have ended by referring them all to one species. My observations have led me to the view, that this species is able to take various forms under different conditions. I dare not deny that any form referred to it may possibly prove on closer examination to be a distinct species, but as I have not been able to draw the limits, I have judged it best to keep them together. The species was first described by Harvey in 1833 and figured by the same author in Phyc. Brit. pl. 313 (1851), where it was represented with tetrasporangia, showing even partly tetrahedral division. The last must at all events be wrong, and it has also been supposed by Tuurer (Le Joris Liste p. 104) and later authors that the statement of tetrasporangia was founded on some mistake. It was then generally accepted, that this species, as well as all other species of Chantransia, had only monosporangia, until Schmitz and HAUPTFLEISCH briefly mentioned (1896 p.331) that tetrasporangia may occur together with the monosporangia in Ch. secundata. Later the same was observed in Ch. virgatula by BorGESEN and Kuckuck (BORGESEN 1902 p. 351), and the observation of Schmitz was confirmed by BORGESEN (1. c. p. 350) and Kyrın (1907) for Ch. secundata. I have also found tetrasporangia in the latter but in particular in a form coming near to the typical Ch. virgatula (f. tetrica). As will be shown below, the forms referred to this species differ principally in the nature and intensity of the ramification, the length of the cells and the number of spores in the sporangia; in other respects they are quite alike. Thus, the structure of the cells is the same. The chromatophore contains an axile pyre- noid situated in the upper part of the cell and gives off a number of branches downwards and upwards; under the chromatophore a nucleus is visible. The ger- mination takes place in the same manner in all the forms, the germinating spore dividing by excentric walls into an inner triangular and three peripheral cells, without changing the orbicular outline (figs. 37 C, 38 A—C, 39 C—D, 40 E, 41 A), (comp. Murray and BARTON (1891) p. 212 pl. 37 fig. 5; Kyrın (1907) fig. 24). Some small differences may sometimes occur (fig. 40 F), but the greater part of the spores germinate as described. The orbicular outline of the basal disc may sometimes hold out for a long time, in other cases some of the peripheral cells grow out to creeping filaments at an early period (figs. 39, 40). The number of erect filaments given off from the basal disc is usually low; the first is produced by the central triangular cell, the following from the neighbouring cells. a, luxurians (J. Ag.). Callithamnion luxurians J. AGARDH Sp. Il p. 14. Chantransia luxurians Kyuın l.c. p.117 fig. 26. Callithamnion virgatulum Crouan Alg. mar. Finist. p. 116. Chantransia virgatula THURET in Le Jol. Liste p.106; Kyrın (1907) p. 116 fig. 25; BoRGESEN, M. A. Fær. p- 351 fig. 52. 110 Trentepohlia virgatula FarLow Mar. Alg. New Engl. p.109 pl. X fig. 3. Fig. 37. Chantransia virgatula a, luxurians. A, plant with sporangia. B, basal part. part of young plant. 260 :1. Cc, part of basal This form which corresponds to the Ch, virgatula in the common restriction of the au- thors is the commonest form in the Danish waters. It has two or three generations of long filaments, which are straight, up to 2mm. long, 10 to 14 » thick, more rarely up to 16 y thick or even thicker, consisting of cells 3 to 5 times as long as broad. There is a distinct contrast between the long filaments and the branchlets which occur in great number, one or two on each cell of the filaments, in the first case often secund, in the latter usually opposite; they are usually 1 to 3 cells high, unbranched or branched and bear generally two or more sporangia and most frequently also one or more vigorous hairs. The spor- angia are monosporous, ovate or broadly ellip- soidal 17—21 (—26) » long, 13—16 (—19) » broad. Under this species I have included two - forms regarded by Kyrın as distinct species, namely Ch. virgatula and Ch. luxurians, because I have not been able to distinguish them after the alleged characters. In most of the Danish specimens the thickness of the filaments varies between 11 and 13 y, thus within the limits indicated for Ch. luxurians by Kyrın, and the dimensions of the sporangia also agree with the measurements indicated for this species. On the other hand, the specimens with thicker filaments, thus agreeing better with Ch. virga- tula KyLın, had not shorter, approximately glo- bular sporangia as indicated by Kyrın, but were of the same dimensions. The thickest filaments were found in some specimens from Lysegrund in Ks (9,5 meters); they varied from 13 to 20 % in thickness, the cells were thick- 111 walled, 3 to 4 times as long as broad, the sporangia 17,5 -19 » long, 14—15 (16) a broad. As a contrast to these some specimens may be mentioned which were found growing on Porphyra umbilicalis in Thyborøn Channel (Lf); they agreed on the whole fairly well with this form, but the filaments were only 7—8 y thick. Such a small thickness I have otherwise never observed in the specimens referred to this form, though certainly in f. secundata which occurs along the west coast of Jutland; I imagine that these specimens may have originated from f. secundala but have developed ina more sheltered locality. It deserves notice that groin no. 63 is more sheltered than no. 62 where f. secundata was found growing, and that the species has otherwise not been found in the Limfjord with the exception of at Hals at the eastern en- trance of the fjord where f. secundata has been met with. — For the rest the specimens referred to this form are on the whole homogenous. This form has been found in all the Danish waters within Skagen, from low-water mark to 11,5 meters depth. The specimens found at Bornholm are typical but not very vigorous and with little branched filaments. It was mostly met with in the summer months and is undoubtedly mainly a summer Alga; for the rest it has been met with in the B months April to November, in all cases AD with sporangia. It was most frequently found growing on Polysiphonia violacea Fig. 38. and nigrescens , further on Ceramium Chantransia virgatula ß, tetrica. A, B and C, young plants 5 5 seen from above and from the side. D, branched filament rubrum a. 0. species, Cystoclonium, Zo- with tetrasporangia mostly on opposite branchlets. E, fila- stera-leaves, Porphyra umbilicalis and ment with sessile tetrasporangia. F, two cells showing the Aa i chromatophore. 265: 1. Sertularia pumila. Localities. Lf: Thyborøn Channel, groin no. 63, otherwise not found in the Limfjord. — Kn: Harbour of Skagen; Hirsholm; Frederikshayn (Th. Mortensen, !); Nordre Ronner; stony reef by Jegens Odde (GM). — Ks; Lysegrund; D, 11,5 meters. — Sa: Ronnen in Begtrup Vig; Kalo Rev; AS, Mejlgrund. — Lb: Fæno. — Sh: Kertinge Vig. —- Sm: Petersværft; Guldborgsund. — Su: BQ, off Ellekilde; Helsingør; Copenhagen. — Bm: QP, Kalkgrund; QR, Gyldenløves Flak. — Bb: Rønne; off Allinge. B, tetrica nob. Filaments (8—) 9—12 thick, cells 2—4 diameters long, sporangia on opposite branchlets or sessile on the jong filaments, all or partly tetrasporous and then 19— 22 long, 13—17 broad. 112 The above diagnosis is made after specimens growing on Porphyra umbilicalis in the harbours of Skagen and Frederikshavn. They are somewhat more branched than f. luxurians and have a little thinner filaments and shorter cells. The spor- angia are very numerous and, at least in many specimens, all tetrasporous. They are in a great measure placed on branchlets which are usually opposite, partly also sessile on the sides of the filaments. From the characters mentioned this form is, in spite of its great resemblance, so different from the main form, that I was for some time inclined to regard it as a distinet species, but some other less pronoun- ced specimens have led me to the result that it is closely related to the f. luxurians and still more to the f. secundata. Thus I found at Middelfart some specimens having chiefly monosporangia, 16—20 „ long, 11—13 » broad, but also some tetrasporangia, and the spor- angia were placed on the filaments as well as on the branchlets. These specimens might be regarded as intermediate between f. lua- urians and f. tetrica, but they were also re- lated to f. secundata, differing however by longer cells (8—5 diameters long). The re- semblance between the f. fetrica and f. secun- data will be seen on comparing fig. 38 with fig. 39. To this form at least some of the Færoese specimens mentioned by BORGESEN (1. c. fig. 53) may be referred. Only found in summer, the typical spec- imens growing on Porphyra umbilicalis. Localities. Kn: Harbours of Skagen and Frede- rikshavn. — Sa: Middelfart, on Cladophora. — UI ba 5 x Cs, 5 AD) \\ 7, secundata (Lyngb.). == . Callithamnion Dawiesii 5, secundatum Lyngb. Hydr. Be, p.129 tab. 41. Chantransia virgatula 7, secundata. Plants growing 2 3 a on Porphyra umbilicalis at Esbjerg. A and B, bran- Acrochetium secundatum Neg. Beitr. Ceram. p. 405. ched filaments with monosporangia. Cand D, young Chantransia secundala Thur. in Le Jol. Liste p. 106; plants. 260: 1. BORGESEN, M. A. Fer. p. 350; Kuckuck in OLTMANNS, Morph. Alg. I p. 650; Kyrın (1907) p. 115. That Ch. virgatula and Ch. secundata are nearly related and often difficult to distinguish from each other has often been admitted, also by BorGESEN and Kuckuck, who think however that for the present they ought be kept distinct (BORGESEN I. c. p.354). I have also wished to regard Ch. secundata as a distinct species, but I have ended by referring it as a form to Ch. virgatula, as the limit between them, accor- ding to my experience, cannot be drawn without arbitrariness. As mentioned above, 13 tetrasporangia have been found together with monosporangia by earlier authors in this form; I have found the same in Danish specimens in some few cases, but I was then usually in doubt whether the specimens ought to be referred to this or \\ | UA D A 2 NEUE Va VS ‘ IE 5 Is. = NN RN Fig. 40. Chantransia virgatula Y, secundata. Plants growing on Porphyra umbilicalis at Thyboron. A, much branched plant with mono- sporangia. B and C, basal portions of plants. D—F, young plants seen from above. 260:1. to the foregoing form. They pass really, in my experience, gradually into each other. The filaments are much branched, more than in f. luxurians, often very much branched, and the branches are then usually lying in one plane, being secund or oppo- site. There is no distinction be- tween branches and branchlets. The filaments are 7—12 (—14) » thick, the cells 1—3 times as long as broad. The sporangia are nearly always Fig. 41. Chantransia virgatula ÿ, secundata. Plants growing on Porphyra umbilicalis at Thy- boron. A, young plant. B, plant with monosporangia. 260: 1. monosporous, (13—) 15—20 (—21) » long, (9—) 10—14 (—15) » broad. They are ses- sile on the sides of the filaments or terminal and lateral on the branchlets. The sporangia as well as the sporangia-bearing branches are often secund, and then sit- uated on the upper, inner side of the branches (fig. 40 A), but they may also be opposite or at least situated two on the same cell (figs. 39, 41). The basal layer is D. K. D. Vidensk. Selsk. Skr., 7. Reekke, naturvidensk. og mathem. Afd. VII. 1. 15 114 sometimes proportionally much developed (fig. 41), but like Kyrın I found it al- ways consisting of one layer of cells, while Prinesneim (Beitr. Morph. Meeresalg. p.26 Taf. VII fig. 2), BorGEsEn and Corıns (1906 p. 194) found it consisting of two or several layers. While this form in its typical shape is quite distinct from the typical f. lux- urians, intermediate specimens may sometimes occur. In my opinion it is a re- duced form of the species produced by growing near the low-water mark, where it may sometimes be exposed to the air. On the Danish shores it has only been found at the low-water mark, on the west coast of Jutland even at a higher level. It has been found growing on Porphyra umbilicalis, Sertularia pumila, Chetemorpha Melagonium and Polysiphonia nigrescens, in the months January to August. Localities. Ns: Esbjerg; groin no. 62 by Thyborøn. — Sk: Hirshals mole. — Lf: Hals. — Kn: Frederikshavn, harbour (!, TH. MORTENSEN, C. H. OSTENFELD). 11. Chantransia Macula sp. nov. Thallus minutus membranaceus monostromaticus fere orbicularis, diametro usque c. 70, substrato adhaerens, initio parenchymaticus; dissepimentum primum medianum, sequentia obliqua; postea cellule marginales in fila repentia plus minus radiantia excrescunt. Cellule c. 4 crassæ, diametro sesqui- ad duplo longiores, chromatophorum stellare pyrenoide centrali instructum continent. Fila erecta sparsa brevissima paucicellularia simplicia plerumque e disco egrediuntur. Pili hyalini in filis radiantibus erectisque terminales hinc illine occurrunt. Spor- angia monospora in disco sessilia vel in filis erectis terminalia, ovata, long. 10— 11,5 y, lat. 6,5—7 y. This very small species has been found growing on Polysiphonia violacea to- gether with several other species of Chantransia. It is very characteristic from its thin disc-shaped frond of an irregular outiine, approaching however the circular, and corresponding to the basal layer of the more developed species, while the erect filaments are wanting or much reduced. The germinating spore divides always by a median vertical wall, and oblique walls then appear in the two daughter-cells, frequently resulting in the formation of two inner, triangular and four outer cells (fig. 42 A, B, F). The orientation of the walls may be somewhat variable, but in the central part of the more developed discs one or two triangular cells are usually recognizable, thus indicating the place of the first division wall. In some cases one of the primary daughter-cells only is divided by oblique walls (fig. 42 D), and more rarely both cells are divided by a wall parallel to the first. The plant keeps for some time its parenchymatous character and a fairly regular outline, often up to the eight-celled stage, but then the marginal cells begin to grow out into creep- ing filaments which from the first may be rather irregular but later by the increa- sing number become more regularly radiating, forming a pseudoparenchymatous disc with irregular border formed by the separate ends of the filaments. The 115 filaments branch laterally from the subterminal cells or by subdichotomous division of the terminal cell (fig. 42 H). The cells are somewhat various in shape, usually longer than broad, and contain a stellate chromatophore with central pyrenoid which is usually situated in the median line of the cell, sometimes however nearer to the one side of the cell. The hairs appear in various quantity, sometimes already in the parenchymatous stage (fig. 42 A). The erect filaments, if they are not entirely wanting, appear in rather small num- ber spread on the disc; I have found them one to three cells long, scarcely 4, thick. The spor- angia are placed di- rectly on the basal dise or terminal on the erect fila- ments; they were not very numerous in the specimens examined. The species is Fig. 42. ehe ne marginal cell mamie out iat Manet Le sue nues due able from all other G—I, more developed dises, partly with erect filaments and sporangia. A—E from BH, F—I from AH!. A—D, G—H 390:1; E, F, I 630:1. species by the char- acteristic disc and the position of the sporangia. It has been found in August and September in depths of 7,5 to 11,5 meters. Localities. Km: BH off Gjerrild Klint. — Sa: AH! by Fyens Hoved; MQ, S. of Samse. 12. Chantransia polyblasta sp. nov. Thallus cæspitulosus. Pars basalis e filis repentibus, ramosis, initio saltem inter se discretis, constructa. Spora germinans dissepimento verticali diametrali in duas cellulas aequales dividitur, quarum utraque filum repens procreat. E filo primario lateraliter fila repentia et sursum fila erecta numerosa per totam lon- gitudinem egrediuntur. Fila erecta usque ad c. 270 longa, maxima ex parte brevia, longiora ramosa, ramis ramulisque numerosis in quoque articulo singula vel bina, ramis majoribus eodem modo ramosis. Pili hyalini apicibus filorum et ramulorum impositi occurrunt. Cellule 7—10y crassæ, diametro 2—3 (—4)-plo longiores, chro- matophorum stelliforme, pyrenoide centrali instructum, continentes. Sporangia te- traspora, ovata, (16—) 18—21 » longa, 10—-12 „ lata, in filis erectis primariis vel in ramis lateralia vel terminalia, lateralia sessilia vel in ramulis unicellularibus vulgo singula. 15 in In its mode of growth this species resembles the species Ch. Dumontiæ and Ch. cytophaga described below. The germinating spore divides, as in these, into two equal cells giving rise to two creeping filaments growing out in opposite di- rections and giving off new creeping filaments which appear to be later confluent into a pseudoparenchymatous disc in the central part of the basal layer. Usually one erect filament is given off from each of the cells of the basal layer, the outer as well as the inner, and not rarely the same cell gives off two filaments, the one behindthe other (fig. 43 E, F). Most of the filaments attain only a small size and remain unbran- ched, but some of them grow out and become much bran- ched. The most vig- orous filaments are much and repeated- ly branched; usu- ally each cell bears one or two bran- ches, long filaments or branchlets, but there is no distinc- tion between these two kinds of bran- ches, as transi- tions between them frequently occur. Fig. 43. When two branches Chantransia polyblasta. (From Hals). A—C, young plants seen from above. D, more developed plant seen from above. E, F, plants seen from the side with short erect are borne by the filaments. G, H, more developed, branched erect filaments, I, end of erect filament. Same cell, they are ie Tap ATES very often not oppo- site but placed near each other on the same side of the cell. In fig. 43 E, F the last cell of the creeping filament is seen to be somewhat raised above the sub- stratum and ends in a hair. Transitions between creeping and erect filaments thus appear to occur; however, I have never seen the transformation of a creeping filament into a true erect one. The cells are cylindrical, by ramification frequently a little broader at the upper end. The stellate chromatophore contains a distinct central pyrenoid. 117 The sporangia are very often sessile on the sides of the filaments; the same cell then also bears frequently a branch or a branchlet, or it may bear up to four lateral organs (fig. 43 J). But the sporangia may also be terminal on Ihe filaments or on one-celled branchlets. It also sometimes happens that the sporangia are produced directly by the creeping filaments. The sporangia are always tetrasporous; monosporangia were never observed. As mentioned above, the mode of growth somewhat resembles that of Ch. Dumontie; it differs mainly by being throughout epiphytic. In examining numerous sections of Cystoclonium covered with Ch. polyblasta, I have once only seen a creep- ing filament penetrating through the surface of the host, but the surface was there evidently injured. As another difference may be named that the chromatophores have a distinet pyrenoid in Ch. polyblasta while such a body is not to be found in Ch. Dumontie. As to its relation to Ch. humilis see this species. The species has been found in spring (April, May) in two localities in the northern Kattegat and at Hals at the eastern entrance to the Limfjord. It occurred in greatest quantity in the last named locality, where it was found growing on Cystoclonium purpurascens, collected by Dr. BORGESEN; in the other localities it was growing on Polysiphonia nigrescens. Localities. Lf: Harbour of Hals (Børgesen). — Kn: Krageskovs Rev, 4—5,5 meters; harbour of Frederikshavn (Bergesen). 13. Chantransia humilis sp. nov. Thallus pulvinatus. Pars basalis e filis repentibus ramosis breviarticulatis in parte centrali demum confluentibus, constructa. Spora germinans in duas cellu- las æquales divisa est, quarum utraque filum repens procreat. E filis primariis lateraliter fila repentia et superne fila erecta numerosa per totam longitudinem, e quaque cellula 2—3, egrediuntur. Fila erecta brevia, 2—4-cellularia, c. 60 „ alta, simplicia; cellule apicem versus sensim incrassatæ, superne 5,5 —7y crassæ, dia- metro 2—3-plo longiores, chromatophorum axile, pyrenoide centrali instructum continentes. Pili hyalini apicales crebri. Sporangia monospora ovata vel oblonga, long. 11—14 4, lat. 7u, in filis erectis terminalia vel lateralia. In its mode of growth and the structure of the cells this species somewhat resembles Ch. polyblasta, from which it differs however by its short, unbranched, erect filaments and by the smaller, monosporous sporangia. The basal layer de- velops as in the species named; as shown in fig. 44 D, the germinating spore is nearly globular, much higher than the primary creeping filaments, and the two primary cells are for a long time recognizable from the other cells in the basal layer. In fully developed plants the creeping filaments are more or less confluent in the inner part of the plant; the cells are there usually short, roundish, 7—9 u broad. The formation of the erect filaments begins as a rule when the basal layer is two-celled (fig. 45) but I have in some cases seen an erect filament given off from a basal cell still undivided. Hyaline hairs frequently oceur at the end of the 118 erect filaments, more rarely at the sides of them. It appears that the usual dis- placement of the originally terminal hairs oceurs also in this species, but that the hairs soon disappear; the fact that the upper end of the cells is usually prominent at one side is in accordance with this supposition. The hairs may appear already in the two-celled stage of the plants (fig. 44 C). The erect filaments seem to be always unbranched; their great number in conjunction with their small size give the plant a pulvinate appearance. The cells of the erect and creeping filaments, as well as the sporangia, contain a stellate chromatophore giving off a number of branches towards the periphery. The species has hitherto only been found in one locality, growing on Polysiphonia nigrescens in May. Locality. Sb: pier at Spodsbjerg, Langeland. Fig. 44. Fig. 45. Chantransia humilis. A—C, germinating plants, C with a hair. D, Chantransia humilis. A, young plant, seen from the two first creeping filaments are given off; the pyrenoids are above. B, part of a plant showing the basal layer shown. E, adult plant seen from above. F, G, plants seen from and erect filaments with terminal sporangia. C, above, G with sporangium. H, I, plants seen in vertical section, basal layer seen from below. 560: 1. I with lateral sporangia. A—F, H, I 390:1. G 300:1. 14. Chantransia leptonema sp. nov. Thallus minutus e filis repentibus et filis erectis numerosis constructus. Fila repentia irregularia, lateraliter ramosa, plerumque ut videtur inter se libera, cellulis plus minus tumidis, lat. 3—4 », diametro sesqui- ad triplo longioribus. Spora ger- minans discum parenchymaticum serius in fila repentia excrescentem gignit. Fila erecta simplicia vel parce ramosa, usque ad 300 u longa, 3—4 yw lata, cellulis dia- metro duplo ad 5-plo longioribus, cylindraceis vel, in cellulis brevibus, leviter tu- midis, chromatophorum cylindraceum pyrenoide centrali munitum continentibus. 119 Pili hyalini terminales occurrunt. Sporangia monospora (et tetraspora?) in filis primi et secundi ordinis lateralia vel terminalia, plerumque sparsa, unilateraliter seriata, rarius opposita, nonnunquam in ramulis unicellularibus bina vel solitaria, etiam in filis repentibus sessilia, ovata, long. 10—12,5 y, lat. 5,5—6,5 y. The above diagnosis is essentially made after specimens growing on Chondrus crispus found at Hanstholm, on which | it formed a fine felted covering. One erect filament is usually given off from each cell in the creeping fila- ments, except the outermost ones. In the most developed erect fila- ments the cells are cylindrical, usu- ally 3—4 diameters long (up to 17 long), while in shorter filaments and in the fructiferous parts of the longer the cells are shorter and often some- what swollen. The shape of the chro- matophore was not easily discernible, as I had only dried material at my disposal; in some cases, however, a chromatophore was visible, consist- Fig. 46. Chantransia leptonema (Hanstholm). A—C, E, G, erect filaments ing of a cylindrical parietal plate with sporangia. D, F, H, creeping filaments with erect fila- : PR: ments. 300:1. and an axile part containinga central pyrenoid lying in the upper part of the cell (fig. 47 A). Most of the erect filaments attain only a small size and remain unbranched, but some grow longer and may then bear one or some few vege- tative branches. Terminal hairs fre- quently occur and may give rise to e sympodial branching. The sporan- gia are in great measure lateral on the erect filaments and then as a rule seriate, a position which often causes a recurvation of the filament Fig. 47. (fig. 46 A,G). The sporangia are more Ce eat eh eet en €. Meenas ately opposite, but they are frequent. ments seen from below and two erect filaments, e. 620: 1. ly terminal, in the long filaments as well as in the very short (figs. 46, 47): in the specimens from Hanstholm sporangia sitting directly on the creeping fila- ments were not observed. Sporangia borne on unicellular branchlets also occur, one sporangium being terminal, the other lateral (fig. 46 6, C). The long filaments are only sporangia-bearing in their upper part. The sporangia are only a little varying in shape and size, nearly twice as long as broad. They appear to be 120 usually monosporous; in some cases, however, the contents seemed to be divided into two or four parts (fig. 46 A), but conclusive observations were not arrived at. On Polysiphonia urceolata dredged near Hirshals I have found, growing in company with other interesting Algæ (Erythrocladia irregularis and subcontinua, Chan- transia emergens), a small Chantransia which I believed at first to be a different species, most of the rather few specimens consisting only of creeping filaments, bearing sporangia either directly or on unicellular stalks (fig. 48). Later however I found other specimens with numerous erect, partly sporangia-bearing filaments fully agreeing with the above described specimens growing on Chondrus, and I therefore have no doubt that they belong to the same species. The dimensions were the same; I found however that the sporangia borne directly on the basal layer were somewhat shorter, 8—9 » long, 6 broad, perhaps only because they were not fully ripe. The chromatophore showed the same ap- pearance as in the specimens from Hanstholm, but the pyrenoid appeared not to be central; as the material from both localities was only dried, the question must however be left open. B In some fairly juvenile plants I succeeded in finding that the first divisions of the germina- ting spore take place in a similar manner as in Ch. virgatula, three peripheral cells being cut off round an inner triangular cell (fig. 48 B). This species appears to be distinct from all hitherto described species especially by its mode Fig. 48. of growth and its slight thickness. Ch. chiloensis a Eee a a Reinsch (Contrib. ad Alg. et Fung. Vol. I 1877 p. 37 bearing sporangia. B, fairly young plant seen Taf. XI fig. 1) which was found at St. Thomas, Be en West Indies, growing on Acanthophora Thierii, differs according to REINSCH by the greater length and thickness of the filaments, by the short creeping filaments consisting of shorter cells and by broader sporangia. Localities. Sk: Hanstholm, Roshage, on Chondrus crispus in 2 m. depth, YU", August; XO, Mellegrund off Hirshals, on Polysiphonia urceolata, 11,5 to 15 m., August. 15. Chantransia reducta sp. nov. Thallus filiformis ramosus repens substrato affixus. Spora germinans in cel- lulas duas divisa est quarum utraque filum repens procreat. Cellule filorum repentium leviter tumide, c. 4. crassæ, longitudine diametro fere æquali vel sæpius duplo longiores, chromatophorum parietale, pyrenoide fere axili munitum, conti- nentes; utraque cellula demum superne sporangium aut filum brevissimum gerens. Fila erecta 1—3-cellularia simplicia, rarissime ramosa, 4,5—6 y lata, cellulis dia- metro fere æquilongis vel paullo longioribus, nonnunquam pilum hyalinum apicalem brevem gerentia. Sporangia monospora in filis repentibus sessilia aut in filis erectis terminalia, ovata vel subsphærica, long. 7—9,5 y, lat. 5,5 —7,5 y. The erect filaments are extremely reduced in this species; only in Ch. Macula among the epiphytic species here mentioned are they as much reduced. In most cases the reduction process is carried so far that the erect filament has completely disappeared, and the sporangium is situated directly on the creeping filament, or it is represented by a single stalk-cell. The erect filaments, however, may be some- times two- or three-celled, and I have, though very rarely, seen such filaments bearing a unicellular branch (fig. 49 C). In hardened material a parietal chroma- tophore with a large pyrenoid was easily visible; the latter were apparently lying in the median line of the cell, but were, in some cases at least, cer- tainly excentric (fig. 49 A, B). The two cells resulting from the division of the germinating spore remain easily recognizable by their greater breadth and rounded outline (fig. 49 A, G, H, I). In this mode of germi- nation the species recalls Ch. humilis (p.117) which has also little deve- loped erect filaments, but this spec- ies differs by its greater dimensions, by two or three erect filaments given off from each cell in the basal layer, and by stellate chromatophores. The Ch. leptonema just described may also occur in a much reduced form re- 2 Fig. 49. sembling Ch. reducta ; but that form Chantransia reducta. A and B (Frederikshavn), creeping filaments differs by a different mode of divi- Showing the chromatophores. C—F, plants in vertical section z 5 5 with sporangia. G, young plant seen from above. H, more de- sion ofthe germinating spore (fig. 48). veloped plant seen from the under side. J, plant seen from The species has been found above. K, fragment of plant in vertical section, with a stalked P sporangium. L, fragment of plant with sessile sporangia, in growing on Polysiphonia nigrescens vertical section. C—L from GM. 560:1. and Rhodomela subfusca collected near the low-water mark in the northern Kattegat, in July and September. Localities. Kn: Hirsholm; harbour of Frederikshavn; dry rock near Jegens Odde (GM). Group III. Frond partly or entirely endophytic. 16. Chantransia cytophaga sp. nov. Thallus czespitosus, ad 0,2 mm. altus, e filis 1° repentibus plantæ hospiti af- fixis, 2° erectis sporangiferis et 3° endophyticis constructus. Spora germinans disse- pimento verticali in duas cellulas divisa est quarum utraque filum horizontale D, K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk, og mathem. Afd. VII. 1. 16 122 procreat. E filis primariis lateraliter fila repentia, subtus fila endophytica et su- perne fila erecta numerosa egrediuntur. Fila endophytica brevia ramosa, in cellulas hospitis penetrantes. Fila erecta simplicia vel parce ramosa, 7—10 y lata, apicem versus paullo attenuata. Cellule diametro fere duplo longiores, superne vel medio tumidæ, chromatophorum stelliforme, ut videtur sine pyrenoide, in parte superiori cellulæ situm continentes. Pili hyalini adsunt. Sporangia in filis lateralia, sessilia, in utroque ar- ticulo plerumque 2—3, mono- spora aut tetraspora, ovata vel ellipsoidea, latitudine fere duplo longiora, monospora (11—) 13— 17 y longa, 7,5—8 y lata, tetra- spora c. 19 longa, 10 „ lata. This species forms small cushions on the margin and at a small distance from the margin of the frond of Por- phyra umbilicalis. It reminds one in its mode of growth as well as in other respects of Ch. Dumontiæ but is smaller. The basal layer develops as in Ch. polyblasta and Ch. humilis and finally consists of filaments ra- diating on all sides though often rather irregularly, and it some- times happens that one fila- ment is growing over another (fig.50 D). When the Chantransia \ is situated on the margin of the K Porphyra, the filaments make Fig. 50. their way on both sides of the Chantransia cytophaga. A, Filament with monosporangia. B, plant flat frond. From some of the seen from above. C, filament with tetrasporangium. D, young plants lls in th fil t : fastened to the margin of the frond of Porphyra. E, transverse section ceils 1n ese aments are given of Porphyra with the parasite. F, two spores on the point of germi- off haustorial filaments pene- nating on the margin of the Porphyra. G, two-celled plant. H, more 9 0 developed plant with three erect filaments, e. J and K, plants with trating into the host. The place two erect filaments and haustorium. A—G 300:1. H—K 400:1. of the endophytic filaments is indistinct, but they appear to be mainly given off from the central part of the basal layer. They make their way through the outer wall of the host and pene- trate into the nearest cell, the protoplasm of which is more or less displaced by the intruding haustorium (fig. 51). As shown in fig. 51 A two haustoria may some- 123 times penetrate into one cell. The filaments often branch within the host cell, and some of the branches may again become free, growing outwards through the wall of the host, and the same occurs with endophytic filaments without branching (in fig. 51 the free endings of the haustorial filaments are not shaded). As far as I have observed, these filaments do not penetrate from one cell into another, and therefore do not serve as propagating organs. The protoplasm of the host cell is more or less shrunk and evidently yields nourishment to the Chantransia which is thus a veritable parasite. À great number of erect filaments are given off from the creeping filaments, from the peripheral part as well as the central. As new erect filaments are con- stantly produced, a fully developed plant shows numerous erect filaments of different sizes, giving the plant a cushion-shaped appearance. Most of (ian these filaments attain only an inconsiderable eam length, the greatest are about 200 » long; they \ are either unbranched or bear one or a few : | branches which are much shorter than the main APN filament. Hyaline hairs frequently occur at the ends of the filaments, becoming lateral by the continued growth of these. In the lower part of the filaments the cells are more or less swollen at their upper ends or in the middle. The struc- ture of the cell is the same as in Ch. Dumontiæ (see p. 124), the chromatophore being stellate without pyrenoid, while a body staining inten- sely by hæmalum and undoubtedly a nucleus is Fig. 51. to be seen under the chromatophore. Chantransia cytophaga. A, plant growing on Th . I il th id the margin of the frond of Porphyra umbili- € sporangia are alw ays sessıle on e sides calis, to the left two haustoria penetrating into of the erect filaments, in their whole length. From the same cell. B, plant growing on the flat > side of the frond seen from above, showing the first each cell bears one sporangıum, but Very three haustorial filaments. The endophytic fila- soon one or two others appear and each cell ments are shaded, their free emerging ends are 3 à white; p, protoplasm of the host cell. 50:1. bears thus usually two or three sporangia, the two being as a rule opposite. The latest formed sporangium is sometimes seated at a lower level than the other, near the middle of the cell. Terminal sporangia were not observed. Nearly all the sporangia were monosporous, very few tetra- sporous; the latter were somewhat larger than the other. Possibly some of the undivided sporangia were unripe tetrasporangia; I imagine, however, that most of them were really monosporangia. The structure of the cell and the mode of growth bring this species near to Ch. Dumontie; it differs from it ir particular by the intracellular haustoria, by shorter, less branched erect filaments, by shorter cells and by the want of terminal 16" me sporangia. Ch. polyblasta and Ch. humilis differ by the want of endophytic filaments and by the presence of a distinct pyrenoid. Locality. Su: Only found at Helsingor, growing on Porphyra umbilicalis on the outer side of the southern mole in September. 17. Chantransia Dumontiæ sp. nov. Thallus cæspitulosus ad 0,5 mm. altus, e filis 1° horizontalibus epiphyticis 2° erectis ramosis sporangiferis et 3° endophyticis constructus. Spora germinans disse- pimento verticali diametrali in duas cellulas æquales divisa est quarum utraque filum horizontale procreat. E filis primariis lateraliter fila repentia et superne fila erecta egrediuntur. Fila endophytica intercellularia ex parte saltem e filis erectis egrediuntur. Fila erecta a basi ramosa, ramis numerosis sparsis plus minus ramosis; cellule diametro fere triplo longiores, superne 6,5—9 » crass, inferne tenuiores, chromatophorum stellare, ut videtur sine pyrenoide, in parte superiori cellule situm continentes. Pili hyalini terminales vel pseudolaterales adsunt. Sporangia tetraspora oblonga—ovata, latitudine fere duplo longiora, 15—19 » longa, 8—11 y lata, in filis lateralia et terminalia, plerumque sessilia, sparsa vel opposita, nonnunquam in ra- mulis unicellularibus singula vel bina. The species forms numerous small, dark-purple tufts or cushions on fronds of Dumontia filiformis, They consist of numerous erect branched filaments given off from the creeping filaments, partly also from the endophytic threads. The ger- mination takes place as in Ch. cytophaga and others of the above described species (fig.52 A, B). The epiphytic creeping filaments are often somewhat irregular, thick and short-celled, and, as shown in fig. E, they are not always densely attached to the surface of the host. I am not able to say if the first endophytic filaments are given off from the underside of the creeping filaments or not. At all events endo- phytic filaments are also given off from the base of the erect filaments (fig. D). The endophytic filaments are much branched growing intercellulary in the host, and free erect filaments may again be given off from them through the surface of the frond. I believe that this may take place also at a greater distance from the point of departure of the endophytic filaments, these thus serving to propagate the Chan- transia in the host. The free filament shown in fig. D has probably emerged from the endophytic one. It appears that relatively few endophytic filaments are given off in the same cushion. The erect filaments arise in great number from the creeping filaments, from their peripheral as well as their central parts, and the plant forms therefore tufts or cushions of '/2—1 mm. in diameter. These filaments are fairly strongly branched, as a rule from the base, and often a branch is given off from each cell in a great part of the primary filaments, and the branches may also be branched. The cells are usually broader at the upper end than below, depending on the abundant ram- ification. In the central part of the stellate chromatophore I was not able to detect any pyrenoid staining stronger with hemalum than the remaining substance of the chromatophore, while the nucleus, lying under the chromalophore but near the periphery of the cell, more rarely at the same level as the chromatophore, was very intensely stained by this reagent. Fig. 52. Chantransia Dumontiæ. A and B, young plants seen from above. C, plant with tetrasporangia, below hori- zontal and descending filaments. D and E, transverse sections of Dumonlia with Chantransia, showing endo- phytic, horizontal and erect filaments of the latter. F, two cells and a sporangium, the cells showing chro- matophore and nucleus. A—E 3%:1, F 550:1. The sporangia are most frequently sessile on the sides of the filaments, or they are placed on unicellular branchlets singly or two together, or lastly they 126 may be terminal on the long branches. From the first the cells bear usually only one sporangium or a sporangium-bearing branchlet, but later further sporangia may develop so that a great number of the cells bear two or three sporangia. When two sporangia occur, they may be opposite or near to each other, but a spor- angium may also be placed under another sporangium or under a branch (fig. C). The cells giving off a branch bear frequently a sporangium opposite to it. Mono- sporangia were not observed. Identical specimens were found in two localities on the north coast of Sealand, growing in Dumontia filiformis in the month of May. It cannot be confused with any other known species. As to its relation to Ch. cytophaga see this species. Localities. Ke: Harbour of Gilleleje, inner side of the mole. — Su: Harbour of Helsingor. 18. Chantransia Nemalionis (De Not.) Ard. et Straf. ARDISSONE e STRAFFORELLO, Enum. delle Alghe di Liguria, Milano 1877 p. 167. Callithamnion Nemalionis DE NoTarıs, Erbar. Crittogam. Italiano, no. 952 (c. descript.); ARDISSONE, Pro- spetto delle Ceramiee italiche, 1867 p. 17, Tav. I fig. 1—3. Acrochetium Nemalionis BORNET (1904) p. XX. Chantransia Saviana (Menegh.) ARDISSONE, Phycol. Mediterr. 1883 p. 276 ex parte. As shown by Bornet, the Callithamnion Nemalionis described by DE Noraris has a system of filaments endophytic in the frond of Nemalion lubricum, on which it forms numerous 4—5 mm. high tufts. The same mode of growth was observed in a Chantransia growing in Nemalion multifidum at Struer in the Limfjord. As it fully agreed with the description of DE Noraris and with his above-quoted original specimens, which I have been enabled to examine through the great kindness of Dr. BornET, I refer it to the same species without any doubt. ARDISSONE has later confused this species with one or perhaps more others under the name of Chan- transia Saviana (Menegh.) Ard.; as however MENEGHINI’s description refers to a species growing on Zostera leaves and certainly different from DE Noraris’ species, it is unwarranted to replace the name of the latter with that of MENEGHINI. The plant has long ramified filaments growing widely in the interior of the host and here and there sending out through the surface of the host free filaments giving rise to new tufts; the number of tufts occurring on the same frond of Ne- malion may therefore be very great. The walls of the endophytic filaments are often a little sinuous on account of their growth between the cells of the host; the cells are usually 8 to 11» thick, 3,5 to 5 diameters long. They contain in the middle a narrow belt-shaped chromatophore with a parietal pyrenoid. When the endophytic filaments rise from the basal part of the erect filaments they are given off from the lower end of the cells while the upright branches are given off at their upper end, and a similar polarity is as a rule, though not always, present in the endophytic filaments (fig. 54 A). The erect filaments greatly resemble those of Ch. corymbifera and Ch. Thuretit; they form up to 5mm. high tufts with spread branches which are multilateral but with some tendency to unilaterality. The cells are cylindrical, not constricted at the transverse walls, (7,5—)9—11 (—12)y broad, 3—7, usually 4—5 diameters long. They contain a parietal chromatophore with a large parietal pyrenoid much pro- jecting into the interior of the cell. In the older cells the chromatophore is larger than in the younger and perhaps somewhat lobed. Hyaline hairs do not occur. The germination was unfortunately not observed. The sporangia are borne on branch- lets, usually placed on the inner side of | MER the branches near their base, very often S NN two or three seriate. The branchlets N. RA are as a rule one- or two-celled; in the SK first case it bears a terminal and a la- teral sporangium, in the latler the upper cell behaves in the same way, while the N EN lower cell bears one or two sporangia. Ÿ, | It happens however that the branchlets _ WW f may consist of more than two cells and = that they may be branched (fig. 54 D). SS Only rarely the sporangia may be ses- sile directly on the filaments. The spor- angia are always monosporous, oblong, ik 1 18—19 » long, 9—10,5 » broad. Renewal ofthe emptied sporangia from the under- lying cell frequently occurs. \ As already said, the Danish spec- Se \ 7 imens agree with the original specimens N \V of DE Noraris from Genoa. ARDISSONE IN LS Vp figures certainly only two single, appa- Xa lg FE rently sessile sporangia (1867 fig. 3); the \ IF sporangia are however nearly always i borne on branchiets at least two together hy in DE Noraris specimens as well as in W mine. | This species greatly resembles Ch. ; corymbifera Thur.!, which srows on Hel- Chantransia Nemalionis. en with sporangia, below minthocladia purpurea. It differs from an endophytic filament. 95:1. it by the absence of sex-organs and by the want of a larger cell originating from the germinating spore and giving off erect filaments and descending endophytic filaments. In spite of repeated search I have never found such a cell and that is in accordance with Bornet’s statement 1 G. THURET in LE Jouis Liste p.107; Borner et THURET, Not. alg. | p.17 pl. V; Borner 1904, p. XX. 128 that the cell rising from the germinating spore is not different from the cells which it produces. To judge from the figures of Borner and THURET the spor- angia become a little larger in Ch. corymbifera than in Ch. Nemalionis, namely up to 22 u long. It is interesting that this species hitherto only known from the Mediterranean and the Gulf of Gascony has been found in the Limfjord, a water with relatively high salinity and summer temperature. Locality. Lf: Struer, outer side of the mole, September. 19. Chantransia endozoica Darbish. O. V. DarBIsHIRE, Chantransia endo- zoica Darbish., eine neue Florideen- Art. Ber. deutsch. bot. Ges. 1899, Bd. 17 p.13 Tafel I. The greater part of the frond of this species grows in the thick outer wall of the Bryozoan Alcyonidium gelati- nosum. The endozoic filaments are dichotomously branched and give off numerous free, short, branched fertile fila- ments bearing monosporangia. I have only met with very few Fig. 54. specimens and must therefore Chantransia Nemalionis. A, endophytic filaments giving off a number of content mvself by referring to erect filaments. B, upper end of erect filament showing chromatophores > with pyrenoid. C and D, filaments with sporangia-bearing branchlets. the above-quoted paper of Dar- gere BISHIRE. I regret that I am not able, any more than this author, to give information on the form and structure of the chromatophore. The sporangia were 13,5—17 y long, 9—10 4 broad. Locality. Sk: In a specimen of Alcyonidium gelatinosum washed ashore on the beach of Hirs- hals, August, with ripe sporangia. 20. Chantransia emergens sp. nov. Fila vegetativa endophytica infra cuticulam hospitis (Polysiphoniæ urceolatæ) horizontaliter expansa, ramosa, ramis sparsis vel oppositis, sub angulo recto plerumque 129 egredientibus, cellulis subcylindricis medio vel paullo supra medium plus minus inflatis, 6 —10,5 y longis, 2—3,5 y latis. Chromatophorum ut videtur, unicum pa- rietale pyrenoide instructum. Pili hyalini desunt. Monosporangia extra cuticulam emergentia solitaria breviter stipitata, stipite unicellulari, rarius in filis endophyticis sessilia, ovata, 5—6,5 longa, 3—4 7 lata. In a specimen of Polysiphonia urceolata dredged in the Skagerak off Hirshals Fig. 55. Chantransia emergens. A, filaments growing under the cuticle of the host, seen partly from the face partly in profile (at left); a pericentral cell of Polysiphonia is shown. B, transverse section of Polysiphonia with the endophyte. C, endophytic filaments. D and E, cells showing the chromatophore and the supposed pyre- noid. F—I, filaments with sporangial branchlets seen in profile, in G an emptied sporangium, in Fa new sporangium is formed besides an emptied one. A—B 290:1, C—I 610: 1. this little species was found rather abundantly, growing in the outer wall close within the cuticle but never penetrating into the radial walls between the pericen- tral cells. The filaments are very thin, the cells very thin-walled, usually 3—5 dia- meters long; they were in the dried specimens, the only ones I examined, uni- formily rose-coloured and seemed to contain a parietal chromatophore occupying the greater part of the periphery of the cell. In the middle or somewhat over D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 17 130 the middle of the cell a body staining in hæmalum is visible, probably a pyre- noid. The branches are given off at a certain distance from the acroscopic trans- verse wall, sometimes from the middle of the cell or even, though rarely, a little under the middle. All the vegetative branches are given off in a plane parallel to the surface of the host, while the extremely short fertile branchlets break through the cuticle in a direction perpendicular to that plane. These branchlets consist of a short partly immersed stalk-cell and an entirely free sporangium, but sporangia arising directly from the endophytic filaments also occur. In the fertile part of the plant a sporangium is usually given off from each cell in the endophytic filament (fig. 55 A). After the evacuation a new sporangium may be formed within the empty sporangial wall, but it may also occur that a new lateral sporangium is given off from the stalk cell besides the emptied terminal one. The species appears to be nearly related to Acrochetium endophyticum BATTERS (Journ. of Botany Vol. 34 1896 p. 386) living in “the cortical layer” of Heterosiphonia coccinea. As far as can be seen from BATTERSs’ description this species is distin- guished from Ch. emergens mainly by longer erect filaments, which are composed of from one to three cells. Locality. Sk: Mellegrund off Hirshals (XO), 11,5 to 15 meters, with ripe sporangia in August. 21. Chantransia immersa sp. nov. Thallus endophyticus; fila omnino immersa, intercellularia, varie ramosa, ramis sparsis vel ex una cellula pluribus egredientibus. Cellule nunc cylindricæ plerumque tamen medio vel supra medium inflate, 8—10 „ late, 40—53 y longe, nunc, pr&cipue superficiem hospitis versus, breviores plus minus rotundatæ, usque ad 15 4 late. Chromatophorum unicum stellare pyrenoide centrali et ramis longis sursum et deorsum protractis munitum. Cellule ultimæ breves obovate vel ro- tundatæ, in superficie hospitis prorumpunt, cellulas periphericas illius plerumque non superantes, nonnunquam pilum hyalinum gerentes. Sporangia, transformatione cellularum ultimarum orta, obovata, 15—17,5 » longa, 11—12 „ lata, monospora, post evacuationem sæpe sporangio novo e cellula suffultoria formato repleta. This species occurs in Rhodomela subfusca and in species of Polysiphonia. As the endophytes are essentially identical in structure, they are referred to the same species, but as their behaviour to the different hosts is somewhat different, two forms may be distinguished. Forma Rhodomelæ. In Rhodomela I have only found the endophyte growing in tumours and occurring in fairly great quantity at Frederikshavn in July 1895 and 1896. These tumours are irregularly roundish and somewhat remind one in form and size of Harveyella mirabilis. I conclude that they are occasioned by this endophyte, but it deserves notice that these tumours also contained an endophytic Ectocarpus or Streblonema and the very common endophyte Bolbocoleon piliferum. The Chantransia grows intercellularly through the whole tumour, the filaments running mainly in a radial direction. The swellings have essentially the same 131 structure as the normal branches; there appears to take place only an acceleration of the growth, their structure assuming the appearance of that of much older branches. In the interior of the tumour the cells of the endophyte are usually several times as long as broad, nearly cylindrical; towards the peri- phery they become shorter, lastly only a little longer than broad. At the same time the filaments become more bran- ched. The outermost cells reaching the surface of the host bear sometimes a short hair ca. 4,5 # thick at the base but -@- PL aeg ® c E Fig. 56. Chantransia immersa f. Rhodomele.* A, section of tumour of Rhodomela quickly tapering upwards. with the endophyte; a new sporangium is about to be formed within an emptied sporangial-wall. B and C, ends of filaments with hair. D, The structure of the cells filament with sporangia, one emptied. Æ, filament showing the chro- matophores. 300: 1. was studied on material har- dened with picric acid. The pyrenoid is large and contains an angular body, pro- bably a crystalloid. It is situated nearly in the middle of the cell but not always Fig. 57. Chantransia immersa f. Rhodomele. Cells showing the chromatophore ; hardened with picric acid. A, young cells, p, pyrenoid, n, nucleus. B, the pyrenoid contains a crystalloid. C, the chromatophore with long arms, the pyrenoid excentric. A 730:1. B 580:1. C 1100: 1. in the axis of the cell (fig. 57 B, C). The arms of the chromatophore are long and narrow and extend from the central part containing the pyrenoid upwards and downwards to the ends of the cell. The nucleus is difficult to see; by aid of borax-carmine it was deter- mined in young cells, lying in a pit in the chromato- phore near the pyrenoid (fig. 57 A, n). The sporangia arise almost without change of form from the outermost cells lying at the level of the sur- face of the host or a little prominent. After the eva- cuation a new sporangium may be formed within the emptied wall from the under-lying cell (fig. 56 A). Forma Polysiphoniæ. Of this form which has been found growing in Polysiphonia nigrescens and P. violacea I have particularly examined specimens infesting P. ni- grescens collected at Hirsholmene in September. It oc- casions here no tumours but grows intercellularly be- tween the central cell and the pericentral cells as well as between the latter mutually. Long straight filaments consisting of cylindrical or feebly swollen cells often run longitudinally between the central cell and the pericentral cells, sending off between the pericentral cells radiating filaments ending with short cells breaking through 17° 132 the cuticle of the host (fig. 58 C, E). But longitudinal filaments running a short dis- tance from the surface between the pericentral cells also occur, and these filaments give off short unicellular branchlets (fig. 58 F). The peripheral cells may reach the surface of the host or be somewhat prominent, and the same is the case with the sporangia; these are only seldom so prominent as that shown in fig. 58 C. The pe = peripheral cells bear some- 8 mn à PA times a hair which may be i d more vigorous than in f. Rho- domelæ and two hairs in one cell may even be observed (fig. 58 A). The chromato- phore has the same structure as in f. Rhodomelæ, and the sporangia are also alike. For- mation of a new sporangium within an emptied sporangial wall frequently occurs, appa- rently repeatedly (fig.58 C, D, G). The sporangia were as a rule better developed than in f. Rho- domele, probably on account of the later season. The more or less immersed monosporangia distinguish this species from all other described endophytic Chan- transie known to me. Fig. 58. Chantransia immersa f. Polysiphoniæ. A, filament giving off an emerging cell bearing two hairs. B, end of filament with hair. C, transverse section of Polysiphonia nigrescens with the endophyte. D and E, longitudinal fila- mole. ments giving off radiating filaments with sporangia. F, longitudinal fila- Forma Polysiphonie. Kn: Hirs- ment with unicellular branchlets. G, filament with sporangia-bearing branches. 300:1. Localities. Forma Rhodomele. Kn: Frederikshavn, outer side of the holmene, in Polysiphonia nigrescens, September; dry rock at Jegens Odde in the same, Sept.; Trindelen (NI), 9,5 to 10,5 met., in Polys. violacea, Sept. 22. Chantransia Polyidis sp. nov. Thallus endophyticus; fila in cortice exteriori et interiori hospitis (Polyidis rotundi) intercellularia, vario modo, in directione radiali et transversali vel etiam intermedia, præsertim tamen radiali, peripheriam versus crescentia, ramosa, ramis sparsis. Cellule forma varia, plerumque cylindricæ vel utriculosæ, sæpe aliquantum curvatæ, long. 30—56 », lat. 10,5—14 », peripheriam versus breviores, adultæ ut videtur chromatophorum unicum valde ramosum, fere reticulatum continentes. Cellule ultimæ rotundatæ, oblong vel clavate, superficiem hospitis attingentes sed 139 non superantes, raro pilum paullo evolutum porlant. Sporangia in apice filorum radiantium singula vel rarius bina, immersa, superficiem hospilis non vel vix su- perantia, monospora, oblonga, long. 15,5 —18 y, lat.9 y. This species was found only once in dried specimens of Polyides rotundus collected in the Northern Kattegat in September. In mode of growth it reminds one somewhat of Ch. immersa from which it is distinguished in particular by the form of the chromatophore. It does not occasion any deformation of the host plant in the intercellular sub- stance of which it lives. It grows principally in a radial direction but has also stoloniform filaments grow- Nenn | \ J Ÿ | ù N ing out in a transverse direction | À CN and giving off new radiating fila- | I: ments (fig. 59). The filaments are A en B ig. 59. as a rule fairly strongly branched, Chantransia Polyidis. A, radiating filament with fasciculated however, one branch only is given branches. B, transverse section of Polyides with Chantransia N showing transverse and radiating filaments. 300:1. off from each joint, and some cells bear no branch. Sometimes the branches are fasciculated in the radial filaments (fig. 59 A). The cells are usually somewhat swollen; at some distance from ‘ the surface very thick cells, over 20 broad, may frequently be met with. Hyaline hairs seem to occur only in very small quantity and feebly developed. The end-cell shown in fig.60 B is. probably a young hair which has not yet reached above the surface of the host. As I possess only dried material I cannot give a sufficient account of the structure of the chromatophore, which seems to be rather peculiar. In the end-cells the chromatophore appears often as a compact mass filling out the greater part of the cell, in the centre of which a body is visible which seems to be a Fig. 60. Chantransia Polyidis. A, radiating filament show- ing the chromatophores. B, end of filament the pyrenoid (fig. 60 A). In the somewhat older end-cell of which is apparently about to form a h hr Oh ft L an hair. C, branched filament with partly emptied cells the chroma opnore shows O ten an upper sporangia. D, end of filament with terminal spor- dome-shaped part while the rest of it is divided angium. À 390:1. B—D 300:1. 2 i into a number of strands or plates, concerning which I am not able to decide if they are all continuous or partly separate. The dome-shaped part soon disappears and the supposed pyrenoid was also as a rule not visible in the more developed cells. The whole process has apparently the char- acter of a vacuolization of the chromatophore. The sporangia are terminal on the outward growing filaments. Besides the really terminal sporangium another lateral is often developed, inserled at the same level. The sporangia are entirely immersed or only a little prominent above the surface of the host; they are about twice as long as broad. Locality. Kn: Tonneberg Banke, TP, 16 meters, September. Subgenus Grania. Group IV. Frond epiphytic (or partly endozoic); chromatophores long, usually spiral- shaped, more than one; carpogonia often intercalary, carpospores seriate. 23. Chantransia efflorescens (J. Ag.) Kjellm. KJELLMAN, N. Ish. algfl. p. 166 (Alg. Arct. Sea p. 129) tab. 12 fig. 1—2 (f.tenuis Kjellm.); Gran, Kristianiafj. Algefl. p.19 tab. I fig. 1—3; E. LEHMANN, Beitr. z. Kenntn. yon Chantransia efflorescens J. Ag. sp., Wiss. Meeresuntersuch. N. F. 6. Bd. Abt. Kiel 1902 p.1, Taf.1; BORGESEN (1902) p.355; KyziN (1906) p. 113. Trentepohlia Dawiesii a. ARESCHOUG, Phyc. Scand. 1846 p. 117. tab. V D. Callithamnion efflorescens J. AGARDH, Sp. Vol. II p. 15. Rhodochorton chantransioides REINKE, Algenfl. p.23, Atlas Deutsch. Meeresalg. Taf. 21. Much has been added to our knowledge of this interesting Alga during the last thirteen years. GRAN described the sex-organs in 1896, showing that the for- merly known clusters of spores were cystocarps. According to Gran and other observers the sexual plants do not bear sporangia; but later, sporangia have been observed on other individuals supposed to belong to the same species. Thus, in 1902 E. LEHMANN recorded monosporangia-bearing plants growing together with sexual plants on stones in the bay of Kiel, and in the same year BORGESEN men- tioned similar plants with monosporangia found at the Faeroes, while sexual plants were not met with. Finally, KyziN has shown in 1906 that Rhodochorion chan- transioides REINKE belongs to this species, representing an asexual generation pro- vided with tetrasporangia. KyLiN doubts, however, that the asexual plants men- tioned by LEHMANN and BorGESEN ought to be referred to this species, as they bear monosporangia and have somewhat thicker filaments than the Swedish specimens. Referring to the careful description of the species by Kyrın, it must be pointed out that I do not fully agree with this author in the delimitation of the species, as I have found that it may have monosporangia as well as tetrasporangia, and that the filaments may often be somewhat thicker than stated by him. While the filaments according to KyziN are 5 y thick, I have found, on the basis of a great number of measurements, that in plants from all Danish waters they are usually 5—6 w thick, but that the thickness varies from 4 to 7,5 ». My observations are not sufficiently numerous to allow any certain conclusion as to the influence of the outer conditions upon the thickness; I shall only state that the specimens from the Baltic were 4—5 » thick, while plants collected in the North Sea in 38 meters depth were 64 thick. The germination, which was hitherto unknown, has been studied in specimens growing on the theca of a hydroid polyp, collected in the Samso Waters (YV) in 135 June. The germinating plants were found among fully developed plants bearing monosporangia and originated undoubtedly from monospores. As shown in fig. 61 the germinating spore becomes a hemispherical basal cell the diameter of which is much greater than that of the filaments, namely 8—10 p- This cell keeps its form, at all events for some time, and divides only by peripheral walls, by rami- fication. An erect filament is early given off from the upper face of the cell, and from the margin small cells are cut off which grow out into irregularly bent creeping filaments. In somewhat older plants x 1 two erect filaments rising from the basal cell | and an increasing number of radiating creep- \ / | ing filaments are visible (fig. 61 E). In some | cases it was observed that a filament, after having run some distance on the surface of the wall of the hydroid, had suddenly pene- trated the wall and continued its way within it (fig. 61 E), I do not know if this species can also penetrate the Algze on which it grows. LEHMANN figures a basal part of the f. petrophila described by him (1. e. fig. 10), which is rather different from the young stages observed by me, as it is a parenchy- matous disc giving off three erect filaments from three different cells, and no cell is distinguishable as being the originally single basal cell. The difference may be possibly due to the difference in age, in part also to the different substratum. As shown by Kytin, free descending fila- ments often occur in the lower bau! of the Chantransia RE ape plant on tube plant; they are met with in the asexual of Hydroid, from YV, June 194. A, spore, provided individuals as well as in the sexual plants; il, membran bu il ante ha el in the first named, however, they are often same stage. D, ereeping filaments are given ofl from ti the periphery of the basal cell. E, the basal cell has ya: given off two erect and four ereeping filaments; one The chromatophores are, as shown by of the latter has penetrated into the membrane of o a the Hydroid. The endozoie part of the filament is REINKE and Kyrın, parietal spiral-shaped i shaded. 560:1. bands. Usually there appears to be two, sometimes only one, and in other cases they are more irregular, either more nu- merous or more branched, a matter difficult to decide. LEHMANN states expressly that the cells contain one much-branched chromatophore only, the apparently dis- tinct chromatophores being always connected by anastomoses. Though this state- ment is in contradiction to the figures of Kuckuck (REINKE, Atlas Taf. 21 fig. 3) and Kyrın and though I also think I have observed more than one chromatophore / TZ | | A 136 in the cells (fig. 64), I dare not deny it decidedly, as it is in reality very difficult to convince oneself of the absence of anastomoses between the chromatophores, which never run quite regularly. According to Kyzix (1. c. p.115) the chromato- phores contain small granules which are interpreted by him as pyrenoids. I have observed the same granules but cannot give any information as to their nature: their appearance seemed not to be constant. While the cells in LEHMANN’s spec- imens contained fat and no starch, I found in cystocarp-bearing specimens the vegetative cells containing no fat but minute starch-grains staining red-brown in iodine, and the cystocarps, especially the carpospores, contained a great quantity of the same substance. The reaction with iodine was rather similar to that of glycogen. L The sex-organs develop, as shown by GRAN, on | special fertile branchlets, generally very near each other. Later, Kyzin has accounted for the various combinations of the sex-organs on the same branch- let, but he has not noticed the curious fact that the carpogonia are not always lateral on the fertile branchlet but often intercalary, rising by transfor- mation of the second or even the third cell from the top. The intercalary carpogonia, which were already observed in 1893 by the late Professor Fr. Schmitz who mentioned them in a letter to me, are very common. À very frequent case is represented in fig.62 A, C, D where the lower cell in a two-celled branch has become a carpogonium, pushing forward a trichogyne from the upper end of the cell along the upper cell which in all cases is sterile bearing two antheridia. In fig. 62 B both Fig. 62. the cells have developed into carpogonia, the one rer re Bee ee superposed on the other. In fig. 62 G the carpo- produced by them after fertilisation are gonium has arisen from the lowest cell in a three- shaded. 4—D 0:1. E 30:1. FH: celled branched branchlet, and in fig.62 E and F they are lateral. In the same branchlet a lateral and a terminal carpogonium frequently occur. The intercalary carpogonia show very often a swelling at the base of the trichogyne (fig. 62 D) which may formerly perhaps have been inter- preted as the whole ventral part of the carpogonium. Fertilized carpogonia with adhering globular spermatia frequently occur. After fertilization the separation of the trichogyne takes place in the intercalary carpogonia at the upper end of the swelling (fig. 62 G). Thereafter the fertilized carpogonium increases in length, the trichogyne is pushed aside, and the lengthened body divides by a transverse wall a little under the insertion of the trichogyne (fig. 62 E, F, H). Even in this stage and later the trichogyne with adhering spermatium may yet be visible. In fig. 62 H the primary filament of the young cystocarp is three-celled and has produced a 137 branch. The further divisions and branchings I have not followed; they result in the formation of a glomerule of radiating filaments, the two or three last cells of which are swollen and produce each a carpospore. As each fertile branch bears as a rule more than one carpogonium, the glomerules may perhaps sometimes be composed of two or even three cystocarps, being thus syncarps. The position of the antheridia in the neighbourhood of the carpogonia results in emptied anthe- ridia being frequently visible in ripe eystocarpia amongst the spore-producing fila- ments (fig. 63). I have no doubt that Kyrın is perfectly right in referring the Rhodochorton chantransioides to this species, as it agrees with it in all but the reproduction. However, the tetraspore-bearing plants are as a rule smaller, ca. 2 mm. high, and it may be added that they usually form continuous felted coverings while the sexual plants form isolated tufts. On the other hand specimens fully agreeing with those des- cribed by REINKE and Kyrın, only bearing mo- nosporangia instead of tetrasporangia, also occur. Young still undivided tetrasporangia are out of the question in this connection, for I have in many cases met with specimens bearing nume- rous well-developed monosporangia, some of which were emptied but not one with divided contents. Usually each plant bears either tetra- sporangia or monosporangia, but the two kinds of plants often grow together side by side, as the plants represented in fig. 64. The only differ- ence is that the monosporangia are smaller than the tetrasporangia. The monosporangia I found (10—) MS y long, Il] (—8,5) [2 broad , the Chantransia efflorescens. Branchlet with ripe tetrasporangia 15-28 L long, 8—12,5 m broad. cystocarp showing still two emptied antheridia 5 ee 5 at the top of the branchlet. 85:1. Referring to the above quoted descriptions it may be added that two sporangia-bearing branchlets are frequently sitting on one cell in the monosporangia-bearing as well as in the tetrasporangia-bearing plants; they are usually opposite but may also be placed near each other on one side of the filament (fig. 64). The species has been met with in the Danish waters in the months April to August. Sporangia-bearing plants occur in April to June, more rarely in July. Sex- organs have been met with in all the months named, fully developed cystocarps only in June to August. This in connection with the fact that the two kinds of reproductive organs occur in different individuals suggest the existence of an alter- nation of an asexual generation appearing in spring with a sexual one occurring prineipally in summer. If this supposition is right, the germinating plants men- tioned above (fig. 61) must be young sexual plants. Unfortunately LEHMANN does D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 18 138 not mention if the basal disc figured by him (l. c. fig. 10) belonged to an asexual or a sexual plant. The species attains in the Danish waters a length of 5 mm., but it is rela- tively seldom more than 3 mm. high. As mentioned above, the asexual plants are as a rule smaller than the sexual ones; however I have found in the Little Belt a specimen with monosporangia measuring 5 mm. in length. It grows principally on other Algæ; I have recorded it on 15 different species, most frequently on Delesseria sangvinea, Furcellaria, Desmarestia aculeata, Cystoclonium purpurascens, Polysiphonia elongata, further on leaves and roots of Zostera, on tubes of Hydroids, Ascidians, shells of Buccinum and finally on stones. It has been met with in depths of 7,5 to 38 meters, most frequently 11 to 23 meters. In the following list of localities the depth is only indicated when it is outside the last named limits. It is interesting that this sub- arctic species has been met with in nearly all the Danish waters, also in the Baltic, but not in the Lim- fjord nor in other shallow waters where the summer temperature is comparatively high. Localities. Ns: AG near the Jutland Reef, 28 met. — Kn: FG, Herthas Flak; FH near Frederikshayn 4—7,5 met.; VU and VT, 9,5 met., N. of Læsø. — Ke: FC; ZE!and VY, Fladen: IK, Lille Middel- grund; IA, Store Middelgrund; RL. — Km: XF, Læso channel, 8,5 met. — Ks: OS, Hastens Grund. — Sa: FS, Vejre Sund; YV, south of Hatterbarn; DK, Bolsaxen. — Lb: XP, Middelfart; common around Fæno. — Sb: Z; near Sprogo (Ostenfeld); Langelandsbelt: UH, UT and LB. — Su: bM, south of Hveen; OG. — Bw: LC, south of Lange- Fig. 64. Chantransia efflorescens. A, filament with monosporangia, partly emptied. land; Femerbelt: UL and KX. — Bb: XZ#, Davids Banke, 19 —20,5 met. B, filament with tetrasporangia. 560: 1. 24. Chantransia pectinata Kylin. Kyrın (1906) p. 120. I have repeatedly met with a Chantransia agreeing with KyLın's description and figures of this species, which appears to be related to Ch. efflorescens. The only discordance is that in some cases I have found free descending filaments near the base of the erect filaments, while Ch. pectinata according to KyLın is distin- guished from Ch. efflorescens just by the want of such filaments. They occur how- ever seldom and are not so long as in the latter and they appear to have partly the character of stolons, growing out in horizontal direction (fig. 65 C). In spite of the presence of these filaments I regard the two named species as quite distinct, Ch. pectinata being characterized by thicker filaments, shorter, more thick-walled cells and by the sporangia-bearing branchlets being seriate on the inner side of the lateral filaments. 139 The main filaments were in my specimens 6—9 » thick near the base; they are repeatedly branched. Opposite branches sometimes occur (fig. 65 D). The branches are tapering upward, finally only 3,5—4 » thick. The cells of the main filaments are usually 4—7 times as long as broad. As shown by Kyrın, the chro- matophores have almost the same shape as in Ch. efflorescens; they may also con- tain small refractive bodies which are possibly pyrenoids. The sporangia-bearing branchlets are sometimes composed of more than 3 cells and transitions to longer filaments may then occur. Sometimes the sporangia may also be terminal on long filaments (fig. 65 A). The sporangia are always mono- sporous; after the evacuation a new sporangium is often formed within the f) 1 Oe | emptied membrane. In some cases the N AL" sporangial wall was distinctly lamellate, ne NN ey consisting of two layers at least (fig.65 A, B) \ H/ M in other cases this could not be observed. | i | | The sporangia were in the Danish spec- H is |] imens 10—14 » long, 5,5—7,5 y, most H | | frequently 7# thick. | |] The species has been found in depths H a | of 13 to 24,5 meters, growing on Phyllo- PEN) phora Brodici, Desmarestia aculeata, Bucci- SÆBE num undatum and Flustra foliacea, in June and July. Localities. Ke: VZ, Groves Flak. — Lb: Fænø Sund and N. and W. of Fænø. PB, cimbrica var. nov. 2 É = E : Chantransia pectinata. From Little Belt near Fæno. A, Filis principalibus erassioribus in- end of long filament with terminal sporangium and late- 3 2 au 2 5 ral sporangia-bearing branchlets. B, 4-celled sporangia- ferne 8—10,5 4 Crassis, Sporanslis partim bearing branchlet. C, lower part of erect filament with 3 =) re ” sær descending and horizontally outgrowing filaments. D, [ES DOTS 18 19 2 lougis, 10,5 13 u erect filament with opposed branches. E, fragment of latis, partim monosporis, 11—13 longis, a filament of the basal layer with erect filament. A. B, D : 20:1. C 560:1. E 350:1. 6—8 yp, latis. In the Skagerak a Chantransia was found in May, growing on Flustra foliacea, which differed from the typical Ch. pectinata by thicker filaments and by the pre- sence of tetrasporangia, but for the rest resembling the latter so much that it must be considered as a variety or form. Some specimens were almost the same as the typical species or only differing by a little thicker filaments, having the typical seriate sporangia-bearing branchlets with monosporangia. But others showed less numerous fertile branchlets bearing at most 2 sporangia, which were larger than the others and containing 4 spores. As I have had very scarce material I cannot say if the two kinds of sporangia may occur in the same individual. At all events 18" 140 some specimens bore exclusively monosporangia; the tetrasporangia occurred only in small quantity. As in the main species short descending filaments occurred at the base of the Fig. 66. Chantransia pectinata 3, cimbrica. A, lower part of erect filament. B, upper part of the same with sporangia; one of these showing a transverse wall. C, branched filament with tetrasporangia. D, filament with branch- lets bearing monosporangia. E—G, cells showing the chromatophores. A, B 260:1. C, D 340:1. E—G 550:1. erect filaments (fig.66 A). The branches taper upwards, at last 5,5 x thick. There is more than one chromatophore, parietal, long and narrow, sometimes spiral- shaped but more frequently rather irregular. 141 Similar specimens to those just described, but bearing only monosporangia, were found attached to Flustra foliacea near the Jutland Reef. To this variety may also be referred some small specimens found nearly in the same place as the first described, and on the same substratum (no.7109). Their primary erect filaments were up to 114 thick but consisted of rather short cells, 1,5—5 diameters long, and the fertile branchlets were placed more irregularly, often on the primary fila- ments and occurred often in small quantity. As they otherwise agreed with the just described f. cimbrica they must be regarded as poorly developed specimens belonging to this variety. Localities. Ns: aG, near the Jutland Reef, 38 meters, August. — Sk: N.W. of Hirshals, 13—15 meters, May. Kylinia gen. nov. Plante minutissimæ, habitu et crescendi modo Chantransiæ. E cellula basali ger- minatione spore orta fila libera plus minus ramosa horizontaliter egrediuntur. Mono- sporangia in filis terminalia vel lateralia. Antheridia singula vel bina, in cellulis androphoricis erectis, multo angustioribus quam cellulis vegetativis, hyalinis, ter- minalia. Carpogonia terminalia vel lateralia vel in cellula basali sita, post foecun- dationem primo latitudine aucta et longitudinaliter divisa. Carpospora ut videtur pauca oblonga vel leviter curvata, in una planitie subflabellatim disposita. 1. Kylinia rosulata sp. nov. Cellula basalis hemispherica fila plura, usque ad 7, horizontaliter emittens. Fila simplicia vel plus minus ramosa, ramis plerumque oppositis horizontaliter egredientibus. Cellule 4,5—5,5 » crassæ, latitudine vulgo 1,5—2-plo longiores, rarius ultra, chromatophorum parietale continentes. Fila nonnunquam pilo hyalino te- nuissimo terminata. Sporangia terminalia vel lateralia, ovata, 6,5—8,5 » longa, 5—5,5 y lata. Cellule androphorice 1—1,5 y late, c. 4—7 y longæ, ad apicem et dorsum cellularum vegetativarum vel, ut videtur, carpogoniorum, singulæ rarius bine. Antheridia 2—4y longa, 1,5—2,5 lata. Cystocarpia, ut videtur, paucicellu- laria, carposporis c. 3. This curious little plant has only been met with once in the Northern Kattegat where it was found growing fairly abundantly on a specimen of Sporochnus pedun- culatus. It occurred only on the assimilating filaments which form a tuft on the fertile branches of this plant, and their number was often so great that these fila- ments were rose-coloured in spite of the extreme smallness of the epiphyte. Its appearance is that of a Chantransia of the group with one basal cell; it is indeed somewhat similar to Chantransia hallandica 7, parvula. The basal cell is hemi- spherical, attached to the substratum by a thin layer of cementing substance (fig. 67£). It gives off at all sides in a horizontal direction, but not from the upper side, a number of filaments, in well developed plants 6 or 7. These filaments grow out along the surface of the filament of Sporochnus but are not attached to it; they are thus growing in a cylinder, and the branching takes place in the same plane. The filaments attained only an inconsiderable length; I found them at most 5-celled. As I possess only dried specimens of the plant, I have not been able to determine with certainty the form of the chromatophore; I can only state that it is parietal and probably single. In the spores it appeared to be distinctly belt-shaped (fig. A—D, N). In some cases I believed I saw a pyrenoid (fig. H, P). The end-cells Fig. 67. Kylinia rosulata. A—D, plants with sporangia. E, basal cell, still undivided, bearing a hair. Æ, plant con- sisting of a basal cell giving off a one-celled branch which bears a terminal hair and an androphore-cell with an antheridium. G, plant with androphore-cell. H, J, plants with androphore-cell bearing two antheridia. K, a cell giving off two androphore-cells. L, the outer cell in a two-celled filament transformed into a car- pogonium; two spermatia adhering to the trichogyne (compare text). M, the cell given off from the basal cell seems to be a carpogonium; the threadlike organ to the right is probably the trichogyne, that to the left an androphore-cell. N, to the right probably a carpogone with adhering spermatium; at the upper side a short filament with sporangia. O, the thin cell to the left is probably a young androphore; above possibly a lrichogyne. P, the basal cell bears to the right an androphore-cell, above a three-celled complex, probably a young cystocarp; this bears an androphore-cell with two antheridia and a trichogyne. Q, plant bearing above a three-celled, presumed young cystocarp and to the left a more developed cystocarp. 550: 1. bear frequently a very thin, hyaline hair tapering upwards; such a hair is also sometimes given off from the upper side of the basal cell even before branching. The plants are often much reduced, the basal cell giving off only one or a few short filaments consisting of one or very few cells (fig. E—M, P). The sporangia-bearing plants bear usually no other reproductive organs. The sporangia are often terminal on primary filaments, being frequently separated from 143 the basal cell only by one sterile cell (fig. A—D). Sporangia sitting immediately on the basal cell I have not observed. The antheridia arise at the end of peculiar narrow, cylindrical, colourless or feebly coloured cells given off from the apical end of the end-cells, not rarely from cells sitting directly on the basal cell; in fig. P such a cell is even situated directly on the basal cell. These androphore-cells, as they may be named, are not given off in the same plane as the other branches but rise more or less vertically from the horizontally directed cells. Usually one androphore only is given off from the same cell, but two androphores situated near each other also occur (fig. K). As mentioned below, the androphore-cells may also be situated on the carpogonia. The end of these androphore-cells gives rise to one or two antheridia. In the first case a small cell, a little longer than broad, is cut off by a transverse wall (fig. F, G, K), in the latter the antheridial cells are cut off by inclined walls from the end of the androphore-cell, leaving a little point between the two antheridia (fig. H, I); this point may sometimes be lengthened into a short hair-like organ. As to the carpogonia and cystocarps, I am sorry to say that I have not arrived at clearness, on account of the state of preservation of the material and perhaps also because these organs occurred in very small number and in insufficient stages of development. In particular it appeared difficult to find unquestionable tricho- gynes. I think however that the cell shown to the right in fig. N is really a car- pogonium with a spermatium attached to the trichogyne. In fig. P a cell-complex, probably a young cystocarp, is seen bearing an androphore and quite near to it a thin thread, which is perhaps a trichogyne, but no spermatium is attached to the latter. A similar case is shown in fig. M, where a cell bears two thin, threadlike organs, the one being certainly an androphore-cell, the other probably a tricho- gyne. The great resemblance between the androphore-cells and the trichogynes cause great difficulty, in particular when the antheridia are formed on the side of the androphore-cell. Thus the case represented in fig. L might perhaps raise some doubt. The resemblance between the filiform organ figured here and the andro- phores represented in figs. H and J might perhaps suggest that it is an androphore with two antheridia and prolonged point; the continuity of the protoplasmic con- tents in the filiform organ and that of the cell from which it is given off goes however to prove, that these two organs belong together, being a carpogonium, and that the two spermatia must have come from elsewhere and become attached to the trichogyne. Small round cells looking like spermatia have sometimes been found attached to various points on the surface of the plants (fig. A, O, Q). In the latter case (fig. Q) the small cell was adhering to a hyaline curved cell, the signi- ficance of which I do not know. Of stages which could be supposed to be fertilized carpogonia or cystocarps I have only found very few. The three-celled complex situated at the side of the basal cell turned upwards in fig. P I regard as a young cystocarp. A similar three-celled stage is shown in fig. Q at the upper side, partly hidden by an over- 144 lying filament. If this interpretation is right, the fertilized carpogonium is first di- vided by a vertical wall and thereafter one of the daughter-cells is divided by a wall perpendicular to the first. The cell-complex shown to the left in fig. Q I take to be a more developed, perhaps a fully ripe cystocarp. The three larger, upwards directed cells are probably the carpospores; they are somewhat diverging, lying in one plane, the same as that of the branching of the plant. A stage so much devel- oped was only once observed. In spite of the likeness of our plant to the genus Chantransia in habit and in the monosporangia, it seems correct not to refer it to this genus but to regard it as the representative of a new genus, characterized in particular by the androphore cell being very different from the ordinary cells, and further by the development and structure of the cystocarps. Among the sexual species of Chantransia, Ch. hal- landica seems to be the one where the cystocarp offers most similarity with that of Kylinia, but unfortunately its development is not known. The fact that the androphore-cell is often situated on the carpogonium is analogous to the above de- seribed case, that an antheridia-bearing cell is often superposed on the carpogonium in Chantransia efflorescens. The genus is called after the Swedish phycologist, Dr. H. Kyrın, who has con- tributed so much to our knowledge of the northern marine Algæ. Locality. Kn: TP, Tenneberg Banke, 16 meters, on Sporochnus pedunculatus, September. Tribe Nemaliee. Nemalion Targioni Tozzetti. 1. Nemalion multifidum (Web. et Mohr) J. Ag. J. Agardh, Linnæa Bd.15 p.453, Spec. II, p. 419, III p.508; Harvey, Phye. Brit. pl.36; Bornet et Thuret, Rech. féc. Florid., Ann. sc. nat. Veser.t.7, 1867 p. 141, pl. 11 fig. 1—5; Janczewski (1877) p.113, Plate 3 fig.3; Wille, Ueber die Befrucht. bei Nemal. multif., Ber. deut. bot. Ges. 1894 p. 57; Grace D. Chester, Notes concerning the development of Nemalion multifidum, Botan. Gazette Vol. 21, 1896 p. 340 PI. XXV and XXVI; J. J. Wolfe, Cytolog. Stud. on Nemalion, Annals of Botany, Vol. 18, Oct. 1904; Oltmanns (1904) p. 539, 540, 542. Rivularia multifida Weber et Mohr, Naturhist. Reise 1804 p.193 Taf. III fig. 1. Chordaria multifida Lyngb. Hydr. p_ 51; Flora Dan. Tab. 1669. As to the structure of the frond reference may be made to the descriptive works and the paper of GRACE D. CHESTER. The ramification is said to be dichot- omous and it may possibly be so, but it may also be lateral, as shown in fig. 68 A, representing a young plant. The structure of the cells has been studied by WOLFE, from whose statements it appears that the presumed pyrenoid is not a true pyre- noid but a vacuolar cavity without organized contents. While the chromatophore is in general stellate, I found it in a basal dise globular without branches given off towards the periphery of the cell. As stated by Miss CHESTER the germinating spores develop at first into short branched, creeping filaments consisting of short rounded cells. Later on filaments composed of long, narrow cells with less protoplasmic contents are developed in the continuity of the primary ones. They form later at their upper end fasciculated branches reminding one of the peripheral assimilative filaments in the older frond. The author named supposes that such thin erect filaments may meet and twist together, thus giving rise to an erect frond. I have not observed the species in this stage of develop- ment. In February at Gilleleje I found crusts apparently formed by densely united creeping filaments like those described by Miss CHESTER, but almost no erect filaments were observed. Young plants with the normal structure are shown in fig. 68; the assimilative filaments were only less numerous in the lower part of the plants than later. The assimilative filaments terminate in hya- line hairs of various length, generally rather short. The shortest are almost entirely filled with protoplasm, while in the longer the pro- toplasm with the nucleus is concentrated in 14 > œ Fig. 68. Nemalion multifidum. Young plants from the mole at Gilleleje, November 1902. C.33:1. the upper end, the rest of the cell containing only a thin parietal layer. When a hair dies a new one is often formed at the same place from the subjacent cell: the lower part of the old membrane remains however Ey of the assimilative WOLFE. 5 surrounding the base of the new hair as a sheath. A 3 new hair may also be formed beside and below the ter- minal one, and this may also be renewed (fig. 69). The antheridial branches form clusters at the ends filaments as described by Borner and THURET (1867) and Wozre. Each cell in the an- i theridial branch gives rise to four antheridia or fewer bi (fig. 70). The spermatogenesis has been worked out by The carpogenic filaments are terminal on the assi- milative filaments and usually 3-celled, (according to WOLFE 2- to 5-celled). Concerning the fertilization and the development of the cystocarp reference may be Fig. 69. made to the quoted papers of Borner and THURET, Nemalion multifidum. End-cells of JanczEwski, SCHMITZ, WILLE and WoLFE. The fertilised assimilative filaments with hairs; in D the nucleus is visible. 60:1. Carpogonium divides by a transverse wall into a basal or placental cell, remaining undivided, and an upper cell dividing by vertical walls into a number of cells giving rise to branched spo- rogenous filaments, the end-cells of which produce carpospores. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 19 146 The species occurs in all the Danish waters except the Baltic, growing in the littoral region, thus being out of the water at low-tide. It varies but little in shape in the different localities; it attains very often a length of ca. 20 cm., but larger specimens not seldom occur; thus specimens measuring 40 cm. were met with at Harboore and Gilleleje. It has been found in the months July to November; in the remaining part of the year it is probably represented by the creeping filaments described by Miss CHESTER which were, as mentioned above, observed by me in February. It may be supposed that the germination takes place immediately after the setting free of the spores but that the erect plants only develop in the next summer. I found however in November on the mole at Gilleleje young plants from less than 1 mm. to a few cms. in length; they would probably have perished during the winter, but possibly the basal portions would have been able to produce new erect fronds. i The species is said to be as a rule monoecious; I found it however most frequently dioecious in the Danish waters. In the proportionally few monoecious À specimens (about 10 per cent) I found the two kinds of 2 sexual cells near to each other in all parts of the plant and there is thus no reason to believe that the dioecious specimens would have proved to be really monoecious N on closer examination. Antheridia occur in all the months Cy July to November, but in the last months they are in Cie TINS) a great measure emptied. Ripe cystocarps may occur Aine TD already in July; in August a great part of the spores are often set free as well as later, in November how- ever cystocarps containing most of the spores may still be found. In autumn or the beginning of the winter the plants gradually die, the assimilative filaments being the first destroyed. This may begin already in Au- gust, but on the other hand fairly well-kept specimens are to be found still in November. The species prefers agitated water; it therefore grows on the outer, not on the inner sides of the moles. It occurs on stones but also on wood, often together with Fucus. Nemalion multifidum. Antheridial branches at the ends of assimilative filaments. 340:1. Localities. Ns: Groins at Harbogre and Thyboren. — Sk: Hanstholm, on a boulder near land; Lenstrup (Warming); Hirshals (!, Bergs.); Skiveren, on wreck. — Lf: Oddesund; Struer; Ejerslev Ren. — Kn: Frederikshavn; harbour of Vesterø, Lesa; Hornex, Læsø (J.P. Jacobsen). — Ke: Gilleleje Lyngb.. !). — Km: Anholt harbour; Herringholm (Lyngbye). — Ks: Grenaa harbour; Tisvilde (C. Rasch); near Klintebjerg. Odsherred (J. Vahl); Isefjord: Nykøbing; Lynæs: off Nordskov; Ours; Holbæk Fjord: Bramsnæs Vig. — Sa: Kyholm, in the middlemost Fucus-zone: Szlvig (Hjalmar Jensen); Koldby Kaas; Hofmansgave (Hofm. Bg., Lyngb., C. Rosenb.); Juelsminde. — Lb: Bogense. — Sf: Redlok Grund off Nakkebølle Fjord: Svendborg; Birkholm; Rudkøbing. — Sb: Kerteminde; Korsør; Lohals. — Sm: Guldborg. — Su: Hellebæk; Helsingør; Humlebæk (Henn. Petersen); near Hveen (Ørsted); Trekroner near Copenhagen (Ørsted). 147 Helminthocladia J. Agardh. 1. Helminthocladia purpurea (Harv.) J. Ag. J. Agardh, Spec. II, p. 414, III, p. 506; Flora Danica tab. 2699; Schmitz, Chromatophoren der Algen, p. 63 fig. 11—12. Mesogloia purpurea Harvey in Hooker Brit. Flora II, 1833, p. 386. Nemalion purpureum Chauv.; Harvey, Phye. Brit. PI. 161; Kützing, Tab. phyc. 16. Band Pl. 62 c, d. The structure of the frond is somewhat similar to that of Nemalion mullifidum, but the assimilative filaments are composed of larger cells, of which the terminal ones are the largest (fig.71). These terminal cells bear no hairs, and these organs are upon the whole rare in the older parts of a Hh the plants, while they occur fairly abun- dantly in the younger parts. They are given off from thinner branches not reach- ing the surface of the frond and are partly terminal, partly lateral; they have the same structure as other similar hairs, are fairly thick and attain a considerable length (fig. 71 A, B). Besides the hair a little cell with : à | | fairly dense contents is visible; such cells SD 107 are also to be found in the older parts of | EN Z the frond without hairs. The chromato- phores which are particularly large and well developed in the terminal club-shaped cells, contain as shown by Scumirz (l.c.) a large central pyrenoid which in some cases was readily visible as a dense body, while in other cases they conveyed rather the impression of being vacuolar cavities like Fig-571. those stated for Nemalion by Worre (figs. minthetadic purpurea, À end el asimiative fhe 71 A, 72 A, B). C, young ‘celled carpogenic filament. D; assimilative The antheridia form dense, often hemi- Tu hen nal na Dach en er spherical clusters at the end of the assimila- ?celled earpogenie filament. F, carpogenie branch tive filaments. The outermost cells are then ot Sa DVD alin D small and bear a number of short much branched antheridia-bearing branchlets. These branchlets are shorter than in Nemalion and Helminthora and their joints are often nearly globular (fig.72 A—C). In some cases a number of globular cells were found crowded together at the upper end of the last cells in the assimilative filaments (fig. 72 E, F). These cells, which were larger than the antheridia and contained a thin chromatophore, might be suggestive of monosporangia; they were however certainly no such organs but probably only checked antheridial branches, 19° 145 which had not produced antheridia. The case represented in fig. 72 D goes to prove the correctness of this interpretation. The carpogenic filaments are, as stated by Scumirz and HAUPTFLEISCH (1896 p. 333), lateral on the assimilative filaments and consist usually of 3 cells, the lowest of which is often wedge-shaped (fig. 71 D, F), 4-celled carpogenic filaments however also occur (fig. 71 C). Only once have I seen a carpogenic filament terminal on a vegetative filament which bore also a 2-celled lateral carpogenic filament (fig. 71 E). After fertilization the carpogonium is not divided, as in Nemalion and Helminthora, by a transverse wall into a stalk- cell and an upper cell producing the sporogenous filaments, but it divides by an oblique wall going from the upper side of the D Fig. 72. Fig. 73. Helminthocladia purpurea. A—C, ends of Helminthocladia purpurea, Al, fertilized carpogonium, still undivided assimilative filaments with clusters of an- but with divided nucleus. B, fertilized carpogonium dividedf,by an theridia. D, checked antheridial branches oblique wall. C, similar stage, the one daughter-cell appears about which have developed only very few an- to divide. D, more advanced stage. E, the sporogenous filaments theridia. E, F, ends of filaments bearing begin to grow out. F, median section of ripe cystocarp. A—D, F 350:1, globular cells, probably sterile antheridial E 560:1 branchlets, A—D 560:1, E—F 350: 1. cell to the margin of the basal wall (fig. 73 B, C) and thereafter follows variously orientated walls, giving as result a cell-complex growing out into numerous radia- ting, branched sporogenous filaments, the end-cells of which produce carpospores. The succession of the divisions in the carpogonium I have not been able to follow; they seem to take place in such a manner that a number of peripheral cells are cut off while a larger placentar cell remains in the centre (fig. 73 F, a). The spo- rogenous filaments are rather long-celled, the mother-cells of the carpospores long and narrow. After the discharge of the carpospore a new mother-cell may be pro- duced by proliferation from the subterminal cell. At the time when the divisions 149 of the carpogonium begin the sterile cells in the carpogenie filament and the nearest-lying cells in the supporting filament give off branches forming an involucre round the young cystocarp. The ripe cystocarp is a somewhal flattened capitulum, the filaments of which radiate outwards and to the sides. All the specimens examined were monoecious. The largest specimens were 57 cm. long. The species has only been found on the Skagerak coast, either washed ashore or in a seine, and no certain information can therefore be given as to the condi- tions under which it occurs. At Skagen I took it in a seine fishing in ca.7 to 9 meters depth, and at Lokken I found it on the beach attached to Lithothamnia washed ashore. Probably it grows near the land in relatively small depths. It has only been met with in August and the beginning of September. Localities. Sk: Tværsted (M. L. Mortensen), washed ashore; Løkken; 2 miles W. of Skagen, on the beach (Caroline Rosenberg Sept. 1st 1859); in a seine off the Marine Hotel on Skagens Gren, 7—9 met. Helminthora J. Agardh. 1. Helminthora divaricata (Ag.) J. Agardh. J. Agardh Spec. IJ p. 416, III p. 507; Bornet et Thuret, Féc. Flor. p. 142 PI. 11 fig. 7; Janczewski (1877) p.114 Pl. 3 fig. 4—6; Thuret, Etudes phycolog. p. 63 PI. 32. Mesogloia divaricata Ag. Syst. Alg. p. 51. Mesogloia Hornemanni Suhr, Flora Dan. tab. 2202 (?). Of this species, which is easily recognizable from the two foregoing species by its distinctly limited inner axis giving off the assimilative filaments, I have only had very little material from Danish waters; I shall therefore content myself with referring to the above quoted works, in particular those of JAnczEwSskI and THURET. The species has only been found in one locality and was represented only by two slightly developed specimens; the largest measuring 5,5 cm. in length was not much branched and bore numerous antheridia. They both grew on Polyides rotundus!. i Locality. Kn: TL, W. of Nordre Rønner, 4—5,5 meters, September. Fam. 3. Chætangiaceæ. Scinaia Bivona. 1. Scinaia furcellata (Turn.) Biv. J. Agardh Spec. I, p. 422, II p. 512; Bornet et Thuret, Not. alg. I p.18, Pl. VI; Schmitz, Befrucht. 1883, p. 15, Taf. V fig. 5—7; Schmitz and Hauptfleisch, Rhodophyc. p. 337; Oltmanns, Morph. I p. 556. Ulva furcellata Turner in Schrader, Journal für Botanik 1800 p. 301. Ginnania furcellata (Turn.) Mont.; Harvey, Phye. Brit. Pl. 69. 7 When the printing of this paper was almost finished, L. Kurssanow has published interesting investigations on the cytology of the three last-named genera of Helminthocladiaceæ (Beiträge zur Cy- tologie der Florideen. Flora 99. Bd., 4. Heft 1909, p. 311), but further reference could not be made to them here. 150 Two specimens of this widely distributed species, the occurrence of which on the shores of Europe extends from the Mediterranean to Scotland and Helgoland, were found washed ashore at Lokken. As they were quite fresh and were attached to a fragment of an acorn shell, they must undoubtedly have grown near the place where they were found. They attained a length of 6,5 cm. and contained ripe and unripe cystocarps. Small antheridial groups were also found on the surface of the frond. As to the structure of the frond and the structure and development of the fruit I have no new observations; reference may be made to the above quoted papers, in particular those of BornET and THURET, and Scumitz. The species is easily recognizable by its soft, cylindrical, dichotomous frond having a thin solid axis and by the characteristic, immersed cystocarps provided with a dense fruit-wall. Locality. Sk: Washed ashore at Lekken, August. CORRIGENDA. P.9, 1.9 from top, for “Antithammion” read “Antithamnion”, for “Litho- thamion” read “Lithothamnion”. P. 56, 1. 8 from top, for “cushon” read “cushion”. P. 80, 1.5 from top, should read “Fam. 2”. P. 88, 1.14 from top, for “egrediunt” read “egrediuntur”. P. 91, 1.11 from top, for “egrediunt” read “egrediuntur”. P. 97, 1. 6 from bottom, for “egrediunt” read “egrediuntur”. EXPLANATION OF PLATES. All figures are photographs after dried specimens, about "I; nat. size. Plate I. Porphyra umbilicalis (L.) J. Ag. 1. Monoecious specimen showing a longitudinal limiting line between the male and the female part of the frond. (Helsingor, September). Small male specimen (f. laciniata); the marginal zone has produced antheridia. (Helsingør, September). m 3. Female plant. The fertile zone above shows irregtlarly ramified spots caused by earlier maturation of the cystocarps here than in the surrounding parts. (Norre Sundby, Lim- fjorden, September). Plate II. 1—3. Porphyra umbilicalis (L.) J. Ag. f. linearis (Grev.). 1, monoecious, 2, female, 3, male specimen (Frederikshavn, December—January). 4—13. Porphyra leucosticta Thur. 4—7. Sexual plants, (harbour of Skagen, April 1905, M. L. Mortensen). 8. Asexual plant, possibly producing gonidia, (harbour of Skagen, July 1907). 9—13. Small specimens being the under part of specimens which have exhausted their sper- matia and carpospores, (harbour of Skagen, July 1905). ED Fidensk Selsk. Skr. IR. n. m. Afd VI. 1. 1.Kolderup Rosenvinge . i, Chart of the Danish waters N | with curves of depths and dredging places. : TED, BB i i; En NORTHERN PART. J Ly | 3 4 SS | © Vegetation of Age. X. Zostera (e) Loose Age. © Pay scarce Age. x Zostera and Age. O Ho vegetations Places investigated mith algal vegetation near land nue I ausekineu I TRESTENS-REV EEE more han 40 Meter —— . — 100 Meter. © BORREBJERG SLAURS-REV À Lae Lögstör CZ 2 J à gs JYDSKE= j 2 Ve par. REV oa 3 7 2 A (al EU | = a | bine (\ cD LA ER EN ; a NS / Se \ A if a Er rl" REOELS REY LA Al \ TANGEN | er VE i >= @ NC Ë STORE Ey : MIDDELGRUN y | JL : Be ¥ pH, raster. Be dt ©. Br Uhr Lyle ith HUM: à Var TN he awe. ja fe x af Si i re VAN ina aN 6 ED. Vidensk. Selsk. Skr: TA. n. mv. Ad. FI. 1. L. Kolderup Rosenvinge . 7 a Boserun SJÆL AN 74) e ) °. ae del as a 4 Rx ENKÖVES-FLAK N SE E | OKRISGERSIz 75 (FLAK with curves of © Tegetation of Age. © Fey scarce Age Chart of the Danish waters = faces investigated with algal vegetation near land. more than 40 Meter. depths and dredging places 5 SOUTHERN PART x Zostera (e) Loose Algae % Zostera and Age. O No vegetation, L._ ._.] 0-10 Meter, 10-20 u = =) 20-49 « NS Fr 14 «JS. SS U, KTe WO, SS. QE" GHEE © wali SVERIGE Che Lito? hith Zus. K.D.VIDENSK. SELSK. SKR., NATURV. OG MATH. AFD. VII. 1 |L. KoLberur ROSENVINGE Porphyra umbilicalis (L.) J. Ag. . D.VIDENSK. SELSK.SKR., NATURV. OG MATH. Arb, VIL. 1 |L.KoLverup ROSENVINGE 9 10 [I 12 13 1—3 Porphyra umbilicalis (L.) J. Ag. f. linearis. 4—13 Porphyra leucosticta Thur. Pr II THE MARINE ALGÆ OF DENMARK CONTRIBUTIONS TO THEIR NATURAL HISTORY PART II RHODOPHYCEA II. (CRYPTONEMIALES) BY L. KOLDERUP ROSENVINGE WITH TWO PLATES D. Ker. DANSKE VIDENSK. SELSK. SKRIFTER, 7. RÆKKE, NATURVIDENSK. OG MATHEM. AFD., VII. 2 +. LR CR + KOBENHAVN BIANCO LUNOS BOGTRYKKERI 1917 i Be; a0 he Wan I À a, ad | i ' I 4 N Be" LR } 2) BAY) aes Lo à UMA NAN |. VER AJ L 7 rey, j PAR i i x ta) mL u å NU AE i ÆT À j 9 ut i ; } Te 0 JA ET ok ae j ! KN Vi 1 4 on D Å I im a) i i. == #) ts 3 ee eh ee ai TR { ) | A à ee I eo 0 Ae > is i \ | i 1! Su ” f A S i net i (9 SE - - É ( Ill. Cryptonemiales. Fam. 4. Dumontiaceæ. Dumontia Lamour. 1. Dumontia inerassata (O. F. Müll.) Lamour. Lamouroux, Essai. Mus. d’hist. nat. Paris 1813; Batters, Catalogue, 1902, p. 93. Ulva incrassata O. Fr. Müller, Flora Danica tab. 653, 1775. Ulva spongiformis O. Fr. Müller, Flora Danica tab. 763 fig. 2, 1778 (2). Fragment not determinable with certainty. Ulva filiformis Hornemann, Flora Danica tab. 1480,2, 1813. Gastridium filiforme Lyngbye, Hydr. p. 68 tab. 17. Gastridium filiforme var. intestiniformis Liebman, Flora Danica tab. 2457, 1845 —f. crispala Grev. Dumontia filiformis (Hornem.) Greville, Alg. Brit. p. 165 tab. 17 (cystocarp); Harvey, Phyc. Brit. pl. 59 and 357B; Nægeli, Die neueren Algensysteme 1847, p. 243 Taf. IX fig. 4—8 (structure of frond); J. Agardh, Spec. II p. 249, III p. 257, Kützing, Tab. phyc. 16. Band Taf. 81 (transverse section of tetraspore- bearing plant; Schmitz, Befr. Flor. 1883 p. 18,20, fig. 22 (carpogonial filament); Reinke, Algenflora d. westl. Osts. p. 26; G. Brebner, On the Origin of the filamentous thallus of Dumontia filiformis. Journ. Linn. Soc. Bot. Vol. 30, 1895, p. 436; Kuckuck, figure of a young basal dise in Oltmanns’ Morph. I, p. 573; Okamura, Icones of Jap. Alg. Vol. I No. IV pl. 16 figs. 1—8, p. 65. The fronds arise from a crustaceous disc produced by the germinating spore. A 5 days old plant is shown in fig. 74 A. It is not much larger than the tetraspore from which it arose, but it is divided into a number of small cells and has become a hemispherical body from the border of which short one- or two-celled filaments proceed.! A later stage is figured by Kuckuck (OLTMANNS I. c.); a group of short- celled filaments is here seen given off from the upper side of the disc, and it is said that only one of these filaments serves to form the erect frond, some of the others forming the bark on the base of it. The basal discs may be perennial (REINKE, BREBNER); they form large expansions on stones, Mytilus, Chondrus a.o. In sunny localities they have a light violaceous colour and often show radial folding (in a dried state), in greater depths they are darker, They are easily distinguishable by their structure and by the occurrence of groups of short-celled filaments giving rise to new erect fronds. As shown by BREBNER (I. c.) the fronds may be endogenous 1 The germination of the tetraspores has quite recently been described by Kyrın (Uber die Kei- mung der Florideensporen. Arkiv for Botanik. Band 14. N:o 22. Stockholm 1917, p. 9). The author kept the sporelings in culture during more than two months but did not obtain any production of erect shoots. The sporelings produced after 10 days long unicellular hairs, but after addition of nitrate to the culture no hairs were produced. 20* 156 or exogenous and, according to this author, the cells of the short-celled filaments are divided by intercalary divisions. The structure of the frond has been described in 1847 by NÆGELI (l. c.). It terminates in an apical cell which is said to be divided by oblique cell-walls pro- ducing segments at all sides, and this is affirmed by Scumirz and HAUPTFLEISCH (ENGLER u. PRANTL, Nat. Pflfam. I, 2 p. 517); it is however at least not general. The young fronds arising from the basal disc have at all events an apical cell divided by horizontal parallel walls, and this is also the case with young slender branches (fig. 74, B, C). In thicker shoots still in development I have found the segment walls somewhat inclined, but not so much that they reached the foregoing segment wall (fig. 24, C). The cells of the frond contain a single nu- cleus and a number of disc- shaped chromatophores. Some of the surface- cells may produce a hya- line hair of the same cha- racter as in other Florideæ (fig. 74, D). In spring (March to May) they are most devel- oped, numerous, long and rich in protoplasm; at other seasons they are often wanting. Fig. 74. Dumontia incrassata. A, five days old plant from germinating tetraspore. à 2 B, upper end of side branch showing transverse segment walls. C, tip of vanced age it becomes ir- cylindrical, but in an ad- A etn pees au F, transverse section of frond showing the development of the antheridia. crisped (£. crispata Grev.). A 300:1. B,C, E 390:1. D, F 630:1. In agiater an in Badel localities it is dark red-brown, while in sunny places in spring and summer it has a light yellowish colour, the tips at last becoming green. The central cavity contains a thin ‘slimy matter which seems to consist of pectic substances; it forms a network in the cavity, the meshes containing probably only water. The sporangia are, as is well known, immersed in the wall of the frond; they are born of a cell in the inner cortex bearing moreover at least two cortical fila- ments (comp. Kirzine Phye. gen. tab. 74 II). The sporangium is connected through a pit with the bearing cell but not with other of the cortical cells (fig. 74, E); thus it is terminal and not intercalary as in Dilsea. The division is always cruciate; but The frond is at first 157 it is often somewhat irregular, the longitudinal walls being inclined. I have not been able to decide if real cell-walls are formed between the spores in the sporangium. The latter is surrounded with a distinct wall consisting of more than one layer; at the lines of separation between the spores the inner layer is seen to be continuous, without penetrating between the spores. The sporangia develop in the main axis as well as in the branches down to 1 to 2 cm. from the base. The antheridia (spermatangia) form a continuous layer on almost the whole surface of the male individuals. They are cut off by inclined, often upwards convex, intersecting walls of the upper end of the antheridia-bearing cells (SVEDELIUS’ sper- matangial mother-cells), at two (or perhaps more than two) sides (fig. 74, F). The form of the antheridia-bearing cells is rather variable according to the varying length and breadth; they contain a single nucleus but seem to be destitute of chrom- atophores. Beneath a fully developed antheridium a new one can arise, a little cell very rich in contents being cut off in the same direction as the former. In the middle of fig. 74 F above, the oldest antheridium is seen to be connected through a pit with the youngest one formed right under it. The continued formation of antheridia thus takes place by intercalary divisions, and the antheridia are placed in two (or more) series, but owing to the evacuation of the spermatia, at most two antheridia are to be seen at the same time in the same series. The antheridial development in this plant thus does not correspond with any of the types set up by SvEDELIUS (Martensia, K. Sy. Vet. Ak. Handl. Band 43. No. 7. 1908 p. 76). The development of the cystocarp was found to agree with what Okamura found in examining Japanese specimens. The carpogonial branches arise from the inner part of the wall of the hollow frond, frequently from a cell in a longitudinal fila- ment or from a cell given off from it. They are 5-celled and curved, in particular at the'upper end, where the carpogonium is cut off by an oblique wall intersecting the underlying wall (comp. Scumirz |. c. fig. 22, Okamura |. c. fig. 4). The auxiliary-cell filaments, being very numerous, as the carpogonial filaments as well, have a similar position to these. They are somewhat curved, and consist of 4 to 5, more rarely 6, rather low cells with rich contents. They are frequently placed quite near the carpogonial filaments; it may even happen that a carpogonial filament arises from the base of an auxiliary-cell filament (fig. 75 A). After fecunda- tion, fusions take place between the carpogonium and one or more cells in the carpogonial filament, resulting in the formation of a great fusion-cell of very ir- regular form, giving off sporogenous filaments in various directions; in fig. 75 E 4 such filaments are present. The auxiliary cells with which they become connected are usually the second cell from the base of the auxiliary-cell filaments, sometimes the third or even the fourth cell. After fusion, the auxiliary-cell, when giving rise to a cystocarp, produces, at the convex side of the filament, a number of cells which after several divisions form a group of carpospores placed around a placentar cell originating from the auxiliary cell (or the fusion cell). A curious anomaly is shown in fig. 75 F. In the ventral part of the carpogonium no nucleus was visible, but Fig. 75. Dumontia incrassata. A, two carpogonial branches, the upper representing a side branch of an auxiliary-cell filament. B, carpogonial branch; the carpogonium does not reach the third cell from the top. C, carpogonial branch and auxiliary-cell branch. D, carpogonial filament after fecundation; the fertilized carpogonium has fused together with the three uppermost cells of the carpogonial branch, has become very enlarged and formed sporogenous filaments. E, the fertilized carpogonium has fused with one or two cells of the carpogonial filament and has given rise to four sporogenous filaments. At right a four-celled auxiliary-cell filament; the auxiliary-cell after having fused with a sporogenous filament has produced a young gonimoblast. , F, the trichogyne of the unfertilized carpogonium contains two nuclei, while the ventral part contains no nucleus. The lowest or second cell from the base has fused with a sporogenous filament from another carpogonium. G, auxiliary-cell filament; the auxiliary cell has fused with a sporo- genous filament and produced a new sporogenous filament. H, auxiliary-cell filament with young cystocarp. J, trans- verse section of frond with ripe cystocarp. a, auxiliary cell. af, auxiliary-cell filament. s, sporogenous filament. t, trichogyne. A, B, D, E,G, H 380:1. C,F 610:1. J 220:1. En GE 159 in the middle of the trichogyne two bodies were found which were probably nuclei. As no spermatia were found fixed to the trichogyne, the two nuclei must have derived by division from the original carpogonial nucleus, the undermost represen- ting probably the sexual nucleus, the upper the trichogynal nucleus. It must however be admitted that the upper end of the trichogyne was not quite distinctly visible. This filament is further remarkable in that the second cell from the base acts as an auxiliary cell, having fused with a sporogenous filament from another carpogonium. It is however not fully clear if the great fusion cell has arisen from the second cell or by division from the first cell, which is rather small and half enclosed by it. In the first case the carpogonial filament has been 6-celled. The species is widely distributed on the Danish coasts, and occurs often abund- antly. It grows particularly in somewhat sheltered localities, and attains there the greatest dimensions. In Sk, Lf, K, Sa, Lb and Sf it has been found only at low- water mark or a little lower; on the other hand, in the southern and eastern waters (southern parts of the Great Belt and of the Sound and the Baltic) it has also been met with in depths of 4 to 12 meters, and it occurs in a similar manner in the western Baltic according to REINKE (l. c.), while it otherwise appears to grow only at a slight depth. On the shores of North Europe it grows, where tide occurs, in the middlemost part of the littoral region (“a mi-maree”). The explanation of this peculiar distribution in the western Baltic and the adjacent waters might perhaps be sought in the lesser salinity of these waters. It deserves to be mentioned in this connection that the species, according to Crouan (Fl. Finist. p. 144), in the neighbourhood of Brest occurs particularly where fresh water runs out. When growing at low-water mark in Danish waters of comparatively high salinity, the plants are also temporarily exposed to fresh water at least by rainy weather during low-water. On the other hand it will be seen from the following maximal lengths for specimens collected in a series of localities in the Sound ranged from North to South that the length decreases with much decreasing salinity: Hellebæk 47 cm, Humlebæk 30 cm, Sletten 28 cm, Trekroner (Copenhagen) 20 cm, Dragør 8 cm. These specimens were all collected near the low-water mark. A length of over 50 cm has been met with in specimens from Lb, Sf (70 cm) and Sb. In the other waters the following maximal lengths have been recorded: Sk 37, Lf 28, K over 30, Sa 40, Su 47 cm. The species has been found with erect fronds at all seasons, but only abund- antly in the first half of the year, from the middle or the end of the winter to the beginning of the summer. Most of the specimens die in June or July; only single, rare specimens are therefore met with in the more advanced summer and in autumn. As the spores germinate easily immediately after having been shed, the species must be supposed to endure the summer in a crustaceous form, originating for the most part from the spores shed in the last spring but partly also of older date. The sexual organs have been met with in winter and spring and in September, ripe cystocarps in May to July, ripe tetrasporangia in May to July, once even in August 160 (SK). Sexual organs and tetrasporangia occur always in distinct specimens. The same is the case with the antheridia and the carpogonia; I have found, however, some few specimens which seemed to be monoecious, but the supposed antheridia were not fully developed. Localities. Sk: Lonstrup (loose on the shore); Hirshals, mole and reef. — Lf: Oddesund; Nykøbing (Th. Mort. F. Borg. ! Glyngøre; Agersund (Th. M); Aalborg (Th. M.); Hals (F. Borg.). — Kn: Hirsholm; Kelpen; Frederikshavn; Nordre Renner. — Km: Anholt, harbour. — Ks: Harbour of Grenaa; Hessels; Isefjord: Lynæs, harbour. — Sa: Coast below Ris Skov; Aarhus, harbour; Odense Fjord: inner side of Enebærodden; Hofmansgave (Lyngbye, Hofm. Bang, C. Rosenb.). — Lh: Bogense; Fredericia; Middelfart; Kongebro; Snoghøj; Fæns Sound; Assens; Faaborg; Dyreborg. — Sf: CT west of Taasinge; Svendborg; Marstal, specimens up to 70 cm long, among Zostera in shallow water, frequently on Littorina; Skaaruper; Lohals. — Sh: South side of Refsnæs; Kerteminde; Korser; Nyborg, harbour and Avernak- hage; Vresen; Spodsbjerg, harbour; DQ, 5,5 meters; UR, 7,5 meters. — Sm: VC, Venegrund 4—4,5 meters. — Su: Hellebæk; Helsingør (Liebman, C. Rosenb., !); Humlebæk; Sletten; TF‘, Staffans Flak, 12—13 meters. OG”, between Trekroner and Middelgrund, c. 9,5 m; Trekroner (Liebman, Ørsted a. o.); RH, Knollen, 9,5 m; Drager; PR, off Drager, 7,5—9,5 m. — Bw: KU, Schönheyders Pulle, 6,5 m. Dilsea Stackhouse. 1. Dilsea edulis Stackhouse. Stackhouse, Mém. soc. Mose. II, p. 55,71 (non vidi). Fucus edulis Stackhouse, Ner. Brit. 1. ed. p. 57 (non vidi), II. edit. 1816 p. 22, tab. 12 (good). Halymenia edulis (Stackh.) Agardh; Flora Danica tab. 2258, 1839. Iridea edulis (Stackh.) Bory; Harvey, Phye. Brit. pl. 97; Areschoug Phye. scand. p. 89; Kützing, Tab. phye. 17. Band, tab. 3a. Schizymenia edulis (Stackh.) J. Agardh, Sp. g. o. II, 1851, p. 172. Sarcophyllis edulis (Stackh.) J. Agardh, Sp. g. o. III, 1876, p. 265. From a basal dise a number of flat fronds arise. Their number may be considerable, but when they are numerous they are for the greatest part feebly developed. They attain not seldom a length of about 30 cm; the largest specimen I have measured was 61 cm long in a dried state. As to the anatomy of the frond, reference may be made to the papers of WILLE (Bidrag til Algernes physiologiske Anatomi. K. sv. Vet. Ak. Handl. Bd. 21, 1885, p. 71. tafl. V fig. 61—67, and Beiträge zur Entwickl. d. physiolog. Gewebesyst. Nov. Act. Leop. Car. Ak. Bd. LII Nr. 2, 1887, p. 83, Taf. 5 fig. 72—74 and Taf. 6 fig. 75). In summer the species is always sterile. It is evidently fructiferous in winter, just as on the British coasts. Tetraspores were found in specimens collected in February to April; they were confined to round or oblong patches measuring at : the most 1cm in diameter. In a specimen collected in May the spots were still visible, but the sporangia were emptied. The sporangia are more or less deeply immersed in the cortex. They arise directly from cells of the inner cortex, and are thus intercalary, being outwardly connected through pits with filaments of the cortex (fig. 76). The ripe sporangium is surrounded by a double sporangial wall. The spores are paired, decussately or cruciately, the dividing walls are often inclined. The spores contain a number of small chromatophores. The cystocarps are situated in the inner cortex, or at the limit between it and 161 the medulla. The carpogonial branch is five-celled, the auxiliary-cell branches are curved, and composed of a great number of short cells (fig. 77). Ripe cystocarps have been met with in March. — Antheridia have not been met with. The species is distributed in the Skagerak, in the northern and eastern Kattegat and in the northern part of the Sound. In the Skagerak it does not attain the same dimensions as in the Kattegat, its length scarcely exceeding 30 cm, probably owing to the more agitated water. It has here only been met with at compara- tively slight depths, viz. 4 to 9,4 m. In the Kattegat it is mainly distributed in the eastern part, where it has been met with almost only at depths of 16 m or Fig. 76. Fig. 77. Dilsea edulis. A, six sporangia showing various forms and modes of Dilsea edulis. A, carpogonial branch. B division. 220:1. B, transverse section of cortex with a sporangium. 390 :1. auxiliary-cell branch. 390:1. deeper, where the salinity is high and little variable and the variations of tempe- rature are also relatively small; it attains here its greatest size. — In most localities it is taken only in small quantities in the dredge; I have found it most abundantly at Hanstholm (Sk), where it was dominant in some places at 7,5 meters depth. LynGBye found it off Gilleleje on the North coast of Sealand, 12 miles from land at 26 meters depth, abundantly in places where other algæ are not met with, but only Mytili and other molluscs, barnacles etc. It was here often fixed to the mytili and attained a size of up to 63 cm; the fishermen called it here “rode Klude” (red rags). Localities. Sk: YT off Hanstholm lighthouse, 7,5 met., rather abundantly; Thorup Strand, washed ashore (C. M. Poulsen); Løkken, washed ashore, FK Kongshoj Grund off Lønstrup, 8,5 met.; NW of Hirshals, 30 met., some fragments (A. C. Johansen); west side of Hirshals mole, 4 met., washed ashore by Lonstrup and Hirshals, Tværsted (V. Schmidt) and Skagen. — Kn: Herthas Flak, 20—22 met., 6 cm long; Hirsholmene, 5,5—7,5 m, 6 cm long; North of Læsø (Edy. Bay), 29 cm long; IX, 11 m; TR near Trindelen, 23,5 m. — Ke: Fladen, ZF, 22,5 m, and IQ, 22—30 m; south side of Groves Flak (Bergesen); D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk, og mathem. Afd. VII. 2. 21 - 162 IK Lille Middelgrund, 17—19 m, 61 cm; IH, south side of Lille Middelgrund, 20—28 m; ER, Fyrbanken east of Anholt, 23 m, 28 cm; IA, Store Middelgrund, 16,5 m; same locality (Bergesen); off Gilleleje, 12 miles from land (Lyngbye); Nakkehoved (Lyngbye). — Su: Washed ashore at Hellebæk (Rasch, Børgesen), 29 cm, and north of Helsinger (Steenberg, C. Rosenberg, !) 26 cm, bM, south of Hveen, 22,5 m, loose, 40 cm. Fam. 5. Nemastomatacee. Platoma (Schousboe) Schmitz. 1. Platoma Bairdii (Farlow) Kuckuck. P. Kuckuck, Beiträge zur Kenntn. d. Meeresalgen. 12. Ueber Platoma Bairdii (Farl.) Keck. — Wissensch. Meeresuntersuch. Neue Folge. V. Bd. Abt. Helgoland, Heft 3. 1912, p. 187—203. Taf. IX—XI. Nemastoma (?) Bairdii Farlow, Proceed. Amer. Acad. Arts and Sciences, 1875, p. 351; Mar. Algæ of New England, 1881, p. 142; Batrers, Cat. Brit. Mar. Alg.. 1902, p. 94. Helminthocladia Hudsoni Batters, Journ. of Bot. 1900, p. 377. Tab. 414 fig. 15 —16, non J. Agardh. In July 1915 I found by dredging in Lille Belt some small specimens of this interesting Alga, hitherto only recorded from three widely remote places (coast of Massachusetts, coast of Northumberland and Helgoland). As the structure and de- velopment of the species have recently been exhaustively treated by Prof. Kuckuck, I shall only make some few remarks upon the Danish specimens, referring for the rest to Kuckuck’s excellent description. The plant forms small bundles on a granitic pebble, each given off from a well developed basal disc, and reaching only a length of 1cm. The upright fronds are more or less branched, rarely unbranched, terete, or the thickest fronds some- what flattened. As shown by Kuckuck, the frond branches by dichotomy‘, but one of the shoots produced by the division often becomes more vigorous than the other, and the ramification then seems to be lateral. Hyaline hairs were not met with; according to Kuckuck their occurrence is variable. | The plants bore either tetrasporangia or carpogonia and cystocarps, while antheridia were not met with either here or at Helgoland. The two kinds of indivi- duals were quite distinct; no carpogonia were observed in the tetrasporiferous speci- mens or vice versa (comp. Kuckuck |. c. p. 192). The emptied sporangia were fre- quently replaced by a sporangium produced from the subjacent cell. “Prospory” 2: production of sporangia from the basal dise, was not met with in the Danish specimens. Locality. Lh: At Lyngs Odde, right opposite Middelfart, stony bottom, about 20 meters depth. = Kuckuck thinks (I. c. p. 190) that the dichotomy in this plant is only apparent, as it cannot be derived from a longitudinal division of the apical cell. This, however, must be considered a too nar- row definition of the conception of dichotomy. In my opinion, dichotomy exists in all cases where the growing point divides into two equal parts by a vertical dividing plane or furrow, the two parts at first diverging equally from the original direction of growth, no matter whether the growing point consists of a single cell (Diciyofa) or of several cells (Furcellaria, Lycopodium, Selaginella, roots of Isoëtes etc.) or is a part of a coenocytic organism (Thamnidium, Piptocephalis). Halarachnion Kützing. 1. Halarachnion ligulatum (Woodw.) Kützing. Kützing, Phycol. gener. p. 394, Taf. 74. 1; Berthold, Cryptonem. d. Golfes von Neapel, Leipzig, (1884) p. 22 — (an eadem species ?); T. H. Buffham, On the Antheridia etc. of some Florideæ. Journ. of the Quekett mieroscop. Club, Vol. V, ser. II p. 299, tab. 14 fig. 37—39. Ulva ligulata Woodward, Linn. Trans. III p. 54. Halymenia ligulata (Woodw.) Agardh, Spec. Alg., 1821, p. 210; Flora Danica tab. 2199 (1836) from Helgo- land; Harvey, Phyc. Brit. vol. I pl. 112, 1846; J. Agardh, Spec. g. o. Alg. Il,» 1851 p. 201; Bornet et Thuret, Notes algologiques, fasc. 1, Paris 1876, p. 44 pl. XIV, XV. I have only found a few small specimens of this species and have not sub- mitted them to closer examination As to the structure of the frond, reference may be made to the descriptive works and the quoted figures of Harvey, ‚KüTzıng, Bornet and THURET, which show that the inner part of the compressed frond consists of a slimy substance through which run widely spread medullary fila- ments, while the cortex is com- posed of two or three layers of cells. Colourless, rather thin hairs proceeding from peripheral cells were observed in specimens from Hirshals, but none in the other Fig. 78. examined specimens. BERTHOLD iranien ligulatum : from XJ. 4 and B, tips of slender shoots show- ing two filaments reaching the top. — C, surface of male plant. 630:1. (1. c. p. 7) did not observe them. In a small specimen from Herthas Flak I found in slender shoots two filaments running to the very end of the shoot, with the two apical cells at ihe same level and higher than those of the other filaments (fig. 78 B). In thicker shoots such structure is not to be found; the end of the shoot seems to be composed of a greater number of equal filaments. Sporangia have never been found in this species. The antheridia occur in the same specimens as the carpogonia (comp. BORNET et THURET, |. c. p. 45; BERTHOLD, |. c. p. 9). They have been briefly described and figured by BuFFHAM (I. c.). According to this author they arise from “a cell which produces four male cells above, and these emit the pollinoids, which are minute.” I found their arrangement less regular, their number, seen from the face, varying from 1 to 4 (fig. 78 C). As I had not occasion to examine them in transverse sections, I am not able to decide whether the small cells shown in the figure are really the antheridia (spermatangia) or possibly partly antheridia-producing cells (spermatangial mother cells after SvEDELIUS), as BUFFHAM's fig. 39 may suggest. The carpogonial branches are 4-celled, situated on the inner side of the cortex, and bent outwards (BorNET and THURET |. c. fig. 1). According to BERTHOLD and ScHMITZ, the fertilized carpogonium gives off in various directions a number of 21* 164 sporogenous filaments which fuse with the auxiliary cells occurring in great numbers on the inner side of the cortex. After the fusion the auxiliary cell produces on its inner side the gonimoblast (BORNET and THURET |. c. fig. 2—5). The ripe cystocarp is globular or somewhat lobed; it projects in the slimy medullary space (KüTziNG l. c., Bonnet and THURET fig. 2—4). The species has only been found in three localities in the northern Danish waters. The largest specimen (from TQ) is 4,5 cm long, 3 mm large. It has been found with antheridia and carpogonia in July, with cystocarps in August and Sep- tember. It occurs on stony or gravelly bottom. — At Helgoland it has been found in well developed specimens, and it has been met with at Väderöarne, Bohulän. Localities. Sk: 1 mile NW of Hirshals, 15 m. — Kn: XI, Herthas Flak, 20—22,5 m; TQ, at Trindelen light-ship. Furcellaria Lamouroux. 1. Furcellaria fastigiata (Hudson) Lamouroux. Lamouroux, Ann. du Mus. XX. 1813, p. 46; GREvILLE, Alg. Brit. 1830, p. 67, tab. XI; Kürzıng, Phyc. gener. 1843, p. 402, Taf. 71 (habit and anatomy); Harvey, Phyc. Brit. I, 1846, pl. 94, III, 1851, pl. 357 (cystocarps and tetraspores); ARESCHoUG, Phyc. Scand. mar. 1850, p. 88, Tab. IV A; Caspary, Observations on Furcellaria fastigiata, Huds. and Polyides rotundus Gmel. Ann. & Mag. N. Hist. Ser. 2, Vol. VI, 1850; J. AGARDH, Spec. I, 1851, p. 196; Taurert, Rech. s. L fécondation des Fucacées et des anthéridies des Algues. II. Ann. d. sc. nat. 4e ser. tome 3, 1855, p. 42 pl. 3 fig. 6—7; Kürzıng, Tab. phyc. Bd. 17, tab. 99, 1867. REINKE, Allgem. Botanik, 1880, p, 134 fig. 97 (longitudinal section of extremity of frond). Algenflora w. Ostsee, 1889, p. 26 (f. aegagropila); WILLE, Alg. physiolog. Anatomi, 1885, p. 55, 63, 84 ex parte, not Tafl. VIII fig. 14, Beitr. physiol. Gewebesyst., 1887, p. 86, Taf. 6 (VII) fig. 76—78; KoLkwiızz, Beitr. z. Biol. der Florideen. Wiss. Meeresunters. N. Folge. 4. Bd. Abt. Helgoland Heft 1. 1900, p. 31, 46, fig. 4; SvepeLius, Stud. Östersj. hafsalgfl., 1901, p. 130; Ortsanss, Morph. u. Biol. d. Alg. I, 1904, p. 545, fig. 329 (longitudinal section of upper end of frond and transverse section of frond); Denys, Untersuch. an Polyides rotundus Gmel. und Furcellaria fastigiata Lamour., Beih. z. Jahrb. d. Hamburg. wissensch. Anstalten. 1910. Fucus fastigiatus Hudson Fl. angl. ed. 1. 1762, p. 588; Oeder, Flora Danica tab. 393, 1768 (with adventi- tious shoots). - Fucus furcellatus Oeder Fl. Dan. tab. 419, 1768. Fucus lumbricalis Gmel., Hornemann, Flora Dan. tab. 1544, fig. 6, 1816 (tetrasporangia). Furcellaria lumbricalis Lyngbye, Tent. Hydr. p. 40, tab. 40 A, 1—4. Fastigiaria furcellata (L.) Stackhouse, Le Jolis, Liste Alg. Cherbourg, 1864, p. 124. The mode of growth, ramification and structure of this common alga has so often been described and figured that it may be sufficient to refer to other works, adding only some supplementing remarks. The apex of the frond consists of a great number of densely joined cell-fila- ments which are parallel and vertical in the middle, becoming gradually more divergent towards the periphery. (“Springbrunnentypus” of OLTMAnNs). The central filaments continue downwards in long longitudinal filaments, which constitute an essential part of the medulla, while the more peripheral ones gradually develop into the cortex, which consists of radiating, dichotomously branched filaments. The — 165 outer small cells form an assimilatory tissue; the cells of the inner cortex are much larger, containing also several bandlike and ramified chromatophores, but the total mass of these bodies is small compared with the volume of the cell. WıLLE men- tions these cells as store-cells, “Speicherzellen” (1887 p. 87), as floridean starch is stored in great quantity in them. These cells are connected with each other by small pits. The cell-rows of the cortex depart from the longitudinal filaments of the central tissue, which consists not only of these filaments but also of irregular hyphæ origi- naling as outgrowths from the barrel-shaped cells of the inner cor- tex (fig. 79). The dif- ference between these two kinds of filaments in the medulla has al- ready been remarked by older authors as KüTzING and CASPARY; WILLE on the other hand (1885 and 1887) only refers to the se- condary hyphe but not to the primary longitu- dinal filaments’. The difference is conspi- cuous, the longitudinal filaments running very regularly and consi- sting of long cylin- SE Co my meee oe "REE AKER rer RR Fig. 79. 5 Furcellaria fastigiata. A, transverse section of frond, at the limit between the me- drical cells connected dulla and the inner cortex. B, longitudinal section of the same. c, inner corlical cells; I, longitudinal filaments; h, hyphæ. After living material, April. (190:1). with large pits, while the hyphæ run irregularly, though chiefly in a transversal direction, and are com- posed of more heterogenous cells, those of the proximal part being more or less inflated, while the cells of the distal part are cylindrical. The cells of the hyphæ contain narrow, partly branched chromatophores. In the longitudinal filaments I did not observe any chromatophores, but Denys (I. c. p. 10) states that their cells contain colourless ones. This author states that the hyphæ are given off from the longitudinal filaments’; it is possible that they may also be produced by these, For illustration of the anatomical structure of this species WILLE gives only a copy of a figure by Kürzıng (Phycol. gener. tab. 72 fig. 6; Wırre Taf. VIII fig. 14), representing Furcellaria lumbrialis; but this is identical with Polyides rotundus, which differs from Furcellaria just in the structure of the medulla. OrLrmanns makes the same error (1904 p. 546 fig. 330). ? Denys calls the longitudinal filaments “Längshyphen,” but incorrectly, as these filaments have not the active apical growth combined with slipping growth (“gleitendesWachsthum”) characteristic of the hyphe. 166 though I have not observed it, but when Denys says that they “schliessen nach kürzerem oder längerem Ver- lauf an die inneren Zellen der mittleren Rinde” (1. c. p. 10) he must have misinterpreted the facts observed. WILLE’S statement (1887, p. 87) that these cells “mit einander sowohl als auch mit den Speicherungszellen durch Poren in Verbindung treten” might be understood as if the pits were secondary, whereas in reality they are primary. Whether secondary pits may be formed between the hyphæ, or between these and other cells, I have not ob- served. — In late summer, autumn and winter these cells are rich in starch. As to the starch compare for Fig. 80. the rest KoLkwirtz (l. c.) All the vegetative cells contain Furcellaria fastigiata. Adventitious a single nucleus. Hairs are never produced. shoot in longitudinal section. 95:1. As to the stolons reference may be made to the descriptive works and to KozkwiTz (1. c. p. 46) and Denys (1. c. p. 8). The erect fronds are, as is well known, branched by dichotomy, but besides this normal ramification adventitious branches sometimes occur, especially in the inner Danish waters (Sa, Sf, Sb, Su, Bw) (Flor. Dan. tab. 393). They originate from a little group of superficial cells. In developing they increase early in thickness so that their basal plane is much larger than their plane of insertion (fig. 80). They may be very mumerous, as for instance in some specimens dredged in January in Store Belt (NU, no. 4250) at 11 meters depth, the shoots of which were, for a lengih of one to three cm or longer, more or less densely beset with very short adven- titious shoots; some older shoots of this kind had again produced adventitious buds. The cause deter- mining the appearance of these shoots is unknown; the plants producing them may be fertile. Another sort of adventitions shoots develop from the scars arising from the decaying and falling off of the fructifying parts of the shoots (fig. 81, comp. Harvey, Phye. Brit. Plate $4). As shown by Caspary (l. c. p. 93, fig. 10) this regeneration can be once or twice repeated. The reproductive organs are produced in the upper part of the fronds; their develop- ment begins at the end of the summer or in the beginning of Fig. 82. Fig. 81. Furcellaria fastigiata. Adventitiousshootsgrow- the autumn. In August very Furcellaria fastigiata. A, young sporangia ing out from scars. Hirs- å in transverse section of frond, August. 220:1. hals June. 1,5:1. young Sporangıa may be found B, ripe sporangium. 230:1. 167 in the inflated ends of the frond. They appear as small cells cut off from the outer end of the large cells of the inner cortex, and differ from these by the want of starch, by the higher staining power in presence of hæmatoxyline, and in con- taining a large, intensily staining nucleus (fig. 82 A). The sporangia increase in Sep- tember and October; in November specimens with undivided and divided sporangia may be met with. In December the sporangia are always ripe; at the end of Nil Gr artes plate Lars Fig. 83. Furcellaria fastigiata. A, part of frond with emptied tetrasporangia, December. B and C, parts of fronds with ripe cystocarps, December. D, part of frond with antheridia, March. Nat, size. December and in January they are often emptied, but in February many sporangia containing spores are still to be found. As is well known, the sporangia are oblong and “zonate” 9: divided by parallel walls; the spores contain numerous small chromatophores (fig. 82 B). The parts of the frond producing tetrasporangia are somewhat inflated, fusiform; after the exhaustion of the spores they are a little more inflated, soft and green, while the other parts of the frond in winter are dark red-brown. The upper tip of the frond sometimes remains sterile and therefore retains its dark colour. Downwards the fertile part is sharply marked off from the sterile frond and loosens here in decaying during the winter (fig. 83 A). The antheridia cover the surface of small terminal inflated segments of the frond; which are about 1cm long, of a pale rose colour (fig. 83 D). They are given off from small cells, not infre- quently smaller than themsel- ves. In a transverse section of ‚ the frond these androphore- cells, which seem to contain chromatophores, are seen bear- ing two antheridial cells of different age. Probably they may sometimes bear more than two, and the production of an- theridia may possibly be con- tinued after the first has been = 1 SE = | Fig. 84. Lee Bi Furcellaria fastigiata. Trans- exhausted. The antheridia al- x ET) verse sections of antheridia- ways occur in particular male À A bearing fronds, Decemb. 835:1. 9 plants; they were first described Fig. 85. Br : Furcellaria fastigiata, Carpogonial bran- fe} and figured by Tuurer in 1855. Fully developed ches. AandB two.cailen caran antheridia have been met with in December, but they 4celled. In D, the carpogonium has pro- may probably occur much earlier. Antheridia con- en ne taining ripe spermatia have further been found in syne is very short and unfertilized. A, 3 3 September, 230:1, B—D, August, 390:1. January to March, and in May I have still found spe- cimens with white antheridial branches containing numerous spermatia (no. 5793, UL, Øjet, in Bw, 20 meters depth). The carpogonia appear atthe end of the summer, and in August young goni- moblasts may already be met with. The carpogonial bran- ches arise in the inner cortex or at the limit between the cortex and the central tissue; they are frequently placed in small groups, and two or three of them may be given off from one of the large storage cells. They are almost always two- or three-celled. The inferior cells of the carpogonial bran- ches are globular or ovate, they contain one or two nuclei, small chromatophores and numerous small starch grains. The car- ‘pogonium is much narrowed Di 0s over the basal part, the nar- Furcellaria fastigiata, sections of fronds with young eystocarps, August. 3 E a, auxiliary cell; s, sporogenous filaments, g, gonimoblast. 210:1. rowing being deepest on one side (fig. 85 B). I cannot give any details about the contents of the carpogonium, as on staining with hæmatoxyline it was in a great part very dark and intrans- parent. In the specimens collected in August and September numerous carpogonia with short trichogynes were found; other carpogonia had long trichogynes making their way outwards through the corlex, and tips of trichogynes protruding through the surface of the frond were also met with, but I have not yet seen spermatia fixed to them, and it remains thus to state whether fertilization takes place normally or the cystocarp may develop parthenogenetically, as in Platoma Bairdi. The car- Fig. 87. Furcellaria fastigiata. Sections of frond with young cystocarps. c, carpogonia; a, auxiliary cells; g, gominoblasts. September. A 180:1: B 19:1. pogonium shown in fig. 85 D seems to agree with the latter assumption, as an out- growth is given off from the base of the carpogonium, while the trichogyne is very short and unfertilized. The auxiliary cells (a in the figs.) arise, as stated by Scamirz (Engler u. Prantl, p. 526), from single cells in the inner cortex which seem to be at first but little different from the vegetative cells. They fuse with the long sporogenous filaments produced by the carpogonia and growing widely between the inner cortical cells and the medullary filaments. The fusion takes place at the inner end of the cell. After the fusion the auxiliary cell soon begins to produce gonimoblast cells laterally _ and at the inner side, and thus young cystocarps may occur already in August (fig. 86). The auxiliary cell after fertilization contains a number of nuclei, four or more, some of which certainly derive from the original nucleus of the cell, while the others are sporogenous (fig. 86 A, 87). The cell increases in volume and takes a more ir- regular outline. Fusions between neighbouring cortical cells seem to occur (fig. 87). D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk, og mathem, Afd. VII. 2. 22 Fig. 88, Furcellaria fastigiata. Section of young cy- stocarp. At right several carpogonia. s, spo- rogenous filaments. The cells of the young eystocarp contain minute starch grains while those of the surrounding cells are much larger. August. (200:1). I have also in the same specimens observed the production of small cells at the under end of the large cells of the inner cortex, resembling the forma- tion of secondary pits in the Rhodomelaceæ, but what their significance may be I do not know. The cortical cells situated outside the auxiliary cells have richer contents and stain deeper with hæmatoxyline than the others, forming thus a darker stripe towards the surface (fig. 86 B). The ripe cystocarp appears as a globular heap of car- pospore cells, grouped around the auxiliary cell or containing in the centre also a few other sterile cells. The particular gonimolobes are usually not distinguishable. At the periphery of the cystocarp some long cells are frequently found forming an incomplete envelopé around it, as shown by ARE- scHouG and Caspary, Il. cc. At the time of ripe- ning a pore is formed in the cortex through which the spores are exhausted. This pore arises by destruction of the cells of the darker stripe mentioned above. The fructiferous part of the female fronds is more or less inflated, almost as in the sporangia-bearing ones, but the upper part of the fronds frequently remains sterile; this part may be 1 to 2 cm long and branched (fig. 83 C). Germinating spores of what must be supposed to be Furcellaria fastigiata are frequently met with on various Alge, as Delesseria, Phyllophora a.o. They are at first hemispherical, and are divided by rather regular anticlinal and periclinal walls A Fig. 89. without changing form, but increasing in size (fig. 89 A). Later on, a cylindric upright shoot of the typical structure is produced from this hemispherical body, the shoot being a little narrower as the basal part (fig. 89 B). These shoots later branch and produce rhi- zomes at their base. This Alga is one of the com- monest and most widely distributed in the Danish waters. It attains its highest degree of development in the Kattegat and the Belts, where it be- comes up to 28cm high. In the Furcellaria fastigiata. A, germinating spores, seen from above western Baltic it attains a length of and from the side. B, older stage showing a cylindric shoot growing out from the hemispherial body. 24,5 cm, whereas at Bornholm I have 171 not found it higher than 9 cm. In the inner Baltic Sea Sveperıus found il scarcely more than 10 cm high. He refers the plants here found to f. minor Agardh, a form differing only by smaller dimen- sions, in citing Fl. Dan. tab. 393 and AREscHouG, Alg. Scand. exs. No. 257. In the most feebly de- veloped specimens the erect shoots are not bran- ched, or but little so (fig. 90). — Furcellaria grows usually on stones or pebbles, but may also be found fixed on other Algæ, as Phyllophora, Chon- drus. In some places north of Fyn (especially aZ, near Fyns Hoved) it was found growing in com- pany with other, mostly loose, Algæ forming a dense Fig. 90. cover over the bottom,which consisted of coarsesand. Furcellaria fastigiata. Plants from the Baltic I am not certain whether these specimens were at SF Gudhjem, Bornholm. Nat. size. first loose or originally fixed at this stationary bottom. In other places detached speci- mens lying loose on the bottom are met with, often in great quantities, particularly in fjords, as Limfjorden, but also in the Kattegat, e. g. around Anholt. It is appa- rently able to live long in this condition, for plants in which the under part is in a state of disorganization are often met with. Some of these plants are not much different from the normal ones; in other cases they are more branched, and form globular bushes corresponding to those mentioned by REINKE (1889) and SvEDELIUS as f. ægagropila (fig. 91). The species has been found in depths from 2 to 28 meters and once in 38 m depth (near Bornholm). It is of- ten a predominant element of the vege- tation, particularly in depths of 4 to 15 m. It is perennial, but the fructifying shoots are shed in winter. In sunny lo- calities the upper parts of the fronds are green in sum- mer. Localities. Ns: Only found at ZQ, jyd- Fig. 91. ske Rev, 24,5 m and at Furcellaria fastigiata egagropila. From Guldborgsund. Nat. size. 172 Orhage by Klitmøller inside the point at 2 meters depth, farther from land off Klitmøller only a few small specimens. — Sk: Collected at various places (Hanstholm; Bragerne; washed ashore by Svinkløv and Blokhus; Lenstrup; Hirshals: Skagen) in 2 to 13m depth, in most of the places only in small and scarce specimens. Found in greatest number and best developed at Hirshals, near land in 5 m depth, in company with Polyides. Greatest length observed 15cm. — Lf: Widely distributed, down to a depth of 6,5 m, but in most places loose, often in abundance on soft bottom (f. @gagropila). Reaches a length of 8—14cm. — Kattegat: Common and often abundant everywhere on stony bottom in depths down to 15cm. It reaches here a length of up to 28cm and is very often over 20cm high. It has also been dredged in several places in greater depths, down to 30m (e. g. ZB, Trindelen, about 30 m; ZS, Fladen, 26,5 m; HZ, Store Middelgrund, 25,5 m), but it is more frequently missing than present in these greater depths, and, at all events, it occurs only in small quantities. In Herthas Flak in Kn, where I have dredged several times in 20 to 24,5 meters depth, it has never been met with. In Isefjord it has been recorded in various places, in Holbæk Fjord it occurs abundantly in a loose condition. — Sa and Lh: Common in depths down to 24m; at aZ growing gregariously over coarse sand (see above). — Sf: Several places. — Sb: Common in depths down to 20 m, greatest length observed 27cm; generally well developed specimens. — Sm: Several places down to 12 m depth; greatest length observed 10,5 cm — Su: North of Helsinger up to 25 cm high, south of Helsinger in depths down to 13m, up to 16cm high. — Bw: Found in depths down to 20 m; greatest length observed 24,5 cm. — Bm: Greatest length observed 12 cm. — Bb: Found in depths from one to 38 m (YA, east of Bornholm) in several places, but reaching only 9cm in length. Fam. 6. Rhizophyllidacee. Polyides Agardh. 1. Polyides rotundus (Gmel.) Grev. Greville, Algæ Britann., 1830, p. 70, Tab. XI. Harvey, Phycol. Brit. pl. 95, 1840. Caspary, Ann. and Mag. N. Hist. Ser. 2, Vol. VI, 1850, p. 93. Thuret in Le Jolis Liste des Alg. mar. de Cherbourg, 1864, p. 140. Thuret et Bornet, Etudes phycologiques, 1878, p. 73—80, pl. 37—39. Guignard, Développ. et const. des anthérozoïdes. Revue gén. de Botanique. I, 1889, extrait p. 44, pl. 6 fig 10—12. Fr. Schmitz, Kleinere Beitr. z. Kenntn. d. Florideen. II. La Nuova Notarisia. Ser. IV. 1893, Estratto p. 8. Kolkwitz, Beitr. z. Kenntn. d. Florideen. Wiss. Meeresunters. N. F. 4. Bd. Abt. Helgoland. Heft 1, 1900. Denys, Anatom. Untersuch. an Polyides rotundus Gmel. und Furcellaria fastigiata Lamour. Beih. z. Jahrb. d. Hamburg. wissensch. Anstalten 1910. Fucus rotundus Gmelin, Hist. Fucor., 1768, p. 110 tab. VI fig. 3. Flora Danica tab. 1544a (Hornemann 1816). Furcellaria rotunda Lyngbye, Tent. Hydr., 1819, p. 49. Polyides lumbricalis C. Agardh, Spec. Alg., 1822, p. 392, J. Agardh, Sp. g. o. II, 1863, p. 721. Furcellaria lumbricalis Kützing, Phycol. gener., 1843. p. 402, Taf. 72, Tab. phycol., Bd. 17, 1867, pl. 100. The external resemblance between this Alga and Furcellaria is well known and has often been mentioned, as well as the difference of the basal part being a disc in Polyides, while in Furcellaria it consists of branched rhizomes. The struc- ture of the erect frond has already been thoroughly studied by KüTziNG (1843)! and Caspary (1850). The structure of the upper end of the frond is that of the foun- tain type (Oltmanns’ “Springbrunnentypus”) as plainly shown by Kérzine (1. c.). As to the structure of the erect fronds, reference may be made to the papers of * The troublesome synonymy of this Alga is responsible for the fact that WILLE (Bidr. t. Alg. phys. Anat. K. Svenska Vetensk. Ak. Handl. Bd. 21. 1885, tafl. VIII fig. 14) and Orrmanns (1904, p. 546, fig. 330) have used copies of Kürzıng’s figures of it to demonstrate the anatomy of Furcellaria fastigiata (comp. p. 165). 173 KÜTzınG, Caspary, THURET (1878, p. 75, pl. 37, fig. 6) and Denys. The outer cortex consists of a greater number of layers of small cells (up to 4 or 5) than in Furcel- laria. The longitudinal filaments of the central tissue are mostly thicker at the ends than in the middle “so that they have the form of a femur” (Caspary, p. 94). The cells which form the connection between these filaments and the cortical ones are arranged in regular feebly curved rows running obliquely upwards, while secondary hyphæ are wanting’. Hyaline hairs produced by superficial cortical cells may occur, according to THURET (1878, p. 75, pl. 37, fig. 6). I have not observed these hairs, but in specimens collected in April I found that some of the peripheral cells were colourless, narrower and longer than the others; probably they were about to develop into such hairs. As to the cell-structure, reference may be made to the paper of Denys. The pit in the transverse wall between the cortical cells is very narrow, while that of the longitudinal filaments is broad, and provided with a double plate. Secondary pits do not occur. The structure of the basal disc has been figured by Ktrzine (1843); according to Korkwirz (1900, p. 51) older dises are stratified. The tetrasporangia arise at about the limit between the outer and inner cortex (comp. Caspary, 1850, fig. 21, THURET, 1878, pl. 36, fig. 6 and 7). As shown by THURET, an issue is formed outwards to each sporangium by removal of the cells from each other, through which issue the contents of the sporangium is emptied. Specimens with undivided sporangia have been met with in October, with ripe sporangia in January and with emptied sporangia in April. The antheridia arise, as shown by THURET, in nemathecia in particular indi- viduals. According to GUIGNARD (1889, p. 44, pl. 6, fig. 10—12) they are placed in tetrads directly on the nemathecial filaments, while Schmitz asserts (1893, p. 8) that they are situated on short cells given off from the filaments. I cannot give any information on this point, as I have not met with male plants in the Danish waters. As to the structure and development of the female nemathecia, reference may be made to the classical researches of THURET and Bornet (1878, p. 77—80, pl. 38—39). These bodies begin to develop in the Danish waters in August or September. In specimens dredged at the entrance to Vejle Fjord, August 20th, nemathecia with well developed but unfertilized carpogonia were found. Similar carpogonia but also others with fertilized carpogonia are frequently met with in September. Ripe cy- stocarpia were found in December and January. After the exhaustion of the carpo- spores, the nemathecia are thrown off, while the fronds which have produced them possibly may continue growing. — The germination of the carpospores has been observed by THURET et BORNET (1878, p. 79, pl. 39, fig. 32); they obtained hemi- spherical bodies producing rhizoids from their under face. 1 Denys speaks (1. c. p. 7) of “Querhyphen, welche die Masse der längs verlaufenden durchflechten und seltener auch zwischen die Elemente der grosszelligen Rinde eindringen”. But as he designates the longitudinal filaments also as “‘Hyphen”. it is not clear if it is a case of real hyphæ or only of the above named connecting filaments. As he says, on p. 18, that they occur only “ganz vereinzelt”, it seems that he has really observed secondary hyphæ, although in very small number. 174 This species is only little variable in shape and size. It often reaches a length of 14 em, even in the Baltic, almost to the limit of its distribution. The largest specimens, 18 cm high, were found in the Skagerak and the South Fyen waters. The depth has no influence on its size, save that when growing at low-water mark it does not become longer than 6 em. The greatest length is reached in 5,5 to 9,5 meters depth. Adventitious shoots from scars left by decayed ends of frond frequently occur, as in Furcellaria, but rarely developing from the surface of the frond. The species grows on stones, but is frequently met with loose on the bottom, particularly in the Zostera formation, but also on bare sandy bottom, as for instance around Anholt, where it occurs in great quantities together with Furcellaria fastigiala. It occurs in all the Danish waters, with exception of the eastern Kattegat and the Baltic around Bornholm, from a little below low-water mark to about 11 meters depth. In greater depths it occurs more rarely; certainly it has been found in several places down to 23,5 m depth, but in most cases it was certainly or probably loose. As sure deeper localities may be named, in the Skagerak: off Hanstholm and Lonstrup, 13 m; and in the Kattegat: Tonneberg Banke, 16 m. It does not thrive in fjords; in the Lim- fjord it has however been found in one locality. Specimens with tetraspores seem to occur much more rarely than sexual spe- cimens in the Danish waters; I have met them only in one locality in the Skagerak and in two in the northern Kattegat, while female specimens have been found in several places from the Skagerak to the Baltic. Localities. Ns: Orhage, 2m. — Sk: Hanstholm, 5,5 to 13 m, abundantly in 13 m depth; washed ashore by Blokhus and Svineklev (P. Petersen); off Lønstrup 8,5—13 m, most well developed in 8,5 m depth; Hirshals, near land 1—4,5 m, in some places dominant. — Lf: Only found on the mole of Lemvig, 6 cm long. — Kn: Harbour of Skagen; Hirsholmene; Krageskovs Rev; Frederikshavn; N. Renner 1—5,5 m; several places north of Læsø, 2—9,5 m; Trindelen, about 18,5 m; Tonneberg Banke, 16m. — Km: NE, NW of Fornæs; around Anholt, abundantly loose. — Ks: Hesselo (Lyngbye). — Sa: PN (Kalovig); PE (Refsnæs); Hofmansgave (Hofman Bang, J. Vahl, C. Rosenberg): OA (Æbelø). — Lb: AX (Bjornsknude), 9,5 m; Middelfart (Rasch, !); Fano Sund, 1m; DF; CC; DB; UX. At several places it reaches a length of 18cm. — Sf: CU. — Sb: GQ; harbour of Kerteminde; DO; Y; UR. — Su: North of Helsingør (Lieb- man, Joh. Lange, !); Taarbæk Rev; RK; PS, off Charlottenlund. — Bw: UY!, 18 m, probably loose. LC (Gulstav) ; South of Nysted. — Bm: QM (Juels Grund); washed ashore at Stevns. Fam. 7. Squamariaceæ. Petrocelis J. Agardh, 1. Petrocelis Hennedyi (Harvey) Batters. Batters in Holmes Alg. Brit. Exsicc. No. 89 (non vidi), Mar. Alg. Berw. Tweed, 1889, p. 94, tab. XI, fig. 3—4. Actinococcus Hennedyi Harvey, Natural History Review, Vol. 4, 1857, p. 202, pl. 13 A, fig. 1 (non vidi). Cruoria pellita Lyngbye Hydroph. 1819, p. 193, tab. 66 ex parte, teste specim. Chetophora pellita Flora Dan. tab. 1728, 1821. Petrocelis Ruprechtii Hauck Meeresalg. 1883, p. 30. The species forms dark-red fleshy crusts, in a dried state glossy, 1—3 cm in diameter. The basal layer is a monostromatic disc composed of radiating filaments. 175 The margin is somewhat lobed, and the filaments of the basal layer radiate towards the border of the lobes (fig. 92 A). When the surface of the substratum is uneven, small rudimentary rhizoid cells may be given off from the basal layer (fig. 92 C). Fusions between the cells of this layer have not been met with. The upright fila- ments which are given off from the acroscopic end of the cells in the basal layer are decumbent at the base, so that there often seem to be more than one layer of basal cells. At the border the filaments are directed obliquely forwards. The upright filaments have almost the same thickness in the upper and the lower part Fig. 92. Petrocelis Hennedyi. A, basal layer seen from the under face (230:1). B, vertical section of border of frond. C, vertical section of older part of frond. B and C 390: 1. of the crust; in the upper part they are 4—6 y thick. They are imbedded in a glutinous intercellular substance which swells greatly in fresh water, whereby the filaments are separated. The upper end of the filaments is nearly always a little attenuated, the uppermost cell usually being narrower than the other, and more or less conical, or the upper part of the filament is gradually tapering (fig. 95). In some cases, however, particularly in thin crusts, I found the filaments of the same thickness to the very end (fig. 96). The cells are usually twice or thrice as long as broad, they contain a nucleus and a cap-shaped chromatophore with more or less lobed border; in a specimen examined in July the cells contained numerous small starch grains. The upright filaments are simple or little branched. The ra- mification is lateral, subdichotomous or sometimes sympodial; the latter reminds one of the false ramification of the Cyanophyceæ, the penultimate cell growing out and throwing aside the apical cell, which does not usually develop further. In fig. 93 B the wall of the outgrowing cell is seen to have been burst. Hyaline 176 hairs are sometimes found given off from intercalary cells in the vertical filaments. The cells producing them are usually more or less projecting, but the hairs are feebly developed; they do not ordinarily reach the surface of the frond, and soon decay. Once only have I seen a few such hairs projecting over the surface, as in fig. 94 E where the hair, however, is terminal on a one-celled branchlet!, — The crusts may certainly reach an age of more than one year. In crusts growing on stems of Laminaria hyperborea a stratification is often visible which seems to be due to the cessation of the growth in winter; in the part of the crust beneath the limitating line empty or abortive fructifications may be Fig. 93. found, while new fructifications have not yet been produ- Petrocelis Hennedyi, from the 0 Limfjord (ZY), showing peculiar Ced in the upper part of the frond apparently formed after ramifications of vertical fila- the hibernal rest. ments. 390:1. Characteristic of the genus are the intercalary spor- angia. In this species there are as a rule several consecutively in the same fila- ment, in Danish specimens frequently six at least in a row, but there may be up to nine. The row is never interrupted by sterile cells. The sporangia are situated in the upper part of the vertical filaments, only the (1—) 2—5 uppermost cells being sterile. The sporangiferous vertical filaments are usually unbranched, but sometimes a branch is given off, rarely from the articles transformed into sporangia, more frequently from the cell subjacent to the sporangial series (fig. 95). The spor- angia are first divided by an inclined transverse wall and then by two walls per- pendicular to the wall first formed. The latter are frequently parallel, but the lines of intersection with the transverse wall do not coincide. These seriate sporangia are of about the same height as breadth, 14—17 y broad, 16—23 » high. In most of the crusts only seriate sporangia are present; but in some cases the sporangia were single or at most two in a series. These sporangia are more lengthened than the seriate ones. A transi- tional case is shown in fig. 95 D, where the series contains only two sporangia. But in fig. 95 G and H single, terminal or subterminal sporangia are A represented. In fig. 95 H the sporangium seems to À be terminal, but I cannot assert that there has not aie Gi : been one or more sterile cells which may be de: Petrocelis Hennedyi. Vertical filaments with cayed DL possibly removed by the preparation. hyaline hairs. A—C from Begtrup Vig; in Similar sporangia were found in a thin crust with C the hairs have been thrown off, the chromatophore of the cells is visible. DE the ends of the filaments truncate; fig. 96 shows from Hellebæk, E after a living plant with a well developed hair at the top of a uni- 7 Comp. L. KoLDErup ROSENVINGE, Hyaline hairs (Biol. cellular branchlet. A—D, 400:1; E, c.200:1. Arbejder, tilegn. E: Warming, 1911, p. 206). Fs 177 at left a sporangium with a single small sterile cell at the top and at right an apparently terminal sporangium. There is no doubt that the sporangia here men- tioned are transformed cells of the filaments in which they are situated; this is more doubtful in the case represented in fig. 95 J, where the sporangium has the appearance of being lateral, but as it has been found in the same crust as those figured in fig. 95 FH, it must be sup- posed that it has really been terminal. The single sporangia are 2 to 3 times as long as broad, 26—50 » long, 11--14 u broad. Their great length depends pro- bably on their terminal or subterminal place, which permits them to develop unhindered by sporangia or sterile cells lying above. In some crusts only such ‘lengthened sporangia, singly or in pairs, are found; in others they are found in company with the ordinary seriate ones, as a rule, however, in different parts of the frond. By this fact it is shown that the two kinds of sporangia really belong to the same species. Single sporangia have been met with in three places in spring (Ks: Hastens Grund; Sa: Ronnen - in Begtrup Vig and Lb: off Middelfart). There is no resemblance between the single sporangia of this species and those of Petrocelis cruenta J. Ag., which are strictly intercalary and globular (comp. LE JoLıs Alg. mar. Cherb. pl. III, fig. 4). In specimens gathered in November in the Great Belt I have found spores germinating in the seriate sporangia (fig. 95 E). The spores were divided by va- riously orientated walls and some of the uppermost resulting cells were growing out upwards into filaments. The antheridia arise in the upper part of the vertical filaments, where they form small lateral bushes, rather similar Fig. 95. Petrocelis Hennedyi. Vertical filaments with tetrasporangia. A, six still undivided sporangia, November. B and C, ripe sporangia, July. D, filament with two sporangia only, April. E, tetraspores germinaling in the sporangia, April. F-I, from Begtrup Vig, May, F with seriate spor- angia, G with subterminal, H and I apparently with terminal sporangia (in J possibly lateral ?). A,D,E,G,H 390:1 B,C,F, I, 300: 1. to those of Cruoria. They are borne on the upper end of small, usually unicellular, more rarely bicellular, branchlets, two D. K. D. Vidensk. Selsk, Skr., 7. Række, naturvidensk. og mathem, Afd. VII. 2, 23 178 or three on the same stalk (fig. 97). Some- times they appear to be produced directly from a cell of the vertical filament. The carpogonial branches are si- tuated laterally on the vertical filaments. They are somewhat variable in shape and number of cells. Usually they are two-celled, and the undermost cell then frequently projects considerably down- wards beyond the insertion point (fig. 99 A). SEES ETT] Fig. 96. Petrocelis Hennedyi,thin Sl Fig. 97. Petrocelis Hennedyi, from the . North Sea (Klitmøller), August. Vertical filaments with anthe- ridia. 390 :1. More rarely the carpogonial filament is 3-(or 4-)celled. A carpogo- crust from Lillebelt, nium situated directly on the vertical filament was also met with, March. Vertical fila- ments with truncate but the cell from which it was given off had in this case the end-cell. Sporangiasub- character of the cells of carpogonial branches (fig. 98 A), its con- terminal or terminal. 390 : 1. tents being more homogenous and staining more intensely by Fig. 98. Petrocelis Hennedyi, from Bornholm, July. A, carpogonium situated directly on the vertical filament. B—D, two-celled carpogonial branches; in B and D the supporting cell has the same character as those of the carpogonial branch. E, carpogonial branch with short sporogenous filaments given off from the carpo- gonium and the subjacent cell. F, carpogonial branch producing (sporogenous ?) filaments. G, vertical filament with two larger cells, one of which bears a hyaline hair. H, vertical filament with a presumed auxiliary cell with scar after a decayed hair. J and K, auxiliary cells in contact with sporogenous filaments. L, probably young gonimoblast. A—E and L, 630:1 F—K 390:1. heematoxyline than the ordinary cells. This may also sometimes be the case with the cell bearing 2-celled carpo- gonial branches (fig. 98 B). The cell bearing a carpogonial branch is frequently swollen, re- sembling the auxiliary cells. The auxiliary cells arise from single cells in the vertical filaments, which become some- what swollen and more susceptible to colouring matter. They appear to arise in some cases from cells having pro- duced a hair (fig. 98 G, H). The develop- ment of the cystocarps has not been follow- ed; I have only obser- ved a few stages suc- ceeding the presumed 179 fertilization '. Sporogenous filaments are found given off not only from the carpo- gonium but also from other cells in the carpogonial branch; in the latter case, however, fusion between these cells and the carpogonium could not always be dis- cerned, as for instance in fig. 98 E, where two young sporogenous filaments are seen projecting from the carpogonium and the subjacent cell. Older stages are shown in fig. 99 C and E; in C the filaments causing the fusion ‘between the cells of the carpogonial branch are easily visible. The sporogenous filaments are here seen growing out in a horizontal direction from the carpogonial branches. Fig. 98 I, K show auxiliary cells in contact with sporogenous fila- ments, and fig. 99 G represents probably the same after the fusion. The stages shown in figs. 99 D and 98 L are probably young go- nimoblasts, though sporogenous filaments are not visible. Ripe cystocarps are shown in figs. 99 H, I; they consist, as shown by Batters (1. c. pl. XI, fig. 4), of an almost spindie-shaped heap of carpospores which easily segre- gate on preparation. The spores are 14 to 17 » in diameter. The species has been found in almost all the Danish waters, in depths of 1 to 19 meters. It Fig. 99. grows on stones and shells of Petrocelis Hennedyr. A, two-celled carpogonial branch, January. 0 5 o 9 6 B-D, Begtrup Vig, May. B, three-celled carpogonial branch, un- Mytilus edulis and Littorina littorea, fertilized. C, carpogonial branch after fertilization (?), giving off en conpany with CE eS ee ee Lithothamnia and growing over nous filaments (Skagerak, April). F-G, Hellebæk, July. F, carpo- om, m ee ee gerak it has principally been found fully developed, Lysegrund, May. I,ripecystocarp, Storebelt, January. growing on the stem of Laminaria er ERE hyperborea. The sporangia begin their development as a rule in the autumn; they were found undivided in September and November, ripe in January to July, emptied or abortive in June to September and November. But young sporangia G 1 Spermatia have not been found adhering to the trichogynes, and in some cases carpogonia having produced sporogenous filaments show no interruption of the protoplasm over the ventral part (fig. 98 E, 99 E) which might suggest a parthenogenetic development of the cystocarp. 23* 180 were also met with in July. The antheridia have only been met with in particular male specimens from the North Sea and the Limfjord, collected in August, and a cystocarp-bearing specimen from Lillebelt collected in July also appeared to bear emptied antheridia. The cystocarps develop, as it seems, at about the same seasons as the tetrasporangia. They have been found ripe in January, May and June, emptied or degenerated in August. The carpogonia seem to arise at various sea- sons. In specimens collected in November I have found very young carpogonia still without trichogynes, but in crusts collected at Bornholm in July carpogonia with long trichogynes, partly also with sporogenous filaments, were met with (fig. 98), and unfertilized and fertilized carpogonia (at all events producing sporogenous fila- ments) have also been found in spring. In some cases sporangia and cystocarps have been found in the same crust. Localities. Ns: Klitmøller, on the stem of Laminaria hyperborea washed ashore; Hanstholm (YU), 2 meters. — Sk: 4 miles N"/4E of Svinkløv beacon (A.C. Johansen); Løkken, on Lam. hyp. on the shore; off Lønstrup, about 9 m; off Hirshals, on Lam. hyp. — Lf: Nissum Bredning off Helligse, 6 m (C. H. Ostenfeld); at Mullerne (ZY), 4,5 m; Sondre Ron near Lemvig; Holmtunge Tange (MK). — Kn: Krageskov Rev (TV). — Ke: JO, Fladen; OO, Seborghoved Grund, 8,5 m. — Km: XC, NW of Anholt. — Ks: OS, OS!, Hastens Grund, 14—16m; HQ, Lysegrund; EJ, entrance to Isefjord. — Sa: GD, near Sejerø; FS, Vejre Sund; Ronnen in Begtrup Vig, 1 m; North side of Refsnes Reef, 13 m, (Ostenfeld); DK, Bolsaxen; MQ, South of Paludans Flak, 12 m; Halsgab near Hofmansgave, “in saxis maris Hindsholm“ (Lyngbye, Hofman Bang); DJ, east of Æbelø. — Lb: FZ, Kasserodde, 6,5 m; North of Fano Kalv; off Middelfart, about 15 m. — Sb: Stavreshoved; GP, Halskov Reef; NN, SW of Sproge, 19m; Avernakhage near Nyborg, 2m; GZ, north of Egholm; DN, Vengeance Grund; near Vresen (Ostenfeld); DP, north of Onsevig. — Su: BQ, off Ellekilde, Ellekilde Hage, 11m; North of Lappegrund, about 20 m (H. E. Petersen). -- Bw: DU, off Dimesodde, 11m. — Bm: QQ, off Rødvig. — Bb: YG, Arnager Rev, 7 m. Cruoria (Fries). 1. Cruoria pellita (Lyngb.) Fries, Areschoug. El. Fries, Corpus florar. prov. Suec. I. 1835, p. 317; J. E. Areschoug, Algarum pug. sec. Linnæa, Vol. 17, p. 267, tab. IX fig, 6—8, 1843, ex parte, Phyceæ scand. mar., 1850, p. 157; Alg. scand. exsice, No. 309 (1872); J. Agardh, Sp. II, 1852, p. 491, III, 1876, p. 377; Le Jolis, Liste alg. Cherbourg p. 108, pl. IV, fig. 1—3; Batters, Mar. Alg. Berw. 1889, p. 95, pl. XI fig. 5. Chetophora pellita Lyngbye Hydr., 1819, p. 193, pl. 66 B, ex parte (quoad specim. feeroéns.). Cruoria adherens Crouan in J. Agardh Sp. II, p. 491, III, p. 377, (comp. Le Jolis, Liste, p. 108). An examination of the specimens of Chetophora pellita in LyNGBYE's herbarium has shown that this name includes two distinct species, the specimens from the Ferges belonging to Cruoria pellita, while those from Denmark belong to Petrocelis ‚Hennedyi (comp. p. 174). The description and the figures, which treat only of sterile specimens, agree tolerably well with both species; it appears most pro- bable, however, that they have been worked out after the Danish specimens, as the filaments in the fig. 2 are not thicker towards the base, and as they are described as “æqualia, apice parum attenuata” (I. c. p. 194), which agrees best with the last _181 named species. The genus Cruoria, to which the species of LyNGByE was referred in 1835 by Fries, was also very ill defined. ARESCHOUG and the later authors, how- ever, have applied the name of LYNGBYE and Fries to the species here treated of, and it must be used in the future in the same sense, as the specific name of LYNGBYE in fact comprises both species. This species, in habit quite resembling Petrocelis Hennedyi, forms crusts on the stems of Laminaria hyperborea, stones, shells of Mytilus and barnacles, more rarely on Fucus serratus and the basal part of Halidrys siliquosa, from 1 to 12 cm in diameter or more. The crust has at first a basal layer con- sisting of one layer of cells from which the vertical fila- ments are given off. The fila- Fig. 100. Fig. 101. Cruoria pellita. A, border of frond seen from above. B, verlical ‘section Cruoria pellita. Basal layer of frond seen of under part af frond showing basal layer and sub-basal layer. C, simi- from the under face, showing creeping lar, older crust. A, B 390:1. C 230:1. rhizoidal filaments. 390:1. ments of the basal layer are radiating towards the margin (fig. 100 A). According to Scumitz and HAUPTFLEISCH (1897, p. 535) the thallus is quite coalesced with the substratum and without root-hairs (Wurzelhaare); the first is true, but the latter assertion is not quite correct. As shown in figs. 100 and 101, short filaments are here and there given off from the under side of the basal layer; these filaments have first the character of unicellular rhizoids, but increase in length and form long septate filaments running under the primary basal layer, and in older crusts they may form a continuous layer consisting of one to more layers of variously disposed cells, the undermost of which may have the character of rhizoids pene- trating into the unevennesses of the substratum, while the upper cells in thicker fronds resemble those of the primary basal layer. According to Scumirz and Haupr- FLEISCH (I. c.), rhizoids are frequently produced in the undermost part of the cor- tical layer. 182 The vertical filaments are ascendent at the base; they are thicker near the base than in the upper part, and consist there of somewhat swollen cells, about 12,5—14 4 thick, while the cells of the upper part are 6—11 », frequently 7,5—9 » thick. N The lower part of the filaments ta- || pers gradually upwards, while the upper part is usually of equal thickness. The ultimate cell is truncate or rounded, but never pointed. The cells contain a nucleus and a single A B C calotte-shaped chromatophore, the border of which seems to be more or less lobed. The | … Fig. 102. å cells, particularly those of the undermost part Fig. 103. Seer = REA oe of the filaments, are usually filled with starch Cruoria peltita. Bran- a carpogonium (?); the cells grains. The filaments are sparingly bran- oes eae aed a ea ar ched, by lateral ramification (fig. 102 A). fringent contents. filament with young sporan- Hyaline hairs were not observed, but I some- nn De, times found septate branches thinner than the filaments and with more refringent contents, reaching the same level as the ordinary filaments (fig. 103). The tetrasporangia and the sexual organs occur as a rule in distinct indivi- duals; carpogonia have, however, been met with in tetrasporangia-bearing crusts. The tetrasporangia are lateral on the vertical filaments. As shown in the figure published in Le Jolis Liste (1. c.) they are attached in such a manner that their under part projects below the point of attachment. They are very large and divided by three horizontal walls. In specimens from Frederikshavn they were 250—283 u long, 45—60 » broad. A young sporangium is shown in fig. 102 B. In one case the spores seemed to contain several nuclei, but the observation was not certain, owing to the numerous starch grains contained in the spores. The antheridia form small lateral tufts at the upper end of the vertical fila- ments, as shown by THuRET (LE Joris |. c. pl. IV fig. 3). They are usually produ- ced in small numbers on the upper end of a unicellular branchlet (fig. 104). The antheridia are linear, but the liberated spermatia, according lo THURET (|. c.) are globular. I have only once observed antheridia, in a specimen collected at Frede- rikshavn in July, having also carpogonia and cystocarpia. The development of the cystocarps has only been incom- pletely followed. The carpogonial filaments are lateral on the vertical filaments. Their number of cells may be variable, at most four (fig. 105 A), more frequently less, e. g. two in fig. 105 B, and in fig. 106 A, where the trichogyne reached over the sur- face of the frond. Most of the carpogonial filaments observed Fig. 104. had short trichogynes, and were probably young or abortive. Cruoria pellita. Upper ends Carpogonia sitting directly on the vertical filaments also occur, of filaments with antheri- dia, mostly emptied. 39:1. but in such cases it was often difficult to decide whether they were really carpogonia. Such dubious cases are shown in fig. 105 C, D; I have been in- clined to interpret them as carpogonia, since they had the same refringent and colourless contents as the others. In some cases the supporting cell in the vertical filament had a similar appearance (fig. 105 C, D) (Comp. Petrocelis Hennedyi, p. 178). The undermost cell in the carpogonial filament is sometimes connate in its whole length with the suppor- ting filament. Sporogenous filaments were not seen in connection with the carpogonium, but they were found fusing with the auxili- ary cells. These cells are intercalary in the vertical filaments and differ but little from Fig. 105. Cruoria pellita. Carpogonia À, four-celled carpogo- nial branch. B, two-celled carpogonial branch. C, presumed carpogonium sitting directly on the ver- tical filament; the supporting cell and the next fol- lowing have the same homogenous and refringent contents as the carpogonium. D, Carpogonia given off directly from the vertical filament. A, D 300:1; B, C 390 :1. the other cells, possibly sometimes swollen before fusion. The sporogenous filaments run principally in a horizontal direction, but sometimes give off upward branchlets, Fig. 106. Cruoria pellita. A, two-celled carpogonial branch. B, filament with a somewhat swollen cell *, possibly an auxiliary cell. C, auxiliary cell fused with sporogenous filament. D, similar; the sporogenous filament has given off a branchlet upwards. E, auxiliary cell fused with a sporogenous filament which has given off two upwards directed branchlets. F, auxiliary cell in connection with an incompletely developed cystocarp the auxiliary cell with the neighbouring cells in the vertical filament are marked with a x. auxiliary cell; s, sporogenous filament. G, ripe cystocarp; the pits connecting c, carpogonium; a, A—F 39:1. G 300:1. the signification of which is unknown (fig. 106 D, E). An incompletely developed cystocarp is shown in fig. 106 F, it consists of a very small number of upwardly directed filaments, which have been somewhat displaced by pressure; the auxiliary cell has produced a lateral outgrowth, but is otherwise not swollen. Fig. 106 G shows a ripe cystocarp; the auxiliary cell, or better, the fusion cell, is here seen as a large cell connected by pits with the neighbouring cells of the vertical filament. All the cells of the cystocarp seem to produce a very large carpospore. The ripe cystocarp consists of a spindle-shaped heap of large cells, few in number, reaching downwards considerably beyond the insertion of the auxiliary cell; it has earlier been shortly described and figured by Batters (I. c.). The species occurs from low-water mark down to 30 meters depth. In some places in the eastern Kattegat it occurs abundantly, covering the stones with ex- tensive crusts, forming an association. The sporangia arise in autumn; they are found ripe in winter and spring, emptied in spring and summer. Carpogonia were met with at all seasons, often abortive however; cystocarps have only been met with once in July. Localities. Sk: Off Lønstrup (ZK°), on Laminaria hyperborea. — Kn: Herthas Flak (!, Børgesen); TX, at Hirsholmene; Krageskovs Rev; Busserev at Frederikshavn; harbour of Frederikshavn; VU, east of Nordre Ronner, 15 m; TO, TP, Tonneberg Banke, 16—18 m; FF, TR, Trindelen, — Ke: IR, IT and VZ, Groves Flak, 24,5 m; IQ, ZE!, Fladen; II, IK, Lille Middelgrund; Store Middelgrund (Borgesen), 30 m; IA, Store Middelgrund, 16 m; OO, Ssborghoved Grund. — Km: XC, NW of Anholt, 11 m, on the base of Halidrys; D, north of Isefjord, on Fucus serratus, 11m. — Sa: BF, off Sletterhage, 14m; PH, Lind- holms Dyb, 20,5 m; Northside of Refsnæs (C. H. Ostenfeld), 19m; DK, Bolsaxen, 14 m. — Lb: CC, South side of Hornenæs, on Mytilus, 7,5 m. — Sh: NN, Southwest of Sprogø, 19 m. — Su: bM, South of Hveen. Cruoriopsis Dufour. Dufour, Elenco delle Alghe della Liguria, Genova 1864, p. 35 (non vidi), Schmitz and Hauptfleisch in Engler u. Prantl. I, p. 535. 1. Cruoriopsis danica sp. nov. Crusta sanguinea, diametro c. 2—3 mm, ad 744 crassa. Stratum basale uni- stratosum, substrato arcte adnatum, e filis radiantibus compositum, cellulis 4—9 » plerumque c. 6—9 „ latis, c. 6—7 „ altis, latitudine plerumque c. duplo longioribus, nonnunquam lateraliter confluentibus. Fila erecta 4—7-cellularia, «qualia vel in inferiore parte nonnunquam sursum paulo attenuata, 5—11,y lata, cellulis longitu- dine vario, inferioribus nonnunquam non nisi dimidiam partem latitudinis attingen- tibus, superioribus latitudine sæpe duplo longioribus, chromatophorum singulum continentibus. Pili hyalini terminales nonnunquam sparse occurrunt. Sporangia in filis erectis terminalia, solitaria, rarius bina, ellipsoidea, 23—30 » longa, 14—18 u lata, oblique cruciatim divisa. Organa sexualia ignota. Cellule auxiliariæ (?) bre- vissimæ in parte media vel superiori filorum seriatæ. The cells of the basal layer form regularly radiating filaments of varying breadth. Lateral fusions may be wanting in some cases, while in others they occur in great numbers (figs. 107 I, 108 A). More than two cells may sometimes fuse together. The cells of the basal layer are low, and the same may also be the case with the under- most cells in the erect filaments, while those of the middle and the upper part of the filaments may reach a length of up to 2,5 times the breadth. The erect filaments have almost the same breadth in their whole length, frequently, however, they are a little thicker towards the base, and the uppermost cell may be a little thicker than the second from the top. The filaments are rather firmly connected, but not or only to a slight degree united by a gelatinous collode. In the undermost partofthe frond fusions may sometimes take —— = place between == 7 contiguouscells of different fila- ments, as in the following spe- cies. The sur- face is cove- red with a ra- ther firm out- er wall. Each cell contains a Fig. 107. calotte - shaped Cruoriopsis danica. A—H from M. A—D, vertical sections of frond, in Ba young hair, in C, chromatophore a more developed hair, in D, fully developed erect filaments, a little swollen at the top, E, P unripe sporangium. F, new sporangia formed within emptied sporangial walls. G, H, ripe and a small sporangia. I, K from MK. I, basal layer from the face showing fusions. K, erect filament ending in hair. 390:1. nucleus, little susceptible to staining reagents. The frond is, at all events in some cases, poly- stromatic to the border (fig. 108 F). Here and there some of the erect filaments terminate in hyaline hairs; these occur in varying quantity, usually solitary. They are fairly rich in protoplasm. The subjacent cell is somewhat lengthened, conical (fig. 107). The sporangia arise from the terminal cell of erect filaments. They reach the surface of the frond and are originally, like the vegetative cells, covered with a thick outer wall (fig. 108). The first wall is inclined, the two following perpendicular to it (figs. 107 G, 108 E). After evacuation of the sporangium a new one may some- times be formed from the subjacent cell within the emptied sporangial wall (fig. 107 F). In specimens dredged in the Little Belt in July 1915 I found very short-celled fila- ments which were supposed to be auxiliary-cell filaments, though carpogonia were not found. They arose from erect filaments, which in a smaller or greater extent of their length consisted of low, disc-shaped cells, the undermost and one, or more rarely two or three, of the uppermost cells showing the ordinary length. The short cells were of a feebler colour than the other cells; they resembled the auxiliary- D. K. D. Vidensk. Selsk. Skr., 7. Reekke, naturvidensk. og mathem. Afd. VII. 2. 24 186 cell-rows of several other Cryptonemiales, but they seem to be different from those found in Cruoriopsis cruciata Dufour, which, according to Scumirz (Sitzungsber. d. Fig. 108. Cruoriopsis danica. A—E from Groves Flak. A, basal layer from the face. B, vertical section of frond; at left probably two young sporangia. C, two emptied sporangia on the end of a filament. D, E, ripe sporangia. F—H, from Lille Belt; F, vertical section ofthe margin. G, H.supposed auxiliary-cellfilaments. A—E390:1. F—H 695 :1. niederrhein. Ges. für Na- tur- u. Heilk. zu Bonn. 1879) are lateral and 3- to 5-celled. As may be judged from the above descrip- tion, our species much resembles Cruoriopsis Hauckii BATTERS, ac- cording to the descrip- tion given in the Journ. of Botany 1896 p. 387 (New or critical Brit. mar. Algæ), and I have indeed been much in doubt, whether it might not be identical with it. BATTERS’ species differs however, by the erect filaments consisting to- wards the apices of longer and narrower cells, three or four times as long as broad and only 4 or 5y in diameter, while at the base of the filaments the cells are 10—15 x in diameter. species, had I not, ihrough the kindness of the late Mr. BATTERS, received from him a microscopical preparation with two sections of a plant designed as Cruoriopsis Hauckii Batt. Plymouth 24% (| { \1 nun Vy NY URL [1 Or Fig. 109. Cruoriopsis Hauckii Batt. after preparation sent; from Batters. 4, basal layer from the face. B, vertical filaments. C, sporangium. 390:1.- Nevertheless I should perhaps have referred my plants to the named = få EX | \ (ne) = m oy SNEEN EN JAY ZN JE IN) = (EY N N A Dale Ops Fig. 110. Cruoriella armorica Hauck, after specimen from Naples, from Hauck’s collection. A, basal layer from the face. B, vertical section, showing unripe sporangium within an emptied sporangial wall. C, ripe sporangium. 390:1. 187 January 1896, thus apparently a type specimen, but differing from the author’s description in the dimensions of the erect filaments and the sporangia, the first being thin in their whole length, 3,5—5 » in diameter, not broader at the base, thus much thinner than in our species, and consisting of much more lengthened cells (fig. 109). Further, the crust appeared to have another consistency than the Danish plant, the filaments being connected by a gelatinous substance, while the special membranes of the cells were not distinct. The sporangia were smaller, more lengthened, 18—25 » long, 7—11 broad. Hyaline hairs were not present. I think it therefore best to consider the Danish alga as representing a distinet species. According to BATTERS (I. c.), Cr. Hauckii is identical with Cruoriella armorica Hauck, Meeresalg. p. 31 (non Crouan). An examination, through the kindness of Mrs. WEBER-VAN BOSSE, of a microscopical preparation of this species from Haucx’s collection, labelled Neapel 1878, has shown me that this plant is different from the Danish, and also from BATTERS’ species. The crust is thicker, up to 164 y, the basal layer consisting of much larger cells, the erect filaments are thinner, more loosely united, sometimes dichotomous above, the sporangia regularly cruciate and much larger, 46—56 » long, 26—28 » broad (fig. 110)’. Cr. danica reminds one not a little of Cr. arctica K. Rosenv. (1910, p. 102); it forms, like this, small, thin, blood-red crusts on stones. It differs by lower cells in the basal layer, occasionally fusing with the neighbouring cells, by the presence of hairs, by the oblique division of the sporangia, and by the fact that the spor- angia are always terminal, never lateral. It must be admitted that two sporangia may sometimes be found at the end of an erect filament, one of which must pos- sibly be regarded as lateral, but they are in fact both placed terminally on the filament (fig. 108 C), while in Cr. arctica, true lateral sporangia occur. Finally, the sporangia are somewhat larger. The species grows on stones in 1 to 17 meters depth; it has been found with ripe sporangia in April (Groves Flak) and September (Sondre Ron by Lemvig). Localities. Lf: M, Sendre Ron by Lemvig, c. 1m; MK, Holmtunge Tange, 1—2 m. — Ke: North end of Groves Flak (Børgesen). — Lh: At Lyngsodde off Middelfart, 15—19 m. 2. Cruoriopsis gracilis (Kuckuck) Batters. E. A. L. Barrers, Catal. of the Brit. Mar. Algz (Suppl. to the Journ. of Botany 1902), p. 95. Plagiospora gracilis Kuckuck, Bemerk. z. mar. Algenveg. v. Helgoland II. Wiss. Meeresunters. N. F. II. Bd. Heft 1, 1897, p. 393. Cruoriopsis cruciata Batters, New or critical Brit. Mar. Alg&. Journ. Bot. 1896, p. 388. In July 1915 I found by dredging in the Little Belt near Middelfart a few crusts on stones, agreeing perfectly with the plant described by Kuckuck under the name of Plagiospora gracilis. A few additional remarks may be given here lo Kuckuck’s rather short description. 7 Another specimen in Haucx’s herbarium, labelled Cruoriel la armorica, from Royigno was sterile, and evidently belonged to another species, possibly a species of Cruoria. 24* 188 The crusts are thin, bright purple, up to 1,5 cm in diameter. The basal layer consists of isodiametrical cells. The erect filaments are 4,5—5,5 » thick. Not un- frequently transversal fusions between contiguous cells in different erect filaments occur (fig. 111 B). The sporangia are normally lateral on the erect filaments and sessile. In some cases however I found them pedicellate, on a one-celled stipe, as shown in fig. 111 C, D. The sporangia are first divided by an oblique trans- versal wall (fig. 111 A) and later by two walls perpendicular to the first; at maturity they are 21—22 y long, 11—14 » broad. Kuckuck has established the genus Plagiospora on the oblique division of Fig. 111. the tetrasporangia. As such divisions Cruoriopsis gracilis. A, erect filament with two-celled spor- OCCUr not only in Hildenbrandia, as men- a 40:1, fusion hatten cal of Ivo Sen “tioned by Kuckuck, but also inl Grund stipe. B--D, 730:1. opsis (and further in Petrocelis), and as in the genus Cruoriopsis both terminal and lateral sporangia occur, even in the same species (Cr. hyperborea), it is justified to refer the species here mentioned to the genus Cruoriopsis. Locality. Lb: At Lyngsodde, right opposite to Middelfart, about 15 meters, with sporangia in July. Cruoriella Crouan. 1. Cruoriella codana sp. n. Thallus tota superficie inferiori paulum calcaria substrato adherens, rhizinis unicellularibus affixus, diametro 2—5 (?) cm latus, purpureus. Stratum basilare (hypothallium) e lobis lateraliter conjunctis e filis flabellatim ramosis compositis for- matum, cellulis 14—33 » longis, 9—14 4 latis, 9—11 „ altis. Thallus adultus e pluribus frondibus superpositis compositus. Fila verticalia frondium singularum plerumque e cellulis 3—10 formata. — Paranemata nematheciorum sexualium sur- sum attenuata, e 4—5 cellulis composita, basi 7—8 y, superne 2—3(— 4) 4 lata. Anthe- ridia, in nematheciis specialibus aut in iisdem ac carpogonia, divisionibus trans- versalibus et longitudinalibus filorum orta, diametro 2 4. — Carpogonia in ramulis specialibus 4—5-cellularibus terminalia, membrana obliqua curvata a cellula pen- ultima limitata. Cellule auxiliariz in filis aliis intercalariæ. Cystocarpia e filis erectis paucis parce ramosis composita. Carpospore 11—12, diametro. The specimens on the base of which this species has been described were for a long time referred by me to Cruoriella armorica Crouan!, a species which has 1 Ann. d. scienc. nat. de ser. t. 12, 1859, p. 289. 189 often been confounded with other species. It was only by becoming acquainted with the recently published description of Peyssonnelia (Cruoriella) Nordstedtii Weber- van Bosse! and by the final revision of my material that I arrived at the conclu- sion that it was not idenlical with the former, but more resembled Ihe last named species. As it proved to be different also from this and did not appear to agree with any other well known species, I describe it here as a new species. Cruoriella codana has only been met with once on a calcareous stone much bored by worms. It forms thin crusts of a bright purple colour, brighter than in Cr. Dubyi, and is adherent to the substratum in its whole extent, being fixed to it by unicellular rhizoids. The greatest crust is more than 5 cm in diameter, but it has probably arisen by coalescence of several distinct crusts; the other were at most 1 cm broad. When seen from the underside, the young basal layer appears composed of distinct lobes, which coalesce laterally. The lobes have a flabellate structure. Even when having a continuous outline, the margin is composed of very distinct lobes (fig, 112 A), and the same structure is found in the older parts of the hypothallium, where there are no principal rows of larger cells, as found in P. Boergesenii and P. Nordstedtii by Mrs. WEBER-VAN Bosse (1. c. p. 138 and 140). The cells of the basal layer are 14—33 long, 9—14y broad and 9—11y high. Uni- cellular rhizoids, bounded by a cell wall, are given off from its under face. The marginal cells of the frond divide by vertical cell-walls, and the segments divide immediately by a horizontal wall, the hypothallic cell becoming thus lower than the marginal cell (fig. 114). The monostromatic basal layer or hypothallium is only little distinct from the “perithallium” consisting of the vertical filaments given off from it. These filaments are vertical in their whole extent or slightly ascending; they are only rarely branched. The cells are of almost equal breadth in the same filament, 9—12 y, or the undermost may be a little broader. Their height is as a tule a little less than the breadth, near the surface sometimes much less, more rarely the same or a little greater. The number of cells in the erect filaments usually varies from 3 to 10. Old crusts are composed of two or more fronds growing one over the other. At first observation these superposed fronds might be supposed to come into exi- stence in the same way as recently described by Mrs. WEBER-VAN Bosse in Peys- sonnelia (Cruoriella) Nordstedtii (1. c. p. 141, fig. 146), by the formation of a horizontal split in the frond and following constitution of the part situated over the split as a new crust with a new-formed hypothallium. I have seen several cases which were favorable to this interpretation, in particular some apparently young cases and such where the under face of the upper crust was very irregular, and I might suppose that the new upper frond may really arise in this manner. But in other cases it is without doubt that the upper frond arises from horizontal outgrowths from certain parts of the crust which have preserved their growing power, while the covered ! Rhizophyllidacez in F. BORGESEN, Rhodophyceæ of the Danish West Indies, Dansk Botan. Arkiv, Bd. 3. Nr. 1, 1916, p. 140. 190 parts have lost it by formation of nemathecia or from other causes. The meeting point between the overlapping frond with another similar one or with the forth- growing old frond is usually easily found (fig. 112 B *). The places from which the new fronds are given off are frequently inverted conical, being upwardly en- larged and composed of filaments slightly diverging upwards. The number of these Fig. 112. Cruoriella codana. A, marginal part of frond seen from below. 195:1. the overlapping of the frond by a new lobe; at « the point of concretion of this lobe with another part of the frond; in C the basal layer of the new lobe is not normally developed. In C auxiliary-cell filaments and sporogenous fila- ments are visible 205:1. D, vertical section of frond with antheridial nemathecium. 350:1. B and C, vertical sections of frond showing points of departure is variable; sometimes they are very close, in other places they are more distant. The new-formed fronds coalesce laterally and form together a uniform plain surface. The cells of the basal layer of the overlapping fronds were frequently found connected with pits, a fact which supports the here proposed ex- planation of their development. As the new fronds were evidently not produced at the season when the specimens were collected, I have not been able to follow their development, but must content myself with examining the advanced stages. A further fact confirming my view is that nemathecia are frequently found on the surface of the covered crust (fig. 112 C). The under face of the frond is often irregular; in some places the frond projects downward sand, consists there of larger cells, which may here be up to 17, high. The cells of the frond contain, as far as could be judged from the examination of dried specimens, a vaulted chromatophore in the upper part of the cell. Nu- merous starch grains often fill the cells, particularly in the under part of the frond. The under face of the frond is covered with S ] \ chalk, but the frond itself does 0 VI G N not appear to be In 0) incrusted. @ O B The sexual Al À \ @ 2 J ©) Cc D organs are al- ways situated in to) nemathecia on the upper side of the frond. The nemathecial fil- aments consist of4oröcells,the \ undermost of N which have the . || \ same breadth as I the upper cells @ i of the crust, or @ about 7—8 Us S while the thick- | Fig. 113. | RE oe ee D Onde ren ments tapers to- of fecundation. E—H, auxiliary-cell filaments; a, auxiliary cell; s, sporogenous filament. I, not fully developed cystocarp; a, auxiliary cell or fusion cell. A—D 630:1. E—I 400:1. wards the midd- le and in the upper part it is only 2—3(—4) », without considering the gelatinous outer wall (fig. 112 C). The upper cells are 3 or 4 times as long as broad or even longer. The antheridia arise from the nemathecial filaments by division of all the cells or with the exception of the undermost one or two cells. The cells are divided by transversal walls or at the same time by longitudinal walls in small antheridial cells (spermatangia), which are about 24 in diameter; in a longitudinal section each filament appears as composed of one or two longitudinal series of cells (fig. 112 D). The antheridia occur in particular male nemathecia or in the same nema- thecia as the carpogonia. The carpogonia are terminal on 4- or 5-celled branches given off from the lower part of the nemathecial filaments. They are cut off by an oblique curved 192 wall going from the middle of the longitudinal to the border of the basal wall of the mother-cell. Two young stages are shown in fig. 113 A,B. The carpogonium shown in fig, 113 C is a little more developed, though yet unfertilized; the tricho- gyne is short and thick, the carpogonium encloses completely the right side of the hypogynous cell. The carpogonium represented in fig. 113 D has the appearance of being fertilized, the continuity of the trichogyne with the ventral part being interrupted, but the carpogonium has not reached the surface of the frond, and no spermatia adhere to it, nor have any sporogenous filaments been formed. Later stages of the carpogonia I have not observed. ( The auxiliary cells are more numerous than the carpogonia; l they occur in particular branches given off at the base of ordinary ) nemathecial filaments and are shorter than these (fig. 113 E—H). The @) cells of these filaments have a dense protoplasm and are somewhat swollen, particularly the two uppermost cells, while the third cell © from the top (more rarely the fourth) is not swollen. This latter cell is the auxiliary cell, which may be concluded from the fact that it is sometimes found in connection with thin sporogenous Fig. 114. Cruoriella codana. filaments running in a horizontal direction between the nemathecial filaments. Over the auxiliary-cell filament a space containing a hyaline substance and provided with a membrane open above is 4A. vertical section of margin of frond. B, vertical section of sporangial nema- thecium. 350:1. visible; it resembles an abortive hair (fig. 113). The development of the cystocarps has not been followed, but a cystocarp, not quite ripe it is true, but apparently not far from ripeness, is shown in fig. 113 I. It consists of a few upward directed, slightly branched filaments, the cells of which each produce a carpospore. In the most developed cystocarp I have seen the carposporal cells were 11—12 „ in diameter. The sporangial nemathecia, of which I have only observed one, much resemble those of P. Nordstedtii (Mrs. Weber-van Bosse I. c. p. 142). The nemathecium had a height of 88 », the paraphyses were less tapering than those of the sexual nema- thecia, the upper cells being 4y broad; the undermost cells were usually 2—3 times as long as broad. The tetrasporangia, fixed at the base of the nemathecium, are certainly cruciately divided, but the ripe sporangia were disturbed by the preparation. Some were divided by a transverse or slightly oblique wall, but the direction of the following walls could not be stated (fig. 114). The almost ripe sporangia are about 50: long, 18 » broad. As mentioned above, I at first referred the specimens here described to Cruori- ella armorica Crouan, and I maintained this determination also after having examined, through the kindness of Prof. NORDSTEDT, a type specimen of this species from CROUAN in J. AGARDH’s herbarium at Lund (Nr. 27630), having in one specimen found a still sterile nemathecium with thin upwardly tapering nemathecial filaments as in the sexual nemathecia of the Danish species. The sporangial nemathecia, which at that 193 time were unknown to me in Cr. codana, present, however, such differences that it is impossible to identify our species with that of Crovan, the nemathecial filaments of the latter being forked, fastigiate, and the sporangia being terminal on undivided erect filaments and reaching the surface of the nemathecium, in which respect I found the specimens of Crouan corresponding to his description and figures. Our species is apparently related to Cr. Nordstedtii, which shows resemblances in the structure of the frond and of the sporangial nemathecia, but there seems to be a difference in the superposed fronds arising only by splitting of the frond in Cr. Nordstedtii, while in C. codana they seem to arise principally as excrescences from the surface of the frond. The first-named differs further, according to Mrs. WEBER-VAN Bosse, by the want of principal rows of cells thicker than the others in the basal layer and by the presence of pluricellular rhizoids besides the uni- cellular ones. The sexual nemathecia are unknown in C. Nordstedtii. It is highly probable that this species has been met with earlier, but con- founded with Cr. armorica; this, however, cannot be stated without examination of the corresponding specimens. Localtty. Kn: TR, near Trindelen, 23,5 meters, September. 2. Cruoriella Dubyi (Crouan) Schmitz. Fr. Schmitz, Syst. Übersicht, Flora 1889, p. 20; id. in Kolderup Rosenvinge, Gronl. Havalger, 1893 p. 783; Fr. Schmitz und P. Hauptfleisch in Engler u. Prantl, 1897, p. 536. Peyssonnelia Dubyi Crouan, Ann. sc. nat. IIIe ser. t. 2. 1844, p. 367, pl. 11; id., Alg. mar. du Finistère (Exsicc.) 2e vol. no. 236, Brest 1852; id. Florule du Finistère, 1867, p. 148, pl. 19; Harvey, Phycol. brit. I, 1846, plate 71; J. AcarpH, Sp. II, 1852, p. 501; III, 1876, p. 384; Hauck, Meeresalg., p. 35; Barrers, Mar. Alg. Berw., 1889, p. 90; Kuckuck, Bemerkungen, II, 1897, p. 393, fig. 18 (antheridia). The purple-coloured crusts are 1 to 3 (4) cm in diameter. In a dried state they show characteristic radial folds. The outline of the frond is undulate; the course of the cell-filaments in the marginal part is not regularly radiating, owing to its composition of coalescing lobes, the growth being usually arrested in one of the meeting lobes (fig. 115 C). From the underside of the frond, which is covered with a layer of chalk, a varying number of rhizoids are given off; when fully de- veloped they are separated by a wall from the producing cell (fig. 115 À). The thickness of the frond is variable. As shown in a vertical section, it is divided immediately behind or at a small distance from the border by horizontal walls (fig. 115 A). The cells of the undermost layer, which produces the rhizoids, are usually somewhat lengthened in the radial direction. Two erect cell-rows are frequently given off from one cell in the basal layer or the subbasal layer (fig. 115 B); the cells are therefore greater in the under part of the frond than in the upper. Each cell contains a nucleus and apparently a vaulted chromatophore in the upper part of the cell. To judge from the figure given by Kuckuck (I. c. p. 394, Fig. 18 B) the chromatophore is either divided into ribbonlike branches or there are several bandlike chromatophores; they are not mentioned in the text. The cells, particu- D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 2, 25 larly those of the undermost part of the frond, often contain a great quantity of starch grains taking a brownish colour on treatment with iodine. Old crusts are often composed of several crusts growing one over the other. This is principally caused, as in the foregoing species, by the cessation of growth of great parts of the fronds, particularly those which have produced nemathecia, while in other parts the erect filaments continue growing in the next season, giving rise to a new frond growing in a horizontal direction over the old frond, and this may be repeated several times, so that old fronds may be composed of 6 or more CE CD) ben Fig. 115. Cruoriella Dubyi. A, marginal part of frond in vertical section. B, inner part of frond in vertical section. C, marginal part of frond seen from above. A and B, 295:1; C, 215:1. distinct crusts. The under side of fronds or lobes thus produced is usually rather irregular (fig. 115 A). Overlapping, though in a smaller degree, may also take place in the border of the frond, where the lobes sometimes grow over one another, and the same may occur on the meeting of two of the fronds produced in the manner first described. A formation of superposed fronds by horizontal splitting, as described for Cr. Nordstedtii by Mrs. WEBER-van BossE may also occur (see above p. 189). The sexual nemathecia are cushion-shaped, of various extent. The antheridia occur in particular nemathecia or interspersed in the female ones. As shown by Kuckuck (I. c. fig. 18) the spermatangia arise by transverse and longitudinal divisions of the cells of the nemathecial filaments (fig. 116 A). The nemathecial filaments of the female nemathecia are of equal thickness in their whole length, and consist at the stage of fertilization of about 5 cells, 195 which are a little longer than broad; up to twice as long. When the cystocarps are ripe, the cushion is thicker, the filaments somewhat longer, the constituting cells more numerous and somelimes longer. The carpogonia are terminal on parti- cular (3—)4—5-celled branches given off from one of the undermost cells in a nemathecial filament or from one of the bottom cells of the nemathecium (fig. 116). As in the foregoing species, the carpogonium encloses one side of the subterminal Fig, 116. Cruoriella Dubyi. A, antheridia, upper part of male nemathecial filament, B—E, vertical sections of nemathecia with carpogonia (c), trichogynes (f), sporogenous filaments (s) and auxiliary-cell filaments (af). A, E 630:1; B-D 3%:1. cell, giving off a production reaching beyond the under face of this cell. In some cases no such lateral production was found, but these carpogonia were doubtless abnormally developed, abortive (fig. 116 C*). The auxiliary-cell branches which are given off from the lowest part of the nemathecial filaments consist of about four low seemingly equal cells. In fig. 116 E two fertilized carpogonia are shown, from which sporogenous filaments growing in a horizontal direction are given off. A similar filament in connection with an auxiliary-cell filament is shown in fig. 116 D. The development of the cystocarp has not been followed. At maturity the cysto- carpial nemathecium contains numerous rows of carpospores, each row consisting of up to five almost globular carpospores, each surrounded by a thick hyaline wall. 252 196 The carpospores are 19—29 » in diameter, with the envelope 35—40 y; a nucleus is seen in the centre. How many such rows belong to each cystocarp I cannot say; according to BATTERS (I. c. p. 91) each cystocarp consists of one, two or three rows: Sporangia were only met with in two specimens afler evacuation. According to CRoUAN, Harvey and others they are regularly cruciate !. The species has been met with in several places from Skagerak to the Samsø waters and the Sound, usually in considerable depths viz. from 13 to 25 meters, in Skagerak however also in 2 m and in the Limfjord in 6 meters depth. It grows on stones (granite and flint) and old shells of bivalves (Cyprina, Mytilus modiola a. 0.) and gastropods, and Serpula, frequently in com- pany with Cruoria pellita. It is perennial, but has only been collected in the months of April to Sep- tember. Most of the spe- cimens were sterile, but two specimens with emp- tied sporangia were found Fig. 117. in the eastern Kattegat in Cruoriella Dubyi. Vertical section of nemathecium with ripe cystocarps. 200: 1. April and May, and some collected in the Samso waters in August had antheridia and carpogonia, partly ferti- lized, and long sporogenous filaments. Specimens with ripe cystocarpia were col- lected in August off Lonstrup in Skagerak. According to Barrers it is fructifying in January to June at England’s east coast. Localities. Sk: At Roshage, Hanstholm, near land, 2m; ZK° and ZK® off Lønstrup, 7—13 m. — Lf: Nissum Bredning, off Helligso, 5,5 m. — Kn: Herthas Flak; Bôchers Banke, 29 m; TO, Tenne- berg Banke; ZB, east of Trindelen, about 30 m; TR, FF and TQ near Trindelen; VU, east of Nordre Ronner, 15 m; N.E. of Hirsholmene, 9,5 m (Henn. Petersen). — Ke: IL, IP, IQ, ZE’ Fladen, 21—25 m; ZJ, IR, IS, VZ, Groves Flak, 22,5—26,5 m; Groves Flak (Borgesen); IK, IH, Lille Middelgrund; Store Middelgrund, IA, 16,5 m (!) and 30 m (Borgesen). — Sa: KI, south of Hjelm, 13 m; BF, off Sletterhage, 14m. — Su: bM, South of Hveen, 22,5 m. 1 The above was written long before I received V. Scuirrner’s Studien über Algen des adriatischen Meeres (Wiss. Meeresuntersuch. N. F. 11. Bd. Abt. Helgoland, Heft 2, 1916). The author describes here (I. c. p.148) a species named Cruoriella Dubyi, which he supposes is identical with the Atlantic species of the same name. This supposition, however, seems to be doubtful, the Adriatic plants apparently differing, in the structure of the frond and of the nemathecia as well. Thus, the frond is said to be rarely more than 6 cells thick; nothing is said as to the complex structure of older fronds described above; and the rhizoids seem to be much more numerous. Further, the paraphyses are said to be attenuated upwards. The author says, p. 148, that the species has been wrongly referred by DE Toni to Cruoriella, but p. 501 he approves that Scumirz has made the same determination. en Rhododermis Crouan. Crouan in J. Agardh, Sp. Vol. II, pars 2, 1852, p. 504, 1. Rhododermis elegans Crouan. Crouan in J. Agardh, Sp. Vol. II, pars 2, p. 505. Crouan, Florule de Finistère, 1867, p. 148, pl. 19, fig. 130, Batters, Mar. Alg. Berw., 1889, p. 91, pl. XI fig. 1 (forma polystromatica Batters). Kolderup Rosenvinge, Deux. mem., 1898, p. 18, id., Mar. Alg. N. E. Greenl. 1910, p. 104. This small arctic and north-atlantie species has been collected in several places in the Danish waters. It forms small, thin crusts of a lilac-rose colour with an irregular outline, the diameter of which scarcely exceeds 5 mm. It resembles in many respects Rh. parasitica of which Kuckuck has given an exhaustive description and splendid figures (Beitr. z. Kenntn. d. Meeresalg. 1. Wissensch. Meeresunters. N. F. II, Heft 1. 1897). According to Barrers, one of the principal differences is that the cells of the frond in Rh. elegans are broader than long, while in Rh. parasitica they are longer than broad. This difference is in reality general though not abso- lute, as may be judged from the figures of Kuckuck and from the fact that cells may be found in Rh. elegans, Which are at least as high as broad. Rh. parasitica differs further by its greater diameter, greater thickness and darker colour. A difference exists also in the structure of the border of the frond, this consisting in Rh. para- sitica of distinct filaments (Kuckuck, l. c. p. 7, Taf. VIII fig. 10) while it is continuous in Rh. elegans (fig. 118 A). The basal layer consists of radiating cell-rows, the cells of which are more or less lengthened in a radial direction. In the marginal part of the frond the cell- rows are frequently flabellately radiating towards the irregularly lobed border, here and there showing lateral ramifications (fig. 118 A). The cells are usually 5,5—7 » broad, 11/2 to 3 times as long as broad. In the basal layer lateral fusions between cells belonging to different cell-rows frequently occur, the cells corresponding through a broad open canal. Such fusions may occur at the very margin of the frond. More than two cells may sometimes fuse together (fig. 118 A, B). The crust is at first monostromatic, and a rather broad monostromatic mar- ginal part may often be found. The inner part of the frond was always found to be from 2 to at least 5 cells thick. I have never found it distromatic in a greater extent, and I must therefore suppose that it is only accidentally that Crovan has altributed a distromatic frond to this species, and that there is no reason to main- tain the var. polystromatica Batters. The cells contain several chromatophores as in R. parasitica. In the upper part of the crust the cells are 8—11y broad. In several specimens I found, projecting from the surface, scattered hyaline hairs (fig. 118 C). Their number varied; they were placed between the paraphyses or in the sterile parts of the crust. The sori form irregular spots on the surface of the frond; they consist of feebly curved paraphyses, usually 4- or 5-celled, 40—50 » long, at the base 5—9 4 broad, and between them the sporangia, which are terminal on the vertical filaments of the crust, the upper cell of which has often the character of an upward slightly 198 broader stalk-cell. In some specimens from the Little Belt (Middelfart) the paraphyses were but few in number, in some cases almost wanting; the plant had then a cer- tain resemblance with Rhododiscus pulcherrimus. The sporangia are first divided by a transverse wall; the vertical walls occur at a later moment, for which reason sori containing only bipartite and undivided sporangia are not infrequently met with (comp. Kuckuck 1. c. p. 7 and Barrers |. c. pl. XI fig. 1a). The ripe sporangia are usually 24—33 y long, 16—20(24) » broad. |) WG 5 C Nb N OOA] 5000 250 Os 000 ? Fig. 118. Rhododermis elegans. A, marginal part of frond seen from above. B, basal layer of fructifying frond seen from below. C, vertical section of fertile part of frond with paraphyses, a bipartite sporangium and a hyaline hair. D, vertical section of frond with sorus; sporangia bipartite. E, almost globular ripe sporangium from Hornenæs. F, ripe sporangium. G, regeneration of sporangium. 385:1. The greatest sporangium was found in a specimen from Refsnes; it measured 33 a in length and 24 » in breadth. In the southernmost place in the Danish waters (at Hornenæs in the Little Belt) I found almost globular sporangia, 20—21 y long, 184 broad (fig. 118 E). After evacuation a new sporangium may be produced from the stalk-cell within the empty sporangium wall (fig. 118 G). Sexual organs were not met with. Antheridia are only known in specimens from North-East Greenland (K. Rosenvinge 1910). As to the time of fructification only incomplete information can be given. In winter (October to February) the species has not been met with, but it must be supposed from observations from the coasts of England and of Greenland, that it will be found fructifying in winter with us, and this supposition is in accordance 199 with the fact that it has been found with ripe sporangia in March (Lille Belt) and with empty sporangia in April (Limfjord, Samso waters). On the other hand it has also been found with ripe sporangia in June, July and September, and it seems thus that it may produce ripe sporangia at all seasons. The species occurs on stones (flint, limestone, granite), shells and carapaces of animals (Mytilus, Serpula, Hyas) and Algæ (Polysiphonia elongata, Chondrus crispus, hapters of Laminaria digitata), in 5,5—19 meters depth. Localities. Sk: YN?°, S.E. of Bragerne, 10,5 m. — Lf: XX in Nissum Bredning, 5,5 m. — Kn: TG, north of Læsø, 9,5 m. — Ke: VY, Fladen, 18 m. — Ks: OP, Lysegrund, 6 m. — Sa: Northside of Refsnæs, 19m. — Lb: NV and XQ, near Middelfart, 15—19 m; CC, south side of Hornenæs, 7,5 m. 2. Rhododermis Georgii (Batters) Collins. F. S. Collins in Phycotheca Bor. Amer. No 1299; id., Notes on Algae, III, Rhodora, August 1906, p. 160. Rhodophysema Georgii Batters, New or critical Brit. mar. Algæ. Journ. of Botany, Vol. 38, 1900, p. 377. Kylin, Algenfl. schwed. Westk., 1907, p. 194—196, fig. 41. Rhododermis Van Heurckii Heydrich, Über Rhododermis Crouan, Beihefte z. Botan. Centralblatt, Bd. 14, 1903, p. 243, Taf. 17. Strange to say this characteristic little species was first described in 1900, though it has later proved to be widely distributed. It has also been recorded in’ several places in the Danish waters, always growing, as elsewhere, on Zostera-leaves, but it has further been found growing on uncovered roots of Zostera. The plant begins as a thin monostromatic crust much resembling that of Rho- dodermis elegans, and with the same marginal growth. The marginal part is usually continuous with an irregularly undulating outline, and consisting of radiating fila- ments which are 4—6y broad; more rarely the ends of the filaments are free, not laterally connate. Lateral fusions between cells of these cell-rows not unfrequently occur (fig. 119 A). The crust is early divided by horizontal divisions, which advance from the centre towards the periphery, with the result that the crust usually becomes polystromatic to the margin. The radial growth has meanwhile ceased, so that the diameter of the crust rarely exceeds 300 y. As shown by Heypricu, CorLıns and Kyrın, the species occurs in two forms, a disc-shaped and a globose or pear-shaped or irregularly lobed. In the disc-shaped form, the frond is usually 4 to 5, at most 7 cells thick, when fully developed and fructiferous. The cells of the erect cell-rows are 4—6y thick. As shown by HEypricH and Kyrın, some of the superficial cells may produce long, vigorous hyaline hairs of the usual type in the Florideæ; they are 5—7 a thick near the base, and contain a nucleus near the top. The cells of the frond contain a nucleus and several chromatophores. In the disc-shaped specimens the sorus often originates shortly after the for- mation of the first horizontal walls. The upper cell produced by these divisions in the central part of the frond develops then in a paraphyse or in a sporangium with its stalk cell, and there is only one layer of vegetative cells under the sorus. When the surrounding cells now continue growing in a vertical direction and dividing 200 by horizontal walls, the sorus will finally be placed in a groove in the frond (fig. 119 C, comp. Heypricu |. c. Fig. 3). When rising later it takes a more superficial position. The other specimens arise from disc-shaped ones by very strong enlargment of the under cells of the frond with the exception of the peripheral ones. The figures of Batrers and HEYDRICH show a great number of large hyaline cells in the interior of the frond, suggesting that the erect cell-rows from which they arose consisted of about 10 cells. Such figures represent, according to my observations, eccentric sections in which a greater number of the outward bent cell- rows have been intersected. Accor- ding to Kyrın, the cells of the basal layer remain for a long time un- changed, and differ from the cells of the inner tissue through their small sizeand rich contents. ”Schliess- lich tritt indessen auch eine Ver- grösserung in den Zellen der Basal- scheibe ein, indem sie sich zwischen die vergrösserten Basalzellen der verticalen Zellfäden einkeilen.‘“ This latter assertion is not in accordance with my observations. In specimens attaining only a smaller height, being i Fig. 119. only cushion-shaped, the cells of the ana Geo basal layer seen trom below, bovin basal layer remain often unchanged, vertical section, showing a young hair. C, vertical section of but in typical specimens of the in- disc-shaped frond showing a sorus sunk in a groove. 350:1. flated form they are enlarged at an early period, and there seems to be ordinarily no question of protruding of these cells between those of the second layer. But the cells increasing not only in length but also in breadth, there is no room for all the cells of the basal layer when enlarging their volume, and a number of them must therefore remain unchanged in size. Connected with the growth of the inner cells is the enlargment of the surface of the frond which makes its appearance in the lateral branching of the cell-rows in the periphery of the frond (fig. 120 C). — In the large vesicular cells a number of small chromatophores are easily visible; in some cases these cells were poor in cell-contents, in others they contained small starch grains. The simultaneous occurrence of the two forms of the species on the same leaf of Zostera is very curious. As a rule, the specimens growing on the faces of the leaves are disc-shaped or low cushion-shaped, while those placed on the margins are inflated. Cushion-shaped specimens may, however, be found on the margins and inflated on the faces, thus the two forms of specimens may occur side by side MAN ST apparently under equal external conditions; this may perhaps be caused by a different … | 201 moment of development. The possibility that there might be two distinct forms is quite precluded by the fact that transitional forms are everywhere met with, and by their accordance in all other respects. Specimens are sometimes found which are partly cushion-shaped, partly inflated and bearing sori in both parts of the frond. It cannot be doubted that the inflated specimens arise under certain con- ditions which are usually only realised on the margins of the Zostera-leaves. It = 0} IT Fig. 120. Rhododermis Georgi, vertical sections of the inflated form. A, sterile plant. B, plant with sorus with unripe spor- angia. C, part of sorus with ripe and emptied sporangia, the latter becmoing filled with new sporangia from the stalk-cells. A, B 200:1; C 350:1. might be supposed that the causa efficiens must be sought in the movements of the water which are much greater at the margins than on the faces of the undu- lating leaves. It must be left to experimental studies to decide this and to deter- mine whether it is the friction against the water, or the better conditions for nutrition caused by the stronger movements which induce the increased growth of the inner cells of the frond. The sorus occupies the central part of the frond. Usually there is only one, but sometimes two (or more?) are met with, which perhaps fuse together. As men- tioned above, the sorus may sometimes be sunk in a groove. The paraphyses are D.K.D. Vidensk. Selsk. Skr, 7. Række., naturvidensk. og mathem. Afd. VII, 2. 26 202 curved towards the centre of the sorus; they are 3—5-celled, 6 broad at the base, upwards a little thinner. The sporangia are born of a stalk cell as in the other species; they are 26—32 » long, 21—24 » broad. After the evacuation, a new spor- angial cell is cut off from the stalk cell within the empty sporangial wall. I agree with Hrypricn and CoLLiNs in retaining the species in the genus Rhododermis. When occurring in its disc-shaped form it resembles R. elegans so much that it differs only in the dimensions of the cells of the frond, and there but slightly. The species grows on the leaves of Zostera produced in the foregoing year, but also in shed leaves. It has been met with in the months of April to August, in all these months in disc-shaped and inflated specimens and with sori. In April the sporangia were yet undivided; in May and June unripe and ripe sporangia were met with, in July and August ripe sporangia were found, but also emptied and regenerated ones. The species has also elsewhere been found with sporangia in spring and summer. Localities. Lf: Repeatedly at Nykøbing (!, C. H. Ostenfeld). — Kn: In several places at Hirs- holmene (!, Ostenfeld, Henn. Petersen); Frederikshavn, Busserev, and between Borrebjergs Rev and Marens Rev; ZL, S.E. of Nordre Ronner, 6,5 m and 11m. — Sa: Off Risskov at Aarhus. Fam. 8. Hildenbrandiaceæ. The family of the Hildenbrandiaceæ, established long since (Comp. RABEN- HORST, Fl. eur. Alg. III, 1868, p. 408) and still maintained by Scumirz in 1882 (Hauck, Meeresalgen, p. 37), was later abandoned by this author as the presumed cystocarpia of the genus Hildenbrandia had proved to be conceptacles of tetrasporangia, and he therefore ranged this genus under genera incertæ sedis in 1889 (Flora, p. 22). In 1897 SCHMITZ and HAUPTFLEISCH range it as a dubious Corallinacea. On the other hand DE Toni places it under the Squamariaceæ in a subfam. Hildenbrandtieæ (Sylloge Alg. Vol. IV, sect. IV 1905, p. 1713). I think it better to consider the genus as a repre- sentative of a particular family intermediary between the Squamariaceæ and the Corallinaceæ. Although the sexual reproduction is unknown, the family is sufficiently characterized by the want of incrustation with lime of the frond, by the presence of immersed conceptacles of sporangia, and by the oblique divisions of the spor- angia. The conceptacles resemble those of the Corallinaceæ but develop in another way, as will be mentioned below. Oblique divisions of the sporangia do not occur in the Corallinacew, but are characteristic of several Squamariacee. Hildenbrandia Nardo. 1. Hildenbrandia prototypus Nardo. Nardo, De novo genere Algarum cui nomen est Hildbrandtia prototypus. Oken’s Isis 1843, p. 675; Hauck, Meeresalg. p. 38. Zonaria deusta Lyngbye, Hydr., 1819, p. 19 ex parte; cfr. notula. 203 Erythroclathrus pellitus Liebman in Flora Danica, tab. 2317, fig. 2, 1840 (sterile). Hildenbrandtia rosea Kützing, Phycol. generalis, 1843, p. 384; J. Agardh, Spec., II, pars 2, 1852, p. 495. Hildenbrandtia sanguinea Kützing, Phycol. generalis, 1843, p. 384, tab. 78, V. 3 Hildenbrandia Nardi Zanardini, Synops. Alg. in mar. Adriat., p. 238; J. Agardh, Spec. II, p. 494. When young, the crusts are nearly orbicular, or with a more or less lobed margin. Å number of such young crusts frequently fuse together into a large crust, leaving no traces of the limits between the particular crusts. On the other hand, older crusts may, when meeting, be separated by a very distinct limiting line. The margin is composed of radiating filaments, the ultimate cells of which are long and almost colourless, frequently swollen at the end. Not only the outer- most cell, but also the second cell from the border may be several times as long as broad, longer than the next inward following cells of the basal layer, from which it must be concluded that intercalary divisions may occur. Now and then the number of the cell-rows RR SE DOG) is increased by ramification. The fig. 121 A û 8 N suggests that the cell-rows may branch by Song dichotomy; but a closer examination showed B that their ramification is really lateral (fig. Fig. 121. Len ee g . o y Hildenbrandia prototypus, borders af young fronds, 121 B. The crust represented in this figure seen from the under face. A 350:1. B, showing showed numerous lateral branches, some of thelateralramification and some branches growing which penetrated between and under the pri- RE NTI EN LORD: mary filaments, in the latter case causing irregularities in the structure of the basal layer. In other cases this layer showed a very regular structure; it is densely appressed to the substratum, without rhizoids. Horizontal divisions occur at a small distance from the margin. The adult frond is composed of regular vertical rows of nearly cubical cells, which are 4 to 6,5 broad. The cell-walls are firm, not swelling at the death of the cells. There is a single calotte-shaped chromatophore situated in the upper part of the cell (fig. 123 C). The tetrasporangia occur in immersed conceptacles, which often occupy the whole crust except the marginal part and are uniformly spread over it, but may also be arranged in groups. In a fully developed state, the nemathecia are nearly globular or a little depressed, about 100 in diameter. The sporangia are situated on the bottom and the sides, and even on the under side of the peripheral part of the roof, the thickness of which diminishes towards the aperture. The conceptacle is not prominent; on the contrary, the surface is often a little sunk towards the aperture. The conceptacles arise from a small group of superficial cells which produce tetrasporangia, while the contiguous cells remain vegetative and continue dividing by horizontal walls, with the result that the sporangia are placed in a low cavity. 26* In specimens collected in June I - found such cavities about 6 cells in diameter and not so deep but that the sporangia reached the border of the aperture (fig. 123 A). The spor- angia in these young conceptacles are of different age. Besides fully devel- oped or two-parted sporangia young ones are found, but also aborted . sporangia occur, having sometimes the character of paraphyses (fig. Fig. 122. Hildenbrandia prototypus, vertical section of old crust showing i two conceptacles and limiting lines between the productions of 123 A, B), The production of Spor- three years: 1, angia continues a very long time, usually apparently a year (or more ?), while the crust grows gradually in thickness. When the sporangia have been emptied, new ones are produced on the same place from the cells forming the bottom of the cavity, within the emptied sporangial walls or between them, and at the same time the formation of sporangia extends at the sides and upwards on the lateral walls of the cavity, the cells of the vertical cell-rows limiting the cavity at the sides producing sporangia directed obliquely or horizontally towards the centre of the cavity, which gradually takes a nearly orbicular outline. The spor- angia-producing cells divide into a small stalk-cell and a greater outer cell, the sporangium. The stalk-cells of the lateral sporangia seem usually to decay, and the re- placing sporangia must therefore be produced by the cells of cell-rows situated within the stalk-cells. In such a manner the conceptacle increases in transversal out- line, new vertical cell-rows being gradually engaged in the production of sporangia. The parts of the cell-rows which are active in this manner are consumed by this production, and the continuity between the upper part forming the roof of the conceptacle and the under part is thus abolished. The upper part of these cell-rows therefore finally decays, at least in those situated nearest the aperture, where the regular arrangement of the cells is disturbed; the cell-walls swell, and the contents be- come discoloured and degenerate (fig. 125 A). In the Fig. 123. peripheral part of the roof, the undermost cells of the Hildenbrandia prototypus, vertical interrupted vertical cell-rows often undergo a growth in os of young conceplacles. A and B from specimen collected in a transversal direction, in consequence of which the June (near Refsnæs), C, from ae a collected in January (Store Belt). cell-rows become bent inward below (fig. 122). The above 560 : 1. Ov» UD» cr co TØ 205 described development of the conceptacles has evidently been known to Scamrrz, as can be seen from the diagnosis of the genus Hildenbrandia in Scumirz and Haupr- FLEISCH Corallinaceæ in ENGLER u. Prantl, Nat. Pflanzenfam. I,2, p. 544. It is here said that the conceptacles are “anfangs sehr klein, unter allmählich fortschreitendem Verbrauch des nächst angrenzenden Gewebes allmählich an Grösse zunehmen”, and that they frequently fuse laterally together. The development is de- signed as “lysigen” though it is not lysigenous in the usual significance of the word. The sporangia are somewhat variable in shape and dimensions; they are now ovoid or obovate, e. gr. 21 long, 144 broad, now long, nearly cylindric, e. gr. 30 » long, 9,5 x» broad. The length varies between (16—)21 and 30 », the breadth between 9 and 12(14)». No rela- tion between the dimensions of the sporangia and the locality has been found. The dividing walls are always oblique. The first wall is much inclined to one side, the two following to the opposite side and often parallel to each other. But the first wall is often broken where it meets the following walls, in such a manner that the suc- cession of the walls is not always easily discernible. The upper part of the first wall is often bent downwards so that it goes in continuation of the upper secondary wall, and the sporangium thus presents the appearance of having been divided first into three by two parallel walls and afterwards by a wall dividing the middlemost cell into two (fig. 125 J, B, E, F). The secondary walls nearly always intersect the primary one, but usually near its border; this is true particularly of the undermost wall, which may also meet it at the very border or even intersect the outer wall under the border (fig. 125 C). An ex- treme case is shown in fig. 125 K where the sporangium has the appearance of having been divided by nearly parallel walls; but on Fig. 124. Hildenbrandia prototypus. conceptacle with undivided and empty sporangia. Above a ripe sporangium. 260:1. Vertical section of Fig. 125. Hildenbrandia prototypus. A, left side of conceptacle in vertical section. B-K, ripe sporangia. A—F from Karrebæksfjord, G—K, from Guldborg. 560; 1, regarding only the insertions and not the curvatures of the walls, it 20 will be seen that the middlemost (primary) wall is inclined to the left, the two others to the right; the walls, however, do not intersect, in accordance with the un- usually narrow shape of the sporangium. After the evacuation of the tetraspores, the sporangial walls are kept for a long time; they swell and fill the conceptacle. They have been considered as paraphyses by Kürzınag and others, but such organs do not occur in the adult conceptacles (comp. ScHMITz and HAUPTFLEISCH |. c.). Small Sarcina-like bacteria sometimes form strings between the empty sporangial walls. Conceptacles are met with at all seasons, and ripe sporangia have been found in all the months of the year, most frequently, however, in summer. As a rule empty, ripe and unripe sporangia are found simultaneously, from which it must be concluded that the formation of sporangia continues during the whole year, in the winter only with diminished activity. At what moment the development of the conceptacles begins I cannot say with certainty as I have seen but a small number of young stages. The youngest of the observed stages (fig. 123 A, B) were met with in June, which might suggest that the development of the conceptacles begins in spring, when the growth of the crust must be supposed to be active. In older crusts the periodicity of the growth is marked by distinct limiting lines between the layers of the successive years. The upper line in fig. 121 probably represents the surface of the frond at the end of the foregoing season, but the lower, more irregular line does not represent an old surface; the deepenings are the bot- toms of emptied conceptacles, and the higher parts between them represent the limit of the crust after disorganisation of its upper parts. It really frequently hap- pens that the outer cell-layers die in winter over a greater or lesser part of the crust, and the faculty of growth is then often restricted to limited portions of the frond, which then become higher, and provided with conceptacles, while the other parts are low and sterile. The species is widely spread in the Danish waters, particularly in shallow water, also over the low-water mark, and in sheltered places, where it is often a characteristic element of the vegetation, covering the stones with a red crust in company with Ralfsia etc., frequently under Fucus. But it is also common in deeper water, even in the greatest depths where vegetation has been met with, e. g. in the North Sea at 31 meters depth, in the Little Belt at 26,4-m and near Bornholm at 38 m, but it seems to be less abundant at greater depths. It has repeatedly been met with in a fructiferous state at about 19 meters depth, at Bornholm even at 29 m. In very insolated localities in shallow water it takes a yellowish colour during summer. Localities. Ns: aF, off Thyboron, 31 meters, small sterile specimens; groin at Thyboren. — Sk: YU, Roshage, Hanstholm, 2 m, small sterile spec.; washed ashore near Bulbjerg, sterile; Hirshals, on stones adhering to the hapters of Laminariæ washed ashore after storm, sterile. — Lf: Ronnen near Lemvig, 3m, MA, off Jestrup, 5 m; Oddesund, stone slope, fr.; Nykebing and otherwhere in Sallingsund; aT’, Draaby Vig; Livø Bredning (C. H. Ostenfeld); west side of Feggeklit. — Kn: Herthas Flak, 21—25 m, ster.; Hirsholmene; Deget; Busserev; Frederikshavn; Nordre Renner. — Kim; Mariager Fjord, at Hobro; 207 ND, off Fornæs, 11,5—13 m. — Ks: HR south of Hesselo; shore at Gilleleje; D, off the entrance to Ise- fjord; Oure, near Roskilde and Boserup in Isefjord. -- Sa: FS, Vejre Sund; PG, west of Hatter Rev; north end of Besser Rev; north-side of Revsnæs (Ostenfeld); shore by Koldby Kaas; Bolsaxen; Hinds- holm (Lyngbye); NZ, off Torreso; Odense Fjord, inner side of Enebærodden (!) and shore at Hofmans- gave (Car. Rosenberg); Juelsminde. — Lb: OB, off Stavrshoved; Snoghoj, Middelfart, Fæno a. o. places from 0 to 19 meters; CE, south of Helnæs, 26 meters. — Sf: UV, north of Ærø; Birkholm. — Sb: Refsnæs; Romsø Sund (Ostenfeld); NU, off Strandskoven near Bogense; stone reef at Korsør; GP, Hal- skov Rev; near Sproge, 10—15 m (Ostenfeld); AC, off Knudshoved, 17 m; DN, Vengeance Grund; Ny- borg Fjord, shallow water; near Vresen, 23—24 m (Ostenfeld). UT and US! in Langelandsbelt, about 19 m. — Sm: Karrebæksfjord off Skraverup (Warming); Guldborg (C. Christensen); HF, west of Faro. — Su: bM south of Hveen, 22,5 m; Hvidere; off Charlottenlund; south end of Middelgrund; Trekroner (Rützou); QC, QD, Saltholms Flak; PR! off Dragor, 4m. — Bw: DV, south of Marstal; LC, near Gul- stav, 11m; UP off Kramnisse Gab; UM, Kadetrenden. — Bm: HG, Præstebjerg Rev, 7 m; QS, N. of Moens Klint 21m; at Moens Klint; VD, Bogestrommen; QQ off Rødvig; RG, N.W. of Falsterbo; ON, off Koge Sohuse 6,5 m. — Bb: SF, Adler Grund; SH, Ronne Banke; Off Ronne, 13 and 38 m (Borgesen, !), reef at Ronne; Davids Banke, 29m; off Gudhjem; YA, east of Dueodde lighthouse 38 m; Christianso. 1. Hildenbrandia Crouani J. Agardh. J. Agardh, Spec. G. O. II, 1852, p. 495, III, 1876, p. 379; Batters in Journal of Botany 1897, p. 438. Hildenbrandtia rosea Crouan, Florule de Finistère, 1867, p. 148, pl. 19 fig. 126, non Kützing. In the Little Belt I found by dredging in depths of 15 to 19 meters a stone covered with crusts of a Hildenbrandia which in hanit scarcely differs from H. prototypus. It forms pretty blood-red crusts with similar conceptacles. In the structure of the frond and the shape and dimensions of the conceptacles it agrees also with the named species. The cells are 6—7 u broad and contain a calotte-shaped chromato- phore, the conceptacles are up to 100 in transverse diameter. On the other hand, it differs decidedly by its cylindric sporangia divided by parallel oblique walls, in which respect it agrees with Hildenbrandia Crouani J. Agardh. This species was first described on the basis of specimens sent from Crouan, but, as shown by AGARDH and BATTERS, the brothers Crovan have confounded it both with H. rosea Kitz. (H. protolypus) and with Hematocelis rubens J. AGARDH (Batters lI. c. p. 438). I have had an opportunity of comparing my specimens with those in AcarpnH’s herbarium sent from Crovuan (herb. AGARDH no 27613 “roches de l’anse du Corsens, environs de Brest”) upon which his description is founded, and I have found them fully agreeing. I found also accordance with microscopical preparations from BATTERS in AGARDH’s Herbarium. The conceptacles are similar in structure and development to those of H. pro- totypus. The cell-rows in the peripheral part of the roof are much bent inward below, in consequence of the transverse growth of the undermost cells, as some- times also occurs in H. prototypus (comp. p. 204), while the cell-rows in the inner part of the roof decay. The sporangia are produced, as in H. prototypus, from the bottom and the sides, and also from the peripheral part of the roof. A little stalk- cell is present; J. AGARpH has already perceived that the sporangia are pedicellate, but he wrongly indicates that the stalk is articulated (Sp. III, p. 379). The spor- angia were found to be 19—30 long, 6—7 4 broad; the normal length of the fully ripe sporangia is probably nearest the upper limit indicated. The sporangia have thus the same length as those of H. prototypus, but are narrower. Zonate sporangia, divided by transverse walls, were described and figured in Hildenbrandia rubra Harvey in Phycol. Brit. pl. 250, 1851; but it is rather probable that this figure really represents H. prototypus, as it shows the same shape of the Fig. 126. Hildenbrandia Crouani. Vertical sections of conceptacles. 560:1. sporangia as in this species, and the pretended zonate division might then be due to an inexact observation of the irregularly divided sporangia. Zonate sporangia have further been described in H. prototypus var. kerguelensis ASKENASY (Forschungsreise S. M. S. Gazelle. Botanik, Berlin 1888 p. 30), the sporangia of which are said to be cylindric and divided by exactly parallel walls in 4 parts. As nothing is said with regard to the direction of the walls it must be presumed that they are transverse. It otherwise differs from H. Crouani by its conceptacles being up to 200 „ high but only half as broad, while those of H. Crouani are broader than high. Locality. Lb: Opposite to Middelfart, 15—19 m, July 1900. Fam. 9. Corallinaceæ. J. ARESCHOUG (1852), Corallineæ in J. G. AGARDH, Spec. gen. et ord. Alg. Vol. II pars 2. M. Foszie (1891), Contribution to Knowledge of the Marine Algæ of Norway. II. Tromsø Museums Aarshefter. 14. — (1895), The Norwegian Forms of Lithothamnion. D. kgl. norske Videnskabers Selsk. Skrifter. 1894. Trondhjem. — (1898 I), Systematical Survey of the Lithothamnia. — (1898 Il), List of Species of the Lithothamnia. Ibid. 1898, No 3. ET M. Fostıe (1900), Revised systematical Survey of the Melobesieae. Ibid. 1900. No 5. — (1905), Remarks on Northern Lithothamnia. Ibid. 1905. No 3. (Issued 1906). — (1909), Algologiske Notiser. VI. Ibid. 1909, No 2. F. Hauck, Die Meeresalgen Deutschlands und Oesterreichs. Leipzig 1885 (1882—1885). F. HeypricH (1900), Die Lithothamnien von Helgoland. Wissensch. Meeresunters. N. F. IV. Band. Abt. Helgoland. Kiel und Leipzig. Mme Pauz Lemoine (1911), Structure anatomique des Melobesiees. Application à la classification. Annales de l’Institut Océanographique. Tome II fase. 2. F. MINDER, Die Fruchtentwicklung von Choreonema Thureti. Freiburg i. Br. (s. a.) "R. Pırcer (1908), Ein Beitrag zur Kenntnis der Corallinaceae. Engler, Botan. Jahrbücher. 41. Bd. S. Rosanorr (1866), Recherches anatomiques sur les Mélobésiées. Mémoires de la soc. sc. nat. Cherbourg. Fr. Schmitz und P. HAUPTFLEISCH (1897), Corallinaceae. Engler u. Prantl, Nat. Pflanzenfam. I. 2. Leipzig, SoLMS-LAuBAcH (1881), die Corallinenalgen des Golfes von Neapel. Leipzig. H. F. G. STRÖMFELT (1886), Om algvegetationen vid Islands kuster. Göteborg. N. SvepeLius (1911), Corallinaceae. Engler u. Prantl, Nat. Pflanzenfam. Nachtr. zu I. Teil, Abt. 2. Leipzig. G. THuRET (1878), Etudes phycologiques. Publ. par les soins de M. le dr. E Bornet. Paris. When carrying out my systematic investigations in the Danish waters, I ar- ranged with M. FosLie, the well-known authority on calcareous algæ, that he should deal with the Melobesieæ-group of the family of Corallinaceæ, and forwarded to him accordingly, from time to time, such material as I had collected of these alge, which he also mentioned in various publications. Unfortunately, M. FosLır’s energetic work in this field was brought to a close by his unexpected and prema- ture decease in 1909. Since then, I have collected but few calcareous algæ, and nearly all the present specimens from Danish waters have thus been determined by FosLıe. As we know, this writer repeatedly altered his view concerning the limitation of these difficult species, and his last great work on Northern Melobesiez (Remarks 1905) bears evident witness to his indecision on this point. When, after his demise, I myself took up the task of dealing with this group, I considered it necessary to investigate all species by means of microtome sections, in order to obtain closer knowledge as to the structure of the frond and reproductive organs, being also further instigated hereto by the newly published works of PırgEr, Mme Lemoine and MINDER. In many cases, the results attained were disproportionate to the amount of time involved, partly owing to the fact that the great bulk of the material had only been preserved in a dried state, and also because suitable devel- opmental stages of the various sorts of conceptacles were in many cases lacking. With regard to distinction of species, for the Lithothamnia I have in the main fol- lowed FosLiE in his valuable work above-mentioned; on the other hand, closer in- vestigation has led me to distinguish several new Melobesia species. With regard to structure and development of the frond and reproductive organs, I may refer to the works above quoted by RosAnorr, SOLMS, PILGER, Mme Lemoine, MINDER and SVEDELIUS, as also to what is stated below with regard to the various species. It will here suffice to mention certain particular features. The frond is in all cases composed of branched cell filaments, the cells of which are connected up by pits of the structure characteristic in Floridez, in the middle of the transverse walls. These pits are however, very thin, and are often D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 2 27 210 not distinctly visible in the dried material; they are therefore in many cases not shown in the illustrations, or if so, only in small numbers, though as a matter of fact, they are always present, or have at any rate been so. I mention this point, as Mme Lemoine states that the cells are in some cases connected by open chan- nels, (Struct. p. 35) and that in other instances, neither pits nor channels were found (l. e. p. 37). As illustrations of the latter, the writer in question cites Lithothamnion leve and L. norvegicum; I can here refer to my figs. 129 and 143, where the pits are shown. Pits between cells belonging to different filaments are found in the Danish species only within the genus Lithophyllum, where the cells in the perithallium form transverse layers, in which they lie at equal height, and are then connected by pits with all the cells in the same layer, with which they are in contact. This has, it is true, been known before, but the importance of the fact as a systematic character has not been sufficiently emphasized. The character in question would in particular seem to afford an excellent means of distinguishing between the genera Lithophyllum and Melobesia, which otherwise closely resemble each other. Unfortu- nately, I have not been able to ascertain how these pits arise; they are formed at an early stage, and I must presume that they originate in a similar manner to the secondary pits in the Rhodomelaceæ etc., though I have not been able to demon- strate the co-operation of nuclei in the process, probably owing to insufficient fixing and staining of the material. In all other genera (where, as we have seen, no such transverse pits are found) the cells possess another means of entering into connection with cells in other filaments, viz. by forming an open communication between them, the separating wall being partially dissolved. These fusions, which were first described by Ro- SANOFF, are of common occurrence in the Danish species of the family which do not belong to the genus Lithophyllum. Where the cells lie densely packed and the walls are thin, the fusions make themselves apparent merely by the fact that the longitudinal walls are partially dissolved (Lith. Lenormandi fig. 133 D); where the cell walls are thicker, on the other hand, a distinct connecting channel of varying length is seen. These appear both in the hypothallium and in the perithallium, and may very often take place between more than two cells. They are particularly easy to distinguish in the basal layer of Melobesia and in the central tissue of the upright, branched Lithothamnia. In the latter, they often form characteristically curving partially branched bodies, which may embrace almost all the cells in the central tissue (fig. 139). In the peri- thallium also, however, of the mentioned Lithothamnia, they may be extraordinarily frequent (Lith. calcareum, fig. 144, etc.). Fr. SCHMITZ, who has investigated these fusions with regard to the behaviour of the nuclei, found in 1880 (Untersuch. über die Zellkerne der Thallophyten. Sitzungsber. der niederrhein. Gesellsch. f. Natur- u. 7 Of the species mentioned below, they appear to be lacking only in Choreonema Thureti, where the vegetation organs are highly reduced (cf. Minder 1. c.) and in M. minutula (fig. 172). zahl Heilkunde zu Bonn 1880) that the nuclei, in two fusing cells of Jania rubens did not fuse together. I came to a different result on investigating this point in several other species, especially Corallina officinalis. In a tetraspore-bearing plant of this species I found the fusions followed by a fusion of the nuclei. The process was studied in the central tissue under a young conceptacle where numerous fusing cells were found, partly in pairs, partly a greater number fusing together. As shown in fig. 127, the two nuclei of a fusing pair of cells are frequently found lying near each other at the place where the two cells have fused together, and there is reason to believe that the nuclei have been active in the realisation of the cell-fusion. In some cases the nuclei were found touching, and finally fused cells were found containing only one nucleus situated at the same place Fig. 127. Corallina officinalis. Fused cells from a vertical and derived from fusion of the two nuclei section of a young joint under a young sporangial conceplacle. 730:1. (fig. 127 D). These fusional nuclei seem to be able to fuse with other nuclei when fusion takes place between more than two cells. In fig. 127 D is shown a syncytium produced by fusion of four cells and containing at left two nuclei in mutual contact and near the middle a nucleus which must be supposed to have arisen from fusion of the nuclei of the two cells at right. This nucleus has approached the middlemost opening, where it would perhaps later on have fused with the other fusional nucleus. Syncytia arising from fusion of four cells but containing only one nucleus, undoubtedly produced by fusion of the nuclei of the cells, I have observed in Lithothamnion glaciale var. Granü (fig. 128). Also in Melobesia uninucleated syncytia pro- duced by fusion of two cells were observed. It must therefore be supposed that fusion of nuclei generally occur in the fusing cells. That Schmitz has not observed them may be due to the fact that the process was not so far advanced in the plant investigated by him; it might also be imagined, however, that fusion does not take place in all cases, since mullinu- Fig. 128. Lithothamnion glaciale var. A 2 Granü. Syncytia produced cleate syncytia are found even in older tissue. It is not un- by fusion of from two to four : : 7 or 1 a R cells, all showing only one likely that the nuclei may themselves co-operate in the pro- nucleus; at right a cell con- cess of fusion, the nuclei of the two cells placing themselves taining starch grains. 650: 1. : 0 BMA opposite each other in the two cells and bringing about a dissolution of the cell wall. The reason of their taking up such a position would then be, that a mutual attraction exists between them, in which case it would be natural to suppose that such attraction should continue to exist after the fusing of 97% the cells, finally resulting in a fusion of the nuclei themselves. If this were so, then the fusion of the nuclei would be of no particular importance in itself, but merely a consequence of the cell-fusion. Such supposed co-operation of the nuclei in effecting the fusion of cells is, however, purely hypothetical: I have not with certainty observed the nuclei immediately prior to commencement of the fusions, and it must be admitted that certain cases where cell fusions took place between four cells (fig. 127 D) do not tend to support the theory. Fusion of nuclei in vegeta- tive cells of higher plants has recently been observed in several cases, where cells have, for some reason or other, proved to contain more than one nucleus (cf. for instance Schürhoff, Kernverschmelzungen in der Sprossspitze von Asparagus offici- nalis. Flora, N. F. 8. Bd. 1916, p. 55). The cells always contain, fusions apart, a single nucleus. The only exception is the female plant of Corallina officinalis, where the cells of the central tissue con- tained from two to four nuclei. The chromatophores are small, disc-shaped; there is often a rather small number in each cell (figs. 130, 143 E; comp. Pilger 1. c. p. 253). Starch-grains occur in all the species. They are often very numerous, parti- cularly in the older tissues. Mme LEMOINE distinguishes between single and com- pound (coalescents) starch grains. According to my observations, this distinction appears to depend exclusively on whether the cells are more or less densely filled with starch grains, in the first case the grains may be applanated on the faces where they meet, as also stated by PiLGER (l. c. p. 254), but they are not really connate. In Lithothamnion glaciale var. Granii, which is said by Mme LEMOINE to possess compound starch grains, I found distinct single grains (fig. 128). The starch- grains frequently contain a small air-bubble in the centre in the preparations from dried specimens (comp. figs. 130 B, 143 F, 174). The well known transversal limiting lines which undoubtedly indicate periods of stand-still in the growth occur in all the species of Lithothamnion, except those - with thin crust, but they are also met with in Lithophyllum orbiculatum (fig. 180 A), whereas Mme Lemoine did not find them in any species of this genus (I. c. p. 28). As shown by this author they are very intensely stained by hæmatoxyline; they may pass between the cells, coinciding with the middle-lamella, but more frequently they meet the longitudinal walls of the cells without bending under them (figs. 136, 138, 143, 144, 145). Mme Lemoine describes further alternating zones with varying power of staining with hæmatoxyline. Such zones, not limited by a blue line, were met with in Lithophyllum norvegicum where the ordinary limiting lines were otherwise also present (fig, 143 B, C). In some genera (Melobesia, Lithophyllum, Corallina) unicellular, hyaline hairs occur. They resemble those occurring in numerous other Florideæ (com. L. KOLDERUP ROSENVINGE, Remarks on hyal. unic. hairs; Biolog. Arb. tilegn. E. Warming, 1911, p. 203) but differ, however, in not being limited from the cell producing them by a transversal wall. The hair-producing cells have been long known in the species of Melobesia, particularly M. farinosa, where they were given the name of heterocysts by Rosanorr (1866 p. 70), but as shown by Sorms (1881, p. 24), they are really hairs or hair-producing cells. They are easily recognizable after the hair has been shed, showing a scar left by the latter; I propose to name them trichocytes or hair-cells. The sporangia are always divided by one or three transversal walls, dividing the cells into two or four spore-cells. Vertical divisions I have only found as rare exceptions in Lilhothamnion Sonderi (fig. 137 E, F). The tetrasporie sporangia are first divided by a transversal wall, but the formation of this wall proceeds slowly from the periphery towards the centre, and the formation of the two following walls has frequently begun before that of the first is completed. In Corallina offi- cinalis I found that the primary nucleus of the young sporangia divides into four nuclei which arrange themselves in a longitudinal row in the middle of the spor- angia, and that these rest for a long time in this stage before the divisions, which take place almost simultaneously (fig. 197). Also in Epilithon membranaceum the three divisions are almost simultaneous (fig. 152, comp. otherwise fig. 134). The di- viding wall is shown in figs. 131 B and 142. The number of spores is constant in most of the species, either 4 or 2; but in some species both disporic and tetrasporic sporangia are met with. One of these species is Lithothamnion leve which, however, in the Danish waters has only been found with disporic sporangia. The above mentioned fact that the divisions of the tetrasporic sporangia are, at least in several cases observed, almost simultaneous, makes it improbable that the disporic sporangia can here be interpreted as unripe, not fully divided. It is an incontestable fact that some species may, according to circumstances, have tetrasporic or disporic sporangia. This I have also found to be the case in L. Lenormandi, in which only tetrasporic sporangia were previously known. In Melobesia Fosliei also, and in M. minutula, both kinds of sporangia would seem to occur. In material fixed in Juel’s liquid the protoplasm of the tetraspores showed a foamy structure. The central part containing the nucleus was brighter and distinctly marked off from the outer (figs. 132, 142 B and Plate III fig. 1). The antheridia present considerable differences as to their position and devel- opment. In Lithothamnion Lenormandi they have a similar position to that pre- viously described in L. polymorphum, being produced on the surface of great bushes extending from the periphery towards the centre of the conceptacle (Plate III fig. 2). If this structure is to be found in all the species of the genus, we have here an important generic character. In Epilithon membranaceum, referred by some authors to the genus Lithothamnion, the antheridia are, as shown by GuiGnarD (Rev. gén. de Bot. I. 1889, p. 182) seriate in short filaments clothing the bottom of the con- ceptacle, and in the other genera the antheridia (spermatangia) are also placed on the bottom of the conceptacle, being produced as outgrowths from a layer of small cells, but they are not seriate. The antheridia are more or less lengthened, short cylindrical or upwards somewhat thickened and more or less curved. In Melobesia Lejolisii, the spermatia are produced at the end of long sterigmata, as shown by Mrs. WEBER-VAN BOSSE, and the same was found in Lithophyllum Corallinæ. In the last named species the isolated spermatia found in the conceptacles were seen to contain two nuclei (fig. 189), an interesting fact, as spermatia with two nuclei have formerly only been observed in spermatia fixed to the trichogyne, but not at an earlier term. Concerning the development of the cystocarp in the Corallinaceæ, diverging statements have been advanced. As I have had no occasion of making thorough researches on this question, I must, in referring to the quoted papers of SoLms, SCHMITZ u. HAUPTFLEISCH, PILGER and MINDER, content myself with stating some few facts noted in some of the species in question. The carpogonial filaments are, at least usually, two-celled, being composed of a terminal carpogonium anda cell situated under it, separated from it by a more or less inclined wall; probably an auxiliary cell (fig. 148 C). A hypogynous cell as that described in Choreonema by MINDER (I. c. p. 12) was in no case observed. As shown by Borner and THURET (1878) and Sorms (1881) a large disciform cell, from the border of which the carpospores are produced, arises after the fertilization in the bottom of the female conceptacle. SoLms and Scauirz were of the opinion that in Corallina it arose from fusion of all the auxiliary cells. PıLGEr showed that in Lithothamnion Philippü the two cell-layers situated below the carpogonial branches in fusing together take part in the formation of the disc-cell. On the other hand, MINDER, by a careful study of Choreonema Thureti, showed that the disc-cell arises in this plant from the fertilized carpogonium, which increases, becomes lobed and gradually fuses with all the auxiliary cells, the contents of which is absorbed by the disc-cell, which is thus no fusion-cell. The statements of MINDER appear to be so well founded that they cannot be doubted and it must be supposed that similar processes also take place in other Corallinacee, though with various modifications in the different genera, e. g. combined with other cell-fusions. Having in most cases had only insufficiently preserved material of female conceptacles, I can only stale, that the carpospores are in most of the species examined produced at the periphery of the cystocarp, as in Corallina and others, but that in Lithothamnion Lenormandi and Lithothamnion polymorphum they arise also from various points of the bottom of the conceptacle. In these cases a disc cell could not be observed in the dried material and it was impossible to state whether the aberrant position of the carpospores is founded on the fact that the disc-cell is more irregularly lobed or whether it must be otherwise explained. As to HEypricn’s statement of the devel- opment of the carpospores in Lith. polymorphum, reference may be made to the mention of this species below. Lithothamnion Philippi. Subgenus Hulithothamnion Fosl., char. mut. Conceptacles of sporangia superficial or more or less immersed; the roof plane or vaulted. 1. Lithothamnion læve (Strömf.) Fosl. FosLıE in K. Rosenv. Deux. Mém., 1898, p. 14; Rev. Surv., 1898, p. 15; Remarks, 1906, p. 16 and 131; Algol. Notiser V, 1908, p. 6; K. RosEnvinGeE, Mar. Alg. N. E. Greenl., 1910, p. 100, fig. 1; Lemoine, Struct., 1911, p. 74, figs. 36 and 37. Lithophyllum leve Strömfelt, Isl., 1886, p. 21, tab. I fig. 11—12. Lithothamnion Lenormandi (Aresch.) Rosanoff, f. lave (Strömf.) Foslie, Contrib. IL, 1891, p. 11. Lithothamnion tenue K. Rosenvinge, Gronl. Havalg., 1893, p. 778, figs. 4—7 (Alg. mar. Gr. p. 58). Lithothamnion Strömfeltii Foslie, Norw. Forms, 1895, p. 145. This species, very common in the Arctic Sea, has been found in two localities in the sea north of Sealand, the most southerly stations known in Europe. The specimens from the Kattegat were mentioned by FosuiE in 1906 (Remarks p. 131). I have examined the structure of the specimen from the Sound which was preser- ved in Juer’s liquid. The species is easily distinguished from L. Lenormandi by its smooth surface and the large conceptacles. i The thallus in the Danish specimens is thin. The filaments of the hypothallium are, as pointed out by Mme Lemoine, loosely connected. When seen from the surface, they show here and there transversal fusions. The cells are 21—33 long, 7,5 —9,5 u broad. According to Mme Lemoine, the undermost cells of the hypothallium form rectangular cells directed towards the sub- stratum, thus constituting “une On SSeS = S ære Seer s rangée de rhizoides obliques”. S SEX) SELON: ) I have not been able to see ox YO OD RSIS > ( œ = anything of this kind in the IL CCS eg specimen examined. The fil- eee == Se aments of the perithallium are A ==> composed of a small number of roundish cells, 7 » thick or a little more, up to 104. These I dimensions, which I found in © SE ©) é Ne OC Bog specimens from both localities, © OO Å are in accordance with FosLIE's ao Q \ u statement (Remarks p. 18), ) SO = while Mme LEMOINE gives the © SENG thickness as only 4—5 47. The Ss 7 This indication is not in accor- Fig. 129 ae = g. 129. x nce my ith the figures of NEE LEMOINE, Lithothamnion leve, A and B, vertical sections of crust. C, Hypothal- in which the cells are thicker. lium seen from below. From Hellebæk. 350: 1 cells of the hypothallium and the undermost part of the perithallium often contain a number of distinct starch grains. In the cells of the perithallium a nucleus and a small number of disc-shaped chromatophores could be distinguished. (fig. 130). In the Danish specimens, only conceptacles of sporangia were met with. Their diameter is A å somewhat smaller than in the Greenland speci- mens; in the plants from Hesselø it is 500—650 x, Lithothamnion læve. A, cells from the peri- in those from Hellebæk 600—800 pL The roof SCPE A ER aE CE consists of narrow filaments of cells which are grains. 730 :1. longer than in the vegetative frond, and connected with numerous transverse fusions, while the cells are only rarely fusing in the perithallium. The sporangia I found al- ways disporic when fully developed, 126—129 » long, 67—72 x broad, thus somewhat smaller than in the specimens from Greenland. The species has otherwise been found with two and with four spores in the sporangia. Foslie has (1908, p. 7) given all the localities where it has been found with two-cel- led sporangia only and those where it has been met with only with four-celled sporangia. Both are found in a number aa Rot localitieseingihe A arctic regions and Fig. 132. Fig. 131. ; Lithothamnion læve Lithothamnion læve. A, vertical section of conceptacle at the Norwegian Tetraspore. of sporangia. B, part of a similar section. 200: 1. coast as well. 390 : 1. Localities. Ks: A, S.E. of Hessele, 28m on stone and shell. — Su: Hellebæk Aug., on Mylilus Modiola, Henn. Petersen. 2. Lithothamnion Lenormandi (Aresch.) Foslie. Foslie, Norw. Forms, 1895, p. 150; Heydrich, Lithoth. von Helgoland, 1900, p. 78, Taf. II, fig. 23—25; Foslie, Remarks, 1905, p. 12; Mme Paul Lemoine, Struct. anat., 1911, p. 811; Deux. exped. antarct. franc. 1913, p. 10. Melobesia Lenormandi Aresch. in J. Agardh. Sp. G. o. II p. 514. * Mme Lemoine cites the fig. 7 of my paper, "Grønlands Havalger” as representing Lith. Lenor- mandi; however, it does not represent this species but L. tenue Rosenv. (= L. lœve Strömf.). 217 Lithophyllum Lenormandi (Aresch.) Rosanoff, Rech. anat. p. 85, pl. V, fig. 16 et 17, pl. VI, fig. 1, 2, 3, 5 8. 1, 4, J, 0. (Fig. 5 is said in the text to represent L. Lenormandi, while in the explanation of plates it is attri- buted to L. lichenoides). Hauck, Meeresalg. p. 267, Taf. III fig. 4; Strémfelt, Algveg. Isl. kuster, p- 21, tab. I, fig. 9—10. Lithothamnion squamulosum Foslie, Norw. Forms of Lithoth p. 155, Tab. 19 fig. 24—26. Squamolithon Lenormandi (Aresch.) Heydrich, Die Lithoth. von Roscoff. Ber. deut. bot. Ges. 1911, p- 26, Taf. II. This widely spread species has been met with in almost all the Danish waters. It is particularly characterized by its thin reddish-violet crust with a lobed, whitish border, by its hypothallium composed of densely joined filaments, and at all events in the typical species, by the densely crowded concep- tacles. As pointed out by Mme Lemoine, the hypothallium is composed of more densely joined filaments than in the other crustaceous species. According to this author, the number of horizontal fila- ments in a vertical section is usually 7—8; in thicker crusts it may be greater (fig. 133 B), in thinner it may be only 3—4 (fig. 133 A, C). In Fig. 133. z S Lithothamnion Lenormandi. A, vertical\section of border of frond, not horizontal Sealens through decalcified, made by grinding. B and C, vertical sections of thick and thin the hypothallium transverse crusts, made by microtome through decalcified fronds. D, horizontal sec- fusions are frequently seen tion of hypothallium showing fusions. A 195:1. B—D 350:1. (fig. 133 D). Mme LEMOINE states that the filaments of the hypothallium “se relèvent d’une façon très brusque pour constituer les files du périthalle”. This, however, is, in my opinion, not characteristic of the species, as will be seen in my fig. 133. The cells of the hypothallium which, according to Mme LEMOINE, are 3—4 4 thick, I generally found somewhat thicker, 3,5—6 », in specimens from the Limfjord 5—6 y, the length 12—185y. The cells of the perithallium I found 4—6y thick, 4—13 4 long. In the perithallium also numerous transverse fusions occur, but as the cells are closely joined, the fusion canals are very short. The sporangial conceptacles are very crowded, in particular in f. typica; they measure 200—300 in diameter. The flat roof is, according to Fos.ir, intersected by 25 to 35 muciferous canals, which is in accordance with my observations; I have, however, met with up to 45 canals. Transverse fusions between the cells of the roof are frequently met with. The sporangia which are otherwise always tetra- sporic, are also normally so in the Danish waters. Conceptacles with disporic Sporangia only, however, not infrequently occur (fig. 134 A). It might be suggested D. K. D, Vidensk. Selsk. Skr., 7. Række, naturvidensk, og mathem. Afd. VII, 2, 28 218 that the sporangia in such cases were not quite ripe, and would later on have been divided into four spores, but as in other cases the divisions have shown to be al- most simultaneous (fig. 134 C) it seems most probable that disporic sporangia occur besides tetrasporic ones, as in several other species. Sporangia with 4 spores found in the Limfjord and in the Kattegat were 100—112y long, 34—48 » broad; in specimens collected in Bramsnes Vig (Ise Fjord) they were only 53—91 » long, 14—25 broad. Antheridial conceptacles were found in specimens from Staffans Fig. 134. Flak in the Sound and from Brams- Lithothamnion Lenormandi. A, vertical section of crust with pees Fjord. In both cases they were sporangial conceptacles. B, tetrasporangium in two consecutive = £ à sections. C, tetrasporangium in three consecutive sections. 300—350 u in diameter, thus much AGE Bas larger than stated by FosrıE (150 —200 ). In the specimens from the first named locality collected in September they were fully developed and showed a rather complicated structure, the spermatia being produced on the ultimate ramifications of dendroid systems of filaments given off from several points of the inner surface of the conceptacle, from the bottom and from the upper side as well (Plate III fig. 2). The structure of the antheridial conceptacles is thus rather similar to those of Lith. polymorphum described by HEyprıcr (Lith. Helg. p. 65, Taf. II fig. 1-3). The dimensions of the spermatia seem to be 3x4». The cystocarpic concep- tacles are hemispheric to coni- cal, 320—350 » in diameter. It is remarkable that the car- pospores are not only produ- À ced at the periphery of the bot- / tom of the conceptacle but from the whole face of the floor, a fact by which our species differs, as BEA it appears, from the type not only of the genus but also of the family. The carpospores are 50—63 » long, 21—32 4 broad’. 1 HeypricH has in 1911 (1. c.) established a new genus. Squamolithon, Fig. 135. É: = Lithothamnion Lenormandi. Vertical section of cystocarpic founded on Lithothamnion Lenormandi, conceptacle. 200:1. 219 This species occurs on stones and rocks, and on shells of molluses (Mytilus, Modiola, Trochus, Littorina), from ordinary water-mark to 19 meters depth. Almost all the specimens belong to f. {ypica, a few only have been referred by Fosrie to f. sublevis, which differs by smoother surface and less crowded sporangial concep- tacles. It was rather surprising to me to find the species growing at low-water mark on the granitic rocks of Bornholm, where the salinity of the water is about 7—8 "loo only. It was here fairly typical though sterile, and with numerous adven- titious fronds, and occurred in fairly great numbers. In the other locality in the Baltic (RG), only sterile but rather large crusts were found. Ripe sporangia have been met with in July (partly together with undivided) and September. Antheridial conceptacles with spermatia were found in July and September, and ripe cystocarpic conceptacles in July. Localities. Ns: Thyboren, groin no. 58, stunted specimens. — Lf: Sondre Ron by Lemvig; Thisted harbour (!, C. H. Ostenfeld); Sallingsund (Th. Mortensen); LS!, off Bjorndrup, east of Mors, 5,5 m. — Kn: Frederikshavn, at low-water mark; Trindelen, 15 m (small spec.). — Ke: EU, Lille Middelgrund, 14 m (small specim.); IA, Store Middelgrund, 16 m. — Ks: Oure Sund; Bramsnæs Fjord. — Lb: At Lyngsodde off Middelfart, 15—19 m, large fertile crusts. — Sb: GP, at Halskov Rev, 9,5—11,5 m; Aver- nakhage by Nyborg, low water. — Sm: VC, Venegrund, 3—5,5 m. — Su: TF”, Staffans Flak, 11—13 m; PS, off Charlottenlund, 5,5 m. — Bm: RG, 6 miles N.N.W. of Falsterbo lighthouse, 11,5 m. — Bh: Hellig- domsklipperne, Ro, Bornholm. | 3. Lithothamnion Sonderi Hauck. Hauck, Meeresalgen, p. 273, Taf. III, fig. 5; Foslie, Norweg. Forms, 1895, p. 127; Heydrich, Lithoth. Helgol., 1900, p. 77, Taf. II fig. 20—22; Foslie, Remarks, 1906, p. 23; Lemoine, Structure, 1911, p. 96. Though this species has been met with in a number of different localities in the Danish waters, it has in most cases been found only in small quantities together with other species. I have therefore only little to communicate with regard to it, but must refer to the descriptions of Hauck, FosLıE and Mme LEMOINE. As pointed out by Fosrıe and Mme LEMOINE, the hypothallium is feebly devel- oped. According to the last-named author it consists only of a single layer of cells; “les autres se relèvent très rapidement pour former le périthalle”. The ascending filaments may, however, rise more gradually, and the hypothallium may then con- sist of two or three cell-layers (fig. 136 B). The hypothallic cells measured 5—7 yz broad, 15—21 » long; those of the vertical filaments I found to be 3,5 -7 x broad, 5,5— 11, long. These measurements are somewhat smaller than those of Fosrie and Mme Lemoine. Transverse fusions between the cells are very frequent in the perithallium. In sections stained with hæmatoxyline the middle lamellae are very distinct. In the same sections the horizontal limiting lines are intensely stained; their course is somewhat irregular (fig. 136). Older crusts may have a considerable number of layers. The cells of the under part of the frond are often filled with and characterized principally by cytological statements relating to the development of the cystocarp. These statements are, however, very insufficiently supported, and I have had no opportunity of veri- fying them. 28* 220 starch grains, but in other cases starch is wanting. Fructiferous spe- cimens I have had no opportunity to submit to closer examination. The sporangial conceptacles are, according to FOSLIE very little prominent, 300—500 in diameter, not overgrown, the sporangia tetrasporous. A crust dredged at the beacon of Halskov Rev in Novy. (no. 3171) and referred by FOSLIE : : : ARTE le) 190. veal to this species, differs Lithothamnion Sonderi. A, vertical section of frond with a single-layered hypothal- " lium. B, thinner crust with two or three layers of cells in the hypothallium, con- by having overgrown taining starch grains. C, upper part ofa thick frond with an uneven surface. 350:1. sporangial conceptac- les, but seems otherwise to agree with this species. The conceptacles of sporangia were however a little smaller than usual, 260—280,, in diameter (inner diameter about 200 »). The sporangia were tetrasporous, in some cases showing vertical divisions (fig. 137). Fig. 137. Lithothamnion Sonderi (?), from Halskov reef (no. 3171). À, vertical section through a crust with overgrown conceptacles. 63:1. B, part of a similar section with an overgrown conceptacle, showing the hypothallium. 350:1. C, sporangial conceptacle with sporangium. 205:1. D—F, sporangia with anomalous divisions. 205:1. 221 The species forms crusts on stones and gravel, in depths from 5 to 24,5 meters. In one case it was found growing on a dead specimen of Lithothamnion calcareum. It has been found with sporangial conceptacles and cystocarpie conceptacles in May and September. Localities. Sk: Off Hirshals, 13 met. (F. Borgesen). — Lf: ZY, Nissum Bredning, 5 met. (deter- mination uncertain). — Kn: Herthas Flak, 20—23 met.; FF and TR, Trindelen, 23,5 and 15 met. Ke: IP and IL, Fladen, 20,5—24,5 met.; IK, Lille Middelgrund, 17—19 met. — Sb: GP near the light- buoy at Halskov Rev (no. 3171, see above); Strandby reef, W. side of Langeland (?). — Sm: VC, Vene- grund, 4—5,5 met. 4. Lithothamnion glaciale Kjellm. F. R. Kjellman, Norra Ish. algfl. p. 123 (93) tab. 2 and 3. Foslie, Norw. Forms p. 13; Remarks p. 26. Mme P. Lemoine, Struct. p. 92. Nearly all the rather numerous Danish specimens referred to this species have been determined by FosLıE, who received them from me at different times and ac- cordingly gave them different names. In 1895 he described and figured Norwegian specimens, corresponding exactly to those mentioned here as var. Granii, under the name of L. flabellatum f. Granii. Later on this variety was referred to L. glaciale, an opinion which has only been expressed in Rev. Surv. (1900, p. 11, where after the name L. Granü, which is here a nomen nudum, is added: “(L. glaciale f. ?)”). As late as in 1905 FosLie referred specimens of these algæ to L. glaciale, partly to f. Granii, partly to other forms. But in the same year (Remarks p. 59,') FosLıE established L. Granii as a distinct species. That he has been uncertain at the last as to the limitation of the species can be concluded from the fact that the same species, on p- 10 of the same paper, is mentioned as L. glaciale f. Granii. It is easy to under- stand that it has been difficult to come to a decision as to the delimitation of species when considering that FosLıEe (Remarks p. 28) “found it almost impossible to draw any line between L. Granii, admitted below, and L. glaciale”. L. c. p. 59 is said, as to the relation between L. Granü and L. tophiforme f. divergens, that there are many specimens “which are quite like each other in almost every respect, but that the specimens of one species show a somewhat greater tendency in one direction and the other in a different one”. It is however not to be seen in the named paper on which characters the difference between the two species really rests, save that L. Granii has thinner, usually more ramified branches. Some Danish specimens for- merly determined as L. glaciale, in part as f. colliculosa, are now (Remarks p. 34) referred to L. colliculosum which is here regarded as a separate species, while he had formerly considered it a form of L. glaciale; a description of it is given, but he does not emphasize how it differs from L. glaciale. As I cannot see any distinct difference between these specimens and some of those referred by FosLie to L. Granii I prefer to adhere to FosLie’s somewhat older opinion in regarding L. colliculosum and L. Granii as varieties of L. glaciale. 1 FosLie’s “Remarks” appeard however only in 1906. iw) i) Ne} var. colliculosa (Fosl.) Lithothamnion colliculosum Foslie, Contrib. I, 1891, p. 8, tab. 3 fig. 1 ex p.; Norw. Forms, 1895, p. 75 ex p.; Remarks, 1905, p. 34. FosLiE has referred to L. colliculosum specimens from two localities in the western part of the Limfjord. They resemble arctic specimens of L. glaciale with not much developed processes which are thicker than in L. glaciale f. Granii and, as it seems, less closely placed, up to 4 mm high. The crust is well developed, expanded, and contains conceptacles. These specimens were found growing on My- tilus and stones. var. Granii (Fosl.) Lithothamnion flabellatum K. Rosenv. f. Granii Foslie, Norw. Forms (1895) p. 70, tab. 17 fig. 1—7, tab 22901 L. Granii Foslie, Remarks (1905) p. 59. All the other Danish specimens belong to this variety. It differs from the typical L. glaciale by more closely placed, thinner and often more ramified branches. The thickness of the branches, however, varies somewhat; it is lesser, for instance in f. reducta Foslie. The crust is usually much developed and may be widely expanded over the substratum. In the latter case the processes are frequently small, wartlike and rather spread, and the crust then frequently contains numerous conceptacles (fig. 138 A). When growing on pebbles on gravelly bottom it often completely en- compasses the pebble, and when this is small, branches may project from it at all sides. Usually however, they grow principally to one side, viz. upwards, and these, upward growing branches may branch repeatedly. In branching they often have a tendency to take globular form, and such globular branch-systems may at last be loosened, the conjunction with the pebble being given up. On gravelly bottom, loose individuals, “Ægagropila-forms”, exactly similar to these branch-systems, are often found (Plate IV figs. 1—4). H. Jonsson assumes that the loose Ægagropila-forms of L. Ungeri and L. tophiforme are produced in the same manner off the shores of Iceland". Probably loose individuals may also arise by division of other loose ones. On gravelly bottom the plurality of the individuals may be loose (e. gr. Lille Middel- grund, Ke). In the inmost localities in the Danish waters (Ks, Sa, Lb, Sb, Su) only specimens with well developed crust but small processes were met with. The crust contains a hypothallium composed of few cell-layers from which obliquely ascending filaments continuing in the perithallium are given off. The cells of the hypothallium were in the specimen examined 20—22 » long, 5—7 u broad. Mme Lemoine states the dimensions for L. glaciale to be 12—18=2y. The latter figure, however, must be presumed to be exceptionally low. Mme Lemoine further states that the hypothallium gives off a layer of rhizoids or rectangular cells in- clining against the substratum; this I have not found in the Danish specimens 1 H. Jonsson, Om Algevegetationen ved Islands Kyster. Botan. Tidsskrift 30. 1910 p. 322. — The Marine Alg. Veg. of Iceland. The Botany of Iceland, Part I, 1912 p. 154. 223 (comp. fig. 138). The same author finally states that the filaments of the hypothallium are “formées de cellules arrondies, très serrées les unes contre les autres, de sorte qu’il est impossible de suivre le trajet de chaque file”. As will be seen in my fig. 138, the filaments of the hypothallium are very distinct in well developed crusts. The cells of the perithallium are roundish, sometimes almost globular, usually however longer than broad, 7—10,5 » long, 4—8 u broad. They are often fused together two or three in a horizontal direction. The crust is divided in zones by horizontal lines stained intensely by hæmatoxyline. The branches have a similar structure to the perithallium in the crust. The cells are usually oblong or rectangular with rounded angles. They are sometimes situated more closely toge- ther in the outer layer than in the inner, that is to say, the walls are thinner (fig. 139 A). The cells are 5—7 4 broad, 7—11 long. Transverse fusions between the cells are frequent, often connecting several cells; in tangential sections they are often especially numerous and appear as irregular, curved, partly ramified formations (fig. 139 C). In transverse sections of the central tis- sue they may pre- sent a si- milar ap- pearance © (fig. 139 9 B). These Fig. 138. Lithothamnion glaciale var. Granii. A, vertical section of crustaceous frond with sporangial conceptacles. 65:1. B, part of the same sec- tion, showing the hypothallium and a peri- pheral part of a conceptacle. 350: 1. cell-fusions contain, at least usually, only one nucleus (comp. p. 211, fig. 128). Starch grains appear very irregularly, without relation to the layers. The cells may contain a greater or smaller number of them, and they may consequently be placed closely together; but composed grains (comp. Mme Lemoine, l. c. p. 94) do not seem to occur. Lithothamnion glaciale var. Granii. A, longitudinal Conceptacles are frequently found, but section of upper end of a branch. B, transverse sec- only sporangial conceptacles were observed. tion of branch, from the centre. C, tangential section of branch. 400:1. They are usually placed on the branches, 224 especially on the upper part of them, but they may also occur in the crusts when these are much developed. They are slightly prominent, about 260—350 » in dia- meter. The conceptacles in the crusts show the same aspect as those of the branches (figs. 138, 140). By proportionally few countings I found 30—60 muciferous canals in the roof. The conceptacles are usually gradually overgrown and immersed in the tissue of the branch, and this is also the case with those of the crusts. In such immersed conceptacles the septa between the sporangia are frequently visible for some time (Plate III fig. 4). Slime-strings may also remain distinct after the im- mersion. Conceptacles filled out by tissue pro- war duced from the bottom of the cavity frequently À TJ f N Na occur (fig. 140 A). The sporangia are always S two-parted, 70—110 long, 39—50 broad. x SZ A As mentioned above, the var. colliculosa has only been found in two localities in the Limfjord while a specimen found in a third TOF Cin. locality of the same fjord seems to belong to sr UF Ber, the var. Granü. The specimens from the other Wo SY a WR localities were all referred to this variety, which ze & 2 is best developed in the eastern Kattegat where BE it was found in most of the localities in rather great quantities as branched specimens, partly Fig. 140. loose. In the inner water it occurs only in Lithothamnion glaciale var. Granii. Transverse thesfor f t . itl Hoan sections of branches with tetrasporangial concep: e form ol crustaceous specimens with short, tacles. In A an immersed conceptacle filled out often densely placed wartlike processes. The by tissue from the bottom. 65:1. E 5 species has been found growing on stones, gravel and shells, in the Limfjord in 5,5 meters’ depth, in the Kattegat in 17—30 m, in the Samsø waters in 9,5—19 m, in the Great Belt in 19m and in the Sound in 34 meters’ depth. Ripe sporangia have been found in April—May. Localities. var. colliculosa. Lf: north of Ronnen by Lemvig (6874); Nissum Bredning off Helligso tile-kiln, 5,5 m (C. H. Ostenfeld). var. Granü. Lf: western Limfjord, on an oyster-bed, brought up by a diver; form with rather long unbranched branches. — Kn: FG, Herthas Flak; off Frederikshavn; TR, Trindelen. — Ke: IR and ZI, Groves Flak; IL and IQ, Fladen; IH and IK, Lille Middelgrund, in quantity, on pebbles and gravel and loose; IA, Store Middelgrund (! and F. Børgesen). — Km: Læsø Rende, a crustaceous specimen with scarce low papille, on a piece of coal; ND, N.E. of Fornæs. — Ks: HO, E. of Hesselo; EO, 26,5 m; A, S.E. of Hessele.’— Sa: E. of Samsø (C. Lofting); BE, off Sletterhage, 10 m; KM, E. of Oreflippen; PL, Wulffs Flak; north side of Refsnæs, 19 m (C. H. Ostenfeld); MS, S. of Klophagen by Endelave. — Lb: Middelfart. — Sb: MO, S.W. of Refsnæs (? young specimens); near Sprogø, 19 m (C. H. Ostenfeld). — Su: Oretvisten (Johs. Schmidt); on the beach by Hornbæk (Mrs. M. Fibiger), probably brought by fisher- men from the southern Kattegat; bM, 22,5 m, crusts up to 1,5 cm in diameter with small wartlike processes. 5. Lithothamnion norvegicum (Aresch.) Kjellman. Kjellman, N. Ish. algfl. p. 122 (93), pl. 5 fig. 9—10; Foslie, Remarks 1905, p. 65; Lemoine, Structure, 1911, p. 108 fig. 11 and 48. 225 Lithothamnion calcareum Ellis et Sol. var. norvegicum Areschoug, Observ. phycolog. III. 1875, p. 4. Lithothamnion coralloides Crouan f. norvegica (Aresch.) Foslie, Norw. Forms 1895, p. 62, tab. 16 fig. 1-11. According to FOSLIE, this species is almost always freely developed on the bottom (Remarks p. 66). The specimens found in the Danish waters were all loose. FosLıE has referred them all to f. pusilla which, in his opinion, is “perhaps the typical form of the species”. He observes however (l. c. p. 64 and 67) that they “partly approach stunted forms of L. nodulosum f. gracilescens”. They give off branches in all directions and become up to 3 cm (more rarely 3,5 cm) in diameter. The anatomical structure is not very different from that of L. glaciale. According to Mme LEMOINE, the cells are in the greater part of the frond rectangular, while Fig. 142. Fig. 141. Lithothamnion glaciale var. Granii. A, Lithothamnion glaciale var. Granii. Vertical section of sporangial sporangium; the process of division not conceptacle with ripe sporangium. 350:1. yet completed. B, ripe spore. 390:1. near the periphery they are ovoid. This may be so, but it frequently happens that rectangular cells in the inner parts of the frond alternate with ovoid ones (fig. 143 C). The change may take place at the distinctive lines between the zones or indepen- dently of them. The zones are limited by somewhat irregular lines staining deeply by hæmatoxyline, and the staining power of the single layers may sometimes be a little different, but the limit between such zones is not always marked as a blue line (fig. 143 C). The irregular course of the distinctive lines is probably in accordance with the irregularity of the increase. Transverse fusions between the cells frequently occur, though not so frequently as in L. Granü, and not uniting so many cells as in that species. The cells are 8—14y long, 6—9 4 broad; the rectangular ones are 11—14y long, 6—7 4 broad. The central tissue shows a different aspect in trans- verse section, according to whether the section has fallen in a zone with rect- angular or with roundish cells. The appearance of the starch is variable. It may appear in great quantities in the more deeply stained and in the less stained zones as well, all the cells being filled with starch grains except the outermost ones. In other cases it is entirely or almost entirely wanting. Conceptacles were found in specimens from most of the localities named below; D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk, og mathem, Afd. VII. 2. 29 they were in all cases, when examined, empty and more or less destroyed. I found sporangial conceptacles 300 or somewhat more in diameter. On stony bottom in 10—21 meters depth, usually associated with Corallina officinalis, in some places abundantly. Only found in the Samsø area. Localities. Sa: KI, south of Hjelm; PH, Lindholms Dyb; east of Samsø (Lofting); Stenpladen off Sletterhage (G. Winther); BE and BF off Sletterhage. Fig. 143. Lithothamnion norvegicum. A, axile longitudinal section of branch. B, part of a similar section near the top. C, part of axile longitudinal section of frond. The upper part of the tissue was deeper stained by hæmatoxyline than the under part. The fusion canals with the over-lving cells appear as round figures. D. transverse section of the central tissue of a branch. E, cell-rows from the periphery of a section of a branch. F, cells with starch grains. A 31:1; B—D 350:1; E, F 560:1. 6. Lithothamnion calcareum (Pallas) Aresch. J. Areschoug in J. Agardh, Sp. g. o. II, 1851, p. 523. Foslie, Lith. Adriat. Meeres u. Marokko, Wiss. Meeresunt. VII. Heft 1, 1904, p. 13 and 32, Tafel II; Remarks, 1905, p. 67; Mme P. Lemoine, Repar- tition et mode de vie du Ma£rl (Lithothamnion calcareum) aux environs de Concarneau (Finistere), Annales de l’Institut océanographique, tome I, fasc. 3, 1910; Structure, 1911, p. 102. Millepora calcarea Pallas, Elench. Zooph. 1766, p. 265. - Lithothamnion coralloides Crouan, Flor. Finist., 1867. p. 151, pl. XX no. 133. This species has been found in a few localities, in particular in the eastern Kattegat, but always only in loose specimens without or with imperfectly developed conceptacles. It is, as elsewhere, rather variable. The Danish specimens have been referred by FosLie to the following forms. 1. F. squarrulosa Foslie, Lith. Adr. Meer. Taf. II fig. 1—4; Lemoine, Répart. du Maer] fig. 1, 5, 14, Structure pl. I, fig. 5. To this form approaches f. corallioides (Crouan) Foslie, Norw. Lith. p. 62 pl. 16 figs. 24—25, 27-31. — This form has terete branches spreading in all directions. 2. F. compressa (M’Calla) Foslie, On some Lithothamnia, 1897, p. 9, Lith. Adr. 227 Meer., 1904, p. 32 Taf. II figs. 15—23; Lemoine, Répart. du Maërl pl. I fig. 14. It is “flabellate, the branch-systems spreading like a fan in all directions from the centre of the frond almost in one plane. Sometimes it forms rather thick and compressed fronds” (Foslie, Remarks p. 69). 3. F. palmatifida Foslie, Some new or cril. Lith., 1898 p. 6, Remarks p. 69; Lemoine, Répart. du Maërl pl. I fig. 3, Structure, p. 104. — “With branches more distant and palmate” (Foslie, 1905). 4. F. subsimplex (Batt.) Foslie, Norw. Lithoth. 1895 p. 62 pl. 16 figs. 38—42; Le- moine, Rép. du Maërl pl. I fig. 10, Structure p. 104. Frond “simple or feebly branching” (Foslie Remarks). There are no distinct limits between these forms, which occur together at the same locality. The structure has been mentioned by Mme Lemoine (Structure p. 105), whose description may here be referred to. It will suffice to add some small remarks. According to Mme Lemoine there is always at the periphery a cortex composed by 5 or 6 layers of cells which are rectangu- lar, while the other cells are ovoid. I have certainly observed such a cortex in some cases, but it does not occur normally; the outer tissue, in the sections examined by me, more fre- quently consisted of cells of the same shape as those of the inner tissues (fig. 144). Transverse fusions between the cells are very frequent. The size of the cells is somewhat variable, generally (I ar they are 9—13 y long, 5—7y broad. Starch grains were found in Fig. 144. great quantity in all cells except the outermost. On being treated Lithothamnion calcareum, with acetic acid and iodine in potassium iodide the starch grains er swelled and filled the cells with a homogenous violet-brown mass. an fusions. In a specimen from Trindelen (ZB, July) empty concep- : tacles were found, the kind of which could not be determined; they were almost entirely immersed. Possibly they were antheridial conceptacles. The species has been found in 17 to 30 meters depth, on gravelly or stony bottom, generally associated with other Lithothamnia, in particular Lith. glaciale, and with Corallina officinalis. Localities. Kn: ZB, near Trindelen, 28—30 meters. — Ke: IL and IP, Fladen; IK, Lille Mid- delgrund. — Km: Læso Rende, clayey bottom, small fragments (C. H. Ostenfeld). Subgenus Phymatolithon Foslie. In 1898 Fosrie (Syst. Surv., p. 4) established the genus Phymatolithon, founded on Lithothamnion polymorphum, and distinguished from the genus Lithothamnion chiefly by immersed conceptacles and the roof of the sporangial ones being de- pressed or cup-shaped. Later on he has referred L. levigatum and another species to the same genus. I must, however, agree with Mme Lemoine, who observes (Struct. 29% 228 p. 63) that the characters pointed out by FosLie are not sufficient for generic di- stinction but only for separation of sections beyond the genus. The roof of the sporangial conceptacles is frequently scarcely immersed, and it is often, particularly in L. levigatum, convex within a feebly elevated border. 7. Lithothamnion polymorphum (L.) Aresch. J. E. Areschoug in J. Agardh, Spec. II, pars 2, 1852, p. 524 ex parte; Rosanoff, Melobes., p. 99; Strömfelt, Algveg. Isl., 1886, p. 19, pl. I, fig. 1—3 (sporangia); Foslie, Norw. Forms, p. 86, pl. 17, fig. 17—23 (f. tuberculata, f. valida and f. papillata); Mme P. Lemoine, Structure, 1911, p. 87, pl. V fig. 2. Phymatolithon polymorphum (L.) Foslie, Syst. Survey, 1898, p. 4, Remarks, 1906, p. 75. Eleutherospora polymorpha (L.) Heydrich, Lith. Helgol., 1900, p. 65, Taf. II, fig. 1—14. The species forms more or less irregular crusts extended over larger boulders, of a thickness of up to 6 mm. As to the structure reference may be made to the papers of FosrLıE (1906) and Mme LeE- MOINE. The hypothallium is shown in fig. 145 A. The cells of the perithallium are somewhat variable in thickness, 4—7y, in some specimens proportionally narrow, 4—5 » (fig. 145 B) Mme LEMOINE men- tions as an interesting character that the starch grains are single, very small and grouped at the ends of the cells. This is, however, not always so, for I found the starch grains up to 3y in diameter, and in some parts, frequently the greater part of the crust, all the cells were filled with starch grains, while they were totally Fig. 185. wanting in others, Particularly abund- Showing Ihe hypothaliiam and the lower part of the per Aut Starch grains were found in the tissue thallium. B, vertical fllaments of another frond with nar- filling out the emptied conceptacles in rower cells. C, cells of perithallium with starch grains. 350:1. 2 the inner part of the crusts. Cells con- taining starch grains at the ends of the cells but not in the middle were indeed observed, but only as exceptions. Transversal fusions between the cells of the peri- thallium occur here and there. The increase in thickness of the crust normally takes place by continued growth of the perithallium, which may show several zones limited by horizontal, but some- what irregularly running lines. In older crusts a more complex structure may be found, the frond being composed of two or more crusts one over the other, each with a particular hypothallium. This arises through cessation of growth in thick- ness in certain parts of the perithallium, which become overgrown by new crusts developing from other parts, of the crust. This structure has been mentioned by Mme LEMOINE (Struct. p. 24 and 88, pl. V fig. 2), who appears to consider it as arising through differentiation of the same crust. In the new overgrowing crusts, the limiting lines between the successive zones of tissue are more or less inclined. This complex structure is not always found even in old fronds. Crusts up to 1,5 mm in thickness showing only one hypothallium are frequently met with, The muciferous canals of the sporangial conceptacles open outwards in a low hollow surrounded by a slightly elevated border, but it is sometimes very slight or Fig. 146. Lithothamnion polymorphum, vertical sections of sporangial conceptacles, A, the first division of the sporangium is not accomplished, the following not yet begun. B, with a very long sporangium. C, conceplacle with undivided and fully divided sporangia. D, ripe sporangium. E, empty sporangial conceptacle with covering tissue; below, limiting line of zones and outline of empty conceptacle filled wilh regenerative tissue. A—D 200:1; E 63:1. scarcely perceivable, if at all (fig. 146). The sporangia are at least divided into 4 spores. As stated by FosLiE, the sporangia are 80—110 long, 25—45, broad; the outermost ones, however, reach a greater length (fig. 146). After the evacuation of the sporangia, the conceptacles become sunk in the crust by continuation of the growth in thickness of the frond, but their surroundings may then behave in different manners. 1) The filaments of the roof grow upwards in accordance with those of the surrounding frond, and the conceptacle forms an empty round hole. 2) The roof falls into decay and the conceptacle is filled more or less completely by tissue growing inwards from the tissue which is developed by increase in thick- ness of the surrounding part of the frond and united over the conceptacle. 3) The conceptacle is completely filled by a tissue produced from the bottom of the con- Fig. 147. Lithothamnion polymorphum. Vertical section of emptied sporangial conceptacle, showing two muciferous canals and the covering tissue. About 350:1. a ceptacle. The newly evacuated conceptacles are sometimes covered by a peculiar, rather thick tissue, which is sharply marked off from the roof (fig. 146 E, 147, Plate III fig. 6). Its cells are fre- quently broader than tbose of the roof, (fig. 147). In a living state this covering tissue appears as a white dot. It has been mentioned by FosLie (Re- marks, p.78). A similar tissue also occurs overthe sexual conceptacles. Its signification is unknown. Antheridial conceptacles I have not seen; they have been mentioned by HEyDrıcH (1900, p. 68, Taf. II fig. 1—3) and Foslie (1905). According to the first named author, the spermatia are produced from branched filaments given off from the inner side of the conceptacle, as it seems, in a similar manner as in L. Lenormandi. THURET states (Et. phyc., 1878, p. 91) that the spermatia resemble those of Jania rubens. The cystocarpic conceptacles are, according to FOSLIE, at first convex, but they are not always so, for fairly young, totallv immersed conceptacles may be found (fig. 148). As to the development of the cystocarp more detailed statements are given by HEypricx (1. c. p. 70) which are in several respects in discordance with those of Sots for other Corallinaceæ. They very much need a critical trial, but as I have had only dried specimens at my disposal I can only throw little light upon the matter. Before fertilization the concave bottom of the conceptacle is covered with numerous procarps which aretwo-celled, asshown by Heypricu (fig. 148, Plate III fig. 5). These filaments are intensely coloured by hæm- atoxyline. The lowest cell is probably an auxiliary cell, as maintained by Heypricu, and this is also in accordance with the statements of MINDER for Choreonema (Fruchtentw., p. 12). This cell may be rather long (fig. 148 C). The C= Lithothamnion polymorphum. carpogonia. B, similar, with a rather long neck. C, procarps. section of the bottom of a female conceptacle, showing fusions between the ) Ÿ | I, ) Af. BR Fig, 148. 4, verlical section of female conceptacle with D, vertical cells, A, B200:1. C, D 350 :1. 231 wall between the two cells is more or less oblique, but a hypogynous cell is not cut off from the lowermost end of the carpogonium as in Choreonema. I have not been able to follow the development of the carpogonia after fertilization, but it must be said that there is nothing to support the supposition of Hryprica that each auxiliary cell becomes a carpospore. The only thing which might favour this view is the fact that the carpospores are produced not only at the periphery but also from the central part of the floor of the conceptacle, as shown by HeypricH (I. c. fig. 12), and as I have also observed it (fig. 149). But the carpospores do not arise singly; they are produced in short rows, as shown by earlier authors (SoLMS, PILGER, MINDER) for other Corallinaceæ. This is shown in fig. 149 where a smal- ler (younger) car- pospore is situated under the most developed ones; they have undoub- tedly been produ- ced successively by the sporophyte, but the behaviour of the latter could Fig. 149. not be stated. The Lithothamnion polymorphum, vertical sections of eystocarpie conceptacles with carpo- spores. A 200.1. B 350:1. low cells visible under the youngest carpospores are probably parts of the sporophyte (or of the fu- sion cell, if Sozms’ view is correct); or might there perhaps be more than one sporophyte? The cells situated below the procarps may show lateral fusions (fig. 148 D), but it is doubtful whether these fusions have any relations to those of the sporophyte with the auxiliary cells. The evacuated cystocarpic conceptacles remain empty, or become partly filled with regenerating tissue produced from above. As mentioned above, this species grows particularly on large boulders; it is therefore probably much commoner than might be supposed from the localities given below, while it does not always become loosened from the stone by the dredge. It occurs in all the three forms quoted by Fostie which however, as stated by this author, are “not well defined, as transitions often appear to occur”. It seems to be rather common in the Danish waters to the limits of the Baltic Sea, with the exception of the Limfjord and other fjords where it is wanling. It seems most common in the Kattegat. It occurs in depths of 2 to 19 meters. Tetrasporangia have been met with in April, carpogonia in January and May, and carpospores in May. Localities. Sk: ZK" off Lønstrup, 11,3 m; off Hirshals, 11—15 m. — Kn: TX, north of Græs- holm (Hirsholmene); on stones picked up by Hirsholmene, about 4,5 m, large crusts; east of Deget; off 232. Frederikshavn; UC, TO, 18 m and FF (Trindelen) north of Læsø. — Ke: ZE, Fladen; IB, Store Middel- grund. — Km: XB and XC south of Kobbergrund. -- Ks: HS, Briseis Grund; OU, Schultzs Grund; 00, Seborghoved Grund. — Sa: KK, Klergrund, south of Hjelm; FT, Klepperne. — Lb: Middelfart. — Sb: Reef at Korsor harbour, 2m; NN, south-west of Sproge, 19m. — Su: Off Aalsgaarde, 26m (H. E. Petersen); TF”, Staffans Flak, 14—18 m. — (Bm: Stones picked up near Stevns ?). 8. Lithothamnion levigatum Foslie. Foslie, Norweg. Forms, 1895, p. 139, pl. 19, fig. 21—23; Heydrich, Lithoth. Helgoland, 1900, p. 76. Lithothamnion emboloides Heydrich, Lith. Helgol., p. 74, Taf. II Fig.-15 (teste Foslie). Phymatolithon levigatum (Fosl.) Foslie, Remarks. 1905, p. 79. Judging from Danish specimens, this species appears to be quite distinct from L. polymorphum, whereas, according to FosLıe (Remarks, p. 79), in more southern localities there is no distinct limit between these two species. L. levigatum is charac- terized by a comparatively thin, smooth crust, up to 0,5mm thick, by the roof of the sporangial conceptacles disappearing after the evacuation of the sporangia, and by the two-parted sporangia. When occurring together with L.. polymorphum, the difference between them is evident; the two species are, however, only rarely met with in the same locality, and it must be emphasized that L. polymorphum does not occur in the Limfjord, where L. levigatum has been met with in several loca- lities. I therefore do not doubt that they are specifically distinct. The anatomical structure much resembles that of L. polymorphum. The hypo- thallium is similar, but is sometimes more fully developed. Its cells were found to be 13—-21 y long, 4,5—7 » broad. The cells of the perithallium were less variable in breadth than those of L. poly- morphum; they were almost al- ways 6—7 y thick. The length . was usually 6—9y, most frequently 7—8 vy, or only little greater than the breadth, and the rounded cells thus approach the spherical form; but cells shorter than broad are also met with (fig. 151 A). Trans- verse fusions occur here and there, in the hypothallium and the peri- thallium as well. Starch grains are frequently present as single grains in great numbers in most Fig. 150. Lithothamnion levigatum. Vertical sections of crust from Bolsaxen. Sb, showing sporangial conceptacles and limiting lines between the of the cells, except the uppermost. zones, fig. D also the hypothallium. 65:1. .. Only sporangial conceptacles were met with. They resemble those of L. polymorphum, and the hollow containing the roof is, as in that species, sometimes very slight or wanting, and the elevated border may also be wanting, the surface over the conceptacle thus being quite even or with 233 only a feeble trace of deepening or elevation (fig. 150 C). The roof is sometimes convex, though inserted in the bottom of a hollow. The sporangia are, as stated by FosLiE, always two-spored. I found them to be 95—126 „ long, (18—)37—53 4 broad, thus a little smaller than the dimensions found by Foszie, which might perhaps partly be caused by the fact that my mea- surements have mostly been made with dehydra- ted sections. The concep- tacles are sometimes co- vered bya particular tissue similar to that mentioned for L. polymorphum (p.230). It has also been mentioned Zum: by HEyprIcH and FosLie (Remarks, p. 80). Accor- Cc ding to the first named Fig. 151. author (i. ce. p. 76) it is al- Lithothamnion levigatum. A, vertical section of hypothallium and the under o part of perithallium. B, vertical section of crust with emptied sporangial con- Ways present in L. em- ceptacle filled with regenerative tissue, showing the outlines of older filled boloides which, as shown conceptacles C, vertical section of empty conceptacle with covering tissue. x à F A 350:1. B-C 65:1. by FostıE, is identical with L. levigatum; it is, however, not suitable for use as a specific character, for in some specimens it covers all or nearly all the conceptacles, while in others it is almost or entirely wanting. I have only seen it on emptied conceptacles which still showed muciferous canals (fig. 151 C). It has a white colour. After the evacuation of the sporangia, the roof falls into decay. A regenera- ting tissue, produced from the bottom of the conceptacle, consisting of ascending filaments, may then fill the empty cavity. A new conceptacle is frequently produ- ced at so small distance over the first one that the base of the second is situated within the limit of the first, and the new one is thus partly produced by the re- generating tissue (fig. 150,151). Overgrown empty conceptacles do not occur. The species occurs in depths of 2—24,5 m, most frequently 5—20 m, growing on stones and on Mytilus and Ostrea, often in company with other Lithothamnia, as L. Lenormandi, L.glaciale and L. polymorphum. It has been found growing over L. glaciale, and in one case on the frond of Chondrus crispus. It has been found with ripe sporangia in April and May. Localities. Ns: aF, N.W. of Thyboren, 31 m. — Sk: 4 miles N.1/sE. of Svinklov beacon, 9 m (A. C. Johansen); SY off Løkken, 13m; ZK®, off Lønstrup, 12 m; off Hirshals (Børgesen). Lf: Salling- sund near Nykøbing (Th. Mortensen, !); LS!, 5,5 m and aT!, 4—5 m, east of Mors: Livø Bredning (C. H. Ostenfeld); Lendrup Ren. — Kn: Herthas Flak, 19—22 m; east of Deget near Frederikshavn; Trindelen, near the double broom (Børgesen). — Ke: IL, Fladen, 24,5 m; OO, Søborg Hoved Grund, 8,5 m. — Ks: RL, north of Gilleleje, 15m; HO, N.W. of Gilleleje, 22,5 m; OS, Hastens Grund, 14m. — Sa: KM, east of Oreflippen; BE, off Sletterhage; YV, east of Samso, 15 m; north side of Refsnæs, 19 m (C. H. Ostenfeld); D. K. D. Vidensk. Selsk, Skr,, 7. Række, naturvidensk. og mathem. Afd. VII, 2. 30 SUN DK, Bolsaxen, 13-15 m. — Lb: XQ, off Middelfart, north side of Lyngsodde, 19 m; north of Feng Kalv. — $b: GT, near the broom at Asnæs; GP off Halskov, 10 m; Avernakhage by Nyborg, shallow water; near Vresen, 7—9 m (Ostenfeld). — Su: At Ellekilde Hage 11,5 m. Epilithon Heydrich. Melobesiae, Ber. deut. bot. Ges. 1897, p. 408. 1. Epilithon membranaceum (Esper) Heydrich. Heydrich, Il. c.; Cotton, Mar. Alg. Clare Island, 1912, p. 150. Corallina membranacea Esper, Pflanzenk. 1786 t. 12, fig. 1-4 (not seen). Melobesia membranacea Rosanoff, Melob., 1866, p. 66, pl. II figs. 13—16, pl. III fig. 1; Hauck, Meeresalg., p. 265; Guignard, Dével. et const. des antheroz., Revue gén. de Botanique. I, 1889, p. 182, pl. VI figs. 22—23. Melobesia corliciformis Kützing; Rosanoff, Mélob. p. 76, pl. I figs. 14—16; Solms, Corall. p. 11, Taf. III Fig. 25. Lithothamnion membranaceum Foslie, List of spec. of the Lith., 1898, p. 7; Remarks, 1905, p. 72. As to the morphology of this species reference may be made to the descrip- tions of Rosanorr and FosLie, to which I have only little to add. The cells of the basal layer are, as pointed out by Rosanorr (1. c. p. 67), not arranged in distinct concentric zones; they are often connected through transversal fusions (fig. 152 A). The frond is monostromatic in its marginal part, which may be of greater or lesser extent. Otherwise the frond is often partly distromatic, and near the conceptacles it becomes gradually thicker, the cells dividing by transverse walls. There is thus no distinction between hypothallium and perithallium. The sporangial conceptacles were often somewhat smaller than stated by Fostiz, viz. 110—140 » in diameter. Their outline is frequently oval, as mentioned by Rosanorr (I. c. p. 76) and Mme Lemoine (in Corton, Clare Isl. Sury. p. 150). The number of the mu- ciferous canals was also often some- what less than that found by FOSLIE, namely 8—27, most frequently 16—21, while FostLie indi- cates 20—30. No relation was found between the num- ber of the muci- ferous canals and the locality. The sporangia Fig. 152. apparently arise Epilithon membranaceum. A, frond seen from below showing several fusions. B, tetraspor- En angium not yet fully divided. C, sporangial conceptacle seen from above; a sporangium from the second is seen under the roof, D, vertical section of sporangial conceptacle, A,B,D 345:1. C 200:1. cell-layer. The 235 cells of the basal layer situated at the periphery of the conceptacle lengthen in a vertical direction, fuse laterally two or three together, and are finally disorganized, the upper part of their membrane being dissolved as far as it meets the cavity of the conceptacle. The cells of the same layer forming the central part of the floor of the conceptacle are disorganized in the same Way, their contents finally disappearing, but they do not lengthen. In fig. 152 D the contents of these cells are still visible. In the sexual conceptacles the basal layer is Fig. 153. exhausted in a similar way. The formation Epilithon memb anaceum vertical, somewhat excentric RN 3 section of sporangial conceptacle. 345:1. of the three dividing walls of the sporangia is almost simultaneous, the walls advancing slowly from the periphery towards the longitudinal axis of the sporangium (fig. 152 B, D). The antheridial conceptacles were found agreeing with the description and figure of RosanorF (I. c. p. 59, pl. II fig. 14). The cells surrounding the orifice are elongated and directed obliquely upwards (fig. 154). The antheridia clothe the bottom of the conceptacle; their development and structure have been followed by GuIGNARD, who found that they are seriate in densely placed short filaments. When the sper- matia are to be formed, the protoplasm accumulates around the nucleus in the middle of the cell and becomes surrounded by a thin membrane, while the rest of the contents develop into two appendices, first described by Rosanorr and named “oreillettes”. The orifice of the cystocarpic conceptacles is clothed with similar elongated, hair-shaped cells like those of the antheridial conceptacles, but more numerous; ihey are directed inwards or downwards in the under part, upwards in the upper part of the orifice. The carpospores are only produced at the periphery of the conceptacle; in the central part of the floor carpogonia are still visible, when the carpospores are well developed (fig. 155 B). As to the structure of the procarps I cannot give any certain statement; they seem to resemble those of Litho- thamnion polymorphum. The species, referred by earlier authors to the genus Melobesia, had been transferred by HEYDRICH Fig. 154. in 1897 to a new genus Epilithon membranaceum, vertical section of antheridial conceptacle. 500:1. u a Epilithon, which was re- duced in the following year by FosLiE to a subgenus of Lithothamnion, with whith it agrees by the fructification. The want of differentiation in hypothallium and 30* 236 perithallium seems to justify the distinction of the genus Epilithon. Another impor- tant generic distinction seems to exist in the position and development of the an- theridia, which in the genus Lithothamnion, as far as known, are not seriate, and always placed on a system of branched filaments filling the cavity of the conceptacle (see above pp. 213, 218). The species usually grows on Furcellaria fa- stigiata, but occurs in the Kattegat also on Chon- drus crispus, and has likewise been met with on Phyllophora rubens and Ph. membranifolia. It is rather common in the Danish waters within Skagen to the western Baltic Sea, but does not occur in the Limfjord (and in other fjords), and Fig. 155. = 3 Epilithon membranaceum, vertical sections of cystocarpic conceptacles. À, sho- in the Sound it has only wing the orifice, B, showing carpogonia at the centre and carpospores at the been met with north of periphery. 350:1. Helsinger. It has been found in depths between 1 and 20 meters, and there is in this respect no difference between the different waters. Its absence in the Skagerak depends probably on the want of protection in this agitated water. Localities. Kn: Marens Rev, Deget a. o. locality near Frederikshavn; FF and FE, Trindelen, 9—15 m; UB and TG, north of Læsø. — Ke: IM, Fladen, 16m — Km: XB, south of Kobbergrund; NV, off Randers Fjord. — Ks: FO, Havknude Flak; GG, Sjællands Rev, 4m; D; EJ, entrance to Ise- fjord: RL, near Ostindiefarer Grund, 15 m; OO, Søborg Hoved Grund, 8,5 m. — Sa: FT, north of Samsø, 5,5 m; DK, Bolsaxen; AH and AH!, Lillegrund north of Fyens Hoved; MQ, south of Paludans Flak; AY, Ashoved. — Lb: AX, Bjernsknude, 9,5 m; north of Fæns Kalv; Fænø Sund; UX. at the north end of Ærø, 9,5 m. — Sb: DN, Vengeance Grund; Spodsbjerg; DT, off Magleby, Langeland. — Sm: Venegrund. — Su: BQ, off Ellekilde; off Aalsgaarde. — Bw: DU, off Dimesodde, 11,5 m;.UL, Øjet, 20 m; KZ. off Kramnisse, 4,5 m. Melobesia Lamour. emend. The extent of-the genus Melobesia has in course of time been repeatedly altered, certain species or groups of such having at various periods been detached there- from and referred to new or other previously known genera. Thus in 1889, SCHMITZ removed Melobesia Thuretii, and gave it the name of Choreonema Thurelii; in 1897, M. membranacea was established by HEyprıcH as representative of a new genus, Epilithon, related to Lithothamnion. FosLıE again, in 1898 (List of sp. p. 11) and 1900 (Rev. Surv. p. 21) placed M. pustulata and some related species under a new genus, Dermatolithon, characterised by having a single apical pore in the hemisphe- rical-conical conceptacles, sporangia “with short foot rising from the almost plain disc” and developing, according to Rosanorr, between club-shaped (?) paraphyses. In 1904 (Algol. Not. I. p. 3) however, he comes to the conclusion that these charac- ters had not proved sufficiently constant, and did not form any distinct limit as against the genus Lithophyllum. He therefore no longer maintains Dermatolithon as a genus, but regards it as a sub-genus under the last-named genus, to which Heydrich had already previously (Corallinaceæ etc., Ber. deut. bot. Ges. 15, 1897, p. 47) reckoned Melobesia Corallinæ Crouan, and points out that it is further distinguished by its anatomical structure, the hypothallium being formed by a single layer of inclined cells. In 1909, (Algol. Not. VI, p. 57) however, it is again reinstated as a genus, FOSLIE now attaching greater importance to the mentioned anatomical char- acter, and it was adopted by SvepeLıus in 1911. M. B. Nicuozs, who has subjected some species of this relationship to closer investigation, (Univ. of California Publ. in Botany vol. 3, No. 6, 1909) discusses some of the other characters cited by FOSLIE, viz: the presence of a “plug” in the orifice of the sporangial conceptacles united at the basis by a parenchymatic tap; the position of the sporangia at the bottom of the conceptacle, which in Melobesia is said to be almost flat, in Lithophyllum over- arched; and the presence of a stalk cell under each sporangium in Melobesia. He adopts the standpoint which Foslie then adhered to; i. e. not maintaining Dermato- lithon as a genus, but referring the species concerned to Lithophyllum, (L. macro- carpum, pustulatum, tumidulum). He points out, however, that in so doing, “the characters which separate Lithophyllum and Melobesia are not sufficiently well marked to warrant two separate genera” (p. 361). With regard to the structure of the con- ceptacles and the organs of reproduction, there is doubtless great similarity between the two genera; at any rate, no thoroughgoing differences appear to have been de- monstrated up to now. The vegetative structure seems to me to present an ex- cellent distinctive character, as in Melobesia, we never find transverse pits between the upright cell-series proceeding from the basal layer, whereas such are present in all Lithophyllum species, including the subgenus Dermatolithon. On the other hand, transverse fusions are of common occurrence in the Melobesia species, but are wanting in Lithophyllum. This seems, as a matter of fact, to be the best distinctive character between the two mentioned genera. As to how far there may be reason to make further exclusions from the genus Melobesia, this must be left to further investigations to decide. Fostir, in 1900, (Rev. Surv. p. 21) established a subgenus Heteroderma, which he characterises as having the “thallus composed of more layers of cells” in contrast to Eumelobesia, which should have but one layer, except as regards the frond near the conceptacles. In 1905 however, (Remarks p. 102) a different limitation is made, and in 1909, (Alg. notes VI, p. 56) Heteroderma is raised to the rank of a genus, distinguished from Melobesia solely by the lack of hair-cells. I do not consider that we are justified in distinguishing between two genera merely by the presence or absence of hair- 238 cells, as the occurrence and frequency of these cells seems to depend to a great extent upon external conditions. I therefore attach but little importance to the fact that such have not hitherto been found in two of the species mentioned below (M. minutula and microspora) as it must be considered highly probably that they will be found on further investigation of a greater number of specimens. More- over, hair-cells are found in M. Lejolisii, noted by Foszie under the genus Hetero- derma (see fig. 156). On the other hand, I could well imagine that it may later on be found justifiable to distinguish between those species in which the trichocytes are terminal in the horizontal cell filaments, as in M. farinosa, for instance, and the other, doubtless far more numerous species in which they are intercalary. Another vegetative character which might be thought to furnish grounds for generic distinc- tion, is the lack of- cortical cells shown below in the case of M. microspora. This point, however, still needs further investigation. As regards the cortical cells, it may also here be noted that in M. trichostoma, several of these were found above one another, cut off successively by the same frond cell. Where the frond consists of more than one cell-layer, there is often but slight difference between the basal layer (hypothallium) and the upright cell filaments proceeding therefrom (perithallium). Thus the walls forming the boundary belween these two tissues often lie at different heights, as for instance in M. microspora (figs. 176—179) and M. trichostoma (174—175). The number of spores in the sporangia is in most of the present species con- stant. In four species, 4 spores were found, in M. subplana a constant 2. In M. mt nutula only specimens with 4 spores were found, whereas FosrLıE gives 2, and in M. Fosliei some conceptacles were found with 4, others with 2 spores in the spor- angia. — À small stalk-cell under the sporangium was found in M. subplana. With regard to the antheridia, M. Lejolisii was found to differ from the other species in having the spermatangia formed at the end of long sterigmata, as first shown by Mrs. WEBER-van Bosse. In the other species, the spermatangia are elonga- ted cells, situate on the flat bottom of the antheridia-conceptacles. The orifice of the antheridia-conceptacles was in four of the present species often found drawn out into a spout, as first shown by Mrs. Weber-van Bosse in the case of M. Lejolisii. This is, however, not a constant character, as it may frequenily be lacking in all the species concerned. The carpospores are in all the cases investigated formed only in the periphery of the conceptacle, at the margin of the flat disc-cell. 1. Melobesia Lejolisii Rosanoff. Rosanoff, Rech. anat., 1866, p. 62, pl. I fig. 1—13, pl. VII fig. 9—11; Areschoug, Observ. phycolog. Part. III, 1875, p. 3; Hauck, Meeresalg., p. 264; A. Weber-van Bosse, Bijdrage tot de Algenflora van Neder- land, Nederl. kruidk. archief. 2. Ser. 4. deel 4e stuk, Nijmegen 1886, p. 365; ead. in Hauck et Richter, Phykotheka univers. No. 163; Foslie, Remarks, 1905 (1906) p. 102 (f. typica); Mme P. Lemoine, Struct., p- 180, fig. 103; ead., Calcareous Algæ in Report on the Danish Oceanogr. Exped. 1908—10 to the Mediterranean etc. Vol. II, 1915, p. 19. Among the distinctive characters of this species, used by Rosanorr, in his important paper on the Melobesiacez, the want of “heterocysts” has been of special importance in distinguishing it from M. farinosa, as it permitted determination even in cases where the characters taken from the organs of reproduction could not be used. As shown by FosLıE however, |. c. p. 103, the cells situated under the dicho- tomies are often larger than the others and resemble the heterocysts of M. farinosa. I can confirm Foslies statement, having frequently found these cells in Danish specimens of M. Le- jolisii. They agree indeed completely with the hetero- cysts of M. farinosa, in bearing a hair or a scar left by a shed hair, in being poorer in contents and in bearing no cortical cellsas do the other cells of the mono- stromatic frond. But they differ from the hetero- cysts of the last- named species in being derived, not 18, from end-cells of Fig. 156. filaments, which Melobesia Lejolisi, from Birkholm, Sf. A, vertical section of marginal part of frond, * trichocyte. B, monostromatic frond seen from above; below a trichocyte, numerous fusions. C, marginal part of frond seen from above; two trichocytes are visible, one further, but from with hair. D, vertical section, not median, through a sporangial conceptacle; only un- divided sporangia present. E, vertical section through emptied sporangial conceptacle. 350: 1. do not develop cells situated under a ramification. I have convinced myself that this difference really exists by exami- ning authentic specimens of M. farinosa. Where the included heterocysts of this species are present it is easily seen that the two cell-rows, the separating line of which goes in continuation of the heterocyst, are not given off from this, but from the adjacent cell-rows. As shown by Sous (Cor. p. 24), these cells produce a hair without formation of a transverse wall. The hairs are, according to the mentioned author, very short-lived, and fall off after a separation has taken place at their base by local incrassation of the longitudinal wall. This is also the case with those of M. Lejolisii; sometimes, however, they are more persistent, and appear as long hyaline hairs (fig. 156 C). Their wall is stained very intensely by hæmatoxyline, by which they become very obvious, and the same is the case with the basal part of the cell, after the throwing off of the hair. As these cells are very different from the heterocysts of the Cyanophyceæ, I think it better to give them another denomination; they must be named hair-cells or trichocytes (comp. p. 213). They are somewhat larger than the other cells. Sometimes also, other intercalary cells than the branch-producing ones may develop into a trichocyte, and it may also happen that a trichocyte produces a cortical cell. These cells appear to be of normal occurrence, though varying in number". In the monostromatic part of the crust the cells are 7—10(11) » broad, and usually 1—11/2 times as long. The dimensions are somewhat variable (comp. figs. 156 and 158). In specimens from the inner Danish waters (Sf and Sm) the breadth of the cells was only 7—9z, in specimens from Lf and Kn it was up to 114; this is possibly caused by the difference in salinity of the water. These cells often contain numerous starch grains, but the trichocytes contain no starch. The cortical cells are always longer in transversal than in radial direction. Trans- versal fusions between the cells may occur, some- times in great number (fig. 156 B). In a verti- cal radial section the cells are seen to be of Fig. 157. Melobesia Lejolisii. Vertical sections of conceptacles. A, from Stensnæs, Km, sporangial conceptacles. B and C from Kragenæs, Sm; B, with carpogonia, about the same height as C, with undivided sporangia, in the middle a columella. 350:1. breadth. The marginal part of the frond remains monostromatic, the small cortical cells not taken into account. Only in the immediate vicinity of the conceptacles the frond consists of 2—3(4) layers of cells. As the conceptacles are densely placed in the greater inner part of the crust, the frond is monostromatic only in the marginal part. The statement of Mme Lemorne (Structure, p. 180, fig. 103) that the crust of ! The trichocytes appear to be variable in their occurrence also in M. farinosa. In specimens from LE Joris, Alg. mar. de Cherbourg no. 194, which, as shown by FOSsLIE, is a typical M. farinosa, I found the characteristical trichocytes quite in accordance with the descriptions of Rosanorr and Sorms. On the other hand, in the Melobesia communicated in Crouan’s Exsice. no. 244, which indeed is referred to M. Lejolisii by Fosuie, I did not find any heterocysts at all. This alga agrees, however, otherwise with M. farinosa, by the dimensions of the cells (L1—14 broad, about 11/°—2 times as long) and by the round, not transversely elongated cortical cells. I suppose therefore that it is a form of M. farinosa, in which no trichocytes have been developed. 241 this species consists of three cell-layers, the middlemost of which is composed of high cells, must refer to the fertile part of the crust (comp. fig. 159 D); but the author says that she has observed three layers also at a great distance from the con- ceptacles. Possibly, the specimens referred to this species by Mme Lemoine do not all belong to it. In Calc. Alg. Med., 1915, p. 19, the same author mentions spe- cimens of this species from the Mediterranean consisting only of two layers of cells, the upper being the cortical cells; these specimens thus agree with the Danish ones. The conceptacles of sporangia are usually densely crowded. They are low conical or, when very densely placed, de- pressed, with almost level surface (figs. 156 —158). The orifice is rather narrow, almost cylindrical, not enlar- ged upwards, clothed with unicellular hairs of varying length. In rare cases I found the hairs long and protru- ding outwards in a ver- tical direction (fig.158 D), as drawn by ROSANOFF in fig. 11, pl. I, I. c., but usually they are shorter, Fig. 158. directed inwards hori- Melobesia Lejolisii, from TG, north of Læsø. A, frond seen from above, at left a % trichocyte. B, vertical section of antheridial conceptacle, not yet ripe. C, vertical zontally and not PLO- section of antheridial conceptacle provided with a spout. D, vertical section of truding (figs. 156 E; 157 sporangial conceptacle with well developed peristomial hairs. Æ, the same spor- angium as seen in D, from a following section. B and C 650:1, the rest 350:1. A, comp. ROSANOFF’s i fig. 8). The last quoted figure of ROSANOFF certainly represents a normal, fully de- veloped state. FosLıE, who did not find any protruding crown at all in examining numerous specimens, thought that this- might perhaps be owing to the fact that he had only had dried material for examination, “or it may be that the cells of the corona have a short phase of development and are soon falling to decay”. My investigations do not favour these suppositions; it must be supposed, that the de- velopment of the hairs is variable according to the various conditions. — The roof of the conceptacle is rather thin, consisting of about 2 (1—3) cell-layers, only a little thicker, if at all, near the orifice. The floor of the conceptacle consists of a single cell-layer; more rarely this cell-layer is absorbed (fig. 157 A). In some cases a sterile columella was observed in the centre of the conceptacle (fig. 157 C), but D. K. D. Vidensk, Selsk, Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 2. 31 242 usually no such formation was to be seen. The sporangia are, when fully devel- oped, four-parted, 45—77 » long, 32—49 » broad. While at first vertically placed, they may sometimes finally become horizontal, at all events when the conceptacle contains only one or two developed sporangia (fig. 158 D—E). The antheridial conceptacles are small, often very small, and but little pro- minent if at all. As shown by Mrs. WEBER-VAN BOSSE (I. c.), the spermatia are produced at the end of long sterigmata developed from a layer of very small cells covering the basal layer (fig. 159 A, C). In some cases, however, the cells producing the sterigmata are not placed di- SS ES rectly on the ba- lea Pl sal layer (fig. 158 | WA | | LMI spre | B, C). In some cases the concep- tacle was found provided with a long slightly cur- ved spout agree- ing exactly with that described by Mrs. WEBER (fig. 158 C); but in most cases no Melobesia Lejolisi. A and B from Holbæk Fjord, A, antheridial conceptacle. B, female such spout Was conceptacle, showing carpogonia. C, antheridial conceptacle. D, cystocarpic conceptacle, to be seen. The C 650 :1, the rest 350: 1. ostiole was then a simple small hole without any peristome. The spermatia appeared sometimes as slightly elongated ceils with pointed ends (fig. 159 C). Well developed female conceptacles were only rarely found. The conceptacles shown in figs. 157 B and 159 B are certainly female ones, containing unfertilized carpogonia, and fig. 159 D represents a cystocarpic conceptacle with the carpospores placed at the periphery only. A disc-cell could not be distinguished. Peristomial hairs seem not to be developed. The diameter of female conceptacles was found to be 123—175 ». Ripe tetrasporangia have been found in summer (June to September), anthe- ridia in May and September, and cystocarps (with few spores) in May. I have referred to this species all the specimens growing on old Zostera-leaves and referred by FosrıE to M. Lejolisii f. typica, with the exception of one sample mentioned below under M. subplana. The species has also been found growing on Ruppia. The specimens growing on Algz, on the other hand, seem to belong to other species, which are mentioned below. The species has been found in depths of 1—11 meters. 243 Localities. Lf: Thyboron; Nykobing; LQ, Lendrup Ron; MK, Holmtunge Hage; F, Lunde Hage; ML, Gjols Bredning; stone reef west of Draget; Hals. — Kn: TP, Tonneberg Banke; TG, near Syrodde Pynt. — Km: BO, Stensnæs; EZ and XC, south of Læsø. — Ks: NL, Isefjord; Lammefjord; Holbæk Fjord. — Sa: Besser Rev, Samsø, partly on Ruppia; MT, Horsens Fjord; Odense Fjord (C. Rosenberg). — Sf: Nakkebolle Fjord; Svendborg; U, Birkholm; EA, north of Rudkobing. Sb: Munkebo, Kertinge Nor; Avernakhage by Nyborg. — Sm: CM, Kragenæs; CO; CR, off Dyrefoden; Guldborgsund. 2. Melobesia subplana sp. nov. Crusta orbicularis, 1—2 mm diametro, in statu adulto non nisi margine angu- sto monostromatico, ceterum 2—6 cellulis crassa, cellulis in parte marginali c. 7—8 y latis, cellulis corticalibus rotundatis, in sensu radiali paulo elongatis, trichocytis intercalaribus. Fila verticalia partis frondis crassioris cellulis longitudine vario, 6--9 crassis constituta. Conceptacula sporangifera dense posita, paulo prominula, diametro externo c. 150—200 y, interno 70—105 y; sub conceptaculis 1—2 strata cellularum vegetativarum; tectum subplanum, c. 2—3 cellulis crassum, ostiolo cellulis paulo horizontaliter elongatis, non erumpentibus, vestito. Columella centralis conica. Sporangia 42—60 y longa, 26—32 y, lata, semper disporica. Conceptacula mascula parva, immersa, nonnunquam tubo longo prorumpente munita, fundo cellulis sper- matogenis numerosis elongatis, leniter curvatis, e strato cellularum rotundatarum egredientibus, vestito, spermatiis longis, clavatis, leniter curvatis, c. 11 » longis, c. 2 crassis. Sub conceptaculis masculis 1—3 strata cellularum vegetativarum. Con- ceptacula feminea parva, immersa, initio non prominula, stratis cellularum vegeta- tivarum 1—3 suffulta. Cystocarpia non certe cognita. The specimens which have served as base for this new species were collected near Horsens at the east coast of Jutland, growing on Zostera-leaves. They have been determined as M. Lejolisii typica by FosLıE, and certainly resemble this species very much; they differ however so much from it in some respects that I have thought better to regard it as a distinet species. The frond is polystromatic with the exception of a narrow marginal zone. It consists otherwise of vertical cell-rows composed of 2 to 5 cells, not including the small cortical cells, which are cut off by oblique walls. Near the border, the cor- tical cells are seen to be rounded, narrow, usually a little lengthened in a radial sense, sometimes placed not over the anterior border but over the middle of the cell (fig. 160 A). Hyaline hairs are sometimes numerous, given off from cells without cortical cells, also from the polystromatical part of the frond. The cells of the ver- tical cell-rows are of varying length. There is less contrast between the basal layer and the perithallium than in M. Lejolisii, the upper wall of the cells of the former falling not always at the same level, the cells thus being of somewhat varying height. While in M. Lejolisii the intermedial layer in thicker crusts consists only of one layer of long cells, it is in M. subplana usually 2—4 cells thick, its cells varying from 1 to 3 diameters in height, shorter and longer cells alternating irre- gularly, and the transversal walls falling at different levels in the different filaments. 31* Transversal pores do not occur, but transverse fusions frequently take place, most frequently in the basal layer, but also between cells at a higher level. Abundant starch-grains occur in the ordinary vegeta- tive cells. The sporangial conceptacles are nu- merous and densely crowded. They are only slightly prominent, but where they are very densely placed, the single conceptacles are often not prominent at all, the surface being even (fig. 160 C). It is therefore not always possible to indicate the outer dia- meter of the single conceptacles. The ostiole Fig. 160. is lined by elongated cells radiating towards from the face, B, vertical section of border of frond, the centre of the canal. At last they assume C, vertical section of sporangial conceptacle. 4 and the character of rudimentary hairs directed B 350:1. C 200:1. i ; ; inwards. The middle of the conceptacle is occupied by a conical columella of sterile cells, while the sporangia are placed in the outer part of the conceptacle. A little stalk-cell was frequently seen under each sporangium. The sporangia are always two-celled. I have seen numbers of them, some preserved in alcohol, and can assert that they were really two-celled, also at maturity. I have seen only one or two male plants containing some antheridial conceptacles. These are small, completely immersed. The bottom of the conceptacle is covered by a layer of small, somewhat rounded cells, from which are given off numerous elongated slightly curved spermatia- producing cells a little incrassated upwards. I have not Fig. 161. been able to follow the development of the spermatia, but RARE At arse Mato I do not doubt that the elongated cells in question are at tight pee Spermatia: the spermatangia, which produce long clavate, slightly cur- = ved spermatia (fig. 161). The spermatia are not formed at the end of long thin sterigmata. The ostiole of the conceptacle was in some cases provided with a long spout resembling that of M. Lejolisii (fig. 161), in other cases no such spout was present. Very few conceptacles wilh carpo- gonia were seen. They were small, not prominent; the ostioleseemsto be provided Fig. 162. with a peristome similar to that of the Melobesia subplana. Vertical sections of carpogonial con- sporangial conceptacles. Fig. 162 B shows ceptacles. A with young, B with fully developed carpo- gonia. B, 485:1. 3 420:1. fully developed carpogonia with long 245 trichogynes penetrating through the ostiole. As lo the structure of the procarps, my observations are so incomplete that I must content myself with referring to the figures without any interpretation. The bottom under the female conceptacles was composed of one to three layers of cells. Ripe cystocarps in good condition were not met with; they seem to be rather similar the tetrasporangial conceptacles. As will be seen from the above description, this species differs from M. Lejolisii principally by the structure of the polystromatic frond, by the shape of the spor- angial conceptacles, by the normal presence of a columella, by the two-spored sporangia, and seemingly by the formation and shape of the spermatia. Locality. Sa: On Zostera-leaves at Horsens, September 1893. 3. Melobesia limitata (Foslie) K. Rosenv. sp. nov. Melobesia Lejolisii Rosanoff f. limitata Fosl., Remarks 1905 (1906) p. 102. In his valuable paper on the northern Lithothamnia (Remarks, 1905 (1906) p. 102) FostıE described a forma limitata of Melobesia Lejolisii, characterized prin- cipally by smoother and apparently more solid crusts, and by less crowded con- ceptacles, frequently a little higher and somewhat pointed or subhemispherical- conical, and more sharply defined. He referred to it almost all the Danish speci- mens noted under the species mentioned but growing on Algæ instead of on Zostera. In examining these specimens, I have found that they not only differ in the characters named by FosLiE, but that they must be regarded as representing another species distinct also in several other characters. The crusts have a diameter of 3—4 mm, sometimes they reach 5mm or more. They are more or less irregularly orbicular with lobed margin. Frequently several crusts are confluent. The frond may be mono- ( stromatic from the border to the concep- \ tacles, or the inner part may be distromatic (figs. 166, 167) or even thicker (fig. 163 D). | When seen from the face, the frond pre- sents a similar aspect to M. Lejolisii, but the Fig. 163. al å Melobesia limitata. A—B, marginal parts of frond, cells are usually somewhat longer, VIZ. seen from the face, from M; 4, before, B, after de- (7—)8—10,5(— 12) m broad, 11/2 to 2 times calcification and staining. C and D, vertical sections 6 of fronds, from I, D from the central part. 350: 1. longer than broad. Transversal fusions sometimes occur. The cortical cells are longer in transversal than in radial direc- tion. Trichocytes usually occur; they may be cells situated under a ramification or ordinary intercalary cells in the radiating filaments. They usually lack cortical cells, but such may occasionally be produced (fig. 163 A at left). mi len! ALI d 246 The conceptacles are scattered, usually not contiguous. The sporangial conceptacles are conical or subhemispherical-conical, (170—)230 —325 y in diameter. The outer wall (the roof) is thicker than in M. Lejolisti, it is 3—5 cells thick and has its grea- test thickness near the ostiole. It consists here of very distinct cell- filaments radia- ting inwards and upwards. The longest ofthese fil- aments are those AN 5 LN or) cu) directed towards à een the upper border Fig. 164. ofthe ostiole, and Melobesia limitata from MH. A, vertical section of nearly emptied sporangial conceptacle. which sometimes B, sporangium divided into more than four cells. 350 :1. projectasacrown beyond the border of the ostiole. The filaments forming the crown are given off not only from the inner face of the canal, as in M. Lejolisii, but also from the outer surface (fig. 165). In other cases, however, the filaments do not extent beyond the border of the ostiole and a crown is thus not developed. The ostiole has usually a constriction almost in or under the middle, and over this the ostiole is funnel- shaped or barrel-shaped, according to the development of the upper peristomial filaments (figs. 164, 165). | This space is filled with a hyaline jelly. The con- verging filaments are easily observed when viewing the conceptacle from above. The bottom under the conceptacle consists of one or two layers of cells. The spor- angia seem to be produ- ced only in the peripheral part of the conceptacle, but there is no columella. The sporangia are four- Fig. 165. — o parted, 46—77 iP long, Melobesia limitata A, vertical section of sporangial conceptacle with well devel- 21—46(—61) 4 broad. Un- oped crown. 350:1. B, sporangium. 200: 1. i ae 247 divided and two-parted sporangia were frequently met with. In a specimen from the Limfjord, sporangia were found which were irregularly divided into more than 4 cells (fig. 164 B). The antheridial conceptacles (fig. 166) occur in the same plants as the female ones. They are very small, e. g. 56 y in inner diameter, totally immersed or only little prominent. The bottom is composed of one to two cell-layers. The cells of the roof are often partly disorganized. The ostiole is conical or conical-cylindrical, sometimes, but not always provided with a long spout resembling that in M. Lejolisii. The spermatangia are cylindrical and form a dense co- vering on the flat bottom of the con- ceptacle; they are produced from low cells forming a layer over the bot- tom. The sperma- tia seem to be ob- long, 2—3 times as long as broad. There are no long sterigmata as in M. Lejolisii. The female conceptacles Ke Melobesia limitata. Vertical sections re conceptacles. A—C from I, D from semble the SPOT- Amtoft Rev. A and B, before discharge of the spermatia. D, the ostiole is prolonged in angial ones. A a spout. A and D 650:1. C 560:1. young stage with unfertilized carpogonia is shown in fig. 167 A; a number of car- pogonial branches are placed on the bottom. The short cell under the carpogonium is probably the auxiliary cell. After fertilization, the surrounding elongated cells shown in fig. 167 A are dissolved, the developing cystocarp increasing at the peri- phery. A ripe cystocarp is seen in fig. 167 D, showing a number of carpospores produced at the periphery of the cystocarp, while numerous unfertilized carpogonia are still visible on the middlemost part of the floor. The cystocarpic conceptacles are 210—325 » in diameter; they are of the same shape as the sporangial ones, and the roof and the ostiole have a similar structure. The ostiole is surrounded by similar inward and upward converging filaments, which may sometimes project outwards as a crown. A well developed crown is shown in fig. 167 C, where the free ends of the filaments are distinctly articulated. In fig. 167 D, which shows another conceptacle of the same plant, the free ends of the filaments seem to haye been thrown off, for the converging filaments are only one- or two-celled, and re- ae > \ HINT An D 248 mains of the free ends of the filaments are still visible at the border of the ostiole. On the other hand it is certain that a crown is not always developed, for ripe and emptied cystocarpic conceptacles may be found in which the structure of the ostiole WE Fig. 167. Melobesia limitata. Vertical sections of female conceptacles. with unfertilized carpogonia. with well developed crown consisting of articulated filaments. veloped eystocarpie conceptacle in the stage of emptying; the crown has 4, young stage B, fully developed cystocarpic conceplacle C, fully de- B 650 :1. perhaps been thrown off. From Amtoft Rev. A, C, D 350:1. agrees exactly with that of the young conceptacles shown in fig. 167 A, and which show no trace of a shed crown. As will be seen from the above, this species dif- fers from M. Lejolisii, besides the characters named by FosLıE, principally by the thicker roof of the sporan- gial and cystocarpic con- ceptacles, and by the cen- tral part of the roof con- sisting of long converging articulated filaments, some- times projecting outwards as a crown, and further by the structure of the antheri- dial conceptacles, the sper- matia being not produced at the end of long sterig- mata. I refer to this species the specimens from Nykg- bing, Mors referred by FosLıE with doubt to Me- lobesia farinosa f. borealis (Foslie, Remarks, p. 98). Foslie did not find any he- terocysts, but I found some intercalary trichocytes with or without cortical cells, as described above, thus different from those of M. farinosa, in which they are terminal. All the specimens referred to this species were growing on Algæ, particularly on Fucus vesiculosus, thus all the specimens found in the Limfjord, otherwise on Chondrus crispus, Rhodymenia palmata and Laminaria digitata. In the Limfjord it was always found growing together with Lithophyllum macrocarpum. Sporangia, antheridia and cystocarps were met with in August and September. The species is certainly annual. 29 Localities. Lf: Sondre Ron by Lemvig; Thisted; off Skrandrup and off Hanklit, Thisted Bred- ning; Venø Bugt off Nørreskov; Nykøbing; Amtoft Rev and LQ, Lendrup Ren in Løgstør Bredning. - Kn: Deget by Frederikshavn, on Chondrus crispus; Nordre Ronner; UB, north of Læsø; Trindelen, on Rhodymenia palmata, 19 meters. — Sa: AY, off Ashoved, on Laminaria digitata, 10 meters. 4. Melobesia Fosliei sp. n. Frons minuta ambitu irregulari, monostromatica vel prope conceptacula poly- stromatica. Cellule partis monostromaticæ (6—)7—9(—11) lat, diametro æquilongæ vel ad sesqui longiores; cell- ulæ corticales parvæ, ellip- tice. Trichocyti plerumque adsunt. Conceptacula spor- angifera hemisphærica vel subhemisphærica, diametro 80—140 —185 », dum dense posita confluentia. Tectum 1— 2 cellulis crassum. Cell- ulæ ostiolum circumdantes a ceteris paulo diversæ, non- nunquam ostiolum versus paulo elongatæ, vel papillas horizontales formantes. Osti- olum interdum in rostrum breve protractum. Sporangia quadripartita et bipartita, Fig. 168. Melobesia Fosliei. A—C, from Deget. A, monostromatic frond seen from 42—60 u longa, 18 —30 12 lata. above. B, vertical section of a sporangial conceptacle showing one four- C t I ] x parted sporangium. C, vertical section of sporangial conceptacle showing onceptacula mascula parva one two-parted sporangium. The orifice has not been hit by the section. immersa, paulo prominentia ; D-E from Hirsholmene. D, orifice of sporangial conceptacle seen from above. E, tetrasporangium. 350:1. spermatia lineari-clavata, le- niter curvata in fundo conceptaculi gignuntur. Conceptacula feminea eadem forma et structura ac conceplacula sporangifera. The specimens referred to this species were found growing on the fronds of Polysiphonia nigrescens, Corallina rubens, C. officinalis and on Bryozoans living in com- pany with these Algæ. They are rather variable in several respects, but as the differences are met with not only between specimens growing on different substrata, but also in specimens growing on the same alga, I do not hesitate in referring them all to the same species. Most of the specimens were found growing on Corallina rubens; these speci- mens may first be mentioned here. The structure of the monostromatic frond much resembles that of M. Lejolisii, except that the lateral walls seem to be thinner (less incrustated ?). Lateral fusions are frequent. Trichocytes were usually present, situated at the offspring of ramifications, but in some cases they were searched for in yain. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII, 2. 32 250 The conceptacles of sporangia are proportionally higher than in M. Lejolisü, hemispherical or subhemispherical, the height being frequently the half of the breadth. The cells surrounding the ostiole are usually little characteristic, forming no real peristome; they may be somewhat lengthe- ned towards the opening, but take, as it seems, scarcely the form of papillæ, and do not as a rule protrude outside the ostiolum. In some cases, however, they are elongated, going out in a prolongation of the surroundings of the ostiole in a short spout, resembling that of the antheridial conceptacles of M. Lejolisii and M. limitata, but thicker (fig. 169 A). This character, however, is not constant, being met with only in some of the conceptacles but wanting in others, usually most. When seen from above, the ostiolum appears sometimes surrounded by a rosette consisting, as it seems, of very low papillæ (fig. 168 D), in other cases no such structure is to be seen. 4-parted spor- Fig. 169. Melobesia Fosliei, from Tonneberg Banke. A, verti- . R à B > . cal section of sporangial conceptacle with orifice angıa were found in all the specimens examı- prolonged in a spout. B, vertical section of cysto- 3 ned, but 2-parted ones of the same size were carpic conceptacle. A 350:1. B 560:1. found in the same specimens. As I have examined only dry specimens in which, as is well known, most of the sporangia have been emptied by the desiccation, it could not be stated whether the 2-parted sporangia were fully developed or not. I am inclined to suppose that 4-parted and 2-parted sporangia normally occur simultaneously. The antheridial conceptacles were usually not well preserved in the dried material, but it could be seen that the spermatia were not produced at the end of long sterigmata as in M. Lejolisii. In one case the ostiole was found prolonged in a spout. The conceptacles of cystocarpia were smal- ler than those of sporangia, and a little lower in relation to their breadth; the ostiole was simi- lar in structure to these. The specimens growing on Polysiphonia ni- grescens agree in all essential points with the others; the cells of the monostromatic frond were only a little broader, 9—13 y. A number of the conceptacles were provided with a well Fig. 170. Melobesia Fosliei, from Bragerne. Vertical sec- developed spout, containing elongated cells, the om of frond with antheridial and cystocarpie 0 4 : conceptacle. Below another section of the rest were without any projection. It appeared latter showing the orifice. 560:1. en to me that some of the first were cystocarpic ones. As shown in fig. 170 the antheridial conceptacles occur in the same fronds as the cystocarpic ones. The latter were rather small in these specimens. The specimens growing on Corallina officinalis, collected north of Læsø (ZC!, 7658a, fig. 171), are more vigorous than the specimens previously mentioned. The structure of the frond is the same, but the conceptacles reach greater dimensions. They may be hemispherical, 160—185 » in diameter, or they may be lower, fre- quently fusing together, when the conceptacles are densely placed. The ostiole was provided with small papillæ directed inwards in the conical space of the orifice. When seen from above, the ostiole appea- redsurrounded by a rosette ex- actly like that shown in fig. 168 D. The re- mains of a col- umella were found in the case represen- ted in fig.171 À. The sporangia were always Fig. 171. tet : Melobesia Fosliei growing on Corallina officinalis from ZC!, north of Læsø A, vertical section etrasporic, 2 : 2 3 = of frond with two conceptacles, one hemispherical, the other depressed. B, vertical section 44 —50 L long, of frond with antheridial conceptacle. C, vertical section of cystocarpic conceptacle. 11-16, broad. A and C 260:1. B 420:1. — The antheridial conceptacles are slightly prominent; the spermatangia are pro- duced on the flat bottom of the conceptacle from small cup-shaped cells; they (or the spermatia) are linear-clavate, slightly curved, measuring 7 in length, about 2 in their broader end. — The cystocarpic conceptacles have the same shape and size as the sporangial ones and are, as those, provided with short horizontal papillæ in the ostiole, principally in its under part. I have been much in doubt in determining the specimens referred to this species. Some of them, those from Bragerne, Skagerak, have been referred to M. Lejolisii by Foscie (Remarks, p. 106) and I have also been much inclined to con- sider them as a more or less reduced form of this species. However, I have judged it better to describe it as a new species, considering, besides other characters, especially the higher conceptacles of sporangia, the formation of the spermatia taking place in our species at the bottom of the conceptacle from short cells, while in M. Lejolisii they are produced at the end of long sterigmata, and the long curved spermatia, while those of M. Lejolisii are much shorter. The antheridial concep- 32* 252 tacles more resemble those of M. limitata, but this species is more different prin- cipally by the stronger development of the filaments surrounding the ostiole. It much resembles M. minutula Fosl. (comp. FosLıE Remarks p. 107) from which it differs by its more incrusted frond and by the usual presence of trichocytes. Whether it can be kept distinct from it must be decided by further investigations. Localities. Sk: YN?, south-east of Bragerne, on Polysiphonia nigrescens and violacea, July; Lonstrup, on Corallina rubens, washed ashore, June (C. H. Ostenfeld). — Kn: Within Deget near Frede- rikshavn, on Cor. rub. (C. H. Ostenf.); north-east of Hirsholmene, 6—7,5 meters, August, (C. H. Ostenf.); TL, north of Læsø, on Cor. rubens, Sept.; ZL!, north of Læsø, 9,5 meters, on Corallina officinalis, July; TP, Tenneberg Banke, 16 met., on Cor. rubens, Sept. 5. Melobesia minutula Foslie. Foslie, Algolog. Notiser, 1904, p. 8; Remarks, 1905, p.107. Lithocystis Allmanni Harvey, Phyc. Brit. Vol. II, plate 166, 1849 (?). Melobesia inequilatera Solms, Corall., 1881, p. 12, Taf. III fig. 13—18 (?). Non Epilithon Van Heurckii F. Heydrich in J. Chalon, Liste des Algues mar. obs. jusqu'à ce jour entre l'embouchure de l’Escaut et la Corogne, 1905, p. 207, fig. 1—5. FosLie has referred to this species some specimens growing on Bryozoans attached to Polysiphonia elongata collected by me in the northern Kattegat (comp. Remarks p. 109). They form small, scarcely incrusted fronds consisting of a single layer of low cells, irregular in outline but not lacunose, wherefore it has been re- ferred to f. typica. The frond is monostromatic in its whole extent to the border of the conceptacles. When seen from above, the cells are usually 7—10 £ broad, of the same length or a little longer. Very small hyaline cortical cells are as a rule present, covering the pericline walls. According to FosLie, they “mostly seem to be wanting”, which statement is probably founded on the fact that they are only discernible by rather high magni- fying powers, owing to their small size and transparence. They are narrower than in the other Me- lobesiæ examined by me. They were also found over the periclinal walls situated under the pseudo- dichotomies (fig. 172), a fact in ac- cordance with the complete absence of trichocytes. The sporangial conceptacles are Fig. 172. 6 6 2 0 Melobesia minutula. A, part of a frond seen from above, at right conical-hemispherical with a small the primary disc. The cortical cells have not been drawn in the orifice surrounded by a whorl of upper and under part of the figure. B, a tetrasporangium. 350:1. re r cells radiating towards it. I found them about 90 in diameter (fig. 173). The sporangia were found to be tetrasporic (fig. 172 B), 43—54 » long, 24—31 u broad. FosLıE found them only disporic. — Further statements as to this species cannot be given owing to the very scarce material at hand. The synonyms given are all dubious, as also mentioned by Fosrie. The species described by Heyprıcn resembles FosLie’s species by the structure of the frond, but if his description is correct, it cannot be identical with it, and must even belong to another genus, as the conceptacle is said to have as many openings as it contains sporangia. HEYDRICH's description of the cortical cells also does not agree with those of M. minutula, as they are said to cover,the half of the cells of the disc; in M. mi- nutula they are very narrow, covering only a small part of the underlying cells. It must therefore be Fig. 173. concluded that HEYDRICH's species cannot be identified Melobesia minutula. Part of frond with 3 A conceptacle. 200:1. with M. minutula. The plant was found growing not only on the Bryozoan but also on Ceramium tenuissimum attached to the same Polysiphonia. Locality. Kn: TP, Tenneberg Banke, 16 meters, September. 6. Melobesia trichostoma sp. n. Frons primo monostromatica, dein, saltim maxima ex parte, polystromatica, usque ad 8 cellulis crassa, plerumque tamen e pluribus lobis vel frondibus secun- dariis minoribus, partim sese invicem obtegentibus composita, lobis plerumque usque ad marginem polystromaticis. Cellule frondis monostromatice vulgo 7—8 y crassæ, latitudine plerumque paulo longiores, cellulis corticalibus transverse ellipticis munitæ. Frons adulta e filis verticalibus composita, cellulis longitudine vario, latitudine 1—3-plo longioribus. — Conceptacula sporangifera verruciformia, parum elevata, superne applanata, diametro 160-280 y. Tectum planum, crassum, c. 5 cellulis crassum. Ostiolum pilis numerosis, sursum longioribus, superioribus ex ostiolo pro- minentibus ornatum. Sporangia tetraspora, 42—63 » longa, 17—29 y lata. Concep- tacula mascula non prominula, ostiolo in tubo longo, sæpe curvato, protracto. Spermatangia lineari-clavata in fundo plano conceptaculi e cellulis depressis pro- creata, dense stipata. — Conceptacula cystocarpifera eadem forma magnitudineque ac sporangifera el peristomio simili ornata. The speeimens on which this species is founded formed dull rose-coloured erusts on the shells of living Trochus cinerarius collected in the Limfjord. They were referred to Lithothamnion Lenormandi by FosLıe in 1905 and are also rather like old specimens of that species, especially the forma squamulosa. The frond is at first monostromatic, and the marginal part may remain so, much resembling that of M. Lejolisii, with well developed cortical cells, which seen from above are elliptical. A parietal body, situated closely at the outer wall in these cells is very intensely Be stained by hæmatoxyline (fig. 174 A). Trichocytes may occur. The greater part of the crust is polystromatic, being composed of vertical cell-rows, up to 8 cells high or more. The older parts of the crusts are very irregular, being composed of several smaller crusts or lobes growing partly over each other. These partial fronds or lobes are usually polystro- matic to the very margin. The compound crusts may be composed of lobes of the same frond or of dif- ferent fronds growing to- gether; it is therefore im- possible to state the dia- meter of the single frond. In the thicker fronds, the upper ordinary frond-cell may bear more than one cortical cell, frequently one over the other (fig. 174 A, D). In the last-named figure the three undermost cells at right bear each a cortical cell, the i explanation of which must be that they represent the monostroma- tic border of the frond, which has been overgrown by tissue produced by the neighbouring thicker part of the same frond. A si milar process often takes Fig. 174. place in various parts of Melobesia trichostoma. Å, vertical section of the monostromatic part of a the frond and gives rise to frond growing over the conceptacle of another frond of the same species. : B, monostromatic frond seen from above. C, vertical section of older, com- the complicated structure pound crust. D, vertical section of a thick lobe of frond. E, vertical section of the old crusis, new lobes of sporangial conceptacle. C, 65:1, the rest 350 :1. developing from certain parts of the frond, and growing over the neighbouring parts. — The length of the cells of the vertical cell-rows is highly variable, usually one to three times as long as the breadth, and irregularly varying in the same filament. The undermost cell- layer is not distinct from the others, its cells being of variable height. The cells contain often numerous starch-grains. Transversal pores between the cells of different cell-filaments never occur, but transversal fusions are frequently met with, between the cells of the basal layer and between cells of the upper parts of the vertical cell-rows as well (figs. 174, 175). 255 The outer part of the sporangial conceptacles (fig. 174 E) is low, wart-like, with plane upper face. The outer diameter of the conceptacle is often difficult to state, as it is usually for a great part sunk in the frond, and the outer delimitation often indefinite. One to three layers of cells are present under the conceptacle. The roof is flat, thick, about 5 cells thick. The ostiole is clothed with numerous well- developed unicellular hairs, the uppermost of which are long, and protruding out- side the ostiole; the undermost ones are shorter and more oblique or horizontal. They are all intensely stained by hæmatoxyline. The sporangia do not occupy the central portion of the conceptacle, where a small columella of sterile cells is some- times to be found. The ripe sporangia are always tetraspo- ric. A small stalk- cell is present under the sporangia (not shown in the figure). The antheridial conceptacles (fig. 175 A) much resemble those of M. subplana (comp. fig. 161), being provided with a simi- lar tube, and the an- theridia having the Fig. 175. same shape and posi- Melobesia trichostoma. A, vertical section of antheridial conceptacle. Band C, vertical sections of cystocarpic conceptacles. A and C 350:1. B 65:1. tion as in that species. The cystocarpic conceptacles (fig. 175 B, C) have the same shape and size as the sporangial ones, and the ostiole is endowed with a similar peristome. The thick roof is plane, or a little depressed near the ostiole. The carpospores are, as usually, produced seriately at the periphery of the conceptacle. The species appears fairly distinct from all hitherto described species of the genus Melobesia. The low conceptacles with the thick, flat or a little deepened roof distinguish it from other species of the genus having a well developed peristome (e. gr. M. Lejolisii, coronata). Its occurrence on mollusc shells, unusual for the genus Melobesia, might seem grounds for placing it in the genus Lithophyllum; the want of transversal pores between the frond cells and the fact that these cells are not arranged in transversal rows, however, preclude its adoption in that genus. Locality. Lf: Søndre Ron by Lemvig, near the surface of the water, September. 7. Melobesia microspora sp. n. Frondes suborbiculares, sepe confluentes, 1—2 mm diametro, excepta parte marginali polystromaticæ, e filis verticalibus usque ad 7-cellularibus compositæ; cellulis filorum 6—8 „ latis, diametro vulgo 1—2-plo longioribus, cellulis strati basalis plerumque brevioribus. Cellule corticales desunt. — Conceptacula nume- rosa contigua vel subcontigua. — Conceptacula sporangifera depresso-hemisphærica vel conica, diametro 120—140 y, ostiolo vix papilloso, medio nonnunquam columella munita. Sporangia parva, 17—24 „ longa. (9—)11—12(—16) » lata, semper 4-partita. Sub conceptaculis 1—4 strata cellularum vegetativarum. — Conceptacula mascula parva, paulo prominula vel omnino immersa. Spermatangia elongata vel clavata, fundum planum conceptaculi investientia. Spermatia lineari-clavata, nonnunquam leniter curvata, c. 64 longa, 2 „ lata. — Conceptacula feminea ut videtur forma structuraque conc. sporangiferis similia. — Hab. in fronde Furcellarie fastigiate. The species here described has only been met with once, viz. on a specimen dredged in the bay of Aarhus. The specimens were determined by FosLie as Melo- besia Lejolisii Rosan. forma, but as will be seen from the description given here, it is very different from that species, particularly in the structure of the frond and the small dimensions of the sporangia. The greater part of the frond is polystromatic; only the marginal part is monostromatic, but it is early divided by horizontal walls, and the frond is then composed of vertical filaments composed of from two to seven or eight cells. These filaments are usually 6—8 » broad and consist of cells of varying length, usually 1 to 2 times as long as broad. The cells of the basal layer are rather varying in height, but they are usually lower than broad. There is thus no contrast between the basal layer and the perithallium. Seen from above, the cells of the basal layer show a breadth of 5—8 », about the same length or a little more, and appear to be frequently connected by lateral fusions (fig. 176 C). Such fusions may also occur between cells above the basal layer, but transversal pores (secondary) nowhere occur. It is remarkable that cortical cells as those characteristic of the other Melobesia species do not occur. When seen from above, the superficial cells present them- selves as nearly quadratic cells arranged in rows, but no small cells cut off from them appear, not even after staining with hematoxyline, by which treatment the walls of all the outer cells and the cuticle are very intensely stained. Hair-cells were not observed. The conceptacles are numerous, occupying most-part of the crust, frequently contiguous, giving the frond a verrucose aspect. TheZsporangial conceptacles are depressed hemispherical or more rarely low conical. A more or less developed central narrow columella is not infrequently present. The sporangia which do not occupy the centre of the conceptacle are remarkably small; they are always four- parted, the three septa approaching each other in the middle of the sporangium (fig. 177 A). When seen from above, the small ostiole is seen to be surrounded by 257 small-celled filaments radiating towards the centre. In a vertical section these fila- ments are only little conspicuous, and there are only feeble rudiments of papillæ in the conical orificium (fig. 177). One to four layers of vegetative cells are to be found under the concep- tacles. The antheridial conceptacles are small, sometimes entirely immersed, usually, however, more or less pro- minent. The inner cavity has a flat bottom, and may be about 40, in diameter. The ostiole is not prolonged in a spout. The spermat- Fig. 176. angia form a Melobesia microspora. À, vertical coverin on section of thin crust. B, surface view Se 8 of crust near the border. C, basal the bottom of layer seen from the face, showing numerous fusions. 350:1. the concep- tacle; they are produced from small squarish or trapezoid cells, and are lengthened, upwards incrassated, some- times a little curved cells. Sometimes the spermatangia are produced not di- rectly from the small squarish cells but from cells of the same shape as them- selves (fig. 178 C at left). The spermatia are clavate, broadest in the upper end, Fe m sometimes slightly curved, about 6 „ long, Melobesia microspora. A, Perte section of sporangial and 2 u broad at their broadest end, (fig. conceptacle with a tetrasporangium. B, sporangial con- 178 C). Under the bottom of the con- ceptacle seen from above. C, emptied sporangial con- : ceptacle showing the rest of the columella. 350:1. ceptacles up to 5 layers of vegetative cells may be found. Of female conceptacles I have only met with very few, which gave no clear idea of their structure. They seem to be similar in shape and structure to the sporangial ones. Fig. 179 shows a con- ceptacle containing carpogonia and tri- chogynes; at left is shown a carpogonium from another section of the same con- ceptacle. This species seems to be quite di- Fig. 178. stinct from all well known species of the Melobesia mierospora. A and B, vertical sections of frond senus. The want of cortical cells is in- with antheridial conceptacles. C, spermatangia and sper- 2 matia. A and C 560:1, B 350:1. deed so remarkable as possibly to suggest D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 2, 33 258 that it should be referred to another genus: but as other characters justifying its removal from the genus es are not known, I prefer to retain it under the genus provisionally. The small size of the tetra- BER sporangia seems to be a significant mark dis- er FRI RE tinguishing it from other species. The want of m Na transversal pores between the cells of the vertical 2 ea} / re ON filaments, and the fact that these cells are not dis- ny aa ES] CAE posed in transversal rows, exclude it from the genus ki — Sa LEO ; SS Lithophyllum. Fig. 179. Only found once, growing on the frond of Melobesia microspora. Vertical section of Furcellaria fastigiata, with ripe sporangia, ripe an- female conceptacle; at left a carpogonium BEE EEE à from another section of the same concep- theridia and carpogonia in April. ECO? EE Locality: Sa: PP, Ryes Flak, 5 meters (no: 4670). Choreonema Schmitz. 1. Choreonema Thuretii (Bornet) Schmitz. Fr. Schmitz. Uebersicht, Flora 1889, p. 21 (reprint); id. in Engler u. Prantl, Nat. Pflfam. I p 541; Fr. Minder, Die Fruchtentwicklung von Choreonema Thur. Diss. Freiburg, s. a. Melobesia Thuretü Bornet in Thuret, Etudes phycolog., 1878, p. 96, pl. 50, fig. 1-8; Solms-Laubach, Corallinenalgen d. G. v. Neapel, 1881, p. 12, 54, Taf. III fig. 1, 4—10. Endosiphonia Thuretii Ardissone, Phycologia mediterranea. I. Varese, 1883, p. 451. This interesting Alga, parasitic in Corallina rubens, has been met with in a few localities in the Northern Kattegat and perhaps also in the Skagerak. Unfor- tunately, the collected material was lost, except that from a single locality near Fre- derikshavn; I must therefore content myself with referring to the quoted publications. MINDER has in his important paper given a thorough description of the devel- opment of the cystocarp, which in essential points modifies the statements of SoLMs- LauBacH. After fertilization, the zygote gives off short sporogenous filaments, which gradually fuse with the auxiliary cells, but none of the numerous sporogenous nuclei enter into these cells. From the marginal lobes of the resulting great sporo- phytic cell (which is not produced by mutual fusion of the auxiliary cells, but has been nourished by them) the carpospores are produced, becoming cut off by watch-glass-formed walls. As I have had very few specimens at my disposal, I cannot give any state- ment as to the fructification in the Danish waters, Localities. Sk (?). — Kn: Within Deget near Frederikshavn (C. H. Ostenfeld), and perhaps a few other localities. Lithophyllum Phil. Subgenus Eulithophyllum. 1. Lithophyllum orbiculatum (Foslie) Foslie. Foslie, Rev.”survey (1900) p. 19 (without mention); Remarks (1906) p. 112. Lithothamnion orbiculatum Foslie, Norw. Lithoth. (1895), p. 143, pl. 22 fig. 10—11. 0 — —. — — 259 The crust is generally orbicular, scarcely exceeding 2 cm in diameter. In one locality only I found larger crusts expanded over stones; as these crusts also in other respects differred from the others, they will be mentioned separately below. The crusts are 1 to 1,5 mm thick. According to FosLie, the hypothallic layer mainly resembles that of Lithoth. lœve, being rather feebly developed (Remarks p. 112). I found it, however, always consisting of one layer only, the upright filaments springing out from it in a vertical or nearly vertical direction. The thickness of the perithallic cells varies between 6 and 9; the height is generally Se oo greater than the : g 5 breadth, often about double SD) = (about 134), but KANN 2 OL WZ it may be of ORI the same size or OXY 2 £6 MOK) even smaller. \ AL G ( FosLie descri- OO ¢ Ole bes these cells as squarish; I found them ge- nerally more or less roundish, frequently ap- proaching the ellipsoid or globe. They are Fig 180 connected with Lithophyllum orbiculatum. A, vertical secant of erase: B, under part of the same crust. C, the cells of the horizontal section of crust showing the tranverse pits. D, vertical section of margin of frond. E and F, vertical sections of aberrant specimen (no. 5341), F, showing the hypothallium. 350 : 1. neighbouring fil- aments through transversal pits situated about in the middle of the cells; in trans- verse sections 3 to 5 such pits are seen in each cell (fig. 180 C). The crust is traversed by horizontal limiting lines which are stained intensely blue by hæm- atoxyline; they are often seen crossing the middle of the cells (fig. 180 A). Mme Lemoine did not find such limiting lines in any species of Lithophyllum (Struct. p. 28). The cells of the perithallium are frequently filled with starch grains, par- ticularly in the under part of the crust. The surface of the frond is frequently much inclined towards the border, which in vertical section shows a great marginal cell (fig. 180 D). The conceptacles of sporangia are completely immersed; they had in the spe- cimens examined a transverse inner diameter of 92—116 ~; they are generally almost globular in a vertical section. They haye a single pore in the middle of the roof 37% bp} 260 which is not surrounded by peculiarly shaped cell-rows. The sporangia are four- parted: I found them 70 z long, 2435 » broad, thus somewhat smaller than indi- cated by FosLıE. However, I have only met with a small number of well devel- oped sporangia; I am therefore also unable to state whether they are placed over the whole conceptacle or only in its periphery. A group of sterile filaments in the middle of the floor was not observed. The emptied conceptacles are limited by a sharp inner contour. Supposed antheridial conceptacles are shown in fig. 182. They had a transverse diameter of 60—77 » and the slightly prominent pore surrounded by a number of © Fig. 181. Lithophyllum orbiculatum. A, vertical section of tetrasporic conceptacle showing the pore. B, similar, but somewhat excentric section. C and D, feebly developed, not yet fully divided sporangia. 350:1. peculiarly formed narrow, obliquely upwardly directed filaments, forming the cen- tral part of the roof. The rather plain floor was in some cases covered by a very small-celled layer which had probably supported the spermatangia. In some of these conceptacles small bodies were seen which were supposed to be spermatia. The conceptacles of cystocarps are entirely immersed (fig. 183); they have an ” inner diameter of 112—142 ». (According to Fos ie it is 200—300 », but it is not stated if it is the inner or the outer diameter). The pore is surrounded above by obliquely upward directed filaments resembling those of the antheridial conceptacles; but below them is situated an inner crown composed of obliquely downward di- rected cells. Fig. 183 A shows a number of carpogonia in the central part of the floor, those situated nearest the centre having the longest trichogynes. The carpo- spores are produced from the margin of the disc-cell at the base of the conceptacle (fig. 183 B). The inner crown of the peristome keeps for a long time in the over- grown conceptacles. According to Foszie (Remarks p. 113) “the conceptacles do not become gra- 261 dually overgrown, as far as hitherto seen”. It may happen that the emptied con- ceptacles are filled with filaments growing out from the bottom of the conceptacle, but it also not unfrequently occurs that they are overgrown without being filled, and empty conceptacles are thus found at various depths in the thicker crusts. This was observed with all kinds of conceptacles. As mentioned above, I found in one locality (TL, north-west of N. Ronners Rev, 4—5,5 m, Sept. 1894, n° 5341) some specimens somewhat different from the Fig. 182. Fig. 183. Lithophyllum orbiculatum Supposed antheridial Lithophyllum orbiculatum. Cystocarpic conceptacles, À, show- conceptacles. In A small bodies are seen which are ing the pore and the carpogonia. 350:1. B, excentric section probably spermatia. 350:1. showing the inner crown and two carpospores at the peri- phery of the disc. 200:1. ones just mentioned. They form much more expanded crusts, up to 10cm or more in diameter, and the cells of the perithallium are thicker, 9—12 broad, 7—16(25) x long. These measurements, however, are only little different from those given by FosLie, who has also determined these specimens as Lith. orbiculatum forma. The hypothallium consists, as in the other specimens, of a single cell layer, but the cells are frequently elongated obliquely upwards, in the same direction as the perithallic filaments, and they are similar to the cells of these filaments (fig. 180 E, F). The examined crust contained sporangial conceptacles 77—122,y in diameter, with a single pore; in an old conceptacle a few not exhausted two-parted sporangia were still present. It must be left to further investigations to delermine whether these specimens really belong to L. orbiculatum. FosLıE discusses (Remarks p.113) the question, whether this species might possibly be a northern form of Lithophyllum incrustans. This supposition would not agree with the fact that the last named species, according to Mme LEMOINE (Struct. anat. pl. IV fig. 1), has a much developed hypothallium. On the other hand, a specimen collected by me at Cherbourg and determined by FosrıE as Lithophyl- lum incrustans, showed a one-layered basal layer and on the whole the same ana- tomical structure as L. orbiculatum. The question as to mutual relation of the two species must therefore be left undecided. The species has in the Danish waters only been found in the northern, eastern and southern Kattegat and in the Sound. It has been met with in depths from 16,5 to 24,5 meters. The aberrant specimens were dredged in a depth of 4—5,5 m. Localities. Kn: TL, N.W. of Less, 4—5,5 meters, large crusts, Sept., no 5341 (see above). — Ke: IR, Groves Flak, 24,5 meters; IK and IH, Lille Middelgrund; IA, Store Middelgrund. — Ks: HO, east of Hessels. — Su: bM, south of Hveen, 12,5 meters. Subgenus Dermatolithon Foslie. As mentioned above, p. 236, the genus Dermatolithon was established by FosLie in 1898 (List of Spec., p. 11), only however as a nomen nudum, and the following species of Melobesia were referred to it: M. pustulata, Lejolisii and hapalidioides. In 1900 (Rev. syst. Surv., p. 21) the genus was described and M. macrocarpa was further referred to it, besides two uncertain species, while M. Lejolisii was removed from it. It was founded on characters of the sporangial conceptacles (comp. p 237). Later on (Algol. Not. I, 1904, p. 3), FosLıE judged that these characters were of small systematic value, he pointed out the relations of these species to the genus Litho- phyllum, and transferred Dermatolithon as a subgenus under Lithophyllum, charac- terized by having the hypothallium formed by a single layer of inclined cells, in contradiction to Eulithophyllum and Lepidomorphum, the hypothallium of which always consists of several cell-layers. Three years later (Algol. Not. VI, 1909, p. 58) FosLie raised it again to a distinct genus characterized only by the last-named character. As mentioned above, the species of Dermatolithon agree with Lithophyl- lum in the presence of transversal pits between the vertical cell-rows. A difference is certainly said to exist in the hypothallium being in Dermatolithon monostroma- tical, while it is polystromatical in Lithophyllum; but FosLie admits himself that the hypothallium may sometimes be partly polystromatical in Dermatolithon, (1909, p. 97). And in Lithophyllum orbiculatum mentioned above there is evidently a mono- stromatical hypothallium (fig. 180). Further, in Dermatolithon, the cells of the hypo- thallium are usually long and oblique, but they may also be rather short and only little inclined (fig. 189), which may likewise be met with in Lithophyllum, e. g. in L. orbiculatum, fig. 180 F. It must therefore be concluded that Dermatolithon cannot be kept distinct from Lithophyllum as a separate genus, at all events on the basis of the anatomical structure, but must be regarded only as a subgenus. 263 Lithophyllum Corallinæ (Crouan), which was already in 1897 transferred from the genus Melobesia to Lithophyllum, seems particularly to be a connecting link between Dermatolithon and the typical Lithophyllum. 2. Lithophyllum maerocarpum (Rosan.) Foslie. Foslie, Remarks, 1905 (1906), p. 128; M. B. Nichols, Contribut. to the knowledge of the Californ. spec. of erustaceous Corallines. II. University of California Publ. in Botany. Vol. 3, No. 6, 1909, p. 352, figs. 12, 15, 16, 17; Foslie, Algol. Notiser VI, 1909, p. 47. Melobesia macrocarpa Rosanoff, Recherches, 1866, p. 74, pl. IV, figs. 4—8, 11—20. Dermatolithon macrocarpum Foslie, Rev. Surv., 1900, p. 21; Algol. Not. VI, 1909, p. 58. f. typica Foslie. L. pustulatum (Lamour.) Foslie f. macrocarpa (Rosan.) Fosl., Remarks, p. 117. It seems that only the specimens from one locality growing on Phyllophora membranifolia are with certainty referable to the typical form which, according to FOSsLIE, differs from the following form by the frond attaining a greater thickness and by the sporangial conceptacles being up to 600 in diameter but a little lower proportionally to the diameter. The frond of the named specimens, however, attains only a thickness of 200 1; the sporangial conceptacles measured over 500 y, and under them were 3—4 layers of cells. The other specimens referred by Fos.ie to this variety are partly sterile and only determined with doubt, or they seem not to possess the characters named. Localities. Kn: Trindelen, 15 meters, on Phyllophora membranifolia, July, with ripe sporangia. — Further recorded with doubt from the following localities. Lf: Nykobing, on Chorda Filum, (Th. Mortensen). — Kn: Hirsholmene, on Fucus vesiculosus; Nordre Renner, on Fucus vesiculosus; TG, north of Læso, 9,5 m, on Phyllophora membranifolia, sterile. f. intermedia Foslie. Foslie, Remarks, 1905, p. 117; Nichols, Crustaceous Corallines, II, 1909, p. 352, plate 11 fig. 12, pl. 12 figs. 15—17. L. pustulatum (Lamour.) Foslie f. intermedia Foslie, Remarks, p. 128. Most of the specimens of this species have been referred by Fosrıe to the f. intermedia, which has later been carefully described by Nıcnors, |. c. I have nothing to object against the determinations of FosLiE, and I shall not enter into the question as to whether the species can be kept distinct from L. pustulatum, but will merely remark that I have always found two-parted sporangia. In referring to the quoted descriptions and figures however, some remarks on the Danish species may be added. These are almost all growing on Fucus vesiculosus, where they form crusts measuring 4—7,5 mm in diameter, frequently confluent. The border of the frond, which is not always adherent to the substratum, consists of a single layer of long oblique cells, each bearing a cortical cell cut off by an oblique wall. Later on, the long cells are divided by a transversal wall, the crust thus being composed of two 264 layers of cells, not including the cortical cells, and further transversal divisions fre- quently do not occur except in the immediate vicinity of the conceptacles; it may even happen that the frond is monostromatic in almost its whole extent. The long cells in the upper layers are always connected with transversal pits (fig. 184). The thickness of the frond is rather variable. Monostromatic fronds were 25—42y thick, fronds consisting of two layers of cells 67—105 and fronds containing three layers were 91—123, thick. The fronds are frequently growing over each other. It also frequently happens that new growing edges are produced from certain parts of the frond, growing over the neighbouring parts the growth of which has ceased. The long cells contain a small nucleus in the upper part of the cell, and a number of small chromatophores spread in the cell. The cortical cells are pro- duced early, immediately after the for- mation of the long cells by the divi- sion of the marginal] cell. But at some distance from the margin a new cor- tical cell may be cut off under the primary one by a horizontal or in- clined wall (fig. 184 B), and this pro- cess may be repeated several times. Hyaline hairs may be produced from long cells seemingly not different from Fig. 184. the others, and provided, like these, Lithophyllum macrocarpum f. intermedia. Vertical sections of with a cortical cell (fig. 184 B). The fronds. A, margin of frond. B, part of monostromatic frond showing a hair-cell and two cortical cells cut off from one cell. length of the long cells of the frond G, part of thicker crust: transversal pits” between the cells varies greatly; when the crust is po- of the two upper layers. 350:1 eg lystromatic, the cells of the under- most layer are often rather short. When these cells or those of the monostromatic frond are long, their undermost part is usually more inclined than their upper part (fig. 184 B, comp. NıcHors, L. c. fig. 12, 15). The sporangial conceptacles are very prominent, conical with rounded or ap- planated top, 300—500 z in diameter. Under the conceptacle 1—3 layers of sterile cells are present. Papille projecting inward and upward, lining the pore, as de- scribed and figured by NıcHoLs, may be found in the under part of the pore, but they are usually slightly developed. Seen from above, the superficial cells sur- rounding the pore appear scarcely different from the others, the nearest being only a little smaller (fig. 185 B). The sporangia are only placed in the peripheral part of the conceptacle, the central part being occupied by sterile cells forming a conical columella. NıcHors found also sporangia in the central part, though less numerous there than at the periphery. As shown by this author, each sporangium is born by a stalk cell. A “plug” was found in some rare cases in the ostiole, forming a continuation of the central sterile cells (fig. 185 A), but it seems to be usually wanting, u 265 and was not found by NıcnorLs. The sporangia are disporic; they were found to be 105—140 y long, 35 - 60 broad; the smallest ones, however, were perhaps not ripe. Antheridial conceptacles were not observed. Cystocarpic conceptacles were only found in specimens from one locality (Kalô). They are of the same shape and size (about 400 » in diameter) as the sporangial ones, and the ostiole is of the same structure, being without or only with poorly developed papillæ in the under part. The carpospores are only produced at the periphery. This variety has only been found growing on Fucus vesiculosus and Fucus serratus a little below low-water mark. It is particularly abundant in the Limfjord, probably owing to the high salinity and the high summer temperature of this : Fig. 185. i . Lithophyllum macrocarpum f. intermedia. A, vertical section of not quite ripe sporangial conceptacle. B, orifice of sporangial conceptacle seen from above. C, vertical section of orifice of cystocarpic conceptacle. AandC200:1. B 350: 1. water. Ripe sporangia have been met with in summer, June to September. In April two-parted sporangia were found, but not fully ripe, and in the same month cystocarpia were found. Localities. Lf: Sondre Ron by Lemvig; Oddesund; MH, bank of Skrandrup, MG, off Hanklit, and Thisted in Thisted Bredning; I, Veno Bugt; Nykebing; Sallingsund, pier; Amtoft Rev; LQ, Lendrup Ren; Løgstør. — Kn: Hirsholm and Kelpen near Frederikshavn. — Ks: Isefjord: on the beach near Frederiksværk (Th. Mortensen); Lammefjord; Holbæk Fjord. — Sa: Reef near Kalo; Æbelø. — Sf: near Birkholm. 3. Lithophyllum Corallinæ (Crouan) Heydr. F. Heydrich, Corallineae, insbes. Melobesieae. Ber. deut. bot. Ges. Bd. 15, 1897, p. 47. Melobesia Corallinæ Crouan, Florule du Finist., 1867, p. 150, pl. 20, genre 133 bis, fig. 6—11. Lithophyllum pustulatum (Lamour.) Fosl., f. Coralline (Crn.) Foslie, Remarks, 1905, p. 118. In two localities in the Skagerak a few specimens of a calcareous alga were found growing on Corallina officinalis and agreeing with the short description and D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 2. 34 ee the figures of Melobesia Corallinæ Crovan (l. c.). These specimens have not been examined by FosLie, but as this author regarded Crouan’s species as being only a form of Lithophyllum pustulatum, he would probably have referred our plant “as a de- nominated form” to L. macrocarpum, whereas it has disporic sporangia. A closer exami- nation of my specimens, some of which were preserved in alcohol, showed me, however, such differences from the named species that they cannot, in my opinion, be referred to it, but must be regarded as representing a different species bearing CROUAN's name. The crust is in some cases surround- ing the Corallina-frond, being attached to it in its whole extent and fusing together where the borders meet. In other cases it Fig. 186. _ is only attached by its central thicker Bee ee cage af Ge à Gane eee portion, while the thinner edges) of the or of frond nearly conceplacle i330 LÆGES CHonkot ; frond with sporangial conceptacle. 65:1. bieular, peltate frond are free (fig. 187, comp. +. Crouan, 1. c. fig. 6,7). In the first case the De et frond was up to 105 (over 12 cells) thick, WAL aaa NE in the latter the central part was about NC 350 4 thick, the inner edge 70—105 2 thick. The diameter of the peltate fronds is 2—2,5 mm. The edge of the frond is thick, poly- stromatic to the very margin or nearly so, the cells cut off from the marginal cell dividing early by transversal walls. The marginal cell is much smaller than in L. macrocarpum (fig. 186 A). The under- most cell in the vertical or ascending cell- rows constituting the frond is not longer than the others, frequently even shorter, being only 1—3 times as long as broad; these cells are usually inclined. The cells of the upper cell-layers are frequently much longer; the transversal pits of these cells are always distinct; they are shown VA Fig. 187. Lithophyllum Coralline, from Hanstholm, vertical sec- ın fig. 186. tions of seutate fronds with free edges. Sporangial The sporangial conceptacles are only conceptacles in À and C, cystocarpic conceptacles in i i : = B. Overgrown conceptacles in B and C. 65:1. little prominent, forming low warts with 267 a more or less plane upper face, the cavity being entirely or for the most part sunk in the frond. Their outer diameter is therefore often difficult to state, but it reaches at least 350. The cavity is nearly globular or usually more or less flattened. The ostiole is without or provided with poorly developed papillæ in its under part. In some cases the ostiole was found to be excentric. The sporangia are only placed at the periphery of the conceptacle, the central part being occupied by a conical columella. The sporangia are always disporic, 50—88 » long, 18—32 y broad. The number of sterile cell- layers under the conceptacle varies greatly according to the thickness Fig. 188. Fig. 189. Lithophyllum Coralline. °A; vertical section of sporangial con- Lithophyllum Corallinæ. A, Vertical sections of ceptacle. 205:1. B, vertical section of upper part of a similar antheridial conceptacles. In A some spermatia one. 350:1. show two nuclei. A 350:1. B 370:1 and age of the frond. In thicker, older fronds the first produced conceptacula after evacuation become overgrown by the continued growth of the surrounding tissue and are later found as empty cavities in the under part of the crust, while new conceptacula are formed at a higher level (fig. 187). The antheridial conceptacles are entirely sunk in the frond, not prominent, rather low, with a flat bottom and a shorter or longer orifice. The spermatia are produced at the end of long sterigmata given off from small cells covering the bottom of the conceptacle. The ripe spermatia are globular-ovoid, at one end (the basal one) drawn out ina short point. Two nuclei were distinctly visible in isolated Spermatia (fig. 189 A). 34* 268 The cystocarpic conceptacles have the same shape and size as the sporangial ones. The papillæ lining the ostiole were found more developed than in the spor- angial conceptacles. The structure of the cyslocarp rather resembles that of Corallina, a large disc-shaped cell occupying the bottom of the conceptacle giving off at the periphery seriate carpospores and covered with numerous closely placed oblong cells filled with protoplasmatic contents, the morphological char- acter of which could not be de- termined, as trichogynes were in no cases observed (fig. 190). The cystocarpic conceptacles Fig. 190. become overgrown and sunk in Lithophyllum Coralline. Vertical section of eystocarpie conceptacle. the crust as also the sporangial 350:1. conceptacles. The structure of the frond, being polystromatic to the margin, and the slightly prominent conceptacles being sometimes overgrown and deeply sunk in the frond, are the principal characters distinguishing this species from the foregoing, with which it agrees in its disporic, though smaller sporangia. It is apparently not identical with Melobesia Corallinæ Sorms (Corall. p. 9, Taf. II, fig. 25, III fig. 21—24) which differs, to judge from the figures, by tetrasporie sporangia, occupying the central part of the conceptacle, by the want of columella, and apparently by the structure of the frond, the basal cell-layer being very low. Found with sporangia and cystocarps in July and August. Localities. Sk: YT, YU, Hanstholm, 2--6 meters; Hirshals. on the mole. 4. Lithophyllum pustulatum (Lamour.) Foslie forma? Mention may be made here of an alga recorded once growing on Corallina offici- nalis but which could not be identified ke NY, with certainty on account of the incomplete eS Wee TC = state of the present material. It forms thin AN WE red crusts, the peripheral part of which is PERS, X DOOR 4 monostromatic with cortical cells, only XD” 14—20 „ thick, while the central portion, oO consisting of 2—3 cell-layers, besides the Fig. 191. Lithophyllum pustulatum forma?. Vertical section of cortical cells, has a thickness of up to 80 y. One half of an empty conceptacle. 205-10 allel 269 The cells of the vertical cell-rows are proportionally short, and connected with trans- versal pits. Only empty conceptacles were found. They are about 420-—500 » in diameter, conical-subhemispherical, somewhat lower in proportion to the breadth than in L. macrocarpum. The roof is of solid structure and is very thick near the ostiole. The cells surrounding the upper part of the ostiole are elongated but not projecting as free papillæ. Our alga reminds one of L. pustulatum f. australis Foslie (Remarks, p. 117, Nicozs, Contrib. II, 1909, p. 356, fig. 21—24) from which it differs, however, to judge from Nicnozs’ description, by the want of papille surrounding the ostiole. As the conceptacles were empty, their nature could not be determined. Locality: Ke: Store Middelgrund 19 meters, May. Corallina L. 1. Corallina officinalis L. Linné, Fauna Suecica 1761, p. 539; Kützing, Phyc. gener., 1843 p. 388, Taf. 79, Fig. 1; Harvey, Phyc. Brit. II, 1849, pl. 222; J. E. Areschoug in J. Agardh, Spec. II, 2, 1851-52, p. 562; Kützing, Tab. phyc. Vol. 8, 1858, Tab. 66—68; Kny und Magnus, Ueber ächte und falsche Dichotomie im Pflanzenreich. Botan. Zeit. 1872 Sp. 708; Thuret, Etudes phycologiques, 1878, p. 93 pl. 49; Solms, Corallinenalg., 1881 (Corallina mediterranea); Hauck, Meeresalg., p. 281; Guignard, Dév. et const. des anthérozoides. Revue gén. T. I, 1889, extrait, p. 50, pl. VI fig. 24—26 (spermatia); B. M. Davis, Kerntheilung in der Tetrasporenmutterzelle bei Corallina offic. Ber. deut. bot. Ges. 1898, Bd. 16 Heft 8, p. 266; K. Yendo, Corallinz veræ japonicæ. Journ. Coll. of Science. Imp. Univ. Tokyo. Vol. XVI. Art. 3, 1902, p. 28, pl. III fig. 11—13, pl. VII, fig. 10—13; id., Study of the genicula of Corallinæ. Ibid., Vol. XIX, Art. 14. 1904; id., A revised list of Corallinæ. Ibid., Vol. XX, 1905, p. 29; Oltmanns, Morph. u. Biol- d. Algen, I, 1904, p. 562. The articulated fronds are given off from a basal crust much resembling some crustaceous Lithothamnia (comp. Harvey, |. c.). In some cases it is rather small and gives off numerous closely placed fronds from almost its whole surface. In other cases it is widely extended, up to 2,4 cm. in diameter or more, and bears only a small number of erect fronds (fig. 192). The border is lobed, the lobes being now broad, now narrow. In the latter case the lobes are more or less branched and often keep their independence, being separated by deep furrows when meeting, but it also happens that they grow partly over each other; in other cases, however, they are con- fluent. Concentric zones are sometimes very distinct. In the anatomical structure they resemble the crustaceous Lithothamnia, showing a hypothallium consisting of long cells running in a horizontal direction and a perithallium Fig. 192. : r Corallina officinalis. Basal crust composed of ascending filaments of shorter cells. The last th scattered articulated fronds cell of the latter is very short, the penultimate proportio- or scars after them; at right it . meets with a crust of a Litho- nally long. There seems to be a continuous layer of non- Salon et. 270 dividing cover cells similar to that pointed out for the articulated fronds and for Lithothamnion by Sorms (Corall., p. 27 and 29). The cells of the hypothallium and those of the inner perithallium were, in a specimen collected in July, filled ı with starch grains, while the cells of the outer perithallium showed numerous disc-shaped chrom- atophores and a single nucleus. The articulated fronds are connected with the erust by a geniculum. The ramification is mono- podial, in the typical form pinnate. The branches usually arise near the growing point. At an early stage three (or more) small protuberances are seen at the upper end of the last joint, the middlemost of which develops in continuation of the axis. This Fig. 193. has been interpreted as trichotomy, or polychotomy Corallina officinalis. Border of basal crust (Kny 1872, Sp. 704, Sous 1881, p. 30); I think, in vertical section. 39:1. - however, with Macnus 1872, p. 721, that there is no reason for this interpretation, and that the middlemost outgrowth must be regarded as the principal axis, the others as lateral branches. In f. typica each joint bears two opposite branches, all in the same plane, having for the most part a limited growth, being “pinnulæ”, but there is no distinct difference between the pinnulæ and the longer branches with continual growth. It frequently happens, however, that some joints produce more than two branches; 6 branches are not rarely met with and I have found up to 10 lateral branches placed in the same plane on the upper border of a much flattened joint (fig. 194 A). More rarely the supernumerary branches are given off in different directions at the same level, being thus verticillate (fig. 194 B, Plate IV fig.5); in a specimen from Frederikshavn, a whorl of 8 pinnulæ was found on a joint. It may happen also otherwise, that normal branches are exceptionally given off in a direction diverging from the ordinary plane of ramification. The joints bearing a great number of branches occur principally in the upper part of the shoots produced in a period of growth. Be- sides the normal branches, adventitious ones occur, though rather rarely (Comp. Soins 1, c. p.29). Their position is less regular than that of the normal branches, and they are usually given off from the under part of the joints. Fig. 194. Corallina officinalis. A, seriate branches While in the f. éypica every joint bears usually Placed on the border ofa joint. B, upper part two opposite branches, other specimens, especially nd So ee those growing in deeper water, are less branched, a greater or lesser number of joints bearing no branches, or only one. In these specimens the joints are cylin- drical or nearly so, while the joints of the much branched forms are usually more 271 complanated, especially in the upper end of the shoots (Plate IV fig. 6 ). In speci- mens from deeper water it sometimes happens that some of the branches assume a special character, growing out as slender, unbranched, irregularly curved organs taking not the upward direction but growing in a transversal direction or more downwards. They resemble either rhizomes or tendrils but have usually not the function of either of these organs (Plate IV fig. 7). It may however happen that the end of such a branch fixes itself on any solid substratum, f. inst. molluses, Furcellaria, Zostera, developing an adhesive disc similar to the primary crustaceous frond. It is connected with the ultimate joint by a genicle. Such adhesive discs may also develop at the end of ordinary fronds coming accidentally in contact with any solid body (fig. 195). These discs have the power of producing new articulated fronds, in a similar manner to the primary ones (fig. 195 B). The age of the articulated fronds is not known. They | reach a length of up to 16 cm, usually however only 10 cm. \ | ) Supposing that a long pinnated shoot is produced every year, | N it seems probable that the age of the erect fronds does not \ W exceed 3 or 4 years. N SAR = The joints consist of a central tissue of elongated cells Fig. GE and a cortex not sharply limited from it, the cell-rows at the Gorattina officinalis. A, ad- hesive disc developed at the periphery of the central tissue bending outwards and consisting of cells becoming gradually shorter outwards. The cells of the central tissue are usually 5—8 times as long as broad; they are disposed in transversal zones, their end-walls being situated about at the same level, the limiting lines being, however, convex upwards (comp. Mrs. WEBER, Siboga pl. XVI end of an ordinary shoot on coming in contact with a shell. B, adhesive disc devel- oped from the ultimate joint of a shoot coming in contact with a rhizome of Zostera; scars after articulated fronds developed from the dise but fallen off are visible. 3:1. fig. 15, 1904). The cells are as usual connected with primary pits at the end walls, while secondary pits do not occur"), but lateral fusions between the cells of the central strand are very numerous and more than two cells frequently fuse together. As mentioned above, p. 211, I found these fusions followed by a fusion of the nuclei in a tetraspore-bearing plant. In a female specimen with ripe cystocarps collected in winter at Frederikshayn similar cell-fusions were found, but the behaviour of the nuclei was different, those of the central tissue having divided in two to four, while such divisions were not observed in the tetraspore-bearing plants. It was therefore not easy to decide whether fusion of the nuclei took place in the female plant. It should be of much interest to decide whether there is such a constant difference between the tetraspore- bearing and the sexual plants. The cortex of the joints is covered with a continuous layer of low cover-cells (comp. Solms, Corall. p. 29). 1) PILGER states, however, that the longitudinal walls in the central tissue of Corallina are pro- vided with pits (1908. p. 252). 272 The nodes (genicula) consist of a single layer of very long cylindrical cells with attenuated ends continuing into the joints connected by the node. The state- ment of Sorms (l. c. p. 28) that these cells are later on divided by a number of thin transversal walls has not been confirmed by YENDO (Genicula, 1904, p. 30), neither have I found these walls. The longitudinal walls of the genicular cells are not incrustated with calcium carbonate, while the attenuated ends (their extrageni- cular portions, YENDO) are incrustated as the cells of the joints between which they are inserted. For further in- formation on the chemical qualities of the walls of the genicular cells comp. YENDO (I. c.). The node is more or less covered by a cortex which is interrupted in the middle (comp. Kürzıng, Phyc. gen. pl. 79, I). Hyaline hairs were not observed in the Danish specimens of this species, but as they have been figured by THURET in C. mediterranea (Et. phyc. pl. 49 fig. 2 and 4) they will probably also be found in the typical C. officinalis. The three kinds of conceptacula occur, as far as known, always on different individuals (comp. THURET, 1. c. p. 93). They are either terminal in the ends of shorter and longer branches, or lateral, sessile on the joints, and the three kinds of conceptacula may all be apical or lateral as well (comp. Sos, |. c. p. 5). The lateral con- ceptacula are frequently placed on the edges of the joints, but their position may also be more irregular on various sides of the branches. In a male specimen which was very densely beset with conceptacles, many of them were fused together. Two or three of them were frequently i placed at the same level, forming an incomplete ring at Fig. 196. the upper end of the joint, with the ostioles more or less Corallina officinalis. Partoffrond drawn out in a horizontal slit (fig. 196). with fused male conceptacles. 18:1. As to the structure and development of the concep- tacles, reference may be made to the repeatedly quoted papers of THURET and SoLMs” on Corallina mediterranea, which must be supposed to agree with the typical C. offi- cinalis in this respect. As shown by THURET (I. c. p. 93, pl. 49 fig. 6), the antheridial conceptacles differ from the others in having a conical prolongation containing the ostiole. 1 found the same in the Danish specimens. The development and structure of the spermatia have been studied by THuRET (I. c. p. 95, pl. 49 fig. 7—9), Soins (1. c. p. 36, Taf. II fig. 21--23) and GUIGNARD (|. c.). The development of the cystocarp has been thorough described by SorLms and I must content myself with referring to his paper, remarking however, that the subject needs further examination after the important paper by MINDER on Choreo- 273 nema Thuretii. I have only examined a few fully developed cystocarps on slides made by microtome, and they showed that the formation of carpospores is not always limited to the periphery of the conceptacle, but may also take place from the inner part of the great disc-shaped cell at the bottom of the conceptacle, perhaps only because the border of this cell is lobed. Referring for the structure and development of the conceptacles of sporangia to THURET (I. c. p. 94, pl. 49 fig. 4—5) and Sots (I. c. p. 31, Taf. I, fig. 6—7), I shall as to the sporangia only mention that, after the division of the primary sporangial nucleus into four, a fairly long time elapses before the cell-division begins. A great number of sporangia with four nuclei situated about (not exactly) in a vertical series are therefore to be found (fig. 197 B). This was already observed by THURET, who remarks (1 c. p. 95): “La formation des cloisons est précédée de l’apparition d’espaces clairs qui occupent le centre des futurs spores (fig. 5)”. As elsewhere (comp. THURET, |. c. p. 95, Sos, L. c. p. 5), the sporangia-bearing specimens seem to be more frequent than the sexual ones also in the Danish waters, but I have not sufficient observations to affirm this with certainty. The species is, as elsewhere, rather variable, but cannot be divided into well defined varieties. When growing at low-water mark or in shallow water it is markedly pinnate, almost every joint bearing a pair of branches, and must Fig. 197. be referred to f. vulgaris Kützing (Tab. phye. VIII, p. 32, A ue Tab. 66 fig. 2; C. officinalis a, Areschoug 1. c. p. 562; C. offic. ECC es oes f. typica Kjellman, Alg. Arct. Sea p. 86 (114); C. offic. 7, Yendo 1902, p. 29, pl. VII, fig. 12, comp. Plate IV figs. 5—6). The specimens growing in deeper water are sometimes not much different from the ones just named, but are usually less branched and have longer joints. In f. vulgaris, the length of these does not reach 2 mm, while in the specimens from deeper water it not rarely reaches 3,5 mm, and even a length of 4,5 mm has been met with. In the extreme forms, the ramification is scarce and irregular, not pinnate, and the branches are often given off at various sides, though a tendency to branching in one plane is to a certain degree pronounced. Such forms may be named f. profunda Farlow (Mar. Alg. New. Engl., 1881, p. 179). In the Kattegat and the Samsø waters they are frequently coarser than the typical form, the joints being cylindrical, about 1 mm thick, and agree then fully with the description of f. robusta Kjellm. (1. c. p. 86 (114). This form has been collected in several places in the named waters in depths from 10 to 19 meters (Plate IV fig. 8). The species is commonly spread in all the Danish waters with proportionally high salinity, including the Samso waters, where it is very common. It grows usually on stones, but may also be fixed to shells of molluscs (Purpura, Littorina, Buccinum, bivalves), on wood, and more rarely on Algæ (Furcellaria). It often forms associations D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 2. 35 4 from ordinary low-water mark to two or four meters depth on moles and boulders in Skagerak, the northern Kattegat and the Limfjord, and it does not avoid exposed places. In summer, a narrow belt of dead Corallina may be found at low-water mark when the upper part of the Corallina-association has been exposed to the air during a long period of low-water. It can also occur abundantly and form asso- ciations in deeper water, on gravelly or stony bottom, e. g. in the eastern Kattegat, but it is then frequently associated with Lithothamnia. In the sublittoral region it descends frequently to 19 meters depth, but it has been met with at a depth of 29 meters in the northern Kattegat. As to the vegetative development of the frond during the year I have no personal observations, but it must be supposed that the growth begins in the last part of the winter and ceases in summer, and that old fronds are thrown off in autumn. NELson and Duncan (Histology of cert. spec. of Corallinaceæ. Trans. Linn. Soc. Bot. Ser. 2 Vol. I. 1876 p. 203) indicate that there is not much carbonate of lime in the frond in spring. Old fronds are often corroded by various organisms. Ripe tetrasporangia were repeatedly met with in the months of May to July, unripe in March. Ripe antheridia were found in May, ripe cysto- carpia in May and December. Localities. Ns: ZQ, jydske Rev, 24,5 m; groin at Thyborøn; Klitmøller, 2 m. — Sk: Hanst- holm, various places, 4—15 m; YM, YN, Bragerne, 1-10 m; Bulbjerg and Svinkløv, washed ashore; SZ, Lokken, ZK!, ZK’, Lonstrup; Hirshals, mole and boulders near land, and 2 miles N.W. of Hirshals, 11m; Højen, c. 5m. — Lf: Lemvig; Ydre Ron by Lemvig; ZY; Oddesund; MD; MF, MG, MH, Thisted in Thisted Bredning; harbour of Struer; I; various places in Sallingsund; LS!; MI; Ejerslev Ren; Holm- tunge Hage; Amtoft Rev; LQ. — Kn: Harbour of Skagen; KC, TV, Krageskovs Rev; Hirsholmene; Kol- pen; Deget; Frederikshavn; Marens Rev, Borrebjergs Rev; Nordre Renner; TJ; TL; TH; UC; UB; ZL; Jegens Odde; Trindelen; FF, FE; IX; ZB, 29m; TG. — Ke: IM, VY, IP, Fladen; XA, Lille Middelgrund: EU, ET, II, IK, f. robusta, dominant, at 14 meters depth. Store Middelgrund: 1D, (f. robusta, 19 m), IB, HX, IA, 11—19m; OO, Søborg Hoved Grund, 8,5 m. — Km: XF, Læsø Rende; ZC, Kobbergrund; XB; XD; XC; TS; bK; FM; FN (f. robusta); ND. — Ks: Pakhusbugt, Anholt (loose); EM and EJ, Lysegrund; HS, Briseis Grund; OS, Hastens Grund; OU, Schultz’s Grund; D, Grenne Revle north of Isefjord; aU, off Lumbsaas; GF, Sjællands Rev; FO, off Havknude; NB; FP, Jessens Grund. — Sa: MZ; KK and KJ, south of Hjelm; KM; BE and BF, off Sletterhage, f. robusta, 10 m; MY; PL; Begtrup Vig; Kalo Rev; harbour of Aarhus; PK; FS, Vejre Sund N.E. of Samsø (f. robusta); MP; DK, Bolsaxen (f. robusta, 14 m); MQ; AH!; Korshavn; Hofmansgave (Car. Rosenberg); NZ; PK, Norsminde Flak; BC: aX, south Side of Endelave; Al! and DJ, by Æbelø; FY, off Bjornsknude, 5,5 m. — Lb: Only found at the harbour of Bogense and at FZ, Kasser Odde, the north side of the reef, 6,5 m. Never met with in the neighbour- hood of Middelfart and Feng, where numerous dredgings have been made. — Sb: Harbour of Kerte- minde; NR, at the entrance to the harbour of Korser, only 1,5 m high, on stones picked up in the belt (Nyborg). — In the German part of the western Baltic Sea REINKE records the species from the isle of Als and from Neukirchner Grund in Flensborg Fjord. At Kullen on the west coast of Sweden I have not met with it. 2. Corallina rubens L. Linné Syst. nat. Ed. 12. Vol. I. p. 1305. Kützing, Tab. phyc. 8. Band, 1858, p. 38, Taf. 80; Solms, Corall., p. 42; Hauck, Meeresalg. p. 278. Jania rubens Lamour.; Kützing, Phyc. gener., 1843, p. 389, Taf. 79 II; Harvey, Phyc. Brit. pl. 252, 1851; Areschoug, in J. Agardh, Sp. g. o. Vol. II 1852, p. 557; Kny, Bot. Zeit. 1872, p. 350; Thuret, Etudes phye. 1878, p. 99, pl. L, LI. This species is usually classed under the genus Jania, established by Lamouroux. This genus, however, is, as shown by ARESCHOUG (I. c. p. 554), scarcely different from Corallina by other characters than the normally forked frond. Mrs. WEBER has later (Siboga, p. 85) stated that there is also an anatomical difference, the cells of the central tissue in the joints being of almost the same length as those of the genicula, while they are much shorter in the true Corallina. I prefer, however, to regard Jania as a subgenus of Corallina. The articulated fronds are given off from a small thick crust with lobed out- line, resembling that of C. officinalis but of smaller size. From the crusts examined by me only a small number of fronds, usually 1—3, were given off. The fronds are connected with the crust by a geniculum which may be rather broad (high) (fig. 198 À). The fronds are normally forked, the point of vegetation producing by the ramification no shoot in continuation of the axis, but two diverging equally from its direction. The bifurcations occur in greatly varying frequency, the number of interjacent joints varying from 1 to 10 or more. The planes of ramification of the successive bifurcations do not coïncide, but cross each other under | various angles (comp. Kny, 1872 p. 707). In ( most of the Danish specimens this is the \_ only ramification existing; but pinnate ra- er . 9 Fig. 198. mification may also occur. A greater or Corallina rubens. A, basal part of an articulated frond smaller number of the joints may be com- Springing off from the basal disc. B, adhesive disc 0 o developed at the end of a branch. 65:1. planated, obsagittate and bearing on the up- wardly directed points two opposed simple articulated pinnulæ consisting of a small number of joints. When these pinnulæ are produced in a greater number, on several successive joints, we have the f. corniculata, which has been regarded as a distinct species, but which cannot be kept distinct from the typical species. The joints at the base of the bifurcations may also bear pinnulæ, under the forking branches. The pinnulæ, no doubt, usually arise later than the branches of the bifurcations, and may then perhaps be regarded as adventitious organs; but it seems that opposite lateral pinnulæ or pinnæ may sometimes arise at the growing point, for according to Kny (l. c. sp. 707) “trichotomies” may also occur. This must take place when the ramification is pinnate. In such cases the middlemost shoot cer- tainly represents the continuation of the axis, and the two lateral ones correspond to the branches of an ordinary bifurcation; I have not, however, examined such ramifications. In rare cases the lateral shoots showed a more vigorous development, and were bifurcate as the ordinary shoots. Supernumerary adventilious pinnulæ may 35* 268 sometimes occur under the normal ones. — Hyaline unicellular hairs covering the surface of the frond have been mentioned and figured by THURET (Et. phyc. p. 96, pl. L, LI, fig. 1, 9, 15, 18). Their occurrence seems to be dependent upon the season, as I found them in specimens collected in July while they were wanting in speci- mens from August. The cortical layer consists of two or three cell-layers. It is covered by a con- tinuous layer of low cover cells. The cells of the central tissue are, as mentioned above, almost of the same length as those of the genicula (fig. 199). Lateral fusions take place between the cells of the cortical layer and of the central tissue as well. Adhesive discs are not seldom produced at the end of branches which accidentally come in contact with any solid body, e. g. an Alga or a shell of a bivalve. They are, as in Cor. officinalis, connected with the frond by a geniculum (fig. 198 B). As to the organs of reproduction and the germination, reference may be made to the splendid work of THuRET (1. c. p. 99, plates L, LI); it should only be mentioned that there are but two kinds of individuals, the sexual plants being monoecious. In the Danish waters only tetrasporangia- bearing plants were found. | The species has been met with in several places at the shore of the Skagerak and in the northern Kattegat. In i the Skagerak it occurred partly as f. corniculata or a trans- itional form; in Kattegat it occurred only as f. typica. It Fig. 199. was found growing on several Algæ, in particular Ahnfeltia Corallina rubens, longitudinal plicata, further Chondrus crispus, Phyllophora rubens, Deles- section of joint. 350:1. o . . seria and Corallina rubens. It grows partly in small depth, about 1 meter, near the coast, partly deeper, up to 23,5 m depth. It reaches a length of 2-3 cm or a little more. It has been met with both in summer and winter, with ripe tetrasporangia in June to August. Localities. Sk: YM!, Bragerne, 1—2 m; Lønstrup, washed ashore, partly f. corniculata, (C.H. Ostenfeld); Hirshals, 2m and washed ashore, partly f. corniculata. — Lf: ZY, Nissum Bredning, a small specimen between loose Alge. — Kn: Hirsholm, about 2m; N.E. of Hirsholm, c. 7m (C. H. Ostenfeld); Deget; GM, Engelskmands Banke, 6 m; TP, Tonneberg Banke, 15,5 m; FF, Trindelen, 15 m; TR, near Trindelen, 23,5 m; UB, east af Nordre Renner; TL and ZL! E. of Nordre Renner. Fam. 10. Gloiosiphoniaceæ. Gloiosiphonia Carmichael. 1. Gloiosiphonia capillaris Huds. (Carm.) Carmichael in Berkeley, Gleanings of British Algæ, 1833, p. 45, Tab. 17 fig. 3; Harvey, Phyc. Brit. plate 57, 1846; J. Agardh, Spec., JI, p. 161,1851; Flora Danica, tab. 2574, 1852; Ekman, Bidrag till käuned. DER af Skand. hafsalger. Stockh. 1857, p. 8; Nägeli, Morph. u. Syst. d. Ceram., Sitzber. Münch. Akad. 1861, II, p.387; J. Areschoug, Observ. phycol. III, Upsal. 1875, p. 10, Tab. I, fig. 4; Bornet et Thuret, Notes algologiques, I, 1876, p. 41, pl. 13; Schmitz, Untersuch. Befr. Florid., Berlin 1883, p- 224, 230, etc., Taf. V fig. 8-15; Oltmanns, Z. Entwickl. d. Florid., Botan. Zeit. 1898, p. 109, Taf. V: Oltmanns, Morph. u. Biol. d. Algen I, 1904, p. 572, 698; Kolderup Rosenvinge, Hyaline unicell. hairs, Biol. Arb. til. E. Warming, 1911, p. 205, fig. 1—2, Fucus capillaris Hudson, Fl. Angl. 1762, p. 591. Gigartina lubrica Lyngbye, Hydroph., p. 45, Tab. 12 A ‘teste specim.). The structure of the frond has been described by NÆGEL1 (1861), BorNET and THURET (1876) and OLrmanns (1904); reference may be made to the quoted works. The outer cells of the frond contain narrow branched chromatophores; the number of the latter could not be determined. The Danish specimens, collected in June to August, were always provided with numerous hyaline hairs, at least on the young parts of the frond, but sometimes also on the older parts (comp. KOLDERUP ROSENVINGE |. c.). Strange to say, they have not been mentioned and figured by BoRNET (l. c.) who examined plants collected at St. Malo in June. On the other hand, Kuckuck has found hairs terminal on the erect filaments given off from the germ-disc (fig. 356 in OLT- MANNS’ Morph., p. 572). As shown by Kuckuck in the figure quoted, several fronds are given off from a monostromatic basal disc bearing on its upper Fig. 200. Gloiosiphonia capillaris. Sporelings. À and B two face numerous short simple orslightly branched days old, C three days, D 6 days, E 10 days and c F 29 days old. 350:1. cell-filaments. The fronds arise by transforma- tion of some of these filaments; one of the fronds shown in the figure mentioned arises from a branch of a cell-filament. The fronds are divided by transversal walls in low segments, early producing verticillate branches, and afterwards dividing by vertical walls. — The earlier stages of development have been studied in July 1914 at Hirshals, where the carpospores were brought to germinate (fig. 200). The globular spores after having been fixed to the substratum, e. g. a slide or a cover-glass, surround them- selves with a membrane, and frequently show the first signs of germination within 24 hours, a germinating tube being produced at one side and separated from it by a wall. The circular spore-body is frequently divided by a wall, the orientation of which to the germinating tube is not constant. After 2 days the germinating fila- ment was 3—4 times as long as the spore-body, usually two-celied, the ultimate cell being densely filled with protoplasm, while the undermost were almost empty, and the spore-cell as well. Sometimes two germinaling tubes are given off from the same spore, either diametrically opposed or diverging under an obtuse angle. After four days the first germinating spores had produced long germinating filaments which 278 commenced to branch, producing usually alternating branches at their distal end. The following day a great number of the sporelings had produced a multicellular monostromatic disc arising by further branching and fusing together of the branches, and being terminal on a shorter or longer filament. After ten days the germ discs were larger, some of the cells were divided by transversal walls, and several hairs were given off from the upper surface. Some sporelings continued growing as long unbranched filaments, but producing no disc; they were growing obliquely upwards against the light. It is probably the want of contact with any solid substratum which has caused the absence of a disc. The cultures were continued during up to a month. The sporelings showed at the end of that time no essential differences; they were only somewhat larger, having increased by marginal growth and cell- divisions, and most of the cells were divided by a horizontal wall, which may signify that the upper cell formed may be tke mother-cell of a vertical filament as described by Kuckuck, but these filaments were not yet formed in their definite shape. Numerous hairs were frequently produced by the disc. Fronds emerging from the discs were not observed; they are probably Fig. 201. only produced in the following year, the plant wintering probably Gloiosiphonia capillaris. jn the disc-shaped stage. The outline of the discs is nearly Part of transversal section 4 f of frond with antheridia. Orbicular. The number of the cells in the basal germ filament 670/21. is rather variable; usually it is small, and the filament may be wanting, the branches continuing to the spore-cell. — A similar formation of the germ disc, not from the spore-cell but from the germ-tube produced by it, is known also for other Florideæ, e. g. Dudresnaya (KırLıan, Entw. ein. Florid. Zeitschr. f. Bo- tanik. VI, 1914, p. 237). The antheridia are, as shown by BornET and THURET (I. c. p. 42) found in spots scattered on the plants which bear the carpogonia. They are oblong or obovate, and are produced by transversal divisions of narrow cells covering the surface of the plant. These cells branch, being divided by oblique walls (fig. 201). Regarding the development and structure of the cystocarps, reference may be made to the important paper by OLTManns in 1898 (see also 1904) where it was proved that the double fertilization, presumed by Scamirz for this plant, do not take place. The tetrasporangia were unknown to J. AGARDH, as late as in 1876 (Epicrisis p.115) although they were described by Exman in 1856 and by ARESCHOUG in 1875. They are, according to the named authors, cruciately divided, though often very irregu- larly; the sporangia-bearing specimens are much branched above, bearing dense bushes of branches. Such specimens were found at Christianssund on the west coast of Norway in August, later on the coast of Bohuslän in June by KyLın. On the Danish shores, sporangia-bearing specimens have never been found. All the specimens examined (nearly 200) were sexual plants. The species occurs on stones in exposed places in small depths (1—5 meters). 279 It can support a strong surf and is then living in much polluted water. It attains a length of 15cm in the Skagerak, 8 cm in the Limfjord. It has only been collec- ted in June to August. Nearly all the specimens bore cystocarpia. It has only been found in the saltest waters. Localities. Sk: YN, within Bragerne, 5 m; washed ashore on Grønhøj Strand (Miss Ellen Moller); Hirshals, mole and reefs, 1—5 m. — Lf: Sallingsund, near Nykøbing, east side of Odden (Th. Mortensen, !) and off Gronnerup. In the herbarium of the Botan. Museum at Copenhagen a specimen is to be found, labelled Limfjorden Aug. 1869, probably collected by J. P. Jacobsen. Some general remarks on the Cryptonemiales. 1. Intercalary cell-divisions. The species belonging to this order appear as a rule to follow with great regularity the rule pointed out by Scumirz') for cell- division in Florideæ: that only the terminal cells in the filaments, of which the frond is composed, divide by transverse walls. Some cases occur, however, where transverse divisions of the segment cells have been noted. Thus, according to BREBNER, intercalary transverse divisions take place in Dumontia incrassata in the short-celled filaments, which grow out from the basal disc and form the upright fronds (see above p.156). Another instance I have noticed in Hildenbrandia prototypus, where intercalary divisions may occur in the radiating filaments forming the basal layer, which makes itself apparent in the fact that the cells are shorter at some distance from the margin than at the margin itself (p. 203 fig. 121). It should further be mentioned, that the filaments in several Melobesieæ (Lithothamnion, Corallina) terminate in a covering cell, which does not divide, and which forms, together with the covering cells of the adjacent filaments, an outer layer, incapable of development, the penultimate cell in the filament taking over the function of the terminal cell as an initial one. A deviation from the order of succession in cell division as noted by SCHMITZ may also be found in some species of Melobesia and Lithophyllum, where two or more cortical cells, likewise incapable of division, are cut off one below the other at the end of the same mother cell (p. 254 fig. 174 and p. 264 fig. 184 B)’). 2. Cell-fusions. Secondary pits, which are commonly found in the Rhodo- melaceæ and several other families of the Florideæ *) appear to be altogether lacking in most Cryptonemiales. I have only found them in the genus Lithophyllum. As 1) Fr. Scumirz, Untersuch. über die Befrucht. d. Florideen. Sitzungsber. d. Ak. d. Wiss. Berlin 1883, p. 216. 2) Intercalary divisions appear to oceur throughout the whole of the frond, at any rate in the perithallium in the genus Porolithon, to judge from the drawings of Mme LEMOINE in BØRGESEN, The Marine Algæ of the Danish West Indies, III Rhodophyceæ. Dansk Botanisk Arkiv. II p. 177 and p. 179. 3) Comp. L. KoLpErup ROSENVINGE, Sur la formation des pores secondaires chez les Polysiphonia. Botan. Tidsskr. 17. Bind. Kjebenhavn, 1888, p. 10. 280 mentioned on p. 210, this genus is characterised by the fact that the cells in the upright filaments, of which the frond (the perithallium) is composed, are connected by transverse pits, the origin of which must be of a secondary nature. I have not, however, been able to follow their development, and particularly did not succeed in ascertaining the co-operation of the nuclei in their formation. In the remaining members of the family of Corallinaceæ, on the other hand, there is a different method by which the cells in various filaments may.enter into direct communication one with another, to wit, by dissolution of the separating wall, whereby an open con- nection is established between the cells. This feature has already been referred to above (p. 210) where it was also pointed out that more than two cells may fuse together, and that the cell-fusions may involve fusion of the nuclei (cf. figs. 136, 139, 156 and many others), Only in two of the Danish Corallinaceæ have the fusions hitherto not been shown (Melobesia minutula and Choreonema Thuretii). Entirely similar cell-fusions were demonstrated in various Squamariaceæ, viz, Cruoriopsis danica (p. 185 fig. 107), Cruoriopsis gracilis (p. 188 fig. 111), Rhododermis elegans (p. 198 fig. 118) and Rhododermis Georgii (p. 199 fig. 119). In Hildenbrandia, on the other hand, they were not found. That cell-fusions are important as facilitating connection between cells and cell-filaments not directly in communication by plasma-continuity can hardly be doubted. We find them also particularly numerous in the “roof” above the con- ceptacle lin the Corallinacez, i. e. between cells whose indirect connection below has been interrupted by the formation of the conceptacle. Comparison with Hilden- brandia, which lacks cell fusions, supports this view, as the roof of a conceptacle, which grows in extent through the continued sporangia formation, consists of dead and more or less disorganised cells, save at the margin, undoubtedly cwing to the fact that the connections below have been interrupted, and those to the sides are wanting (cf. p: 204 and figs. 125, 126.). 3. Alternation of generations and alternation of nuclear phases. As we know, there has in several Floridee been shown to exist a regular alternation between a haplophase, consisting of the sexual generation, and a diplophase, consisting of two generations, viz; the cystocarp or gonimoblast, and the tetraspore-bearing plant’). A like course of development must be presumed to take place in all Florideæ with normal fertilisation, and having tetrasporangia. SVEDELIUS has called these Florideæ diplobiontic, in contrast to the haplobiontic, which lack tetraspores, and in which the chromosome reduction takes place by division of the zygote nucleus”). Here then, we have but two generations, the sexed plant and the cystocarpium, both y Comp. H. Kyrın, Die Entwick. u. syst. Stell. von Bonnemaisonia asparagoides etc. Zeitschr. £ Botanik, 8. Jahrg., 1916, p. 570. — J. Buper. Zur Frage des Generationswechsels im Pflanzenreiche. Ber. deut. bot. Ges. Bd. 34. 1916, Heft 8. — O. Renner, Zur Terminologie des pflanzlichen Generationswech- sels. Biolog. Centralblatt. Bd. 36, 1916, p. 337. *) N. Sveperius, Zytolog.-entwickelungsgesch. Stud. über Scinaia furcellata. N. Acta reg. soc. sc. Upsal. Ser. IV. vol. 4 no. 4. Upsala 1915, p. 22. 281 haploid, and the diploid phase is restricted to the undivided zygole cell. To these Florideæ belongs, among the species mentioned in the present paper, Halarachnion ligulatum. Gloiosiphonia capillaris must also be haplobiontie on the coasts of Den- mark, where, as on those of France, tetrasporangia-bearing plants have never been found, though they have been met with on the coasts of Norway and Sweden (see p. 278). On the other hand, there are species which only propagate by tetraspores, not sexually. This applies first of all to the Hildenbrandia species, which are ex- tremely common with tetraspores, but have never been found with sexual organs. In Cruoriopsis gracilis also, and Rhododermis Georgii, sexual organs are quite unknown. Rhododermis elegans again, has always been found with tetrasporangia only, save for the case of some specimens from North-east Greenland, which bore antheridia. There are moreover some Corallinacee which have hitherto been found in Danish waters only with tetrasporangia (Lithothamnion lœve, glaciale, Sonderi, norvegicum, and lœvigatum). In all these, at any rate those first named, tetraspore formation must be supposed to take place without reduction of the chromosomes. It should further be noted that in some species, albeit possessing both kinds of spores, the two kinds do not occur with like frequency. This is probably the case with several of the Lithothamnion species just referred to, the sexual plants being presumably not altogether lacking, but merely rarer than those bearing tetra- spores, and have therefore not hitherto been found. On the other hand, sexed plants of Polyides rotundus seem to be far more common than the tetraspore plants in the Danish waters. All this might seem to suggest that these species have no regular alternation of generations, such as takes place in the typical diplobiontie Florideæ, in which sexual plants and those bearing tetraspores are nearly alike in point of frequency. Parthenogenesis has been shown with certainty in Platoma Bairdii by Kuckuck. In the Little Belt, it appeared in the same manner as at Helgoland, the antheridia lacking, whereas cystocarpia and tetrasporangia were found. Here also the tetra- sporangia must be formed without reduction of the chromosomes. Possibly partheno- genesis may also occur in other Cryptonemiales. Some observations would seem to suggest that this may be the case in Furcellaria fastigiata. The fact that I did not find the spermatia attached to the trichogynes I do not consider as of great importance; more significant, however, is the finding of an unfertilised carpogonium with a short trichogyne, but which had nevertheless formed an outgrowth which could only be regarded as a sporogenous filament (cf. p. 169, fig. 85 D). — In Petro- celis Hennedyi I found, in some instances, sporogenous filaments growing out from carpogonia which showed no interruption of the plasmatic connection with the trichogyne (fig. 98 E, 99 E) and here also, no spermatia were found attached to the trichogynes. Finally, some cases have been noted where tetraspores and sexual organs appeared in one and the same individual. This has occasionally been found in D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 2. 36 282 Petrocelis Hennedyi and Cruoria pellita. Here also it must be presumed that the tetrasporangia are formed without reduction of chromosomes. There are thus a considerable number of Cryptonemiales which differ with regard to the course of development from the typical diplobiontic forms. SvEDELIUS'), referring to the simultaneous occurrence of monospores and te- traspores in one and the same individual of Chantransia efflorescens, considers it not altogether impossible that future investigation of the cruciate tetrasporangia may show them to have been produced without reduction of chromosomes. Up to the present, however, no Floridea with such sporangia has been subjected to closer cytological investigation. The Swedish writer points out in this connection, that such sporangia are first divided by a transverse wall, and thereafter by two perpendicular partitions, which he considers would hardly fit in with a reduction division. It should nevertheless be borne in mind that we find, both in Arche- goniates and in flowering plants, cruciate sporangia as well as zonate sporangia, — though the latter, it is true, are more rare — and it seems not to be apparent that the formation of a cell-wall on the first division would preclude the reduction of chromosomes. As regards the zonate division, it has in several of the Coralli- paceæ been demonstrated with certainty that the three cell-divisions take place almost simultaneously, and that the nuclear divisions are completed before the cell- division sets in (see p. 273). It is hardly likely that there should be any difference in principle between the cruciate and the zonate division; among other reasons, because we find both occurring in the species of the genus Hildenbrandia, — which are doubtless very closely related — where the sporangia must also be presumed to divide without reduction of chromosomes (cf. also Lithothamnion Sonderi, fig. 137). If SvEDELIUS’ supposition were correct, it would involve either that the reduction division must take place by the division of the zygote nucleus, in spite of the presence of tetrasporangia, or that it never occurred among Cryptonemiales, since the tetrasporangia, as far as we know, here never divide tetrahedrically, but always by parallel or cruciate walls, often markedly inclined. The latter alternative would further imply that the cystocarpia were throughout developed by parthenogenesis, which is not in accordance with the actual facts, as, though fertilization has not, it is true, been cytologically demonstrated in any of these alge, which are furnished with tetraspores?), yet spermatia have at any rate been found attached to the trichogynes in Dumontia incrassata (see above p. 158), Polyides rotundus (THURET, Et. phyc. Pl. 38 figs. 14—18) and in certain Corallinaceæ (Choreonema Thuretii, SoLMS, Corall. Taf. III, fig. 4, Corallina mediterranea, Sons, 1. c. Taf. III, fig. 19). On the other hand, it must be presumed that reduction division may also be lacking in tetrahedrically divided sporangia, as cases are also known where such 1) N. SvEDELIUS, I. c. p. 50. *) The fertilization has been cytologically demonstrated in Gloiosiphonia capillaris by OLTMANNS; but this Alga has usually no tetrasporangia. 283 sporangia occur in the same plant as sexual organs, (e. g. Callithamnion corymbo- sum, cf. THURET in LE Joris” Liste d. Alg. mar. de Cherbourg, p. 112). As will be seen from the above, there are many features in the Cryptonemi- ales which call for further cytological investigation, especially with regard to the presence of a fertilisation process and the manner in which nuclear division takes place in the tetrasporangia. The latter point will doubtless be the easier to decide, as the tetrasporangia are in many species easily found, and contain large nuclei. EXPLANATION OF PLATES. Plate III. All the figures are microphotographs after microtome-sections taken by Mr. A. Hessereo. ik en) 1 (6) Lithothamnion leve Strömf. Tetraspore (dispore), showing the nucleus with nucleolus (fallen out) and the structure of the protoplasm. (Specimen from Aalsgaarde). About 225:1. Lithothamnion Lenormandi (Aresch.) Foslie. Vertical section of antheridial conceptacle. (Specimen from TE”). About 200:1. Lithothamnion Lenormandi (Aresch.) Foslie. Vertical section of conceptacle of cystocarp. (Specimen from XQ). About 200:1. Lithothamnion glaciale Kjellm. f. Granii Fosl. Section of crustaceous frond with con- ceptacles of sporangia. ‘Specimen from Læsø Rende). About 180:1. Lithothamnion polymorphum (L.) Aresch. Vertical section of female conceptacle showing procarps. (Specimen from Store Middelgrund, May). Lithothamnion polymorphum (L.) Aresch. Vertical section of emptied conceptacles of sporangia with covering tissue. (Specimen from reef near Korsør). Plate IY. All figures from photopraphs in natural size. Lithothamnion glaciale Kjellm. f. Granii Fosl. 1 and 2 attached to stones, 3 free, 4 similar one being on the point of dividing. (Specimens from IH, 3375). Corallina officinalis L., f. robusta Kjellm. (Specimen from YU, Hanstholm. 7286). In fig. 5 the branchlets are partly verticillate. Corallina officinalis L., slender, slightly branched form with some stoloniform branches growing out in a transversal direction. (Specimen from UC, north of Leso, 5625). Corallina officinalis L. f. robusta Kjellm. With lateral conceptacles. (Specimen from MZ, 4058). D. K. D. Vipensk. SELSK. SKR., 7. R., NATURV. OG MATH. AFD., VII. 2 [L. KoLDERUP ROSENVINGE] Pr. III À 5K N ao HEP Ce Phot. by A. Hesselbo. IV Pr. D. K. D. Vipensk. SELSK. SKR.. 7. R., NATURV. OG MATH. ArD,, VII. 2 [L. KoLverup ROSENVINGE] THE MARINE ALGÆ OF DENMARK CONTRIBUTIONS TO THEIR NATURAL HISTORY PART III RHODOPHYCEE III. (CERAMIALES) BY L. KOLDERUP ROSENVINGE WITH THREE PLATES D. KGL. DANSKE VIDENSK. SELSK. SKRIFTER, 7. RÆKKE, NATURVIDENSK. OG MATHEM. AFD., VII. 3 — DIX xD + — KOBENHAVN BIANCO LUNOS BOGTRYKKERI 1923— 24 INTRODUCTION Sie the first part of this publication was issued I have studied the marine Algæ on the Danish coasts almost every summer. During the last two years my in- vestigations have been more extensive. This is chiefly due to the addition made to the area of the Danish flora in consequence of the reunion of North Slesvig with Denmark in 1920. The boundary on the eastern side of Slesvig having been remoyed from Heilsminde to Krusaa in the interior of Flensborg Fiord, the Little Belt area (Lb) has been augmented by the waters between Heilsminde in the north, and Sonder- borg and Pol at the south-eastern extremity of Als, while the line bounding the Da- nish part of the Baltic (Bw) on the south must now be drawn from Krusaa through the middle of Flensborg Fiord and thence south of Bredgrund south of Als. Though these waters have formerly been examined by Professor REINKE, and their flora and vegetation dealt with in his well-known work Algenflora der westlichen Ostsee Deut- schen Anteils, 1889, I have considered it necessary to study the same waters myself. By the kindness of the fisheries director, Mr. F. V. MortTENSEN,-I have been enabled, with the assistance of the fishery control motor-boat, to make investigations and collections in the waters round Sonderborg in June 1921, and in June 1922 to make similar investigations while onboard the control steamer S. S. Falken (fisheries super- visor TROLLE THOMSEN), along the entire eastern coast of South Jutland and likewise in the waters surrounding Funen. In both cases the material was collected partly, by means of a boat, from stone reefs and in other localities such as breakwaters near land, partly by dredgings from ship at a greater distance from land. In the autumn of 1922 there further occurred an exceptional opportunity to make dredgings in the North Sea and the Skagerak in places otherwise very difficult of access, since the marine research ship S.S. Dana was to make fishery investigations in these waters, and especially in places where one might expect to find Algæ. The Marine Research Committee very readily granted me room onboard, and the leader of the cruise, Dr. A. C. JOHANSEN, did everything in his power to further my investigations. As I was obliged to break off my stay onboard on October 7th, mag. se. Mr. C. A. JORGENSEN was deputed to carry on my investigations of the flora of the Skagerak and the northern and central parts of the Kattegat until the cruise came to an end on October 19th. Mag. JORGENSEN has later, in June 1923, made investigations onboard the Dana in the waters around Bornholm and left the collected Algze at my disposal. omk ol 288 In continuation of the list given on p. 22 et seq. I give below a list of the new dredging stations arranged on the same principles as the one already mentioned. Dredging Places in the North Sea and the Skagerrak. ue ie Mors DAT 5 ge À SIE N Le Tyborée, , Ex Ai PEN It ISKERBANKE | |} oe! J YE Ib) A IN D Signatures . e Vegetation of Alge © Very scarce Alge o No Vegetation — Places investigated with algal vegetation near land. a a0) de td —.-—— 20 —»— —n—. | | | | | | | | | 2. [619 Ef Gr Most of the new dredging places are marked on the charts given on pp. 288 and 290. In the later those places at the shores where investigations and collections have been made are likewise indicated by a mark together with the name of the place concerned. In deep waters the collections have always been made with a dredge where nothing else is indicated. In most other places an otter trawl has been employed. As the markings on the charts and in the list show, there was no vegetation at all in the southern part of the North Sea area even where the bottom was stony. This agrees with what earlier German investigations have shown! and what I myself found in 1905 at Horns Reef (Part I p. 22, Chart II). Further it was in accordance with what Dr. Johansen had found immediately before my arrival onboard the Dana. In thirty localities between 6°07’ and 8°16’ E. and between 55°00’ and 56°08’ N. on fishing with otter trawl no vegetation at all was found. It was confirmed, then, by these investigations that this part of the North Sea is a veritable desert as regards bottom vegetation. In the northern part of the North Sea area, where there were stones or at any rate gravel in nearly all the localities examined, the bottom was almost equally bare, being either entirely destitute of vegetation or showing only very sparse vegetation. This result may, however, be partly due to the late season (the latter part of September) for I have formerly found a fairly abundant flora in some parts of this area at the close of July. In the Skagerak, too, the vegetation is on the whole very poor even on stony bottom, and only in a few places, mostly near land, do we find spots with continuous vegetation, especially at Hirshals, but also at Hanst- holm, Bragerne and Lonstrup. On the other hand, in the Skagerak one often comes across loose, drifting Algæ carried along by the strong current. On groins and breakwaters in the northern part of the North Sea area there is an abundant and fairly varied vegetation. At Fanø and Esbjerg the corresponding vegetation is poor in species and, according to- REINBOLD? and Jaap,® the same is the case with the Algz vegetation on the coasts of Rømø and on the west coasts of North Slesvig; I myself had no opportunity to examine Rømø until August 1923. In the shallow sea between North Slesvig and the islands Zostera marina and Z. nana grow in low water, but there seem to be no Algæ. Mag. R. SpARcK who made dred- gings along the east coast of Fanø at a depth of 4—5 m. has kindly informed me that he got numerous oyster shells and mussel shells and not a few stones in the dredge, but that there was no Algæ vegetation. Only a little loose Fucus vesiculosus without vesicles and some Zostera got into the dredge. The waters washing the eastern coast of North Slesvig are so similar in char- acter to the adjoining parts of the Little Belt and the western part of the Baltic dealt with in Part I, that they do not require further mention here, the more so since they have been treated in REINKE’s above cited work. The depth conditions are shown on Chart II and in map p. 290. 1 J. REINKE, Notiz über die Vegetationsverhältnisse in der deutschen Bucht der Nordsee. Bericht deut. bot. Ges. 1889 p. 367. TH. REINBOLD, Untersuchung des Borkum-Riffgrundes. Sechster Bericht d. Komm. z. wiss. Unters. d. deutsch. Meere. III Heft. ? Tu. REINBOLD, Bericht über die im Juni 1892 ausgeführte botan. Untersuch. einiger Distrikte der Schleswig-Holsteinischen Nordseeküste. Sechster Bericht d. Komm. z. wiss. Unters. d. deutsch. Meere. III Heft. ® O. Jaap, Zur Kryptogamenflora d. nordfriesischen Insel Rom. Schrift. d. Naturv. Vereins d. Prov. Schleswig-Holstein Bd. 12. 1902. 9°2' 30° Dredging Places 1921 and 1922 in the Little Belt and the Western Baltic. Fredericia „U ng Kolding EL BjertStrandz, Sf YO Ih dy JX INf 3D r ZA mae p HE ace © PAT DR ATE: dadersiov I aan: { GEH Eu > 7 IBANKE RANE:SAND \ SEN. et Ÿ Assens 6 Bogense Signatures . Vegetation of Alge . Very scarce Alge Zosterz. Zostera and Alge. No Vegetation Places investigated with algal vegetation near land. N EH eter CUT DER Flens bore = AOL DIR FAD VODRUFS- FLAR x | MG EN 2) SW 1130 "EA BREDGRUND NN XS J 1 SAN K ÿ À LS J Pr + 9920" Lg. E.f. Grw. 30. 291 List of new dredging stations arranged according to the different waters. The localities are designated by letters like the foregoing ones (comp. pp. 22—54). Some of the dredgings of the later years have been made by Dr. HENNING PETERSEN, Mag. P. Kramp or Mr. J. BoYE PETERSEN while I have examined the collected material of Algæ. The dredging stations of Mag. JORGENSEN in October 1922 have been designed with the station figures of the S.S. Dana. North Sea. (Ns) dU. (Dana St. 2835). °7/, 22. 4 miles N.5/, E. of Blaavandshuk light-house. 8 m. — Fine sand. — No vegetation. (Otter trawl). dV. (Dana St. 2836). 11 miles S. by W. of Lyngvig light-house. 15 m.— Fine sand. — No vegetation. eG. (Dana St. 2846). 5°/, 22. 9 miles S.W.1/, N. of Bovbjerg light-house. 24 m. — Gravel, stones. — No Algze, only a fragment of Desmar. acul. eH. (Dana St. 2848). °°/, 22. 14 miles W. by S.1/,S. of Bovbjerg light-house. 27 m. — Sand with few stones. — No vegetation. el. (Dana St. 2849). °°/, 22. 21 miles W. of Bovbjerg light-house. 34 m. — Clay with stones, shells. — No Algæ. eK. (Dana St. 2850). 1/3, 22. Lille Fiskebanke. 46 miles W. by N. of Bovbjerg light-house. 37 m. — Clay, large stones. Scarce Hildenbrandia prototypus. eL. (Dana St. 2851). 1/,, 22. Lille Fiskebanke. 53 miles W.N.W.!/, W. of Bovbjerg light-house. 37 m. — Coarse sand mixed with ooze, with shells. — No Algæ. eF. (Dana St. 2845). 5/, 22. 2,5 miles W. by N. of Bovbjerg light-house. 18—22 m. — Sand, stones, clay. — No vegetation; only Rhodochorton membranaceum in Hydrallmannia falcata. eE. (Dana St. 2844). >/, 22. 12 miles N.W. by N. of Bovbjerg light-house. 26 m. — Gravel, stones. — Scarce Desmarestia aculeata, otherwise only incrusting Algæ (Lithoderma). dY. (Dana St. 2838). >/, 22. 10 miles S.W.1/,S. of Lodbjerg light-house. 18 m. — Clay with single stones. — No vegetation. dX. (Dana St. 2837). #/, 22. 11 miles W.S.W.1/. W. of Lodbjerg light-house. 28 m. — Fine sand. — No vegetation. eD. (Dana St. 2843). */, 22. S.E. of Jydske Rey. 22 miles W. of Lodbjerg light-house. 41 m. — Sand, gravel, stones. — No vegetation; only single specimens of Desmarestia aculeata and fragments of a few other Algæ. eN. (Dal® St. 2853). 1/10 22. Between Lille Fiskebanke and Jydske Rev. 45 miles W. by N. of Lodbjerg light-house. 34 m. — Sand, few animals. — No Alex. eM. (Dana St. 2852). 1/,, 22. Lille Fiskebanke. 55 miles N.W. by W. 7/2 W. of Bovbjerg light-house. 48 m. — Gravel, shells. — No Alge. eA. (Dana St. 2840). #%/, 22. 27 miles W. $/, N. of Lodbjerg light-house. 25—28 m. — Coarse gravel. — Very scarce vegetation: single specimens of Desmarestia aculeata, D. viridis, Corallina offic., Trailliella intricata, Chetopteris, Laminaria (young). eO. (Dana St. 2854). 2/15 22. 4/, miles W. !/; S. of Lodbjerg light-house. 23 m. — Large stones and gravel. — Scarce Phyllophora rubens, Lithoderma and Lithothamnion. dZ. (Dana St. 2839). *8/, 22. 17 miles W. ?/, N. of Lodbjerg light-house. 36 m. — Stones. — Scarce Desmarestia aculeata and incrusting Algæ (Cruoria pellita, Lithothamnion levigatum, Lithoderma). | eP. (Dana St. 2855). 2/10 22. 8 miles W. by N. of Lodbjerg light-house. 24 m. — Gravel and small stones. — Scarce Desmarestia aculeata, single specimens of Phyllophora rubens and Ph. membranifolia. eQ. (Dana St. 2856). 2/,. 22. 8 miles N.W. by W.1/, W. of Lodbjerg light-house. 27 m. — Large and smaller stones. — Mostly incrusting Algæ (Lithoderma, Lithothamnion, Rhododermis elegans). 292 eC. (Dana St. 2842). >/, 22 Jydske Rev. 23 miles W.N.W. of Lodbjerg light-house. 26 m. — Gravel, sand. — In four dredgings only single specimens of Desmarestia acul, Furcellaria, Phylloph. rubens and Corallina off. eB. (Dana St. 2841). */, 22. 21 miles N.W.°/,W. of Lodbjerg light-house. 22 m. — Gravel with small stones. — Two loose specimens of Laminaria saccharina. eR. (Dana St. 2857). 7/;, 22. 9 miles N.W.1/ N. of Lodbjerg light-house. 27 m. — Gravel with stones. — Scarce Desmarestia aculeata, otherwise only few fragments (Phyll. rubens, membran., Trailliella, Plocamium coccineum); stones mostly bare. eS. (Dana St. 2858). */ı 22. 8 miles N. by W. of Lodbjerg light-house. 25 m. — Gravel with small stones. — No vegetation. (Single small specimens of Desmar. acul., Phylloph. Brod., Rhodomela). eT. (Dana St. 2859). ?/;, 22. 15 miles W. by N. of Hanstholm light-house. 34 m. — Gravel, stones. I SCALce vee Laminaria hyperborea and digitata, Phyllophora rubens.. . eU. (Dana St. 2860). =/,, 22. 24 miles W.N.W. of Hanstholm light-house. 50 m. — Gravel, small stones (Aleyonidium gelatinosum in abundance). — No Alge. Skagerak. (Sk) eV. (Dana St. 2864). =/,, 22. 6 miles N. by E. of Hanstholm light-house. 22 —24 m. — Stones, sand with shells and clay. — Scarce Desmarestia aculeata. eX. (Dana St. 2865). ”/,, 22. 10 miles E.N.E.*/, E. of Hanstholm light-house; N. of Bragerne. 16 m. — Gravel, stones. — Mostly incrusting Algæ, rather scarce however, further Laminaria hyperborea (scarce) and Phyllophora membranifol. Dana St. 2904. %/,, 22. 13!/, miles N.E.*/;E. of Hanstholm light-house. 23 m. — Stones, shells. — Very few Algz. (Chetopieris, Sphacelaria, Cystoclon., Polys. urceolata, Antithamnion cruciatum, Lithoderma). Dana St. 2902. #%/,, 22. 12 miles E. by N.1/,N. of Hanstholm light-house. E. side of Bragerne. 15 m. — Sand. — Various Algz, probably all loose (Laminaria sacch. and digit., Fuc. serr., Dilsea, Deless. etc.). (Young-fish trawl). Dana St. 2903. #/,, 22. 12 miles E. Z/, N. of Hanstholm light-house. Near Bragerne. 7 m. — Sand, shells. — No Alge. Dana St. 2907. /,, 22. 26 miles N.W. by W. of Rubjerg Knude light-house. 45 m. — No Alge. — Dana St. 2906. +*/;, 22. 26 miles N.W.1/, W. of Rubjerg Knude lisht-house. — 70 m. — Soft bottom. — No Als. fA. (Dana St. 2868). %/,, 22. E.N.E. of Hanstholm light-house. 18 m. — Gravel, shells. — Single loose fragments of various Algze (Fucus vesiculosus, Halidrys, Furcellaria etc.) and loose Zostera (with rhizomes). eY. (Dana St. 2866). 5/1 22. 18 miles E.N.E.1/ E. of Hanstholm lisht-house. 15 m. — Sand, sto- nes. — Very scarce Alsæ: Halidrys, Delesseria alata, Rhodomela. Furcellaria a. 0. and loose Zostera with narrow leaves. eZ. (Dana St. 2867). 3/;, 22. 21 miles E.N.E. of Hanstholm light-house. 15—17 m. — Gravel, sand. — One specimen of Halidrys, single small specimens or fragments of Dilsea edulis, Deless. sinuosa a. 0.; loose narrow-leaved Zostera. Dana St. 2900. 2/,, 22. 21 miles S.W. 2/,W. of Rubjerg Knude iene house. 9 m. — Sand. — Drifting Algz (Dilsea edulis, Fucus serratus, Laminaria sacch. and digit., Desmar.acul.etc.). (Otter trawl). Dana St. 2899. %/,, 22. 13 miles S.W. by W.7/, W. of Rubjerg Knude light-house. 14 m. — Sand. — Few Algz (Furcellaria, Ahnfeltia, Desmarestia acul. a. 0.), mostly loose probably. fB. (Dana St. 2869). */,, 22. 22 miles N.W.1/, N. of Rubjerg Knude light-house. 47 m. — Sand, shells.— Loose Algze (Desmarestia aculeata, Laminaria sacch., Chorda Filuma.o.) and Zostera. Dana St. 2912. *°/,, 22. 5:/, miles W.2/.S. of Højen light-house. 25 m. — Stones, small shells. — Incrusting Alsæ (Lithothamnion Sonderi) mostly on Modiola modiolus. , 293 cK. %/, 21. North of Skagen; the life-boat station in line with the old church.28 m.— Soft bottom.— A fragment of Laminaria digitata, otherwise no Algæ. — Farther North. 97 m. — Soft bottom. — Some loose Algæ. Limfjord. (Li) bU. *"/, 20. Ejerslev-Næse, E. coast of Mors. 3—8 meters. — Farthest out oysters and stones with very few Algæ. Nearer land Zostera. bT°. ”/, 20. West of Ejerslev Ron. 7 meters. — Firm clay with stones, Mytilus and oysters. — Very few Algæ, mostly Polysiphonia elongata and Trailliella intricala. bT!. *8/, 20. At the broom, Sæbygaards Hage (Fursund). 2 meters. — Stones. — Fucus vesi- culosus, Corallina officinalis. bT:. *8/, 20. Knudshoved, at the N.W. end of Fur. 5,5 meters. — Great stones. — Fucus vesi- culosus, Zostera. — North side of the same point, within the broom. 4 meters. — Zostera and stones with Fucus vesiculosus. Kattegat, Northern part. (Kn) bQ. *8/, 11. Skagen, under the land from the lazaretto to the light-house. — 2 to 3 meters. — Sand and small stones. — Enteromorpha or Chorda Filum. cl. #/, 21. South of Skagen light-house (P. Kramp). 7,5 and 5,5 meters. — Sand and small stones. Ectocarpus siliculosus abundant, further Polysiphonia elongala, and in smaller depth Chorda Filum. el? 3%/, 21. South of Skagens Gren (Kramp). 9,5 meters. — Sand with Zostera. — 13—15 meters. — Clayey sand. — Antithamnion Plumula abundantly on Buccinum and Turritella. cl}. #/, 21. South side Skagens Gren (Kramp). 9,5 meters. — Soft bottom. — Some Algæ on the claws of Pagurus and on mollusc shells. cH. °°/, 21. Off Skagens harbour (Boye Petersen). — Soft bottom with molluses. — Halorhiza vaga, Arthrocladia villosa. cH?. */, 21. Off Klitgaarden, Skagen (Boye Petersen). 4 meters. — Soft bottom. — Brown Algz, in particular Eclocarpus siliculosus and Halorhiza vaga, further Polysiphonia elongata. — 2 meters. — Sand with stones. — Kjellmania striarioides and Delamarea atlenuala. fC. (Dana St. 2870). 3 miles S.W. by S. of Skagen light-house. 15 m. — Ooze with molluses (mostly Turritella terebra). — Polysiphonia elongata and atrorubescens, Cheelopteris on Turritella; Zostera with fruit. fD. (Dana St. 2871). 4/10 22. Off Aalbæk. 8 miles S.%/, W. of Skagen lisht-house. 22 m. — Soft bottom (seine), Pecten islandicus. — Lithothamnion levigatum and L. glaciale on coal, Buccinum undatum o.a. fE. (Dana St. 2872). 4/1) 22. E. side of Krageskov Rev. 7 m. — Sand with Zostera, and various intermingled Algæ. Dana St. 2917. °/,. 22. Hirsholm Nordost Rev, just outside the broom. — Stones. — Rich algal vegetation; Laminariæ predominant with Desmarestia aculeata and various Floridec. fF. (Dana St. 2873). 5/, 22. 4 miles E.S.E. ?/, E. of Nordre Ronner light-house. 8 m. — Sand with stones. — Fucus serratus and Furcellaria dominant, further Polyides, Brongniartella, Halidrys a.o. dR. 2/, 22. The light-ship at Læsø Trindel S.S.E. 11/, miles. 21 m. — Stones with Lifhothamnion leve, other Algæ scarce. fG. (Dana St. 2874). °/,) 22. 3 miles W. of Læsø Trindel light-ship. 15 m. — Sand, gravel, stones. — Laminaria saccharina, L.hyperborea, Halidrys, Lithothamnia (L.calcareum, glaciale) a.m.o. dS. 3/, 22. Læsø Trindel; midway between the light-ship and the broom. — Soft bottom (Pen- natula). — No Algz. dT. °/, 22. S. of Læsø Trindel. 20 m. — Soft bottom. — No vegetation. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 38 294 dT?. #/, 22. Nearer the broom. 11 m. — Stones. — Halidrys, Laminaria saccharina, Furcellaria, Brongniartella, Desmarestia viridis. (Abundant vegetation). dT>. §/, 22.S. of the broom. 26 m. — Shells, stones. — Fucus serratus, Laminaria digitata, Halidrys. Dana St. 2891. 1%/,) 22. 61/; miles S.W. by W.1/, W. of Læsø Trindel light-ship. 8 m. — Sand, stones. — Fucus serratus and Furcellaria dominant, scarce Halidrys. Further various Algæ; Trailliella abundant, with tetraspores. Kattegat, eastern part. (Ke) fK. (Dana St. 2875). /,, 22. 4 miles W. by N. of Fladens light-ship. 39 m. — Sand, shells. — No Algæ. fI. (Dana St. 2877). 6/3 22. 31/, miles W. by N. of Fladens light-ship. 30 m. — Sand, stones, shells. — Few Algæ: Laminaria hyperborea and incrusting Algæ (Cruoria, Cruoriella Dubyi, Lithothamnia, Lithoderma etc.) fH. (Dana St. 2876). %/,, 22. 1 mile W. by N. of Fladens light-ship. 17 m. — Stones, sand. — Laminaria digitata, hyperborea, saccharina, Dilsea edulis, Furcellaria etc. Dana St. 2922. 18/;, 22. 41/, miles S.W.3/, W. of Fladens light-ship. 30 m. — Stones, shells. — La- minaria saccharina and hyperborea predominant, further Halidrys, Desmar. acul., Fur- cellaria, Dilsea edulis, Deless. sanguinea, Brongniartella, Lithothamnion lœve, glaciale, various other incrusting Alge ete. fM. (Dana St. 2881). 7/9 22. 10 miles W.S.W.1/, W. of Fladens light-ship. 23 m. — Sand, stones. — 1) Incrusting Algæ (Cruoria, Cruoriella Dub., Lithoderma, Lithothamnion glaciale a. 0. 2) Halidrys, Desmarestia aculeata. fL. (Dana St. 2880). 7/1) 22. 11 miles W. by S. of Fladens light-ship. 33 m. — Ooze, sand with small stones. — No Algze (a small spec. of Phylloph. membr., also one of Corallina off.) Dana St. 2925. 1%/;) 22. Store Middelgrund. 1#/, miles S.S.E. of Anholt Knob light-ship. Lat. N. 56° 33’, Long. E. 12° 05’. 10 m. — Stones. — Farcellaria predominant, with Laminaria hyperb., digit., sacchar., Fucus serratus and various other Algæ. Kattegat, central part. (Km) Dana St. 2919. 17/,, 22. 6 miles S.S.W.1/, W. of Læsø Rende light-ship. Lat. N. 57°07’, Long E. 10° 37’. 8 m. — Stones. — Halidrys abundant, Polys. nigrescens and elongata and various other Algæ. Dana St. 2884. 5/,, 22. 5!/, miles N. by E.°/,E. of Østre Flak light-ship. 9 m. — Sand, stones. — Zostera in abundance with Furcellaria, further Halidrys, Fuc. serratus a.o. Algæ. Kattegat, southern part. (Ks) bR. 1/, 13. Vesterlandsgrund by Gilleleje. — 7,5 meters. — Stones and gravel. — Vegetation partly continuous, partly interrupted by bare spots: Fucus serratus, Furcellaria, Brong- niartella, Phyllophora Brodiwi a. o. Samsø area. (Sa) CU. °/, 22. North of Fyn, 55°35’ N, 10° 28,5’ E. 9 m. — Zostera with Furcellaria a.o. entangled Algæ. — 7 m.— The same and Fucus serratus. Little Belt. (Lb) eV. 1/, 22. Abreast of Rogle, Rogle Klint S. by W. 19—30 m. — At 30m clay, at higher level small stones. — Few Algæ, Rhodomela, Desmarestia aculeata, Furcellaria, Chorda tomentosa. cX. 18/, 22. Between Strib and Nederballe. 35—44 m. — Firm clay. — Florideæ (Cystoclonium, Polysiphonia nigrescens, Furcellaria), Desmarestia aculeata and Stictyosiphon tortilis. bS. %/, 1917. Outer part of Kolding Fjord, off Ellidshoj. C. 4 meters. — Soft bottom. — Broad- leaved Zostera-vegetation with loose Furcellaria and single Fucus vesiculosus and F. serratus. CY". 4/, 22. Outside the broom at Anslet Hage. 12,5—14 m. Mud. — Dead Zostera leaves. —E cY?. 14/, 22. The broom at Anslet Hage N.E. ”/, mile. 5-8 m. — Dense vegetation of broad-leaved Zostera (flowering), a little loose Furcellaria (f egagropila), Rhodomela and Polysiphonia nigrescens. eZ. 5/, 22. Knudshoved Grund (North of Haderslev Fjord), across the bank. 5,5—7 m. — 1) plain bottom with single stones, a little Zostera. 2) East border: Zoslera-vegetation, a little Furcellaria. dA. 1°/, 22. The bank E. of the broom Fyrrenden N. 6,5—8 m. — Zoslera-vegetation with single stones; Furcellaria, Laminaria saccharina. dB. 15/, 22. South of Linderum. C. 5 m. — Dense Zostera-vegetation vith Laminaria saccharina. dc. 18/, 22. South end of Aarø Sund, S. of the broom on the W. side. 8—10 m. — Dead Zostera, a little Furcellaria, Rhodomela and Polysiphonia nigrescens. — A little further South. 18—-19 m. — Bare sand. dD. 1°/, 22. W. of Schonheyders Flak, 21 m. — Soft bottom. (C REN — No vegetation. dE. 1/, 22. Holsts Banke. 8—12,5 m. — Sand with stones. — Abundant vegetation: Furcellaria, Chetopteris, Phyllophora Brodiei, Rhodomela, Laminaria digitata, Zostera etc. dF. 1/, 22. Starbæk Rey. 1) 5—25 m. — Sand. — Zostera with Algæ, in particular Desmotrichum undulatum and Chorda Filum; further Fucus vesiculosus, Ahnfeltia, Furcellaria, Polysi- phonia nigrescens. — 2) 10 m. — Sand with single stones. — Zostera, few Algæ. cA. 4/, 21. Outside the beacon at Snogebæk, at the N. end of Alssund. C. 10 meters. — Mud with dead Zostera-leaves. cB. 4/, 21. W. side of Arnkilsore, Als, at the beacon. — Mud. — Zostera with broad leaves eC. / 21. Alssund, a small bank, south of cB. — Zostera with Desmotrichum undulatum. dH. 17/, 22. Just E. of Hesteskoen. €. 15 m. — Sand with stones. — Laminaria digitata, Fucus serratus, Delesseria sanguinea, Furcellaria, Rhodomela. dH!. — Same place. 18—19 m. — Laminaria saccharina, L. digitata, Delesseria sanguinea, Phyllophora Brodici. dG. 17/, 22. Hesteskoen. (Alssten). 1—2 m. — Narrow shoal, consisting of small stones. — At the top no vegetation. From 1,5 m. downwards vegetation of Chorda Filum and Ectocarpus, further single bushes of Fucus serratus. dJ. 17/, 22. Sondre Stenron, by the triple broom. 6—7,5 m. — Sand with stones. — Zostera, a little Rhodomela. dQ. *°/, 22. Bank S. of Lyø, 11/. miles south of the S. end. 22 m. — Stones (small). — Lami- naria digitata and L. saccharina, Florideæ, (Phyllophora Brodiwi, Polysiphonia nigrescens, P. elongata f., Rhodomela subfusca f.) Great Belt. (Sb) CT. */, 22. West of Ryggen, 55°37’ N., 10°41’ E. C. 20 m. — In a seine: Laminaria digilala, De- lesseria sanguinea, Dilsea edulis (loose). cS. °/ 22. Ryggen, 55°37’ N., 10°43,5’ E. 18,5—23 m. — Gravel. — No vegetation. CR. °/, 22. Ryggen, 55°37’ N., 10255] E. 13—13,5 m. — Gravel, stones. — No vegetation. eQ. ”/, 22. N. of Romsø, 55° 36,5’ N., 10°47’ E. 22 m. — Soft bottom. — No vegetation. cP. °/; 22. N. of Romsø, 55° 34,5’ N., 10°48’ E. 25 m. — Soft bottom, Ophiuræ. — No vege- tation. CO. °/, 22. N. of Romso, 55°33’ N., 10°48’ E. c. 15 m. — Soft bottom. — No vegetation (a fragment of Dilsea edulis). eN. 5/5 22. S.W. of Musholm, 55° 26,3’ N., 11° 2,3’ E. 18 m. — Stones. — Laminaria saccharina, Deless. sinuosa, D. sanguinea in abundance. eM.®/, 22. N.E. of Sprogø, 55°23’ N., 11°0,5’ E. 25 m. — Mud, stones. — No Algæ. cL. °/, 22. N.E. of Sprogø, 55° 21,5’ N., 11°1,5’ E. 25—27 m. — Stones. — Delesseria sanguinea, D. sinuosa, Furcellaria a. o. bZ. do. dP. Baltic, western part. (Bw) 3/, 21. At the beacon south of Sønderborg, at the side of Sundeved. C. 11 m. — Coarse sand with stones. — Laminaria saccharina, L. digitata a. 0. Alge. 7. 3/, 21. N.E. of the N. end of Kobbel Skov (Sundeved), off the point. 6,5—13 meters. — Stones. — Furcellaria, Laminaria digitata, several Floridez (Polysiphonia nigrescens, Rhodomela, Phyllophora membranifolia a. 0.) 3/, 21. Off the S. end of Kobbel Skov. 5,5—6,5 meters. — Gravel with stones. — The same species as in bV and further Fucus vesiculosus and F. serratus. . 19/, 22. W. of the broom at Kragesand. 14 m. — Clayey sand without vegetation. . 12/, 22. Same place, E. of the broom. 14 m. — Clayey sand with Zostera. . 18/,22. Flensborg Fjord. Bank between Holdnæs and Brunsnæs. 9 m. — Laminaria saccha- rina, Zostera. . 3/,21. Off Sønderskov. 11,3 meters. — First clay with Ophiure, then Zostera with Algæ, in particular Furcellaria and Phyllophora. 6/, 21. Trindelen, reef from the W. point of Kegnæs. 9,5—11,3 meters. — Stones. — Several Algee, Zostera. — 11—19 meters. Stones. Laminaria saccharina. . §/, 21. Middelgrund (Hans Madsens Grund) south of Als, E. side of the bank, by the triple broom. 7,5—11,5 meters. — Sand with stones. — Various Algze, Laminaria digitata, De- lesseria sanguinea a. 0. . §/, 21. The same bank, a little further south, 13—15 meters. — Sand (with stones). — Various Algee. . °%/ 21. 1 mile S. of Kegnæs light-house. In the channel 19 meters, soft bottom, no vegetation. — 8,5 meters, sand with Zostera and Algæ (Phyllophora Bangü). . 17/, 22. Pols Rev, near the bell buoy. 6—7 m. — Stones. — Abundant vegetation of Halidrys, Furcellaria etc. 20/, 22. North side of Bredgrund south of Als. 5m. — Bare sand, single spots with stones. — Fucus vesiculosus and F. serratus, scarce Zostera. *0/, 22. E. side of Bredgrund. 7/, m. — Large stony spots covered with vegetation. — Fucus vesiculosus, Florideæ (Rhodomela, Polysiph. nigrescens, Furcellaria), scarce Laminaria digitata and Zostera. IV. Ceramiales. Fam. 11. Ceramiacez. AGARDH (1828), Species Algarum, Vol. II, sect. 1. GARDH (1851), Species, genera et ordines Algarum. Vol. II pars 1. Lundæ 1851. RESCHOUG (1850), Phyceae Scandinavicae marinae. Act. Upsal. Vol. XIII et XIV. Upsaliae 1850. ERTHOLD (1882), Beiträge zur Morphologie und Physiologie der Meeresalgen. Pringsheim, Jahrbücher für wiss. Botanik Bd. 13. T. H. Burruam (1884), Notes on the Florideæ and on some newly-found Antheridia. The Journal of the Quekett Microscopical Club, Vol. I; Series II, p. 337. —, (1891), On the Reproductive Organs, espec. the Antheridia of some Florideæ. Ibid. Vol. IV ser. II p. 246. —, (1893), On the Antheridia, etc., of some Florideæ. Ibid. Vol. V, Ser. II p. 291. 1893. — , (1896), Notes on some Florideæ. Ibid. Vol. VI, Ser. II p. 183. C. CRAMER (1864), Physiologisch-systematische Untersuchungen über die Ceramiaceen. Heft I. Denkschrif- ten d. schweiz. naturf. Gesellsch. Zürich 1863. L. KoLperup ROSENVINGE (1911), Remarks on the hyaline unicellular hairs of the Florideae. Biologiske Arbejder tilegnede Eug. Warming d. 3. November 1911, p. 203. — , (1920), On the spiral arrangement of the branches in some Callithamnieæ. D. K. D. Vidensk. Selsk. Biolog. Meddelelser II, 5. Kobenhavn. P. Kuckuck (1897), Beiträge zur Kenntnis der Meeresalgen. Wiss. Meeresuntersuch. Neue Folge II. Band, Heft 1. Kiel u. Leipzig. H. Kyrın (1907), Studien über die Algenflora der schwedischen Westküste. Upsala. —, (1915), Uber die Blasenzellen einiger Florideen. Arkiv för Botanik, Band 14 No. 5, Stockholm. —, (1917), Uber die Keimung der Florideensporen. Arkiv för Botanik. Bd. 14 No. 22. Stockholm. —, (1923), Studien über die Entwicklungsgeschichte der Florideen. K. Sy. Vetensk. Akad. Handlingar. Bd. 63 N:o 11. Stockholm. C. NäGELı (1847), Die neuern Algensysteme. Zürich, 1847. — , (1861), Beiträge zur Morph. u. Syst. der Ceramiaceæ. Sitzungsber. der Akad. d. Wiss. zu München 1861. A. NESTLER (1899), Die Blasenzellen von Antithamnion Plumula und A. cruciatum. Wiss. Meeresunter- suchungen. N. F. 3. Bd. Abt. Helgoland, Heft 1. HENNING E. PETERSEN (1908), Danske Arter af Slægten Ceramium (Roth) Lyngbye. K. Danske Vid. Selsk. Skrifter. 7. Række, V, 2. —, (1911), Ceramium-Studies. I and II. Botanisk Tidsskrift 31. Bind p. 97—120, plates I—V. R. W. Puiccips (1897), Development of the Cystocarp in the Rhodymeniales. Annals of Botany, Vol. 11. N. PRINGSHEIM (1862), Beiträge z. Morphologie d. Meeresalgen. Abhandl. d. k. Akad. d. Wiss. Berlin. Jos. SCHILLER (1913), Uber Bau, Entwickl., Keimung u. Bedeutung der Parasporen der Ceramiaceen. Osterr. botan. Zeitschrift 1913 Nr. 4 u. 5. —, (1911), Die Kerne von Antithamnion cruciatum tenuissimum Hauck und Antithamnion Plumula (Ellis) Thur. Pringsh. Jahrb. 49, p. 267. B. ScaussxiG (1914), Bedeutung der Blasenzellen bei der Gattung Antithamnion. Osterr. botan. Zeitschr. 1914. C. A. J.G. A J. BE. A G. B 298 Spermothamnion Aresch. 1. Spermothamnion repens (Dillw.) K. Rosenv. Conferva repens Dillwyn, Brit. Conferv. pl. 18 (fasc. 2, 1802 (?)). Ceramium Turneri Mertens in Roth, Catalecta botan., III, 1806, p. 127, Taf. V. Conferva Turneri Dillwyn, Brit. Conf. PI. 100, 1809. Callithamnion repens Lyngbye, 1819, p. 128, Tab. 40; Kützing, Tab. phyc. XI Tab. 69 I. Callithamnion Turneri (Roth) C. Agardh, 1828, p. 160. J. Agardh, 1851, p. 23. Harvey, Phyc. Brit. I, pl. 179. Kützing Tab. phyc. XI Tab. 80. Callithamnion roseolum C. Agardh, 1828, p. 182. J. Agardh, 1851, p. 21. Ceramium roseolum (C. Agardh) Hornemann, Flora Danica Tab. 2262, 1, 1839. Spermothamnion Turneri (Mert.) Aresch., 1850, p. 113 (with «, Turneri, ?, roseolum and 7, repens). Bornet et Thuret, Notes algol. fasc. I, 1876, p. 24, pl. VIII figs. 4—5. Hauck, Meeresalg. p. 42. Spermothamnion roseolum (Ag.) Pringsheim, 1862, p. 15, Taf. IV—VI. Hauck, Meeresalg. p. 44. Reinke Algenfl. 1889, p. 22. H. Kylin, Über Spermothamnion roseolum (Ag.) Pringsh. und Trailliella intricata Batt., Botan. Notiser 1916. Id. 1923 p. 53. Herpothamnion Turneri (Mert.) Nägeli, 1861, p. 348, figs. 14—16 and 18—19. Herpothamnion hermaphroditum Nägeli, ibid. p. 352, figs. 28—29. Spermothamnion hermaphroditum (Näg.) Janczewski, Développement du cystocarpe d. 1. Floridées. Mem. Soc. sc. nat. de Cherbourg. Vol. XX, 1877, p. 115, pl. 3, figs. 7—14. «, Turneri (Mertens). Branches generally opposite, the tetrasporangia usually in corymbiform clusters. Sexual organs usually present. 8, roseolum (Agardh). Branches generally alternate, the tetrasporangia single or in pairs (small clusters). Sexual organs frequently wanting. Various opinions as to the denomination and the limitation of this species are still maintained. British authors mention Spermothamnion Turneri as common on the British shores but do not mention Sp. roseolum as a distinct species occurring there. On the other hand, C. Acarpn and J. ÅGARDH designate by this latter name the species occurring on the western coast of Sweden which they consider different from S. Turneri, a species which they do not record from the Swedish coast. KyLın follows them in 1907 (Stud. Algenfl. schwed. Westk., p. 149). J. AGARDH (Spec. g. ord. II, 1, 1851, p. 24) quotes the characters by which Callithamnion roseolum differs from C. Turneri, viz. the ramification which is more rarely opposite, the sporangia which are single or placed in pairs while they are aggregate in C. Turneri, the looser and often- longer tufts and the longer cells. These characters are, however, very variable, of which one is easily convinced by examination of a greater number of specimens. I can therefore only approve that J. ARESCHOUG in 1850 referred Call. roseolum as a variety under Spermothamnion Turneri, and it must also be considered that he is justified in referring Conferva repens Dillw. to the same species. - Comp. ScamiTz in Hauck et RICHTER, Phycotheca universalis No. 657, 1895. 299 This species of Dittwyn is the first described plant of this form series. It must be granted that the description only comprises sterile plants, but there is no doubt Fig. 202. Fig. 203. Fig. 204. Spermolhamnion repens. Filament showing the nuclei and the formation Spermothamnion Spermothamnion of the branches. repens. Upper end repens. Two-celled of thin filament. hapter. 158:1. 300 : 1. that it refers to incompletely developed specimens of €. Turneri. Its occurrence on Fur- cellaria fastigiata which is a favourite substratum of S. Turneri speaks decidedly in favour of it. It must therefore be most correct to give the plant Dirzwyw's specific name which is 4 years earlier than that of MERTENS. The Danish specimens may be referred to two IP forms: f. Turneri and f. roseola, which are shortly À characterized above. The first-named form has only 2 been found in the North Sea, the Skagerak and the VL northern Kattegat, while in the specimens from the inner Danish waters the branches are rarely or never opposite and the sporangia are placed singly or in pairs on short pedicels. No distinct line of demar- cation between the two forms can however be drawn, the characters varying considerably even on the same plant. As shown by NÄGELT (l. c. p. 346), there is a distinct morphological difference between the hori- zontal filaments, which constanily grow in a trans- versal direction, and the erect filaments given off N 7 from their upper side. New creeping filaments are a given off from the flanks of the first named filaments \ | while rhizoids are produced from the under face. \\ The cells contain numerous nuclei, not only N the older cells but also the apical ones which con- || tain a considerable number in thicker filaments. . . . ie. 205 They appear in the apical cells as hyaline globular _ RE, 3 = > : = à Spermothamnion repens. Normal and ter- bodies dispersed in the peripheral part of the dense minal hapters. 50:1. 300 protoplasm filling out the cell and not covered by chromatophores. In the other cells the nuclei are smaller and less conspicuous in a living state. In the thinner branches which sometimes occur in f. Turneri the number of nuclei may decrease to 3 or 4 (fig. 203) and the same may be the case with the sterile cells supporting the reproductive organs. The branches arise as small lenticular cells cut off by a concave wall at the upper end of the cell and containing from the first a number of nuclei (fig. 202). The hapters are numerous; they are frequently produced from a number of consecutive cells of the creeping filaments (comp. Dirrwyn |. c., LyxGByE Plate 40 C). They spring normally from the basiscopic end of these filaments and are as a rule unicellular. When meeting the substratum the cell is expanded in an adhesive disc composed of densely joined dichotomous ra- mifications of the cell (fig. 204). The hapters may exceptionally be two-celled (fig. 204), and it may also occur that a hapter is produced at the end of a shorter or longer filament (fig. 205). According to PRINGSHEIM (1862, p. 17, Taf. IV fig. 1 and Taf. VI figs. 1—2) the erect filaments may terminate in a feebly coloured hair and the same may be the case with the involucral branches of the cystocarps. The occurrence of these hairs is however, ac- cording to my ohservations, not normal but a comparatively rare phenomenon which I have observed only in a few -specimens. They arise from terminal cells of shorter or longer filaments, these cells becoming much longer, upwards a little thinner. The nuclei persist and become distincter while the chromatophores vanish and appear only as small feebly coloured grains (Comp. KoLDE- RUP ROSENVINGE, Hyaline hairs. Biol. Arb. tilegn. E. WARMING. 1911, p. 210). Transitional forms between hairs and hapters may occur (comp. PRINGSHEIM and K. ROSENVINGE Il. cc.). The tetrasporangia are in the simplest case solitary and borne on a stalk-cell. This occurs particularly in the f. roseola; but a Fig. 206. second sporangium is here frequently present, terminal on a late-. Spermothannion repens ra] stalk-cell given off under the first. In the specimens from nuclei and numerous the North Sea, the Skagerak and the Northern Kattegat, which mal Cr PS are in great part referable to f. Turneri, the sporangia are placed in cymoid clusters, the ramification continuing in various degree. These clusters may be opposite or secund. In the f. Turneri verticillate clusters, in ternate whorls, may occur beside the opposite ones. The sporangia con- tain from the first one nucleus only, while the supporting cell contains several nuclei (fig. 207 B). This comes in existence, as far as I have observed, in the way that the sporangium only receives one nucleus by the division by which it is se- parated from the stalk-cell. Any disorganization of supernumerary nuclei as in 3 Martensia a. o. (comp. N. SvE- DELIUS, Bau, Entw. d. Flori- deengatt. Martensia, K. Sy. Vet. Ak. Handl. Bd. 43, no. 7, 1908) could not be observed. The spores, which arise by tetrahedrical division, con- tain each one nucleus (fig. 208 A). A cell-wall separating the spores is shown in fig. 207D. A small number of sporangia containing more than 4 spores, up to 8, was met with on a plant from the North Sea (aF, fig. 207 E). They had the same shape and size as the normal spor- angia or were only a little ER longer. The SPORES produced Spermothamnion repens. er A (Hirsholm), sporangia in ey- seem to be somewhat smaller moid cluster. B, young sporangia with one nucleus. C—D (North Sea). than the normal ones. C, sporangia in company with a procarp. D, sporangium without the outer LENE sporangial wall. E, two sporangia and a young procarp; the one sporan- The antheridia form gium with 8 spores. A—C, 150:1. D-E, 260:1. irregularly ovate stipitate or sessile bodies which may appear on particular plants or branches but more fre- quently occur in company with the procarps. In the first case they are frequently seriate on the inner side of shorter branches. The an- theridia-producingbranchlets are divided by transversal walls in a number of seg- ments which remain short exceptthe undermost segment which usually develops into a stalk-cell. The other seg- ments divide by vertical and oblique walls in a number of smaller cells all containing EE AU: = Spermothamnion repens. Sporangia. A (Hirsholm). B, € (North Sea), in one nucleus only, the outer- company with antheridia and procarps. B, € 150:1. D.K. D. Vidensk. Selsk, Skr., 7. Række, naturvidensk, og mathem. Afd. VII. 3. 39 302 most of which are smaller and become the antheridia. An axile cell as those figured by Näcerı (1. c. fig. 28) may be present, but only in the under part of the anthe- ridial cluster. The upper segments divide by anticlinal walls in a number of cells, meeting almost in the axis of the segment and producing at the periphery a number of smaller cells, the an- theridia (fig. 209). The stalk-cell, which usually con- tains a number of nuclei, produces also by peripheral divisions a number of unicellular antheridia-produ- cing cells (SvEDELIUS “Spermatangienmutterzellen”’). The procarps are situated at the end of short branches, The apical cell of such a branch produces by two transverse divisions two short segments, the uppermost of which undergoes further divisions, giving rise to the procarp, while the undermost and the apical cell remain undivided. By the first of these divisions the upper cell receives only one nucleus while the segment cell, becoming the stalk cell, con- tains several nuclei (fig. 210 to the left). Only rarely is the stalk cell also uninucleated (fig. 211 A). By di- vision of the uninucleated apical cells two cells, each containing one nucleus only, result, the undermost of Fig. 209 which is the mother-cell of the procarp. ne The development of the procarp has been des- ridial body. A 63:1. C 350:1. B, D560:1. cribed by NÄGELI (1861), PRINGSHEIM (1862), BORNET and THURET (1876), JaNczEwskr (1877) and recently more thoroughly by Kyrın (1923 p. 53—55), to whose description we may here refer. As shown by this author, the cell next to the top divides by longitudinal walls in a central cell and three pericentral ones the middlemost of which does not divide further. One of the lateral cells gives rise to a peripheral sterile cell (figs. 211 B,C, G,I') and to the carpogonial branch which becomes opposite to the median pericentral cell. The undermost cell-wall of the carpogonial branch is often oblique (fig. B, E, comp. JANCZEWSKI p. 115), the under- most cell being nearer to the lateral cell from which the carpogonial branch is given off. All the cells of Fig. 210. the procarp are uninucleated from the first. The nucleus Spermothamnion repens. Young procarps bearing branches showing the first di- RE. DE EU ae =. : : i of the young carpogonium divides into two, the upper En Cia, of which enters into the trichogyne where it appears as a rather hyaline body with a distinct nucleolus (figs. D, E). As shown by KyLin, two small sporogenous cells are cut off from the fertilised carpogonium and these cells fuse with the two auxiliary cells which are cut off from the two lateral peri- 303 central cells; one of these sporogenous cells is seen in fig. F. The cells of the carpogonial branch were often found fused together after fertilisation, most frequently so that they all took part in the fusion (figs. F, G). The in- terpretation of the case represented in fig. I? is somewhat uncertain. À fusion cell is seen under the carpogonium and on either side of the fusion cell a small cell has been cut off. It has the appearance that the sporogenous cells have been cut off not from the ferti- lized carpogonium Fig. 211. but from the upper Spermothamnion repens. Development of procarps. A, young procarp-bearing filament; il 1] f tl the stalk-cell is uninucleated. B, the carpogonial branch is formed; its first cell is sterile ce 0 1e partly hidden behind the second one. C, procarp seen from the dorsal side; D, E, lateral carpogonial branch. view; the trichogyne nucleus is visible. F—K after fertilisation. F, a sporogenous cell is visible. G, the cells of the carpogonial branch fused together; young gonimoblasts. 2 It seems however I procarp seen from the ventral side, I! at a lower, I? at a higher level of the same that this case must procarp. The pericentral cell to the left has produced a sterile cell and an auxiliary ie merne cell, for the rest see text. K, lateral view; the auxiliary cell in beginning division. DS UD BG EUINANE D, E 455:1, the other 284:1. other way. The cell situated to the left of the carpogonial branch in fig. I? is evidently the first cell of this branch, being attached to the pericentral cell to the left in fig. J’. The fusion cell has undoubtedly arisen by fusion of three cells. The upper of these cells must have been the carpogonium or more exactly a part ofthe carpogonium, undoubtedly containing the sporogenous nucleus, while the small cell situated over the fusion cell must be the rest of the carpogonium, probably without any nucleus. If this inter- pretation is true, the two small lateral cells must be true sporo- genous cells, on the way to fusion with the auxiliary cells just cut Spermolhamnion re- x ni 5 BUR Poe | Olt from) une peripheral cells (comp. fig. I). i ns 350 : 1. The upper sterile cell in the procarps may sometimes divide and grow out in a sterile filament. JANCZEWSKI (I. c. p. 117) found it sometimes replaced by a cluster of antheridia. The statement of PRINGSHEIM (1. c. p- 19) that it may sometimes develop into a “Sporenmutterzelle’ (carpospore), is certainly erroneus. I once observed two procarpia situated one over the other, ori- 39* 304 ginating without doubt in the following way: the first uninucleated apical cell (comp. fig. 210) has produced two uninucleated segments each developing into a procarp. The procarp of the undermost procarp protruded obliquely at the side. The development of the gonimoblasts has been described by Ky in (1. c.). The ripe carpospores contain one large nucleus (fig. 212). During the development of the cystocarp a number of involucral branches grow out under its base; there are usu- ally 3 or 4 more rarely up to 8. When sexual organs are present, they almost always occur on the same plant and further in combination with sporangia: the three kinds of reproductive organs are as a rule to be found in the immediate neighbourhood of each other on the same system of branches or branchlets, in various combinations. Usually the procarps are terminal in such complexes of branches, and branchlets bearing antheridia or spo- rangia are given off under them. A cytological study of such plants is much needed (comp. Kyrın 1916). The species is widely distributed in the Danish waters except those with slightest salinity (the Baltic around Moen and Bornholm and the Sound south of Helsingør). It occurs scantily in the Limfjord but has otherwise not been met with in the fjords except ihe Isefjord where it has been found in the entrance. It attains its greatest development in the North Sea and the Skagerak where it has been found in almost all the places investigated and frequently in great abundance. It occurs here in dense tufts up to 5 cm high and may be referred to f. Turneri; it is usually fructiferous in summer and frequently bears sexual organs together with sporangia. Similar specimens are found in the Northern Kattegat, scarcely however exceeding 3 cm in height, and transitions to f. roseola are frequently met with, the sporangia- bearing branchlets bearing only a very small number of sporangia. In the more southern waters the species is usually sterile, even in summer; in some places, how- ever, it has been found with tetraspores, but nowhere with sex organs (except once at Helsingor), The branches are rarely or not at all opposite and the sporangia are placed singly or in pairs on the pedicels. Also in the southern waters transitional forms may be met with: e. g. specimens collected at Lohals in Sh have partly nu- merous opposite branches and well developed corymbiform sporangial clusters. Spermothamnion repens grows epiphytically on various Algæ, principally on Fur- cellaria fastigiata, also frequently on Phyllophora membranifolia, Ahnfeltia plicata and Corallina officinalis, further on several other Florideæ, on Fucus serratus and Lami- naria hyperborea and digitata, and finally it has been met with growing on Bucci- num undatum. It is perennial, but most of the upright filaments perish in the au- tumn, and the tufts are therefore only 2—10 mm high in winter. It is fructiferous only in summer, June to September (October). Ripe sporangia have been found in all these months. ripe cystocarps only in July to September. The species has been met with from low-water mark to 31 meters’ depth (North Sea); in the Kattegat it has been observed down to 25 meters’, in the more southern waters only to 13 meters’ depth. 305 Localities. NS: ZQ, jyske Rev, 24,5 met, SO +"; aF, 31m. 4 O +; Klitmøller (Hornemann); XR, off Orhage and within Orhage, on stony bottom with Mytilus edulis, sterile (fixed to the pebbles or loose ?). — Sk: YT and YU at Hanstholm, 2—13 m, 4 © —+; eY, 18 miles E.N.E.*/,E. of Hanstholm light-house, 15 miles N. of Bragerne 16 m; YN’, S.E. of Bragerne, 10,5 m 4 © +; Bulbjerg (J. P. Jacobsen); SZ and SY, N. of Løkken, 13 m +; washed ashore at Løkken, $ © +; ZK off Lønstrup, several places, 1—19 m, SO, or only +; XO and VJ and several other places near Hirshals, 1—15 m, gO +, or only +; Tannisbugt, washed ashore (V. Schmidt); Højen, between first and second shoal. — Lf: LZ, Nissum Bredning; Oddesund, 6,5 met.; MH, Thisted Bredning; I, Veno Bugt; in all places sterile. — Kn: Harbour of Skagen; Krageskov Rev; Hirsholmene, 4 © +; Frederikshavn, harbour and several places in the neighbourhood, e. g. Deget; YP and UD, 30 +; VT, +, ZP, UC, TL, +, near Nordre Ronner; Vesterø Havn; GM, near Engelskmands Banke, +; Tonneberg Banke, 15,5 m, +; FE, Trin- delen, 10 m, +. — Ke: FD, E. of Læsø; VY and ZE?, Fladen 15—18 m; XA, S.E. of Kobbergrund; E. end of Anholt; 14/; miles S.S.E. of Anholt Knob lightsh. 10 m (C. A. J.); HZ, Store Middelgrund; GI, Ostindiefarer Grund; off Gilleleje, +; Nakkehoved (Lyngbye), +.— Km: 6 miles S.S.W.1/; W. of Læsø Rende light-ship, 8 m; 51/2 miles N. to E. ?/, E. of Østre Flak light-ship, 9 m (C. A. J); BO, Stensnæs; BN, W. of Asaa; YY, ZC! and ZD Kobbergrund; XD, S. of Læsø; XB, S. of Kobbergrund; VN,S.E. of mouth of Randers Fjord; Gjerrild (Lyngbye); BJ, Gjerrild Flak; BH, off Gjerrild Klint. — Ks: EP, Pakhusbugt Anholt; OP, EM and EJ, Lysegrund; HP, S. of Lysegrund; Hesselo (Lyngbye); OS', Hastens Grund; FP, Jessens Grund, 4m, +; GG and GF, Sjællands Rev; D, N. of Grønne Revle, 11,5 m, +; EH, W. of Lynæs. — Sa: Begtrup Rev, +; FT, N. of Samsø; FX, off Dyngby Hage; MP, Falske Bolsax; MQ, S. of Paludans Flak; AJ’, N. of Æbelø, +; AH’, N. of Fyns Hoved; Hofmansgave (Lyngbye, Hofm. Bang., C. Rosenberg). — Lb: AX, Bjornsknude; Linderum; DB, Lillegrund (Reinke, !); CD, Helnæs Hoved Flak; DA, off Bojgden; CC, Hornenæs, +; LG, off Vidso, Æro; DX, Vodrups Flak. Does not occur in the middlemost part of the Belt between AX and Linderum. — Sf: UV, N of Ærø. — Sb: AG, W of Romsø; AF, Mollegrund off Kerteminde; harbour and bay of Kerteminde; NU, off the Strandskov by Bogense, 11,5 m; reef at Korsor; Lohals, harbour, +; UU, Snede Rev. — Sm: CQ, N.N.E. of Kogrund: Q off Vesterskovs Flak. — Su: BQ, oft Ellekilde, 5,5 m; Hellebæk; near Helsingør (Liebman), $ © +; Kronborg (Lyngbye). — Bw: cF, south of Kegnæs, Als, 8,5 m; dK, Pols Rev; DU, off Dimes Odde; LC, off Gulstav, 11,5 m; KZ, of Kramnisse. Trailliella Batters. 1. Trailliella intricata Batters. E. A. L. Barrers, Some new Brit. mar. Algæ. Journ. of Bot. Vol. 34, 1896, p. 10; id. in Journ. of Botany, Vol. 38, 1900, Tab. 414, fig. 14. H. Kyrın, Uber Spermothamnion roseolum (Ag.) Pringsh. und Trailliella intricata Batters. Botan. Notiser, Lund, 1916, p. 87. KoLperup ROSENVINGE, Om nogle i nyere Tid indvandrede Havalger. Bot. Tids. 37, 1920, p. 127. Kylin, Bot. Notiser 1922 p. 346. Spermothamnion Turneri f. intricata Holmes et Batters, Annals of Botany, Vol. 5, 1890, p. 96. Spermothamnion roseolum Kylin, 1915, p. 4. non Callithamnion intricata Ag. Syst. Alg. 1824, p. 132, id. 1828, p. 182, Kützing, Tab. phyc. Vol. 11 pl. 62. It is remarkable that this species which now occurs abundantly in several places has not been observed, as it seems, before 1890 and has been described for the first time in 1896. In mode of growth, it somewhat resembles Spermothamnion Turneri, but differs by smaller dimensions, by the want of opposite branches, by the presence of gland cells and by the structure of the hapters. There is no essential difference between the horizontal and the vertical fila- ments. The cells contain a single nucleus, which is easily pointed out by fixing and 1 S designates antheridia, © cystocarps, + tetrasporangia. Fig. 213. Trailliella intricata. of filaments. 300 :1. are frequently curved a little upwards between the hapters; they usually bear near the hapters a number GAY Fig. 215. Trailliella intricata. Terminal hapters. 82:1. Upper ends 306 staining agents in the apical cell and the young segment cells (fig. 213). As shown by Barrers and KyLIN, the cells contain numerous disc-shaped, or elongated chromatophores. The fully developed cells contain numerous starch-grains. The pits connecting the cells are very distinct. Most of the articular cells bear at their upper end a small gland cell, in optical section triangular, seen from the face roundish. As shown by KyLiN (Il. ce.) they contain a sub- stance which by addition of hydrochloric acid produces iodine. The horizontal filaments are fixed to the substratum through pluricellular hapters, consisting of a downward tapering cell which at its under end bears a whorl ofrepeatedly branched fila- ments closely connate in a conical attachment disc (fig. 214). The rhizomes of branches which are partly horizontal partly upright. The upright filaments are sparsely and irregularly branched; there may be two generations of branches. The Fig. 214. Trailliella intricata. with hapter. Creeping filament 260 : 1. branches are scattered; they arise a little below the upper | end of the filaments and are cut off by a watch-glas-shaped wall (fig. 213). The filaments are of almost equal thickness in their whole length, only a little tapering at their upper end; the diameter is 25—38 u, the length of the cells 1—2,5 times as long as the diameter, more rarely up to 3 times as long. The long cells are a little constricted at the transversal walls. Hapters may exceptionally be found terminal on the filaments (fig. 215). The arrangement of the gland cells is irregular; in the horizontal filaments they are particularly produced on the upper convex side. In the upright filaments they have a ten- dency to be alternating, but no regularity exists and some cells bear no gland cell (comp. Kyrın 1915). The plant has always been found sterile in the Danish waters till October 1922 when Mr. C. A. JØRGENSEN found tetrasporiferous specimens in two localities 307 in the Skagerak and the northern Kattegat. The tetrasporangia are formed, as shown by BATTERS, in the upright filaments by longitudinal division of a somewhat swollen cell into two parts of unequal size, the larger forming the tetrasporangium, the other part remaining sterile. The longitudinal wall is often somewhat inclined, the lower end of the sterile cell being broader than the upper. While the sterile cells contain nu- merous coarse starch grains, the developing tetrasporangium becomes dark-red and with more fine-granular contents. The tetrasporangium is first divided by a hori- zontal, slightly inclined wall and then by two nearly yertical walls. The ripe spor- angium is much swollen; it opens by a split op- posite to the sterile cell. As shown in fig. 215 bis the sporangium is connected with the sterile cell through a pit in the middle of the longitudinal wall. The sporangia may be solitary or 2 to 6 together and then variously orientated, always se- parated from the apex of the filament by a varying number of sterile cells. The sex-organs are un- known. BATTERS thought that this Alga was identical with Callithamnion intricatum J. Agardh. If he has founded this supposition only on the short des- criptions of C. AGarDH (Syst. Alg., 1824, p. 132) and J. G. AGarpx (Spec. g. ord. II pars I, p. 19), it must be said that these descriptions are too incomplete to allow of an identification, and the plant re- presented in Kürzıng’s Tab. phyc. 11. Band, Tab. 62,11 is evidently another species, being much coarser and showing no gland cells. Two specimens in the herbarium of the Botan. Museum of Copenhagen from J. AGARDH, determined as Callithamnion intri- Fig. 215 bis. x Trailliella intricata Batt. Parts of filaments catum and collected at Koster Bahusiæ and at with tetrasporangia. A 390:1. B 230:1. Kullaberg, turned out to be Spermothamnion repens. As long as the sex-organs are unknown the systematical position of the genus remains uncertain. The position and development of the tetrasporangia remove it from the other genera of Ceramiacee; the genus in this respect somewhat reminds one of the Rhodomelacew. The species has been found more or less abundantly in numerous places in the Limfjord and the northern part of Kattegat, and recently in several places in the North Sea and Skagerak. It was first met with in the Western part of the Lim- fjord in 1901 but has not been observed there before that year, although numerous 7 KyLiN has recently (Botan. Notiser 1922 p. 346) given a drawing of a tetrasporiferous plant after a slide from Batrers kept in the herb. AGarpu in Lund, not being acquainted with the drawing given by Barrers in Journ. of Botany 1900. 308 dredgings have been made in the same part of the fjord in 1890, 1893 and 1899. In the Kattegat it was not observed till 1909, when it was met with in the neigh- bourhood ot Frederikshavn, although these waters were very carefully explored after 1889. It is therefore very probable that the species has immigrated into the Danish water about the year 1900, a supposition which is in accordance with the obser- vations of KyLiN on the west coast of Sweden (1916, p. 91), where Trailliella was found in three localities on the coast of Bohuslän in 1902—1906, while it was not met with by the earlier investigators, e. g. by STRÔMFELT who made large collections (of Spermothamnion) on the same coast in 1885—1887. At Helgoland it has also been recorded in later years (comp. Kuckuck, Zeitschr. f. Bot. 8 p. 135). In July 1907 I found Trailliella intricata abundantly on various Algæ and Ascidia at Arendal on the south-eastern coast of Norway, and in July 1916 at Anuglen on the West coast of Norway, near Bergen. Trailliella intricata is almost always epiphytic, growing on various alge, e. g. Furcellaria, Corallina officinalis, Phyllophora etc. but it also grows on Mytilus, Tro- chus, Hydroids and on pebbles, from low-water mark to 28 meters depth. Localities. Ns: eA and eR, off Thyboron, 28 and 27 meters. — Sk: eY and eZ, east of Hanst- holm, 15—17 meters; 13 miles S.W. by W. Ur W. of Rubjerg Knude light-house, 14 meters, with tetra- spores, Oct. (C. A. Jorgensen); (2!/; miles N.E. by N. of Skagens reef light-ship, 90 meters, loose, C. A. J.) — Lf: Nissum Bredning: Harbour of Thyborøn; Ronnen near Lem Vig (1901); ZU, near the latter, 4 meters; XV, N. of Ronnen (1901); off Hesdal, Kobberod; ZT, off Osterbol, 4m, abundantly on loose Furcellaria; ZV, 5 m: ZY, 4,5 m; XU, 4 m; Nissum Bredning 1908 (Th. Mortensen); Oddesund. XT, south side of Jegindo Tap, 5 m; Sallingsund, various places, abundantly; aT!, off Alsted, Mors, 5 m; Knuds- hoved, Fur; N. side of Fur; W. of Eierslev Ron, 7 m; off Feggeklit, 4m. — Kn: Harbour of Skagen; fE, E. side of Krageskov Rev, 7 m; various places at Hirsholm, c. 11 m (1909 H. E. P.); near Kolpen, 4m (H.E. P.); Laurs Rev; harbour of Frederikshavn; E. of Nordre Ronner; ZA, Tonneberg Banke, 12—18 m (1904); fG, 3 miles W. of Læso Trindels light-ship; various places near the same 11—21 m; 61/; miles S.W. by W.1/: W. of Læsø Trindels light-ship, 15 m, abundantly, with tetraspores, October (C. A. J.) — Ke: ZE?, near Fladens light-ship, 15 m (1904); 1 mile W. by N. of Fladens light-ship, 17 m, abundantly, Octob.; 147/, miles S.S.E. of Anholt Knob, light-ship, 10 m (C. A. J.). — Km: 51/, miles N. by E. 3/, E. of østre Flak light-ship, 9m (C. A. J.). Callithamnion Lyngbye emend. Key to the Danish species of Callithamnion. 1. All cells uninucleate. 2. Branches generally biseriate; hairs wanting; heaps of paraspores on ihestıppenäsideyofsthegp innulse ee BØRNE SS FE RLENSSEEe C. Hookeri. 2. Branches generally spirally arranged; no paraspores. SE van Torre Th als -255socccoocosbocosomcccecceoscouute C. Brodiei. 3. Pinnulæ usually without terminal hairs. 4. Main axes vigorous, corticated; cystocarps round ............... C. roseum. 4. Main axes feeble, usually not corticated; cystocarps lobed ...... C. Furcellarie. 1. The older cells contain several nuclei. 2. Branching pseudodichotomous; pinnulæ blunt, usually with terminal ATES en N RI RER ne JE EVER C. corymbosum. 2. Branches generally spirally arranged; pinnulæ pointed, never with hairs C. tetragonum. 309 1. Callithamnion Hookeri (Dillw.) Agardh. C. Agardh, 1828, p. 178; Harvey, Manual Brit. Alg. 1841, p. 106; J. Areschoug, 1850, p. 103, tab. IV F (forma a); J. Agardh, 1851, p. 51; Harvey, Phyc. Brit. Vol. III, 1851, pl. 279; Kützing, Tab. phycol. XI tab. 94a, 1861; Kylin, 1907, p. 150. f. Areschougü nob. Areschoug, I. c. forma a, Alg. scand. exsice. No. 311; Kylin, 1. c. f. {ypica. Callithamnion pyramidatum Liebman, Bemærkn. o. Tillæg, Kroyers Tidsskrift II, 1839, p. 479, Tab. VI fig. 1, ex parte. In several places in the Danish waters a Callithamnion has been met with which agrees exactly with Callithamnion Hookeri a Aresch., as described by ARE- Fig. 216. Fig. 217. Callithamnion Hookeri. Upper end of sterile shoots. Callithamnion Hookeri. After a living A 150:1. B 70:1. plant. 160:1. SCHOUG and Kyrın, Il. cc., and bearing, like the Swedish plants, heaps of paraspores but no or scarce tetrasporangia and never sexual organs. The Scandinavian specimens have certainly justly been referred to C. Hookeri Harvey; but as they differ from the British specimens by the presence of paraspores and by the absence of sexual or- gans they might be regarded as representing a particular form of the species. The Danish specimens ordinarily reach only a length of 1,5—2 cm; but they may become up to 3cm high (Skærbæk). The stem and the main branches are very distinct, not bent in zigzag, covered with down-growing cortical filaments. The rami- fication is mainly pinnate, the consecutive cells bearing each a branch alternating with the foregoing. Vigorous branches generally show a pinnate ramification, the pinnulæ lying all in the same plane, and being rather diverging. The lateral branches do not generally reach the level of the top of the main axis, and the outline of the shoot is therefore lanceolate, pointed above (comp. fig. 216). Exceptions may how- D. K. D. Vidensk. Selsk, Skr., 7. Række, naturvidensk. og mathem. Afd., VII. 3. 40 Ui Fig. 218. Callithamnion Hookeri. Young plants. 145: 1. 0m ever be met with (fig. 217). The pinnule become thinner towards the end, but they are not pointed. In growing fronds with pinnate ramification, the dividing walls are inclined and alternating (figs. 216, 217, comp. Kyrın, 1. c. fig. 30 c); in the pinnulæ they are transversal. The lateral branches, the pinnæ, are branched in the same way as the main axis, from the base or so that the first lateral branch of the second order is placed on the 24 or 3% article or even higher (fig. 216). According to Kyrın (1. c. p. 151), the branches of the second order are, when developed, orientated in the same plane as the lateral branch and the mother axis, but, when arising, they are placed in a plane perpendicular on the named plane, thus to the right and to the left, and the later position is arrived at by the turning of the lateral branch. My observations are not sufficient to warrant or disprove with certainty this statement, but at all events it must be said that its validity is not general. The case represented in fig. 216 B is in general favourable to the supposition of Kyrın, however, it will be seen that there are some irregularities, e.g. in the 5' and the 10 branch from the base; and in other cases the plane of ramification of the youngest branched lateral branches coincided with that of the mother branch. Deviations from the pinnate ramification” Fig. 219. Fig. 220. Callithamnion Hookeri. Part of mains axis with cortication. Callithamnion Hookeri. With paraspores. (Frederiks- 70:1. havn). A 70:1. B 145:1. 311 occur rather frequently, in branches of different order (fig. 216 B), principally in the most vigorous main axes, which may bear branches on all sides. J. AGARDH states that the lower branches are given off on all sides, and that I have also found in some cases; but in other cases, the main stem was pinnate from the base, and the same was found in a young plant (fig. 218). The descending filaments constituting the cortex of the stem and the main branches are produced from the base of the cells of the axes and from the base of the branches given off from them; they may completely hide the original cell-filament of these axes. Here and there adventitious filaments are given off from the descending filaments, principally from the base of the branches (fig. 219). All cells contain a single nucleus and nume- rous chromatophores which in the young cells are small lengthened discs (fig. 217), in the older ones long bended, partly branched ribbons. All the fructiferous specimens bear heaps of paraspores agreeing with the description of Kyrın, 1. c. They are more or less obliquely ovate and contain an indefinite number of SER Reo 10-72 res De Callithamnion Hookeri. With a nes (Kerteminde). A, nearly ling the tetraspores; they are ripe heap. B, younger stage. C—G, still younger stages, the heaps of para- placed on the upper pinne spores partly replaced by vegetative branches. 200 : 1. or pinnulæ, usually on their upper side in a number of one or two on the first or on the first and the second joint, more rarely in a number of three or four. In the latter case they are not always placed on the upper side of the branch but partly on the flanks or on the under side, and not rarely it happens that two heaps are placed on the same joint and then one under the other (fig. 221 B) or beside the other (fig. 220 B) or in oblique direction under the other, or they may be opposite, on the upper and under side of the cell (fig. 220). One of the heaps may be replaced by a vegetative branch. The position of the heaps of paraspores is the same as that of the tetrasporangia which in the plants from the Atlantic shores are placed not only on the upper side of the pinnules but also “utroque latere inordinate” (J. AGARDH, I. €. p. 52, comp. Harvey l.c. pl. 279, fig. 4, Kirzine |. c. pl. 94 fig. b). The fact that the heaps of paraspores have a position similar to that of the tetra- 40* LL TER sporangia might suggest that they are transformed tetrasporangia which have been divided in a greater and indistinct number of cells. This supposition, however, is only little probable; at all events the transformation might then be supposed to begin at so early a moment that it was impossible to decide whether the young organ were really a sporangium. The sporangia are early distinguished by their regular outline and by the double firm membrane (fig. 222). The heaps of paraspores are a special form of vegetative propagative organs, more related to the vegetative cells than the sporangia. This conception is confirmed by the fact that transitional stages between the named organs and vegetative shoots frequently occur (fig. 221) and that they may, as named above, be re- placed by vegetative shoots (fig. 221 C—E). Tetrasporangia were found in some cases in paraspore- bearing plants, but in small number (Hirsholm, Frederiks- havn, Grenaa, Kerteminde, Skærbæk). They are usually A EIN | | Al II REN a | AI NN ZN placed on the first or on the first (LAGOS ER | \ \ \# \\ ve . N (( N\ A AV | A) and the second joint ofa pinnu- Py NON ) 3 > SN SSE NSS NS \\ { la. Curiously enough, intercala- =) = \ \\ = | LN = | im | | \ )\ 7 ; j 3 | \ _ ry sporangia may sometimes D. SR ( | \ ‘a \E = FE N al \ be met with, arising from an \\ \ AN) intercalary cell in a pinnula € \\ DNS | (fig. 222 D). In such cases one Fig. 222. of the spores is connected Callithamnion Hookeri. Parts of plants with tetrasporangia. In C the same branch bears a tetrasporangium and a heap of paraspores. D and E, intercalary sporangia. 4, B 145 : 1. C—E 200 :1. with the underlying cell by a pit, another spore with the cell above. Intercalary spo- rangia are hitherto unknown as a normal occurrence in the Ceramiaceæ, as far as I know. The specimens from all the localities with one exception, occurring in depths from 0 to 30 meters, most frequently from 0 to 10 m, agree with Kyrın’s f. éypica, having proportionally short cells, 2—3—4 times as long as broad, and well developed cortex on the principal axes. Specimens from YV in the Samsø area, 15 meters depth, remind one of f. elongata Kylin, 1. c. by its longer cells, 5—6 times as long as broad; but the pinnulæ are scarcely less diverging than in the typical form. The frond is more slender and the cortex is very feeble or almost wanting. These characters are perhaps caused by the greater depth at which the plant was found growing. The heaps of paraspores were not more lengthened than in the other specimens but frequently bilobate (fig. 223). The species has been found repea- tedly sterile in April and May, frequently growing on Furcellaria, further on Fucus serratus, Delesseria sanguinea and Rho- mela subfusca. Twice it has been found with paraspores in May, but otherwise with paraspores in the summer months (June to August) and in November. Tetrasporangia were met with in June, August and September. Localities. Kn: Hirsholmene, littoral region and 9 meters (Henn. Petersen, !); Frede- rikshavn, harbour and Bussserev (!, Henn. Pe- tersen); Ostero harbour, Læsø. — Ke: IO, Fla- den, 10—11 meters; fl, Fladen, 30 meters, small specimen (C. A. J.); OO, Soborghoved Grund, 8,5 m. — Ks: Harbour of Grenaa; OT, Hastens Grund, 9,5 m.—Sa: YV; the light-buoy at Hatter- barn N. 21/, miles, 15 meters (slender form, see above). — Lb: Skærbæk harbour off Kolding Fjord, with paraspores and tetraspores ; DB, Lille- grund, (slender form, sterile). — Sb: Kerteminde, harbour. — Su: Ellekilde Hage (Boye Petersen); Hellebzek,washed ashore; near Helsingør (Liebman, Call. pyramidatum). — Bw: dK, Pols Rev, 6—7m. 2. Callithamnion Brodiæi Harv. Harvey in Hooker, English Flora, Vol. V part 1, 1833, p. 340; Manual, 1841, p. 105, Phyc. Brit. Pl. 129, 1849. J. Agardh, 1851, p. 57, III, 1876, p. 34. Kylin, 1907, p. 162. Phlebothamnion Brodici Kützing, Spec. alg. 1849, p- 655, Tab. phye., 11. Band, Tab. 100n, 1861. Fig. 223. Callithamnion Hookeri. Slender form from 15 meters depth (XV). 47:1. Only some few specimens of the species here mentioned have been met with, growing on Furcellaria fastigiata collected on the Nordvestrev by Hirsholmene, in company with four other species of Callithamnion, Spermothamnion repens and others. They agree perfectly with the quoted figures and descriptions of AGARDH, KüTziNG and Kyrın, and it is probably justly that the name of Harvey has been assigned to them though it is not excluded that two species might have been con- founded under that name. Referring especially to the paper of Kyrın, a description of the Danish specimens may be given here. The specimens reach only a length of 1,5 cm at most. The main axes are very 314 distinct, straight, not bent in zigzag, corticated below. The thickness is 130—150 x below, over the cortication about 75 uw. The cells are 1'/;—5 times as long as broad. From the cells of the cortical filaments growing down in the outer walls small adventitious filaments are given off (fig. 224), probably more numerous in larger specimens. The lateral branches are as a rule much shorter than the main axes the result being that the outline of the main branches become narrow, hastate or pyramidate. The branches are given off on all sides, as a rule one from each joint; they are usually placed in a spiral line, however not in the whole length of the shoot, the angle of diver- gence is about 1/3 or 7/4, the spiral turning to the right or to the left in different shoots (fig. 227). In a long branch the branches were arranged from the base in a spiral turning to the right with an angle of divergence of 1/3, then irregularly, after that in a spiral to the right with an angle of divergence of 1/3 and finally secundate. The ramification of the lateral branches is usually similar to that of the main branches. The first branches of the second order are frequently alternating to the right and to the left or irregularly arranged, and it is only at a higher level that the regular spiral ar- rangement commences. In the main branches this ramification may be repeated several times, but the branches become gradually feebler and ae the later branches have limited growth, are Callithamnion En Part of tetrasporiferous divaricate and more irregularly branched, often plant. 62:1. secundate, bearing only branches on the upper side (fig. 228). As will be seen, this description agrees with that of Kyrın. Secundate pinnulæ are also mentioned and figured by Harvey (Phye. Brit. Pl. 129), but as many and as regularly arranged secundate pin- nulæ as in Harvey's figs. 2 and 3 I have never seen in the Danish specimens. In the main branches dividing walls of the apical cell are inclined, and the axis is at first bent in zigzag but later it becomes straight. In the unbranched or feebly branched pinnule the dividing walls are transversal. The cells contain a single nucleus in the young and the later age, and numerous long ribbon-like, more or less branched chromatophores. Characteristic of the species is the great development of hyaline hairs at the tip of the branchlets, as already figured by Kirzine and Kyrın. The hairs are rather rs 315 short (7—9 « thick, 160—290 w long). The pit connecting the hair with the bearing cell is very distinct. The hair-bearing cell cannot function as apical cell but it may produce a branch which sometimes grows out approximately in the same Fig. 225. Fig. 226. Callithamnion Brodiei. Parts of tetrasporiferous plant. 158: 1. Callithamnion Brodiæi. Parts of male plant. A 77:1. B220:1. direction as the mother axis, the hair being pushed aside (fig. 225 C). In the ob- served cases the hair was pushed towards the dorsal side of the filament. The pro- cess may be repeated in the same filament. The tetrasporangia are placed on the branches of higher order, principally on the upper side of the branchlets, on the first joint, on two or three consecutive ones or more irregularly. There are frequently two on the same joint and then the younger below the older or obliquely beside and below it (fig. 225). The undermost sporan- gium may be placed on the middle of the joint which may also be the case with a single sporangium (225C). A seriate arrangement as regular as in Harvey's figs. 3 and 4 is only met with exceptionally in the Danish specimens (fig. 225 B). The sporangia were 70—76 x long, 61—65 w broad; they are discharged through a transversal split above. The antheridia are produced on the sur- face of long cushions on the upper side of the branchlets which are much divaricate in the male specimens. The cushions are composed of two or more small bushes on each joint fused with each other and with those of the neigh- bouring joints. The outer cells only of these bushes produce spermatia while the under cells remain sterile. The procarps are placed on a branch- bearing cell opposite to the branch. They have the same structure as in Call. corymbosum. In an unfertilised carpogonium the trichogyne was feebly swollen at the base (fig. 227). There are two nearly globular gonimoblasts and under each of them a smaller one which may pro- duce carpospores as well developed as the large ones. The cell bearing the cystocarp is fre- quently shorter than the other cells in the same filament. As pointed out by NAGELI (Morph. Ceram., 1861, p. 372), Call. Brodiwi Crovan (Alg. mar. du Finistère, no. 154, Florule du Finistère, p. 138) is not identical with Harvey’s and Kürzıng’s species. In the specimen of the Exsicc. I found the ramification generally pin- nate in the pinnæ and the pinnulæ as well, the cells much shorter and thicker and hairs totally wanting. Crovan’s plant has been des- cribed as Maschalosporium gallicum (Call. galli- cum Sauvageau, Alg. mar. Golf. Gascogne, Journ. de Botanique t. XI 1897, p. 63). It is probable that Harvey’s description included also this species (comp. Phyc. Brit. pl. 129 fig. 3—4), but it seems to have been worked out principally after specimens of the species mentioned here under Harvey’s name. I have had no occasion to examine authentical specimens. Fig. 227. Callithamnion Brodiei. Upper ends of female plants; A, with fully developed, B, with young procarp. a auxiliary mother-cells; the first cell ofthe carpogonial branch is not visible. A 270:1. B 200:1. Fig. 228. Callithamnion Brodiei. Part of cystocarp-bearing plant. 70:1. C. Brodi@ei cannot be confounded with any of the species found at the Danish shores. C. corymbosum is the only species bearing equally numerous hairs but these hairs are much longer than in €. Brodiei. Localities. Kn: Nordostrev by Hirsholm, 7—9 meters depth, on Furcellaria fastigiata, July 1904; one specimen with cystocarps met with at the same place in August 1922 (C. A. Jorgensen). 3. Callithamnion tetragonum (With.) Ag. C. A. Agardh, Spec. Alg. Vol. II sect. I 1828, p. 176; J. Agardh, 1851, p. 53; Harvey, Phye. Brit. pl. 136, 1849; Kylin, 1907, p. 158. Conferva tetragona Withering, Arrang. Brit. PL, 3¢ edit. Vol. IV, 1796, p. 405. Dorythamnion tetragonum Nägeli, 1861 p. 344—345. Callithamnion brachiatum Bonnem., Harvey, Phye. Brit. p. 137, 1849. This species is here taken in a somewhat wider sense than generally accepted. The typical, first described C. tetragonum is characterized by its thick pinnulæ, having Fig. 229. Fig. 230. Callithamnion tetragonum Ag. From Devonshire, Callithamnion tetragonum (f. brachiata). From ex herb. J. G. AGARDH. 47:1. Cherbourg. 47:1. their greatest thickness above the base (80—140 w according to Hauck, 75—100 u after KyLiN), consisting of barrel-shaped cells and suddenly acuminate. In the very nearly related C. brachiatum the pinnule are thinner (40—80 x) and consist of cylindrical cells 2—3 times as long as broad. This form is, certainly rightly, regard- ed as a form of C. tetragonum by several authors (J. AGARDH, 1. c.; Hauck Meeres- alg., p. 83; Gran, Kristianiafjord, p. 26); it forms further a transition to C. fruticulosum Ag., as principally known from the Scandinavian coasts. J. AGARDH has already stated that the latter is related to C. tetragonum, and Gran (1. c.) declares that the Norwegian specimens determined by him as C. tetragonum 8, brachiatum, show much D. K, D. Vidensk. Selsk, Skr., 7. Række, naturvidensk, og mathem. Afd. VII. 3, 41 318 resemblance to C. fruticulosum. Kyıın (1907, pp. 154—162) points out the accordance in the morphological structure existing between these three forms which he considers as distinct species, and he further describes a new, fourth species, C. spiniferum characterized principally by thinner pinnulæ, 25—40 w thick, and consisting of longer cells, 5—8 times as long as broad, while in C. fruticulosum the pinnulæ, according to Kyrın, are 40—60 x thick and consist of cells 3—5 times as long as broad. I cannot acknowledge the right of distinguishing these four forms as species, at all events not with the delimitation given by Kyrın. The specimens found at the Fig. 231. Callithamnion tetragonum var. divaricata. A, pinna. B, branch-system with tetrasporangia. C, branch with tetra- sporangia and an arrested procarp p. A, B 70:1. C 200:1. North coast of Sealand agree perfectly with J. AGARDH’s description of C. fruticulosum and with specimens from AcarpH (from Kullaberg), and the dimensions of the cells in the pinnulæ correspond also with those attributed to this species by Kyrın, viz. 3—5,5 times as long as broad; but the thickness of the pinnule is the same as that attributed to C. spiniferum, viz. 23—42 u. In specimens found in the Northern Katte- gat, the pinnulæ are thicker and of a structure more resembling that of C. brachia- tum, but in some of the specimens the pinnule were up to 123 w thick and consisted of cells only 1,2—2,7 times as long as broad, thus resembling those of the typi- cal C. tetragonum; the cells were, however, not barrel-shaped and the pinnulæ were thickest at the base. My investigations have led me to consider all these sup- posed species as forms of one species which must bear the name of the first described 319 form, the typical, Atlantic C. tetragonum (With). This apparently rather variable species may very likely comprise a number of elementary species, but as it is im- possible for me to distinguish them, it is preferable to distinguish varieties or forms within the larger species. The typical C. fetragonum has not been found at the shores of Denmark. But plants that must be regarded as forms of this species have been met with in two distinct groups of localities, the one in the neighbourhood of Frederikshavn and Hirsholmene in the Northern Kattegat, the other at the North coast of Sealand Fig. 232. Callithamnion tetragonum var. divaricata. From Hirsholmene. A, part of stem with branches. B, branch. C, branch with procarp; the two auxiliary mother-cells are visible. A 50:1. B 47:1. C 260:1. from Gilleleje to a place a little north of Helsingor. As the specimens from these two groups of localities are different from each other, they may be mentioned par- ticularly. The species is easily distinguished from the other Danish species by its pointed pinnule which never terminate in a hair and by the cells being multinucleated to the top or with the exception of a few of the uppermost cells. Var. divaricata. The species has been found several times in the neighbourhood of Frederiks- havn and at Hirsholmene but only in a few and small specimens, 1,5—2,5 cm high. They pretty much agree with var. brachiata in the structure of the pinnulæ, but 41* 320 these are more divaricate than in that variety. The pinnulæ have their greatest thickness at the base and gradually taper upwards. Their greatest thickness is somewhat variable; it was greatest in a specimen met with in November in Busserey at Frederikshavn, viz. 50—124 u, frequently over 100 w. In small specimens found in the same locality in July it was only 49—63 w. The length of the cells was in the first case 1,25—2,7, in the latter case 2,5—3 times the breadth, and similar dimensions of the pinnulæ were found in specimens from Marens Rev (Ja- nuary) and Hirsholmene (July). In the pinnæ with arrested growth, the last pinnulæ were more or less divaricate (figs. 231—232). The tetrasporangia are placed on the inner side of the pinnæ, usually beside and at a lower level than the branches. Tetrasporiferous pinnæ with arrested growth may form corymbiform clusters. The sporangia are nearly globular, 62—70 w long, 51—59 u broad. In sporangiferous specimens, undeveloped procarps may be found in the same pinnæ as the sporangia (fig. 231 C). Found with ripe tetrasporangia in July and November, with ripe cystocarps in July. Localities. Nordostrev by Hirsholm, in Furcellaria, 7,5—9,5 m; Busserev and Marens Rev by Frederikshavn. ar. fruticulosa J. Agardh. Kolderup Rosenvinge 1920, p. 7. Callithamnion fruticulosum J. Agardh, Symbolæ, Linnæa, 15. Bd. 1841, p. 46, Spec. gen. ord. Alg. II p. 56, 1851; Kylin, Algenfl., 1907, p. 154. Non Roth, Catalecta II, 1800, p. 183, nec Lyngbye, Hydr., 1819, p. 124. Callithamnion Hookeri (Dillw.) b. Areschoug, Phyc. scand. 1850, p. 104. Phlebothamnion fruticulosum Kützing, Tab. Phyc. 11, 1850, pl. 95. Callithamnion Baileyi Harv., Ner. Bor. Amer. II. 1853, p. 231, pl. 35 B; Färlow Mar. Alg, N. Engl., 1881, p- 127, pl. XI, figs. 1—2. Phlebothamnion Baileyi (Harv.) Kützing, Tab. phyc. 11, 1850, pl. 95. Callithamnion spiniferum Kylin, 1. c. p. 159. When J. AGARDH has named this plant C. fruticulosum, it might be. observed that it is not identical with the plants which have formerly been designated by this name. J. AGARDH has himself identified Rorn’s species with C. versicolor Draparn., and C. fruticulosum Lyngbye is at all events also a different species. I do not doubt that our plant is identical with C. Baileyi or with one of the forms of this variable species of which Harvey declares, 1. c. p. 232 that “the most robust forms, with shortest joints, approach inconveniently near to C. tetragonum, from which species the more delicate ones appear widely different.” In North American specimens from FarLtow and SAUNDERS I found cystocarps and antheridial-cushions resembling those in the European species. As mentioned above, I cannot regard C. spiniferum as a species distinct from C. fruticulosum, the dimensions of the pinnulæ offering no distinctive characters. According to Kyrın (I. c. pp. 157—162), the dimensions of the gonimoblasts and the 321 tetrasporangia should in C. spiniferum be greater than in the last named species; in the Danish specimens, these organs reach the dimensions stated for C. spiniferum, the goni- Fig. 233. Callithamnion tetragonum var. fruticulosa. From Hellebæk. Upper part of sterile branch. The first branch of the second order is marked with X. 200 : 1. moblasts being 130—227 «u in diameter, and the sporangia being 74—81 w long, 46—61 w broad. As stated by Kyvin, L. c., all the forms referred here to C. tetragonum agree with each other in branching and all mor- phological characters. Referring to Ky- LIN’s descriptions, I shall here describe the specimens occurring at the North coast of Sealand, all referable, in my opinion, to the variety that J. AGARDH designated by the name of fruticulosum. = Callithamnion tetragonum var. fruticulosa. Part of stem showing cortication and adventitious branches. 50 : 1. The plants reach a length of up to 7 cm; in aspect they resemble the typical C. tetragonum and have the same brownish red colour. The main branches have a pyramidal outline. The main axes are vigorous, straight and covered with a cortex of decurrent filaments, from which here and there adventitious shoots are given off Without any distinct order; young and older shoots may arise intermingled with each 322 other. The branches of the main axes are spirally disposed with an angle of diver- gence of about !/, or between !/; and 14/,. The branches of the second and higher orders are arranged in a spiral as those of the first order, except the first 1—5 which are alternate, biseriate and arranged in a transversal plane. The ultimate short branches bear only biseriate pin- nule. A sympodial ramification does not occur. The branching designated with this term by NA- GELI (1861, p. 305—306) is really monopodial, the end of the growing axes being only bent by the deve- loping branches. For further details of the arrangement of the branches reference may be made to my above quoted paper (1920 p. 7). The pinnulæ are all acuminate when their growth is arrested. Only exceptionally a feebly developed obtuse pinnula may be met with (fig. 234). The lower cells are 3— 5,5 (6) times as long as broad, usually 4—5 times as long. Hairs do not occur. The older cells contain a great number of nuclei, but also the younger cells are polynucleate and this stage is not unfrequently pri- mitive, the apical cell and the youngest segments containing each two nuclei (fig. 235). But in other of cases the uppermost cells are uni- Fig. 235. Callithamnion tetragonum var. fruticulosa. A and B, upper ends of nucleate ; this is particularly the growing plants showing the nuclei. C, upper end of branchlet with case in the pinnulæ when the arresting growth. D, part of stem cell with corticating filaments on 0 1 showing the nuclei. A, B, C 350:1. D 203:1. growth has arrested, but it is also frequently met with in growing axes (fig. 238). In such cases the 4th or 5th cell from the top usually contained more than one nucleus. In the decurrent filaments, the apical cell may contain numerous nuclei (fig. 235 D). The chromatophores are numerous, in the young cells they are rounded or oblong discs, in the older they are longer and irregularly bent. The tetrasporangia are obovate, 74—81 x long, 46—61 w broad, placed on the inner face of the pinnæ, in their under part!, sometimes only on the undermost cell, in * According to Harvey, 1. c. p. 232, pl. 35 fig. 5, C. Baileyi appears to differ from our plant in other cases on two or more consecutive cells. Most of the sporangia are placed on the branched part of the pinnæ, but they may also be placed on the unbranched parts (the pinnulæ). As the pinnæ are pinnate below with transverse branches the sporangia are usually placed beside a branch but at a lower level; but the sporangia may also be opposite to the branches (fig. 236). The sporangia are usually placed singly near the upper end of the cell, but a second, younger sporangium may be produced under the first one or in an oblique direction from it and 323 Fig. 236. Callithamnion tetragonum var. fruticulosa. Branches with tetrasporangia. A 150:1. B c.100:1. then sometimes under the branch given off from the same cell. In sporangiferous individuals procarps are frequently found; thus in a such specimen with nume- Fig. 237. Callithamnion tetragonum var. fruticulosa. Part of plant with antheridial clusters. 215 : 1. rous sporangia a branch was met with bea- ring a great number of procarps above but sporangia below. The antheridia are placed in hemisphe- rical cushions, as described by NAGeE.r for C. tetragonum (I. c. p. 345, fig. 30) and Ky- LIN for C. fruticulosum and C. spiniferum (l. c. pp. 155—161, figs. 32—33). Comp. our fig. 237. These cushions have the same po- sition as the tetrasporangia; they are placed singly or two in the same cell. The anthe- ridia are usually found on the same indi- viduals as the procarps. The procarps always arise in a branch- bearing cell and in such position that the carpogonium is opposite to the branch, the two auxiliar-mothercells lateral. The carpogonial branch is composed of 4 cells the two outermost of which are superposed while the first cells of the branch form a horizontal row. Spermatia were repeatedly found attached to the trichogyne, what the sporangia being placed “near the middle of the ramuli”; in the quoted figure, the undermost cell in the pinnulæ hears no sporangium. 324 makes it probable that fertilisation really takes place. However, it must be said that trichogynes with attached spermatia but with undeveloped auxiliary mother-cells Fig. 238. Callithamnion tetragonum var. fruticulosa. Procarps. To the right in B the auxiliary mother-cell which supports the ~ carpogonial branch. 4. B 270 :1. C 350 :1. Fig. 239. Callithamnion teiragonum var. fruticulosa. Ripe cystocarps. A 76:1. B 145:1. C 200:1. though of rather advanced age were in some cases observed. (These observations are communicated here because sporangia frequently occur on the same plants as the. sexual organs). Each of the auxiliary cells produces a glomerulus which is ovoid- globular or a little irregular. Usually a smaller conical lobe is seen at the base of the glomerulus. As shown in fig. 239 C the glomerulus is supported by a large ste- rile cell, the “Centralzelle” of OLTmanns, while the small lobe is given off from the stalk-cell of the auxiliary cell (the “Basalzelle” of OLrmanns and Kyrın 1923). The conical body cannot therefore belong to the gonimoblast and it must be concluded that it is unable to produce normal carpospores. A similar smaller lobe developed under the primary glomerulus has first been mentioned by JanczEwskı (1877, p. 119) in Call. tetricum and later by OLTmanns in C. corymbosum (1898, p. 118) and KyziN (1907) in C. fruticulosum, C. spiniferum and C. Brodiei, comp. above p. 316. In the cases described by JaAnczEwskı and OLTMANNS, however, the smaller lobe arises from the same cell, the central cell, which has produced the glomerulus and is therefore a part of the gonimoblast. — The cystocarp-bearing cells remain shorter than the sterile cells of the filaments. This variety has been found growing on various Algæ, e. g. Furcellaria and Cladophora rupestris, in 1 to 8 meters depth, with sexual organs and ripe sporangia in May to September, with cystocarps in July to October. Localities. Kn: 6!/, miles S.W. by W.1/, W. of Læsø Trindel light-ship, 8m (C. A.J.) — Ke: Gilleleje; on the shore at Nakkehoved (?) (Lyngbye). — Su: off Ellekilde; Hellebæk; Blokhus Grund (Henn. Petersen). 4. Callithamnion corymbosum (Engl. Bot.) Lyngbye. Lyngbye, 1819, p. 125, tab. 38 C; J. Agardh, 1851, p. 41; Harvey, Phye. Brit. III, 1851, pl. 272; Thuret, Et. phyc., 1878, p. 67, pll. 33—35; Reinke Algenfl. 1889, p. 24; Oltmanns, Bot. Zeit. 1898, p. 114, Taf. VI-VII; Kylin, 1907, p. 165; Kolderup Rosenvinge, 1911, p. 25; 1920, p. 25. Conferva corymbosa Engl. Bot., pl. 2352, 1812. Ceramium pedicellatum Lyngbye, Flora Dan. tab. 1596, 2, 1818.! Phlebothamnion corymbosum Kützing, Spec. Alg. 1849, p. 657, Tab. phye. XII Taf. 9. Poecilothamnion corymbosum Nägeli, 1861, p. 360. Callithamnion hiemale Kjellman in Kylin 1907, p. 170, ex parte. Referring the reader, for the ramification, to the papers of NAGELI, Kyrın and myself (1920), I shall only mention that the branches are usually arranged in a spiral with an angle of divergence varying between !/; and !/;, the spiral turning with equal 1 In the herbarium of the Botanical Museum of Copenhagen a number of specimens of this species from Hofmansgave are to be found together with a leaf with drawings of the same species by LYNGBYE with the following remark in LYNGBYE's handwriting: Ceramium roseum Var.? Nov. 1815 Hof- mansgave, and signed with the letters A—D. The three last of these figures have been reproduced in Fl. Dan. Tab. 1596, 2 (under the name Ceramium pedicellatum). Fig. A which represents the habit of the species in feeble magnification and shows the corymbous ramification is in Fl. Dan. replaced by another figure which agrees fairly well with the fig. 38 C1 of Lynepyr’s Hydr. but does not give a good idea of the ramification of the species. Confusion with another species has perhaps taken place. The fig. C (the undermost, to the left) which shows antheridial bushes has also been rightly interpreted, for LYNGBYE has marked it: “C mas?”. Fig. D shows the upper sporangium opened with a split in the original drawing, but that has not been reproduced in the engraving. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 42 326 frequency to the right and to the left. The ramification of the branches begins from the very base but the first bran- ches are not as a rule included in the spiral arrangement. Most frequently the first two or three branches are biseriate in a transverse plane. The ramification is often pseudodichomous (camptopodial Nägeli), in particular in the upper part of the plants, the branches reaching the same size as the mother axis and di- verging almost equally with this from the original direction of the mother axis, for which reason it is often diffi- cult to decide which of the rays is the main axis and which the branch. When Fig. 240. the pseudodichotomous ramification is Callithamnion corymbosum. À, i upper end of shoot. B, some- Very pronounced, the greater sections vies allen cols 2508 We of the frond may get a semicircular outline; when the main axes are more vigorous than the others, the outline becomes pyramidal. In other cases the outline is more indistinct, the greater complexes of shoots being dissolved in smaller corymbous bunches. Very rarely two branches were found on the same joint; they were not opposite but diverging with an obtuse angle from one another (fig. 241). The young cells contain a single nucleus; later on it divides and as a consequence of continued divisions the older cells contain a great number of nuclei equally distributed over the cell (fig. 242). They are distinctly Fig. 242. visible in the figures of THURET (1878, pll. Callithamnion corym- 33—35). ee pee Hyaline hairs normally occur. They have nuclei. 200 : 1. been mentioned and partly figured by Ktr- ZING, NAGELI, THURET, KYLIN and myself (1911). They are present in the whole season of vegetative development, but are wanting in winter (December, January). No specimens have been collected in February and March, but all the specimens collected in April to October were provided with hairs. Only in very rare cases were the specimens collect- ed in summer devoid of hairs; thus, some large specimens from Herthas Flak in 20 to 23 meters depth had only very few I Fig. 241. Callithamnion corymbo- sum. A joint bears two branches (III) at the upper end. 200: 1. Fig. 243. Callithamnion corymbo- sum.A,Upperend of branch with terminal hairs. B, the hairs are pushed aside by the sympodial develop- ment of the branch. Two hairs are shed but their basal pits are still visible. A 240:1. B 300:1. 327 poorly developed hairs and some scars after hairs which had fallen off. Similar specimens were found in the harbour of Skagen in July, but the ends of the branch- es showed sympodial development and sometimes a pit in the end wall at the point where the hair had been inserted. The hairs are terminal on the branches the development of which is stopped by the formation of the hair, but the hair is often pushed aside by a lateral branch formed under it, and such a sympodial develop- ment may repeatedly occur on the same branch (fig. 243, comp. L. K. R. 1911, p. 212). Not rarely two hairs are to be found on the same terminal cell; the one is then terminal, the other lateral (comp. THURET 1878, pl. 33 and 35). The shoots in full Fig. 244. Fig. 245. Callithamnion corymbosum. Upper Callithamnion corymbosum. À, cortical filaments with adventitious shoots, end of shoot of plant collected in B, part of plant with stoloniform filaments partly ending with hapters. December; the young branches B 50:1. are hairless and incurved over the top. 270 :1. growth do not terminate with a hair but only the shoots with feebler or ceasing intensity of growth. In autumn the hairs are shed, and in the specimens found in December and January the hairless branches are curved in over the summit of the shoot (fig. 244). The main axes increase gradually in thickness downwards and are in the lower part provided with a cortex of decurrent filaments. The cells issuing from the bases of the branches and growing in the outer wall of the joint cells of these filaments contain several nuclei. Small adventitious shoots may issue from them (fig. 245 A). In specimens from the harbour of Kerteminde numerous free filaments were found issuing from the lower end of the cells of the crect filaments and growing out in a direction perpendicular to these filaments; they consisted of long cells and 42° 328 might attain a considerable length without branching, but on meeting a solid body they had fixed themselves to it and produced numerous branches partly adhering to the same body (fig. 245 B). The antheridia always occur on par- ticular male specimens. They form small, often hemispherical cushions on the upper branchlets; they are usually seat- ed, in analogy with the sporangia, on the upper side of the lower joint of the branchlets, near its upper end, but, as shown by THURET, two or three cushions are frequently seated under one another and these may be fused together. The joint may thus be occupied in its whole length or nearly so by a long compound an- theridial cushion, and the joint is then Callithamnion corymbosum. Antheridial cushions. %0:1. usually more or less recurved by epi- nastic growth and bears no vegetative branch. When the production of antheridia is very abundant, they occupy not only the branchlets but also the mother axes. The cushions consist of much branched short branch-systems, the upper cells of which are the antheridia (spermatangia) (fig. 246). With regard to the position and the develop- ment of the procarps and the cystocarps reference may be made to the quoted papers of THURET (1878, pl. 34 and 35), OLTManxs (1898) and N Kyrın (1907, p. 166). A! NM) / As mentioned by earlier observers, the te- NÆS IN 187, trasporangia are seated on the inner side of the AN / / nr ISG .. À j j upper branchlets. on the lower joint. usually at \/ { )\ / its upper end. The first branch of the second order OS i} £ ER 2 N NY, | having a transversal position, the sporangium | | NY then forms a right angle with this branch. The Il 2 | / an GE single or a younger SRE KE ppears under the first formed, sometimes in an FE oblique direction under it or nearly beside it Fig. 247. (fig. 247 4). A third sporangium may rarely be Callithamnion corymbosum. Tetrasporangia. found under the second. In rare cases the spo- 210 : 1. rangium is inserted in the middle of the joint (fig. 247 B, C); in the case shown in fig. 247 C, a second sporangium is seated over the first formed. — As shown by THURET (1878, plate 35 fig. 14), the sporangia open by a transversal split near the upper end of the sporangium; the upper part of the wall then forms a lid fixed by a hinge. At the discharge, which was once observed, the two upper spores first escaped almost simultaneously and shortly after a third. During the liberation, the spores changed form when squeezing through the narrow split and afterwards regained the globular form. A liberated spore was seen to move between some filaments of the same species, likewise changing form when squeezing through the narrow interstice between the filaments. Germination of tetraspores and carpospores is easily realized in cultures, as shown by THURET (1878 p. 71, pl. 35 fig. 15), who obtained, however, only very young stages consisting of few cells. The seedlings in my cultures reached a greater size and began to branch (fig. 248). As mentioned by THURET, the seedlings resulting from the two kinds of spores are alike. N The germinating spore gives off two opposite germinating pn CES Il tubes, the one becoming the primary axis of the plant, the (Wr 0 other growing out to a long articulate rhizine. The original NU || spore-cell remains for a long time distinguishable by its greater \\ M ul thickness, at least in the cultures. The branching of the pri- \ y |) IL\ | mary axis may begin immediately over it or at a higher level. Antheridia have been met with in April to September, eystocarps in June to October, tetrasporangia in June to Decem- ber and in January, but not in the spring. The cystocarp-bearing specimens are often smaller than the tetraspore-bearing ones. Sterile specimens are not rarely found in considerable number between the fertile ones, and they are then often larger than these. In the Smaaland Sea, in the Sound south of Hveen A and in the Baltic Sea, thus in the innermost localities, only sterile specimens were found. The species has been met with .at all seasons; that it PA has not been observed in the months of February and March is Fig. 248. certainly due to the fact that only very few collections have Callithamnion corymbosum. : 3 6 Sporelings from Frederiks- been made in these months. It can without doubt continue jayn. 4. 3 weeks, B, C. 4 alive from one season to the next, but it can also accom- weeks old. 150 :1. plish its life-cycle during a short time, being thus ephemerous, and perhaps produce more than one generation in the season. The duration of life must at all events be short when it is epiphytical on Algæ or parts of Algæ which die in the autumn. It may be met with in well developed specimens at all seasons; it occurs, however, in the greatest quantity in summer and autumn, when it also attains its greatest development. Most of the specimens certainly die in the autumn. The spe- cimens found in winter are not in growth and without hairs (fig. 244) but may still bear tetrasporangia. Callithamnion hiemale Kjellm., Kylin seems at least in part to be such a winter-form of C. corymbosum, for a specimen of the named spe- cies kindly sent me by dr. KyLiN agreed with my winter specimens of the lat- ter by its structure and its corymbous ramification; the number of the nuclei could not, however, be ascertained in the dried state. A few hairs were still pre- So = — Be in => LED sent.” — The growth of the species apparently begins at the end of the winter. As the germination of the spores takes place immediately after the dissemination of the spores, it is probable, that the species usually passes through the winter as small plants having reached only a small size at the beginning of the winter. — It grows on stones, wood, leaves of Zostera and numerous Algæ as f. inst. Furcellaria fasligiata, Ahnfeltia plicata, Fucus vesiculosus, Polysiphonia spp., Phyllophora spp. and many others. The species varies in the length of the cells and the different degree of con- traction of the branches thereon dependent, apparently owing to the various conditions of the environment; further, as mentioned above, in the relation of the longitudinal growth of the branches to that of the mother axis. When the ramification is de- cidedly pseudodichotomous the outline of the sections of the frond becomes semi- circular or nearly circular. The branches are then often more divaricate than usual, thus in the f. intricata Lyngbye (Hydr. p. 125), which occurs in sunny localities in shallow water. The species is spread from the North Sea to the south end of the Sound and to the western part of tbe Baltic. In the North Sea it has only been met with in two localities very remote from land at greater depths (24,5—31 m) and further in the harbour of Thyboren; in the Skagerak it has been collected in several places, mostly at small depths near land, and in the inner waters it is commonly spread from low-water mark to 20 meters depth (in the Limfjord only to 6m). In the Sound south of Helsingør it does not occur at depths smaller than 9,5 m, and in the Smaaland Sea not at depths smaller than 4,5 m. It usually reaches only a length of 5 cm; it may, however, attain 7,5 cm (f. inst. in one of the innermost localities, south of Langeland at 11,5 meters depth) and specimens up to 9cm high were found once, in Grenaa harbour. Localities. Ns: aF, Thyborøn beacon S.E. !/,E., 19,5 miles, 31 m © Aug.; ZQ jydske Rev, 24,5 m; harbour of Thyborøn. — Sk: YU, Roshage, Hanstholm, near land, 1—2 m; YM!, Bragerne; YN, within Bragerne; ZK, off Lonstrup; Lonstrup, near land, 1 m; Hirshals, mole and boulders near land; N.W. of Hirshals, 15 m; Skiveren, on wreck; north Side of Skagens Gren. — Lf: ZS, Kobbered; Ydre Ron by Lemvig; MC; south side of Jegindø Tap, 6 m; east of Jegindø; MH, off Skrandrup, Thisted Bred- ning; Nykøbing (Th. Mortensen); Glyngøre; off Knudshoved, Fur; north coast of Fur; MK, Holmtunge Hage; LQ, Lendrup Ron; Logstor Kanal; Logstor; near Marbjerg Tange (Boye Petersen). — Kn: Har- bour of Skagen; south of Fyrbakken, 4m and south of Skagens Gren, 13—15 m; off Hulsig, 7,5 m (B. P.); Herthas Flak, 19 m; TV, Krageskovs Rev; various places around Hirsholmene; Frederikshavn, harbour and various places in the neighbourhood; BP, off Sæby, VT and TK near Nordre Renner; north end of Nordre Ronner; NH, north of Læsø, 15 m, + in Sept.; Vesterø harbour, Ostero harbour; TP and ZA, Tonneberg Banke, about 16 m; 61/, miles S.W. by W.1/, W. of Læsø Trindel light-ship, 8 m (€. A. J.). — Ke: FD, east of Læso: VY, Fladen, 18 m, sterile in July; XA, S.E. of Kobbergrundene; east end of Anholt; 14!/, miles S.S.E. of Anholt Knob lightsh., 10 m, + Oct. (C. A. J.); Gilleleje. — Km: 6 miles S.S.W.!/, W. of Læsø Rende lightsh., 8 m (C. A. J.); 5!/ miles N. by E.°/,E. of Østre Flak lightsh., 9 m. (C. A. J); BO, Stensnæs; Asaa, mole; EZ, south of Læso; ZC!, Kobbergrundene; BK, Tan- ! Dr. Kyrın has later arrived at the opinion that C. hiemale is a winter-form of C. Furcellariæ (Botan. Notiser 1916, p. 65), as he has found specimens with lobed gonimoblasts. It appears therefore that two species have been confounded under this name. gen; NC, east of Tangen. — Ks: Pakhusbugt, Anholt, 19 m; Grenaa harbour; NB, Havknudeflak; MZ, north of Hjelm; D, north of Gronne Revle; RL; EH and NL, off Lynæs, Isefjord. — Sa: BF, off Sletter- hage; Kalo Rev; Aarhus; PC, between Sejerø and Ordrups Næs; PK, Norsminde Flak; YV, east of Samsø, 15 m (+ and ¢ in June); MX, at Tunø Rev; BC, off Hov Ron; BB, Søby Rev; aV, east of Endelave; DK, Bolsaxen; MQ, Paludans Flak; entrance to Korshayn; north coast of Æbelo; Hofmans- gave (Lyngbye, Hofman Bang, J. Vahl, C. Rosenberg). — Lb: Horsens Fjord west of Aldero; AX, Bjorns- knude; FZ, Kasser Odde; Fæno Sund; cZ, Knudshoved Grund; Aarosund (Reinke, !); CD, Helnæshoved Flak; Sonderborg. — Sf: CC, south side of Hornenæs; banks off Nakkebolle Fjord; UX and UV, north of Æro; CV, Billes Grunde; BX, Svendborgsund; Svendborg. — Sb: South side of Refsnæs; MN, north of Asnæs; GU, S.W. of Asnæs; AG, Romso; Reerso; GQ, west side of Slettings Grund; Kerteminde; Korsor; GY, west of Gjellegrund; Z, off Skagbo Huse; NS, BS near Nyborg; GZ, north of Egholm; Lo- hals harbour, near low-water mark; Snøde Rev, west of Langeland, 4 m, st.; T, Staalgrund, 9,5 m, ©; LB, Langelandsbelt, 17 m, 2. — Sm: CK, 9,5 m; CQ, 4,5 m, st. — Su: Hellebæk (Børgesen, !); north of Helsingor; PZ, east of Hveen, 10—19 m, 2; TF”, Staffans Flak, 11—13 m, st.; RH, Knollen, 9,5 m, st. — Bw: Flensborg Fjord (Suhr, Hansen): Egernsund, Graasten; cX, off the South end of Kobbel Skov; bZ, south of Sønderborg; DV, south of Marstal 9,5—11 m, st; LC, south of Gulstav, 11,3 m, st; KZ, off Kramnisse, 4,5 m, st. 5. Callithamnion roseum Harvey. Harvey in Hooker, The English Flora, Vol. V, part I. 1833, p. 341; Manual Brit. Alg. 1841, p. 106; Phycol. Brit. pl. 230, 1849; Wyatt, Alge Danmonienses No. 44. J. Agardh, 1851, p. 36; Bornet in Borgesen, Mar. Alg. Fær. 1902, p. 377; Le Jolis, Alg. mar. de Cherbourg, no. 162; Kolderup Rosen- vinge 1920, p. 44. Phlebothamnion roseum Kützing, Tab. phyc. Vol. XI, tab. 97, 1861. Callithamnion byssoides K. Rosenvinge, 1911, p. 209. This species grows in certain localities in the harbour of Frederikshavn where it has been met with repeatedly during the last 27 years. Otherwise it is seldom found in the Danish waters. The Da- nish specimens agree with the species as described by Harvey and as understood in the above citations. They are up to 10 cm high. The filaments are branched on all sides, some- times, however, the branches are alternate biseriate, in particular in the undermost part of the upper branches, and then usually placed in a transversal plane, as pointed out by Borner (1. c.). The main axes are distinct, scarcely bent in zigzag. When the branching is regular and the plant is in active growth the segments are cut off by inclined walls. The young segments are only a little longer than broad (fig. 249). The branches are never branched Fig. 249. from the base. The number of joints below the Callithamnion roseum. Upper ends of shoots. first branch varies from 2 to many, at least 25: as In that on the left and in the middlemost im A the branches are arranged in a spiral, in the a rule, it is greatest at the base of the older branches. shoot on the right they are biseriate. 290: 1. 332 A number of branches remain unbranched, though consisting of a rather large number of cells; such branches occur frequently at the base of the longer axes but also near the top (fig. 250). When the ramification has begun, it usually continues uninterrupted, each joint bearing a branch. It happens, however, that one or two consecutive branchless articles may occur here and there, in particular in the lower- most part of the main axis and the branches. The branches of the long shoots are always arranged in a spiral, at all events in the upper part of the shoots, and here Fig. 250. Callithamnion roseum. A, upper end of long shoot. B, shoot with tetrasporangia. 70 : 1. the angle of divergence is usually 1/,; the arrangement of the lowermost branches, however, is irregular or alternate biseriate. (Comp. L. K. R. 1920). It very rarely happens that one joint bears two branches. The filaments are 10,5—14 x broad right under the apical cell. They are not usually terminated by a hair, such or- gans may, however, occur sometimes (fig. 251, comp. L. K. R. 1911 p. 209); the hairs are rather short; they are a little thinner than the end of the filament, about 7 y thick. i The cells contain one nucleus and numerous irregular lengthened chromato- phores; numerous starch grains may occur (fig. 252). The lower part of the principal filaments is corticated with descending filaments 333 given off from the lowermost cell of the branches, sometimes also from the second and following cells. They are frequently formed in a number of three from the basal ? Fig. 251. Callithamnion roseum. A—C, deve- lopment of the hairs. D, Fully developed hair pushed aside by a branch from the subterminal cell. A—C 700:1. D 300: 1. (fig. 254). The number of sporangia on a branch is often Cells bearing more than one sporangium only 1 or 2. cell; they grow in the outer membrane of the filaments but become partly free at the base of the principal axis, here forming free, pluricellular, branched fila- ments which fix the plant to the sub- stratum. The cortical layer may be so much developed that the cells of the filament are scarcely distinguishable. Ad- ventitious shoots do not occur or only : Fig. 252. exceptionally. Br #04 1 AJ à Callithamnion ro- The tetrasporangia are usually seum. Part of cell with chromatopho- res and Floridean starch, placed in a row on the upper (inner) side of the branches of the last order. The tetraspore-bearing branchlets are thus, as a rule, unbranched, but fertile branchlets more or less branched above not unfrequently occur. The tetra- sporangia-bearing branchlets are frequently alternate bi- seriate. The sporangia usually form a short row of 1—4 or-5 on the lowermost cells, one on each cell (figs. 250 B, 254, comp. Harvey, Phyc. Brit. Il. c. fig. 2—3), but the row is frequently interrupted, by single cells bearing no spo- rangium. Sometimes, the un- dermost articles are bare, and the formation of sporangia begins only at a higher level. The sporangia placed at some distance from the base are not always situated on the upper side but frequently on the flanks or even on the outer (under) side of the branch À Im | Fig. 253. Callithamnion roseum. Part of stem with corticating filaments. 50:1. have never been met with. The ripe sporangia are (60—) 70—80 (—84) u long, 45—55 (—70) w broad. Once I found an unusually large spo- rangium measuring 98 x 74 u. The sporangia open by a transversal slit above. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 43 334 The antheridial'clu- position to that of the sporangia, namely in Fig. 254. a row of 1 to 6 on Callithamnion roseum. A, sporangia-bearing branch. B, . n sporangia situated on the outer side of the branch. 4, the upper side of the 52:1. B, 80:1. pinnulæ, usually one on each cell, rarely two, one over the other. Sometimes, the undermost cell or cells bear no antheridial clusters, the formation of these beginning only at a higher level, or the row is interrupted by joints bearing no antheridial bush. The branchlets bearing these organs are usually unbranched, but it occurs sometimes that they are branched above and the case may also be met with that a cell of a branchlet bears a branchlet and an antheridial bush as well (fig. 255 C). The main axis of the antheridial cluster consists of five or six cells, which are usually shorter than their breadth. It is slightly curved towards the top of the branch and bears a number of Fig. 255. Callithamnion roseum. Antheridial clusters. A 205 : 1. B, C 560 :1. sters have a similar ~ Fig. 256. Callithamnion roseum. Procarp before fertili- sation. Only one auxi- liary mother-cell is present, a’, situated be- hind the carpogonial branch. 350 :1. 1335 h Fig. 257. Callithamnion roseum. Procarps before and after fertilisation. a! and a? auxiliary mother-cells, or in D and E auxi- liary cells. a? that from which the carpogonial branch is given off. 1, 2,3, c, the cells of the carpogonial branch. In A a? is wanting. In C fertilisation has taken place;7s sporogenous cell before fusion with the auxiliary cell; under it the rest of the carpogonium. In D and E the auxiliary cells have been cut off, except a? in D; b the stalk cells of the auxiliary cells. The three cells under a! seem to be the young gonimoblast. B 270 : 1, the others 350 : 1. short branches prineipally on its convex side, but on the flanks and the upper side too, consisting of one or few cells and producing numerous antheridia which organs may also project directly from the cells of the main axis. The procarps are nearly opposite to the branch projecting from the same cell. The auxiliary mother-cell (a!) from which the carpogonial branch is pro- duced is situated very near the branch, the other one (a?) is somewhat removed from its other side (fig. 257). The car- pogonial branch consists of four cells, the second of which is situated obliquely over the first, the carpogonium exactly over the third (fig. 257). The one auxi- liary mother-cell (a?) may sometimes be wanting (fig. 256). The cystocarps are composed of two ovate gonimoblasts; Fig. 258. 0 o 3 Callithamnion roseum. Cystocarps, A young, B almost ripe. their outline may be more or less irre- A 260 :1. B 150 :1. gular, but not lobed. A few gonimoblasts on the same specimens were, however, more irregular and lobed, much as in C. Furcellarie. A little special lobe is developed at the base of the gonimoblast, as in other species (fig. 258). In Phyc. Brit. pl. 230 fig. 5 Harvey figures a cystocarp consisting of a small number of cells; perhaps it represents a young stage. I have not seen anything corresponding to the ‘cluster of favellæ’ figured in Harvey's fig. 4 The vegetative cells in the neighbourhood of the cystocarps usually produce rudimentary or more developed decurrent filaments which undoubtedly serve to strengthen the parts of the filaments bearing these heavy organs (fig. 258 B). On a tetraspore-bearing plant were found a number of sporelings apparently of the same species. Some of them were unbranched, others were branched, the rami- fication being irregular, alternate or secund. The species is nearly related to C. Furcellariæ from which it differs in particular by its robuster filaments, by the principal axes being corticated in their lower part, and by the ovate, not lobed gonimoblasts. The above description is founded on numerous living and preserved specimens from Frederikshayn. Elsewhere the species has only been met with in two other places in a sterile state. The basal part of the plants is usually enveloped by dense masses of detritus. In one case, the lowermost Fig. 259. part of the main axis had no cortex while the next Callithamnion roseum. Sporelings 5 2 found on a tetraspore-bearing spe. following part had a well developed cortex. The species cimen of C. roseum. 24:1. has been observed with sexual organs and with ripe cystocarps and tetrasporangia in the months of July and August, the only months in which it has been collected at Frederikshavn. In this locality it has been met with only in the harbour from low-water mark to about one meters depth. In the Smaaland Sea it has been found in 11,5 meters’ depth. Localities. Li: Fuur “apportavit Kjolbye”, Herb. LyxGsye, determined by Lyngbye as C. ro- seum. A specimen from Limfjorden communicated by HoRNEMANN to Lyngbye in the same year (1826) pro- bably originates from the same locality. All the specimens are well developed but sterile. — Kn: Frederiks- havn, in the harbour for boats at the end of the north mole (1891—1923), on the head of the northern transverse mole and at the harbour of the pilots. Vesterø Havn, Læsø. — Sm: (2) Agersosund, 11,5 m, sterile. 6. Callithamnion Furcellariæ J. Agardh. J. Agardh, 1851, p. 57; Kylin 1907, p. 167; Kolderup Rosenvinge 1920, p. 49; Kylin 1923, p. 56. Callithamnion byssoides Areschoug, 1850, p. 107, Tab. V, B; Svedelius, Ostersj. hafsalgfl., 1901, p. 126. Callithamnion hiemale Kjellm., Kylin, 1907, p. 170, teste Kylin, Botan. Notiser 1916, p- 65, ex parte. ? As mentioned above, p. 330, a specimen of C. hiemale communicated to me by prof. Kyrın has turned out to be a C. corymbosum; but as the said author has found lobed gonimoblasts in other specimens, it seems that two species have been confounded under the name of C. hiemale Kjellm. 337 | The Alga here treated has been mentioned for a long time in my annotations under the name of Call. byssoides. As, however, it is doubtful whether it is warranted to refer it to the species of ARNOTT and Harvey and as the limitation of this spe- cies in regard to related forms is uncertain, I prefer to give to the species of the Da- nish waters the name of C. Furcellarie, because it is at all events identical with this species of AGARDH. It must then be left undecided whether it can be identified with the British species wholly or in part; I | must content myself with referring to SCHMITZ's re- marks on the synonymy of C. byssoides and related forms in his paper: Die Gattung Microthamnion in Ber. d. deut. bot. Ges. 1893 pp. 280 and 283. The species occurs in all the Danish waters; it usually reaches only a length of 2 cm or a little more, in the inner waters Sf and Sb, however, it be- comes 3 cm and at Born- holm up to 4 cm high. The ramification has been treated at length by Kyrın (1907, p. 167) and Fig. 260. Fig. 261. by me (1920, P- 49). It is Callithamnion Furcellarie. Upper end of Callithamnion Furcellariæ. Up- less regular than in the plant from Fænø Sund, with irregularly per end of plant from Born- arranged branches and dispores. holm, with biseriate branches. other Danish species. The 70:1. 270 : 1. branches are, however, usually arranged in a spiral, but in several shoots the branches were irregularly arranged or more rarely biseriate (specimens from Bornholm). When the branches are arranged in a spiral, the angle of divergence is more variable than in the other species; the angle of divergence varied in the examined shoots from 67° to 131°. Not rarely did the direction of the spiral change in the same shoot. The branches are usually branched from the base, the first joint normally bearing a branch; but it happens now and then that the first joint is branchless, and in specimens from Bornholm several joints at the base of the branches were branchless. The spiral arrangement as a rule begins at a certain distance from the base, the first branches being irregularly arranged, sometimes, however, partly biseriate in a transverse or oblique plane. In several cases two branches of unequal size were found inserted 338 Fig. 262. Fig. 263. Callithamnion Furcellariæ. Bases of plants with intra- Callithamnion Furcellariæ. À, basal part of plant. B, creep- matrical and extramatrical descending filaments. 4 45:1. ing filaments from the foregoing year. A new erect B 95:1. shoot has broken forth from the remains of an erect shoot Callithamnion Furcellariæ. À, cell showing the nucleus and a number of the chro- matophores. B and C, cells connected by a broad bridge of protoplasma at the periphery. À 195:1. B, C 270:1. from the foregoing year. A 70:1. B 80:1. on the same joint, diverging from one another at an angle of a little over or a little under 90°; the larger one entered into the spiral. For more details see my paper (1920 pp. 49—58). The principal axes are distinct and straight or only a little bent in zigzag. The ramification is thus distinctly monopodial but sometimes it may be some- what corymbose, thus reminding of that of C. co- rymbosum. The length of the cells in proportion to the breadth is rather variable but usually con- siderable, varying from 4 to 12, rarely up to 17, but in the lower part of the main axis the cells are shorter. In the lower part of the principal shoot single descending filaments occur, being partly intramatrical, partly extramatrical, but in the first case not forming a continuous cortical layer. The intramatrical ones may — 339 be free before reaching the base (fig. 262). Moreover, free horizontal shoots arise from the lowermost part of the principal axes, usually given off from the lower end of the cells. They have the character of rhizomes producing new erect filaments. Fig. 263 shows such much-branched rhizomes growing in a bow towards the sub- stratum. In the seed- lings, too, such hori- zontal filaments are to be found (fig. 271). The filaments as a rule terminate without hyaline hairs. This character is so constant that it can be used to distinguish this species from Call. corymbosum. It must, however, be admitted that hairs may occur in rare cases in genuine specimens of C. Fur- cellarie (YV, Hatter- barn, Sa (Fig. 266); D, Ks and UV, Sb). The hairs were much less numerous and feebler developed than in C. corymbosum, only 12—140 w long and 3,5 u broad in no. 7380 (YV). The specimens in question were col- lected in May to Junein Callithamnion Furcellarie. Tetrasporangia. A, showing their arrangement, plant depths of11—15meters. from northern Kattegat (TP). B—G showing the varying arrangement of the spores in the sporangium. A 160:1. B—G 220:1. The cells al- ways contain a single nucleus and numerous long, narrow, more or less curved chromatophores (fig. 264). In specimens conserved in alcohol curious fusions between cells in the older parts of the plants were observed (fig. 264). The transverse wall was dissolved to a greater extent in the periphery and the two cells thus connected by a broad bridge of protoplasma, much broader than the central pit connecting the two cells. This fusion is not followed by any formation of pit-membrane and may be compared with the cell-fusions by the Corallinaceæ and Squamariacee, but they take place 340 between cells which were before-hand connected by a pit. The process is not ac- companied by a migration of nuclei; the two cells fusing with each other contain each one central nucleus like the other cells. The sporangia are borne on the inner side of the branches of the last or penul- timate order. They are 4-parted or 2-parted, most frequently the first, but there is always one sort of sporangia only on the same plant. They form a short row on the inner side of the branches, fre- quently in a number of 3 or 4, but sometimes there is only one, on the first joint. When the number is greater, they are not always all placed on the inner side~but some of them on the flanks of the branches (fig. 265). There is usually one sporangium only on each joint but a young sporangium may sometimes be found under the normal one, more rarely over it. Such small, incompletely developed sporangia were met with in plants with four-parted and with two-parted sporangia as well, most frequently in the latter. The sporangia- bearing branches may be simple but are frequently branched and the bran- ches then issue over the sporangia- bearing part (fig. 266). It is very rare to find a cell bearing at the same time a sporangium and a branch (fig. 273). The sporangia are ovate or obovate or broadly ellipsoid. The tetrasporangia are tetrahedrically divided, but the spores are sometimes so arranged that the spo- i 5 _ Fig. 266 a i rangia seem to have been cruciately Callithamnion Furcellariæ. Part of plant with disporangia. We 3 From YV. 200 : 1. divided (fig. 265), a fact to which Hauck has already paid attention in the species mentioned by him under the name of C. byssoides (Österr. bot. Zeitschr. 1878 p. 288, Taf. 3 Fig. 9). The tetrasporangia are (44—) 53—79 w long, 33—51 w broad. When the specimens from the waters within Skagen only are taken into account, the size is a little smaller, viz. (44—) 53—65 (—67) u long, 33—42 w broad, which quite agrees with the dimensions stated by Kyrın. The specimens from the Skagerak, some of which were not with certainty referable to this species, had larger sporangia, 66—79 w long, (38—) 42—53 u broad. 341 The disporangia are of the same size as the tetrasporangia, or, when only the specimens within Skagen are taken into ac- count, generally larger than the tetrasporan- gia, viz. 56—78u long, 43—65 broad. The size was rather variable in specimens from different localities. Thus in specimens from Feno Sund gathered in June the disporan- gia were 56—60 w long, 43—47 w broad, while in specimens from a locality north of S Æro gathered in May, they were 67—78 u long, 53—63 u broad. The disporangia were formerly mentioned by Kyrın (1907, p. 169) who raises the question whether they might possibly be young stages of tetrasporangia. Fig. 267. He arrives at the conclusion that they are aie ME DA ea fully developed, partly on account of the fact that he found some of them emptied, which conclusion I can fully confirm. The disporangia-bearing specimens in all other respects fully agree with the tetrasporangia-bea- ring ones so there seems to be no sufficient reason to consider them as a special variety. They occur more rarely than the others; in Fæno Sund both kinds of individuals have been met with. The disporangia are di- vided by a horizon- tal wall on each side of which a large nucleus is si- tuated. A finer cy- tological investiga- tion of the dispo- rangia is much ig. 2 he 288, and needed. Callithamnion Furcellarie. A, antheridial clusters. B, eystocarps. From Tonneberg x 2 Banke. A 270 :1. B 195 :1. Both kinds ol D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 44 342 sporangia open by a transversal slit in the upper part ofthe sporangium. The disporangia have been met with in May to July, the tetra- sporangia in June to October. The antheridial clusters have been describ- ed and figured by Kyrın (1907, p. 169, fig. 35b). They are usually arranged in a row on the upper side of the upper pinnulæ, often on the lowermost 4—6 joints, but they may also be borne on branches of penultimate order. On each joint one to three clusters are to be found. Even when seated very densely they are never fused together as in certain other species. The clusters consist in a usually some- what curved axis composed of 3 or 4 cells å which are almost isodiametrical and bear each Callithamnion ee ona In A a! and a number of antheridia mostly on the! convex a? the two auxiliary mother-cells; 1, 2, 3, c, the Side turning downwards. The antheridia are RL hey: were pie mother-cells a? is wanting. A 350:1. B 270: 1. 5 with in July and September. Buffham has described and figured the antheridial clusters in Call. byssoideum (1884, p. 341, pl. X figs. 4, 5); they agree with those of C. Furcellarie by the position and the structure of the axes, but they seem to differ, according to BATTERS, by the antheridia being developed equally on all sides of the cluster and by being “very elongated”. — According to Kürzıns (Tab. phyc. Vol. 12 pl. 8), the antheridial clusters of C. byssoides are, at any rate in great part, axillary. The species of KÜTZING seems, however, to be very different not only from our species but also from Har- vEy’s by its much corticated main axes. — The antheri- dial clusters of C. byssoides Callithamnion Furcellarie. ine SE From Hirsholm. 200: 1. Börgs. from the Danish West Indies (F. BoBGEsen, Mar. Alg. Dan. W. Ind. 1917 (Dansk Bot. Ark. III, p. 218, Fig. 207) are also different, being cushions consisting “of a system of short (bran- ched) branchlets in which the uppermost cells are the antheridia”. They may some- 343 times occupy nearly the whole upper side of the cell of the branch. — The quoted differences in the structure of the antheridial clusters of the various plants referred to C. byssoides suggest that different species have been confounded under this name. The carpogonial filaments are borne on the upper end of joints bearing a branch on the opposite side. They are, as in the other species, composed of four cells ar- ranged in a zigzag line. There are usually two auxiliary mother cells, but sometimes there is only one, a,, from which the carpogonial branch is given off, while a; is wanting (fig. 269). The growth of the procarp-bearing cell is arrested during| the development of the cystocarp and this cell is therefore much shorter than the other cells in the filament, when the cystocarp reaches its definite size, but it has often more protoplasmic contents. The fertilisation and the development of the gonimoblast has quite recently been described by Kyrın (1923 p. 56) and found to be as in C. corymbosum as de- scribed by OLTMANNS. The gonimoblasts are lobed; the lobes are at first cylin- drical, then conical (fig. 268), and finally rounded, ovate (fig. 270). At maturity there is usually a longer end-lobe and a shorter side-lobe, both issuing from a large cell, and sometimes furthermore a small supple- mentary lobe derived, as shown by Ky in, from the auxiliary cell. In some cases the lateral lobe is not developed, and the goni- moblast is then much like that of C. roseum. i å Fig. 205 } x £ Callithamnion Furcellarie. Two sporelings from sown te- The procarps were met with in Juneto Sep- traspores, 4 weeks old. 47:1. tember, the cystocarps in July to October. Tetraspores sown in July at Frederikshavn immediately germinated. 4 days later the sporelings were partly unbranched, about 10- to 13-celled, partly more or less branched. After four weeks they had grown much longer and variously bran- ched but sterile (fig. 271). Filaments having the character of rhizomes were frequently given off from the basiscopic end of the cells, and these rhizomes produced erect filaments. In fig. 271 to the right one rhizome is given off from the basiscopic end, another from the acroscopic end of the same cell, but this cell is perhaps the ori- ginal spore cell. C. Furcellarie has been met with in the months of May to October. The spores produced in summer and autumn are able to germinate immediately and give rise 44* to plants which in part probably only reach a small size before winter. It must be supposed that the plants die in autumn or winter, entirely or with the exception of the basal portion which may survive the winter. New erect shoots may then grow out in spring from the basal remains of the erect shoots from the foregoing year (fig. 263 B). The spe- cies occurs in all the Danish waters except the North Sea where hitherto it has not been met with, and it has been found in depths from 7,5 to 24,5 meters, rarely in slighter depths. It grows on various Algæ e. g. Furcellaria and Polysiphonia elongata, further on Zostera, Flustra foliacea etc. The three kinds of organs of reproduction occur in different individuals. Once only a dispo- rangium-bearing individual was found bearing at the same time some few procarps (fig. 272). A general difference in size of the three kinds of individuals as that stated by ArescHouc (1850, p- 107), could not be ascertained. As a rule the plants are less branched in the inner Danish waters with feebler salinity, which is in accordance with the obser- vations of KyLın at the west coast of Sweden. But, with decreasing salinity the size of the plants rather increases, for while in the Skagerak and Kattegat it reaches So only a little over 2 cm, it is up Callithamnion Furcella. tO 3 and 4 cm in Store Belt and rie. From YY, June. the Baltic Sea, greatest near Born- SE ook eae holm. Specimens with procarps carp. 70:1. and cystocarps were frequently met with in the Kattegat together with sporangia-bearing ones, but in the inner waters south of the Samsø area sex organs were not found, while sporangia were frequently present. The sporangia were in most cases four-parted; disporangia have only been recorded from three localities in Sa, Lb and Sf. Some specimens from Skagerak are dubious. That is particularly the case with a specimen from Fig. 273. Hirshals (no. 7077, Hirshals lighthouse in S.E., 21/, Callithamnion Furcellarie. Aberrant . . . : 5 specimens from Løkken. 4A, a joint miles), differing by the cells not quite young contain- years two opposite branches. B—D, ing more than one nucleus; in other respects it agrees tetrasporangiferous branches. 70:1. with C. Furcellarie, but fully developed cystocarps were not present. The plant might possibly be of hybrid origin. The number of nuclei in the cells is otherwise, according to my experience, a very constant character. Other speci- mens were, as mentioned above, different in having bigger sporangia, up to 79 uw long, so 345 in specimens from SY, north of Lokken. These specimens were more vigorous than the typical C. Furcellariæ and partly showed another arrangement of the tetrasporangia, these being partly terminal on short branchlets (fig. 273). It might further be men- tioned that a small specimen with unripe round, not lobed gonimoblasts but other- wise agreeing with C. Furcellarie was found on Herthas Flak in the Northern Katte- gat. Typical specimens of the same species have repeatedly been found in the same place. Localities. Sk: SY, north of Løkken, 1 mile (+ © 8)! (aberrant); ZK!? off Lønstrup, 8,5 m (+ 8); Hirshals light-house in S.E. 21/, miles 13m (+98), aberrant); XO, Mollegrund off Hirshals 11—15 m (+ 8). — Lf: Oddesund, 6,5 m. — Kn: FG and XJ, Herthas Flak, 19—22,5 m (4 © + 7): ibid. F. Børgesen (+ 9); fE, Krageskovs Rev; Nordostrev at Hirsholm, 7,5—9,5 m ($ © + 7); harbour of Frederikshavn (+ © 7); TP and TO, Tonneberg Banke, 16—18m (4 © + 9); fG, 3 miles W. of Læsø Trindel light-ship, 15 m (© + 10); TR, near Trindelen, 23,5 m (+ 9). — Ke: VZ, Groves Flak, 24,5 m; Groves Flak, F. Borgs. (O + 9); ZF, near Fladens light-ship, 22,5 m (+ 7); 1 mile W. by N. of Fladens light-ship, 17 m (+ ©) 10). — Km: VN, near the entrance to Randers Fjord. — Ks: RL, near Ostindiefarer Grund, 15m ($ © + 7); D, near Grønne Revle, 11,3 m (© 7); aU, Lumbsaas church in S. 32° W., 2 miles (©, sporg. 8). — Sa: YV, near Hatterbarn, 15 m (2 2s 6); AO, Endelaves Sydostflak; GC, north of Fyn, 13 m. — Lb: Fænø Sund (2s + 6); CF, west of Lyø, 15 m; DX, Vodrups Flak, 13 m (sporg. 5). — Sf: CZ, south side of Hornenzes, 9,5—15 m (+ 5); UX, at the North end of Ærø, 9,5 m; UV north of Ærø, 13 m (2s 5). — Sb: cN, S.W. of Musholm, 18 m (2s 6); AF, Mollegrund, 7,5 m; DN, Vengeance Grund, 12 m (sporg. 5); LH, off Bostrup, Langeland. — Su: HK off the N.W. end of Hveen, 9,5—21 m; QC, east side of Saltholms Flak. — Bw: bV, N.E. of Kobbel Skov (sp. 6); Middelgrund south of Als, 13 m (2s 6); bY, off Sonderskov, Als; cG, Trindelen, West side of Kegnæs; cF, south of Kegnæs light-house; LE, North Side of Vejsnæs Flak, 9,5 m. — Bm: QN, off Køge Sohuse, 6,5 m; QS, north of Mogens Klint, 20,7 m (+ 7); VG, north of Moens Klint, 17 m; 7 miles N.E.+/, W. of Hestehoved light-house, south of Moen, 11—13 m (st. 6) (G. A. J.). — Bb: 8 miles S. 1/, E. of Rønne, 11—19 m, (st. 6) (C. A. J.); SL, off Allinge, 5,5—11,3 m (+ 8); 3 miles S.S.E. of Nexo, 21 m (st. 6) (C. A. J.); YD, near Salthammer Rev 19 m; YC near Salt- hammer Rev 24,5 m (+ 7); 7 miles S.E. ®/, S. of Adler Grund light-ship, 20 m (st. 6) (C. A. J.). 7. Callithamnion sp. In October 1922 I found a small specimen of a Callithamnion growing on Desmarestia aculeata dredged in a depth of 30 meters at Fladen in the eastern Katte- gat. As this specimen, which is only 3 mm high, cannot be referred with certainty to any known species, it is described here in the hope that it may later be identified. The branching is strictly alternate, biseriate or pectinate, all the branches falling in the same plane. The branches of the main axis (stem) are regularly distichous from the base, and the ramification of the main branches is the same, with the exception that the two or three first branches of the second order are seriate on the upper side of the branch, and in the lowermost main branches the first 1 to 4 joints bear no branches at all. In the branches on the upper part of the plant the secund bran- ching of the branches is very manifest, in particular in the branches with limited srowth in which the number of pinnule arranged in a row on the upper side of the pinna may be greater, up to 9. This secund branching of the pinnulæ gives the 1 + designates tetrasporangia, 2s disporangia, sp young sporangia, ® procarps, ©) eystocarps, the number at last the number of the month, EEO | plant a peculiar appearance reminding one of the Antithamnia. The main axis is distinct, increasing gradually in thickness downwards. A little above the base it is over 100 x thick and consists there of cells about twice as long as broad, while the cells in the upper part of the plant are 3—4 times as long as broad. The lower- most two or three joints of the stem are provided with cortical filaments which Fig. 274. Callithamnion sp. A 80:1. B 150:1. continue their way into the basal disc. All the cells contain one nucleus and nume- rous elongated chromatophores. The upper end of the branches are 12 « thick; they are rounded, never terminating in a hair or in a point. The plant bears a few sporangia situated in the place of a pinnula. They are tetrahedrically divided, 60 w long, 46 x broad. A pectinate ramification like that described above seems to be rare within the genus Callithamnion. According to J. AGARDH it occurs in C. scopulorum Ag. the pinne of which are “rarius interiore latere pinellis brevissimis secundis quarum inferiores 347 longiores instructe« (Sp. g. 0. II p. 47). In the existing figures of this species, how- ever, the pectinate branching is only shown in one pinna in BorGEsEeN's fig. 56 b (Mar. Alg. Fær.), and it is evidently a rare occurrence, as also stated by J. Acarpn, while in our specimen it is to be found on all the branches. This may possibly be due to the young age of the plant. A similar seriate branching occurs in Phlebothamnion spinosum Kütz. (Tab. phye. 11 tab. 98), but only dispores are shown in Kürzıng’s figure, there is not so great a number of seriate pinnulæ, and the primary axis is corticated (comp. Sp. Alg. p. 653). Call. spinosum is, by the way, recorded by J. AGARDH under species in- quirendæ. In Phlebothamnion Gailloni Kütz. (Tab. phyc. 11 tab. 98 II) two seriate pinnulæ on the upper side of the pinnæ are shown in two pinnæ in the quoted figure, but this species seems to differ more by its fasciculate-corymbose bran- ching. As only a very small specimen is present it remains undecided, whether the main axis is corticated and whether the described branching is characteristic also of the adult plants. Locality. Ke: fJ 31/, miles W. by N. of Fladens light-ship. 30 meters, Oct. Seirospora Harvey. 1. Seirospora Griffithsiana Harv. Harvey, Phye. Brit. Vol. I plate 21, 1846; Kützing, Tab. phyc. Bd. 12, Taf. 17, 1862; Schmitz, Die Gat- tung Microthamnion J. Ag. (= Seirospora Harv.), Ber. deut. bot. Ges. Bd. 11, 1893, p. 277; Jos. Schiller, 1913, p. 207; Oltmanns, Morph. I, 1904, p. 667; L. Kolderup Rosenvinge, 1920, p. 32. Callithamnion versicolor f, seirospermum Harv. in Hooker’s Journ. of Botany Vol. I, 1834, p. 302. Callithamnion seirospermum Griffiths, Harvey Manual 1841, p. 113; Areschoug, 1850, p. 108, Tab. IV G: J. Agardh, 1851, p. 42; Bornet et Thuret, Notes algol. fasc. I, 1876, p. XIV; Thuret et Bornet, Etudes phyc., 1878, p. 70. Pecilothamnion seirospermum Nägeli, 1861, p. 364, Fig. 13. The ramification of this species which somewhat reminds one of Callithamnion corymbosum to which it has also been referred, has been described by NAGELI in 1861 and recently treated at large in my paper (1920) to which the reader may here be referred for more details. The main axes are vigorous, in their lower part covered by a well developed cortex composed of downward growing filaments produced in a number of three from the basal cell of each branch. The branches are almost always arranged in a spiral with a divergence varying between {/; and !/;, most frequently between !/, and 1/3. The spiral arrangement, however, does not begin at the very base of the branches, but the first branches are usually biseriate and arranged in a transversal plane, and the first joint (or 1 to 3 joints) is as a rule branchless. In all the specimens examined from Frederikshayn and Tonneberg Banke the spiral turned to the left. On the other hand, in a specimen from Herthas Flak only 4 of 16 examined shoots had a spiral turning to the left; in 9 it turned to the right, one Fig. 275. Seirospora Griffithsiana. Upper end of shoot, from Frederikshavn (6361). 300 : 1. Fig. 276. A—C from Tonneberg Banke; A, upper end of shoot with spirally arranged branches. B, two branches are borne on the same joint. C, lower part of stem with cortication. D, hyaline hair. A, B 200:1. C 70:1. D 350:1. Seirospora Griffithsiana. 348 had a spiral with changing direction and 2 had irregu- larly arranged branches. The ramification is often pseudo- dichotomous in the upper parts of the shoots, the bran- ches being of the same dimensions as the mother shoot and the latter changing direction by each branch (fig. 276 A). In a specimen from Tonneberg Banke I once found two vegetative branches of equal size on the same joint, diverging from each other at a right angle (fig. 276 B), and in the disporangia-bearing region of a specimen from the same locality I repeatedly found two branches on the same joint arranged now side by side, now one under the other or obliquely under the other (fig. 279). Even three branches were found on the same joint, one of which, however, was probably a young sporangium. The two branches were never opposite. Hyaline hairs do not usually occur. Only in speei- mens from the harbour of Frederikshavn thin hyaline hairs were not rarely met with at the end of the branches (fig. 276 D). As shown by ScHMITZ (1893, p. 277), all the cells contain a single nucleus. The usual thallus cells con- tain numerous chromato- phores which may be rather long (fig. 279 B). Plants with sexual or- gans have not been met with in the Danish waters. For these organs see the quoted papers by BoRNET et THURET and Scumirz. On the other hand, dispo- rangia, tetrasporangia and paraspores were found. The specimens from Herthas Flak were sterile, those from the Samsø area bore only paraspores. The specimens from Frederikshayn, which were fairly numerous, bore 349 many paraspores, but some of them at the same time disporangia and tetrasporangia, though in rather small quantity and partly anomalous. Two specimens were found at Trindelen one of which bore only paraspores, the other only dispor- angia, and specimens recently collected at Trindelen in October bore only tetrasporangia. The tetrasporangia are borne on the inner side, more rarely on the flanks of the upper branches; they are sessile or are sometimes borne on a unicellular stalk, very rarely on a twocelled one (fig. 278A). The sporangium-bearing joints often bear two or even three Be o ao Fig. 277 sporangia in a longitudinal row, j D UN PE calle ss Seirospora Griffithsiana. Tetrasporangia. A, B young, still uninu- the youngest lowermost, sometimes cleated. C, with four nuclei. D division accomplished. 350 : 1. a sterile branch too. The tetra- sporangia are 60—77 w long, 42—53 u broad. The outer wall has two layers, each consisting of a firmer outer layer and a soft, gelatinous inner layer. These two layers are not present from the first; the inner one appears only shortly before the division of the sporangi- um. The division Was in some cases regular, te- trahedrical (fig. 277 D), in others it was irregular, and sometimes more than 4 spo- res were present (fig. 278). Accor- ding to SCHMITZ (1893, p.277) the sporangia in Sei- rospora are paa- rig getheilt (mit zwei gekreuzten Paaren von Sporen) oder zweitheilig (mit gerader oder sattelförmig verbogener Thei- lungsfläche) oder tetraédrisch getheilt”. The most regularly divided tetrasporangium observed by me was evidently tetrahedrically divided (fig. 277 B). Regularly cruciate- ly divided tetrasporangia were not met with. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 15 Fig. 278. Seirospora Griffithsiana. Irregularly divided tetrasporangia. A—D 190:1. E 200:1. F 350:1. __ 380" The disporangia have the same position as the tetrasporangia, but in the spe- cimen in question, two or even three lateral organs were often borne on the same joint. As a rule one of the lateral organs was a sterile branch, the other a sporangium, but two sporangia might also occur on the same joint, the youngest under the eldest. A sporangium may be placed under the branch, but more frequently beside it (fig. 279 B). The disporangia which are usually sessile, but some- times borne on a one-celled stalk are 56—70 w long, 35—40 w broad. They have always a double outer wall, just like the tetrasporangia. The tufts of paraspores are, as well known, ter- minal on the long shoots, and I usually found them so, but lateral tufts, sessile or borne on a unicellular or bicellular stalk are sometimes met with on the upper branches, thus with a similar position to that ofthe sporangia. The usual terminal tufts of paraspores are sharply delimited downwards, all the cells of the axis above a certain level and its branches being trans- formed into paraspo- res, their form beco- ming rounded, their contents much con- densed and the wall & thicker. The branches Fig. 279. of the tufts are crow- Seirospora GrifRihsiana. Disporangia: ded, and frequently A, two very young sporangia on the same joint. B, sporangia besides or two branches are bor- under a ire = at 1. C 200 :1. ne on the same joint. The outer wall of the cells in the tufts is thick and at first homogeneous, but later on it is often composed of two or three layers each of which has a firmer outer mem- brane. In the middle of the dense dark-red contents Fig. 280. a Sr = 7 re Seirospora Griffithsiana. Typical tuft of a large nucleus is visible after staining. A transiti- paraspores. 215 : 1. onal stage between the terminal and the lateral para- spore-tufts is shown in fig. 281, the lowermost one or two cells in the upper branch- es being sterile. In other cases similar lateral tufts of paraspores are found at a greater distance from the apex, borne on a two-celled or one-celled stalk or even sessile (figs. 281, 282). They may then have a similar position to that of the sporangia. There is, however, no reason to consider them as transformed sporangia, (comp. SCHILLER 1913, p. 12), as Fig. 282. Seirospora Griffith- siana. Branch with tuft of paraspores and disporangium. 200: 1. it is only ex- ceptionally that they have the same place as the sporangia. At maturity the paraspore escapes from the thick envel- ope and takes a spherical shape. I have Seirospora Griffithsiana. Fig. 281. A, lateral tuft of paraspores. B, the lower- most cells in the lateral branches of the tuft are sterile. 200 : 1. not ascertained whether the paraspore is naked or provided with a thin mem- brane as asserted by SCHILLER (1913 p. 2%). According to this author the germination takes place without formation of a rhizoid; but that is not in accordance with my observa- tions. In my cultures the spherical paraspores had after two days given rise to a rhi- zoid, and some of these were divided by a transversal wall perpendicular to the rhizoid. At the opposite pole a shoot arose during the following days which soon began to branch in the usual way (fig. 283). In the same culture were found short shoots detached from the plant from which the paraspores were given off; these shoots had also germinated, long rhi- zoids having arisen from their basal end. 1 6 Doch wird der natürlich schon mit einem zarten Hautchen umgebene Inhalt nicht yon der Hiille zur Gänze frei”, Fig. 283. Seirospora Griffithsiana. Sporelings arising from paraspores. A, two days old, the others some days older. 120 : 1. 45* 352 The species has been found growing on stony bottom in 15—22 meters depth in the northern Kattegat and in the Samsø Water and further in the little boat harbour at the end of the northern mole in the harbour of Frederikshayn near low-water mark. In Herthas Flak it reached a length of 17 cm but was sterile. In the harbour of Frederikshayn it attained a length of 10cm and bore abundant paraspores, more sparingly tetraspores and dispores. In the other localities the spe- cimens were only 1 cm high but fructiferous. The species has only been met with in July, September and October. Localities. Km: Herthas Flak‘ (FG, XJ) 20 to 22 m; Frederikshavn (only found in 1896 and 1919); TO, Tonneberg Banke 18 m; iG, 3 miles W. of Læso Trindel light-ship, 15 m (+ 10). — Sa: MS, near Endelave, 15 m, with paraspores. Plumaria Stackhouse, emend. Schmitz. Euptilota Cramer. 1. Plumaria elegans (Bonnem.) Schmitz. Fr. Schmitz, Systemat. Uebersicht, Flora 1889, reprint p. 16; Phillips 1897, p. 361, pl. 18 fig. 17; Kol- derup Rosenvinge 1911 p. 210; Kylin 1923, p. 57. Ptilota elegans Bonnemaison, Hydrophytes loculées ou articulées. Paris 1828. (Not seen). J. Agardh 1851, p- 94; Kützing, Tab. phyc. 12. Bd. 1862, Taf. 56; Pringsheim 1862, p. 32, Taf. 8 Figs. 2—7; Bornet et Thuret, Notes algol. Fasc. I 1876 p. XV: Farlow, Mar. Alg. New Engl. 1881 p. 133; Buffham 1884 p. 342, 1891 p. 247, 1893 p. 303; Wille, Physiol. Gewebesyst. 1887 p. 72 Tab. IV Figs. 42, 43, Tab. VII Figs. 40, 41. Ptilota plumosa ; tenuissima C. Agardh 1822 p. 386; Nageli 1847 p. 206, Tab. VI figs. 3842; Areschoug 1850 p. 97. Ptilota sericea (Gmel.) Harvey Phyc. Brit. Vol. II 1849 Plate 191. Ptilota plumosa Cramer 1864 p. 6, 108, Taf. I Figs. 4—5 Tab. II Figs. 1—5, Tab. III Figs. 1—3. The structure and development of the frond has been carefully described by NAGELI (1847) and Cramer (1864) whose papers may here be referred to.” The longer primary shoots are alternating, being usually separated by two joints. There is no distinct limit between the pinnæ with persisting growth and the pinnule with limited growth. The ramification of the feebler pinne is less regular than that of the vigorous ones. The young branches are more or less curyed inwards, in particular in the most vigorous shoots. Most of the branches become short plumose pinnulz persisting in the older parts of the frond. The frond is sometimes not plane but vaulted, all the tips of the frond being directed to the same side. The convex side seems then to be directed towards the incident light. * In my paper 1911, p. 205, a sterile specimen of Seirospora Griffithsiana has erroneously been recorded as Griffithsia setacea. > OLrmanxs has not noticed the puzzling synonymy of this species caused by CraMER’s unlucky denomination; he has therefore been misled into confounding the genera Ptilofa and Plumaria and has in Morph. u. Biol. d. Algen I Fig. 364 under the name of Ptilota plumosa reproduced figures both of this species (figs. 1, 4) and of Plumaria elegans (figs. 2—3). Comp. Kylin 1923, p. 57. 353 All the cells contain one nucleus and numerous small disc- shaped chromatophores. The colour is brownish-red. By treating old parts of the plant with concentrated sulphuric acid the cell-walls were stained blue, which must be due to the presence of iodine in the plant. The upper pinnule not rarely end in a hyaline hair, as first mentioned by PrincsHEem (1861 PI. VIII fig. 2) and later by myself (1911 p. 210). As shown by me, the young hairs con- tain a number of feebly coloured chromatophores, but these are later reduced, and in the full-grown hairs they are only visible as very small colourless grains (fig. 284). These hairs often cause sympodial ramification, the cell on which the hair is borne growing out about in the direction of the branch and push- ing aside the hair. Such hairs were found frequently but not always in the specimens collected in April to September; in April and partly in May the hairs were short, but in autumn and win- ter (October, November, January) no hairs were met with. The pinnulæ were sometimes found growing out into arti- culated, long-celled filaments the cells of which when lengthening take a feebler colour. They might perhaps be considered as ab- normally de- veloped rhi- zoids. As they are hair-like but different from the nor- mal unicellu- lar hairs they might benam- ed trichoids. They were most strongly developed in a loose spe- Fig. 285. Plumaria elegans. A, form with divaricate pinnulæ. B, pinnulæ trans- Alex © formed into rhizoid-like filaments. 4 150:1. B 80:1. the cortex early covering the pri- Fig. 284. Plumaria elegans. Hairs with numerous small reduced chro- matophores and de- formed nuclei. 240 :1. cimen found in the Baltic where it must have been introduced by the currents. The same specimen was remarkable by its divaricate, acuminate pinnules (Fig. 285). As shown by NäÄGeLı (1847, p. 207, see also CRAMER 1864), RUBE mary filaments is built up of hypha-like filaments fusing together into a dense tissue. In a later stage the cortex shows a pronounced differentiation, as shown by WILLE (1887, p. 72), the innermost layer surroun- ding the axial cell-row becoming a conduct- ing tissue, the intermediate layer a tissue serving for storage, and the outermost, small- celled layer having an assimilatory function. The cells of the central axis gradually in- crease considerably in size and the pits con- necting them increase too. The border of the two callus plates which cover the thin pit-membrane is sometimes bent back and continues their way on the surface of the thick transverse membrane, a phenomenon which is perhaps connected with the peri- pheral growth of the pit (Fig. 286, above). In older shoots the surface of the cortex is often covered by a felt of adventitious shoots of unbranched cell-rows issuing from the superficial cells (Fig. 286). CRAMER (1864 p. 10 and pp. 109—110) has mentioned them and Fig. 286. P even established three forms of the species Plumaria elegans. Longitudinal section of older stem, according to their frequency: at, subglabra; perpendicular to the plane of ramification. p, pit . seen from the face. 200 : 1. ß; pilosa and Y> tomentosa. The sexual organs have never been met with at the Danish coasts. The antheridia according to BurrHam form “yellowish bunches near the extremities of the pinnules’”’' (1891, p. 247 Pl. XVI figs. 6—7). The structure of the procarps has been described by PHırLırs (1897 p. 362). The ripe cystocarps are usually said to be naked or provided with involucral branches. But as the sori of paraspores have really often been confounded with cystocarps it may be supposed that the latter are always provided with involucral branches. Burr- HAM asserts, too, that he has never seen the true cysto- carps naked (1893 p. 303). Tetrasporangia have only been met with once and 5 r Fig. 287. extremely sparsely. In a paraspore-bearing specimen from pymaria elegans. Tetrasporangia Busserev gathered in July 1918 I found a ripe and an un- before and after division. 390: 1. ripe tetrasporangium (Fig. 287). They had a dense, dark- red content and a thick, two-layered membrane. Within the thin firm cuticle two 7 The organs which BurrHan in a foregoing paper (1884, p. 342, Plate XII Fig. 1) took for an- theridia are of dubious nature, possibly foreign sporelings. En distinct layers were present, separated in the young sporangium by a boundary line, in ripe ones by a less refringent intermediary layer. The walls separating the spores were in continuity with the innermost layer of the sporangium. The division was tetrahedrical. The ripe sporangium was 53 « long, 44 w broad. The heaps of paraspores have, as mentioned above, often been confounded with the cystocarps and described as naked favellæ, but they have nothing to do with the female sexual organs. According to Scumirz and HAUPTFLEISCH (ENGL. u. PRANTL p. 493) they occur only in the tetraspore-bearing specimens; the only tetra- sporiferous specimen I have found bore paraspores at the same time. The heaps of paraspores have further a similar posi- tion to that of the tetraspores, namely on the end ofthe pinnulæ, and it has there- fore been supposed that they were mo- dified tetrasporangia (comp. OLTMANNS Morph. p. 667). This interpretation is, however, in my opinion unjustified. While the tetrasporangia are from the first dark-red, darker than the vegetative cells, the young heaps of paraspores are lighter, as emphasized by BurrHam (1893 p. 303) and as it is visible in Prines- HEIM'S figures (1862, figs. 3—5), and as shown in my fig. 288. Further, the outer wall has another constitution. It is to begin with similar to that of the vege- Fig. 288. tative cells, STOWS gradually thicker and Plumaria elegans. Heaps of paraspores. A—C, young may sometimes be indistinctly lamellate stages, feebly coloured. D, eight-celled stage, the chro- 4 matophores more coloured. E and F, stage of maturation, but it is often homogeneous and is in in E about 16 spores. 390 : 1. continuity with the separating walls be- tween the cells of the heap. An end-cell that will develop into a heap of para- spores is distinguishable by its feebler colour and by indistinct chromatophores, while the nucleus appears very distinct. The cell is usually divided by an oblique wall and the daughter-cells are further divided. In the four-celled stage the cells are still rather feebly coloured. During the further divisions the paraspore-heap grows out to a roundish, more or less irregular ovate or obovate or obcordate body and the chromatophores become gradually more distinct and take a deeper red colour. 8-celled and 16-celled heaps are comparatively often met with, but other numbers too occur, f. inst. 5, 6, 12. According to BurrHam the number of spores at maturity is 16, and it is certainly frequently so, but I have found at least 18 spores, and in other cases maturity seems to arrive when the number of cells is much lower, as in the four-celled heap represented in fig. 288 F. 396 The spores when discharged are globular and naked’, but are soon surrounded with a thin membrane. The cell-wall was sometimes found thickened on one side, undoubtedly where the first rhizoid would later appear. The cell is then divided by an eccentric wall in a smaller cell which gives rise to the rhizoid, and a larger cell which divides by walls parallel to the first and gives rise to the primary axis. The rhizoid is separated from the small cell by a trans- versal wall. My pictures (fig. 289) agree with PRINGSHEIM’s figs. 7b, d which represent spores germinating within the membrane of the heap. The species is perennial and has been met with in all seasons. It attains a length of up to 8cm. In winter it Fig. 289. is generally smaller, some of the shoots being shed, but Plumaria elegans. Sporelings new shoots are produced from the remaining parts. The older from germinated paraspores. z = 230 : 1. shoots are often overgrown with Membranipora. It grows partly on stones, partly on various Algæ, as f. inst. Fur- cellaria, Chondrus, Ahnfeltia, Fucus serratus, from low-water mark to 9 meters depth. When occurring near low-water mark it always grows in shadow f. inst. under Ascophyllum nodosum. The paraspores have been met with at all seasons except in spring, in the greatest quantity in summer. Localities. Kn: TV, Krageskovs Rev; Hirsholm, at various places (Hornemann 1815, !); Busse- rey, Brune Rev, Laurs Rey and Marens Rev by Frederikshavn; harbour of Frederikshayn; TL, west of Nordre Ronners light-house, 9—14 m. — Su: Gnetare Grund (Swedish coast, Boye Petersen). — Bm: SD, N.E. of Moen, 23,5 m, loose, with other loose Algæ, a small specimen with divaricate acuminate pinnules, sterile (see above). Ptilota C. Agardh. 1. Ptilota plumosa (L.) Ag. C. Agardh, Synops. Alg. Scand. 1817, p. 39; Lyngbye 1819, p.38 Tab. 9A; Kützing, Phyc. gen. 1843, p. 378, Taf. 46; Harvey, Phyc. Brit. I, 1846, Pl. 80; Kützing, Tab. phyc. Vol. 12, 1862, Taf. 54; B. M. Davis, Developm. of the procarp and cystocarp in the genus Ptilota, Botan. Gazette Vol. 22, 1896; Buffham 1896 p. 189; R. W. Phillips 1897, p. 362 Pl. 18 Figs. 16, 18; Kylin 1913, p. 58. Fucus plumosus Linné, Mantissa pl. alt. 1767, p. 134; Fl. Dan. Tab. 350, 1767. Pterota plumosa Cramer 1863 p. 25 Taf. III Figs. 4, 5, IV Figs. 1—7, V Figs. 1—5, VI Figs. 1—5. The development of the frond has been carefully described by CRAMER whose paper (1863) may here be referred to. Transversal and longitudinal sec- tions of a younger frond have been figured by KirzinG (1843, Plate 46). In both is shown a small-celled outer cortex and an inner layer composed of larger cells and surrounding the axile cell-row. In the longitudinal section it is rightly shown that the opposite pinnulæ only issue from every other joint, but the connection between the pinnulz and the axial cells of the long shoots is not represented. As shown in my * According to BurrHam (1893, p. 303) the paraspores are “possessing a cell wall even before discharge”. If this must be understood to mean that the spores are also provided with a cell wall when discharged, it is not in accordance with my observations. es 357 fig. 290 the central axes of the pinnulæ traverse the cortex of the stem and are con- nected with the central axis of the latter through large pits. The greater part of the cortex consists of large rounded cells which have principally the character of storage cells; they contain numerous starch grains and narrow, branched chromatophores. The outermost cells are small and constitute a one- or two- layered assimilatory tissue. The cells of the central axes going out to the pin- nulæ are also rich in starch, but the central axes of the stems do not con- tain starch; the granular plasma of their cells is concentrated in the upper half of the cell while the lower half has only a thin layer surrounding the va- cuole. In the somewhat older stems a number of thin rhizines arise from the inner corti- cal cells, for- ming a layer surrounding the central Fig. 290. axis and in- Ptilota plumosa. Longitudinal section of frond in the plane 1 fs of ramification. 110: 1. creasing in thickness. This production of rhizines later advances out- wards, so. that the cortical cells in older shoots are partly separated by thick bundles of rhizines, and transverse sections of old stems may in great part be composed of rhizines. All the cells contain one nucleus. Hyaline hairs have not been met with except those which occur near the procarps and which will be men- tioned below. The tetrasporangia are terminal on short monosipho- nous filaments borne on the margins of the pinnule and terminal on the pinnæ; they are tetrahedrically divided (fig. 291, comp. Kyrın 1923 p. 59, fig. 39). The antheridia have been shortly mentioned by Pnır- Fig. 291. Ptilota plumosa. Pinna with tetra- 5 4 | sporangia. 230 :1. Lips (1897, p. 365) who says that they “cover the tips of the branches, and correspond closely in appearance to the similar structures in Plumaria, which have been figured by BurrHam (90)”. I have found antheridia in a dried specimen dredged in the Kattegat in May. They were D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 46 358 borne principally on the edge but also on the flat side of the pinnulæ. They were cut off in a number of 2 or 3 by inclined walls from the low stalk cells (Sperma- tangien-mutterzellen SVEDELIUS) which seem to contain chromatophores (Fig. 292). The cystocarps develop terminally on short pinnulæ and are surrounded by a whorl of sterile branches. The procarps have been de- scribed by Davis and PhHiıtLirs, but the inter- pretations of these authors are diverging. Upon the end of the fertile pinnæ arises a group of short cell-filaments each ending in a hyaline hair. According to Davis (1896) these are groups of procarps the number of which is variable, though typically 5. Davis interpreted B all the hyaline hairs as trichogynes, but as he has never found spermatia adhering to them and as he has not observed antheridia he sup- posed that the cystocarp develops apogamously. Pnırrırs (1897) arrived at another interpreta- tion, the 4-celled external short-celled branch being the only true carpogonial branch while the others are only vegetative structures. KYLIN who has recently (1923) carefully studied the development of the pro- ig, 292 9 ; FER ERP te i carps arrived at the Plilota plumosa. Å, pinna with antheridia. B, pin- å nula with antheridta and two spermatia. 350 : 1. same conclusion. He ob- served the fertilisation and the transmission of a small sporogenous cell to the auxi- liary cell which is cut off from the basal cell immediately after fertilisation. In one specimen dredged in the Sound north of Helsingor in June I found procarps before fertilisation. The trichogyne was usually thicker than the sterile hairs and frequently swollen at the top. It is strange that these vege- tative hairs are normally present while vegetative hairs are otherwise wanting in this species. The gonimoblast according to Davis consists of 2—5 Fig. 293. Ptilota plumosa. Carpogonial nearly globular lobi which are quite separated from one an- branch (to the right) and > à AE R & surrounding sterile filaments other but are all attached to the central cell. The lobes are — ending in hyaline hairs. as a rule in widely different stages of maturity. According to 390 :1. Kyrın (p. 61) the basal cell (“Tragzelle”) fuses more or less with the auxiliary cell and the first cell of the gonimoblast. The number of the involucral branches varies up to at least 8. 359 The three kinds of organs of reproduction (antheridia, procarps and tetraspo- rangia) normally occur on distinct individuals. BurrHam, however, (1896, p. 189) found tetrasporangia on female plants. In one case “the involucre of an old cysto- carp (or possibly of an unfecundated procarp) became branched near the tips and developed tetrasporangia”. The species occurs in the Skagerak, where it has been collected at 11—15 meters depth, in the eastern and southern Kattegat in the under-current with high salinity, in about 20—30 meters depth and in the northern part of the Sound in the same current. It most frequently grows on the stipes of Laminaria hyperborea and L. digitata. It is perennial but has only been collected in the months May to October. It reaches a size of 15 cm. In specimens gathered in June the new shoots had a more clear red colour than the older parts of the frond which were more brown-red. The new shoots in great part formed a continuation of the old ones, but adventitious shoots also occurred, arising from the base of the pinnulæ, as de- scribed and figured by Cramer (1. c.). In August the vegetative growth has ceased. Antheridia were met with in May, unfertilized carpogonia in June, and ripe cysto- carps and tetrasporangia in June to September. Localities. Sk: Off Hirshals, 12 m (Borgesen); XO, Mollegrund off Hirshals, 11—15 m. — Ke: IQ, ZF and fH, Fladen, 17—30 m; 4'/2 miles S.W.°/ı W. of Fladens light-ship, 30 m (C. A. J.). — Ks: Lysegrund, June 1832 (Lyngbye); Nordvestrev by Hesselo, July 1832 (Lyngbye). — Su: Gnetare Grund and Grolle Grund at the shore of Sweden (Boye Petersen); off Hellebæk, soft bottom with shells (id.); north of Helsingør (Liebman, Ørsted). Antithamnion Nageli. 1. Antithamnion cruciatum (Agardh) Nägeli. C. Nageli, 1847, p. 200, id., 1861, p. 378; J. Reinke, Lehrbuch d. allgem. Botanik, 1880, p. 171 Fig. 121; G. Berthold, 1882, pp. 573, 605, Pl. 19 Figs. 1—10, Pl. 20 Figs. 3—4; P. Kuckuck, Bemerk. z. mar. Algveg. Helgoland, Wiss. Meeresunt. Abt. Helgoland N. F. Bd. 1, 1894, p. 254 Fig. 22; Nestler 1899, p- 5, Taf. I Figs. 11—19; B. Schussnig, 1914 p. 2. Callithamnion eruciatum C. Agardh, Flora 1827 II, p. 637; Harvey, Phye. Brit. II 1849, p. 164; J. Agardh, 1851, p. 27; Kützing, Tab. phyc. Vol. 11, 1861 Taf, 87 I; J. Agardh, Florideernes Morfologi, 1879 (K. Sy. Vet. Akad. Handl. Bd. 15 No. 6), p. 103 PI. I Fig. 20 (Cystocarp). &, genuina. | 8, radicans J. Agardh, Symbolae, Linnaea, 1841, p. 44. This species is easily distinguishable from the two following species. Each joint in the long shoots bears two opposite or four verticillate pinnæ. In the Danish specimens I found them only opposite; they were decussate, and thus arranged in four rows. The angle of divergence often diverged from 90° and was variable, and the arrangement in longitudinal rows therefore not distinct. As shown by BERTHOLD (1882, p. 605), the position of the pinnæ is dependent on the light, the pinnæ being inclined to place themselves in a plane perpendicular to the incident light. According to NAGEL (1861, p. 379) the pinnæ in the whorls do not arise simultaneously and the first pinnæ of the successive whorls are arranged in a spiral with the divergence 46* Fig. 294. Antithamnion cruciatum. Part of erect shoot, gland cells dotted. 270 : 1. 360 of '/ı. The primary long shoots arise in the place of a pinna; the joint on which it is borne usually bears no other branch (fig. 294, 4th joint). The primary long shoots have no or only a slight influence on the direction of the mother axis. Besides the primary long shoots, adventitious shoots fre- quently arise from the basal cell of the pinne (NAGELI |. c.). They may be given off from the upper side (REINKE I. c.), from the under side (fig. 297) or from the flanks of this joint which remains short and usually produces no pinnule. i The pinnæ are variously branched. The lower ones, in particular on the creeping parts of the long shoots, are often entirely unbranched (fig. 295) while those on the upper part of the plant bear alternate, secund or opposite pinnulæ. As shown by NÅGELI in‘1847, the pinnæ are usually branched in a transversal plane. The plane of ramification is, however, also dependent on the light (BERTHOLD 1882, p. 605). With regard to the gland cells occurring on the pinnulæ reference may be made to NEST- LER’S and SCHUSSNIGS papers quoted above; they rest on three cells of the pinnula in contradi- stinction to those of A. Plumula. Pluricellular rhizoids arise from the basal cell of the pinnæ in the lower part of the plant; they are particularly well devel- oped in the specimens found in the harbour of Frederikshavn and referred to f. radicans. The long shoots were here creeping in their whole length or almost so, and bore rhizoids issuing from all the basal cells facing the substratum. These rhizoidal Fig. 295. Antithamnion cruciatum f. radicans. A, the pinnæ unbranched, the rhizoids with free ends. B, the outer cells of the rhizoids thrown off. 150 : 1. 361 filaments had usually free ends; they penetrated a layer of detritus bound to- gether by animal secretion, in which the plants grew without fixing themselves on the algæ covered by the layer of detritus (fig. 295 A, comp. Kuckuck 1894 fig. 22). The outer cells in these filaments lengthen, become gradually poor in contents and are finally thrown off, but the innermost cell often remains for a long time and every trace of the decaying of the outermost cells is then effaced, the wall of the upper end of the cell being rounded (fig. 295 B). In Fig. 296 the scar is still visible (x). In other cases, the rhizoids fix themselves on the substratum forming an adhesion disc composed of a number of radiating cell-filaments. According to BERTHOLD (1882, p. 607) the cells of the rhizoids afterwards shorten, the cells becoming barrel- shaped and the cell-wall incrassated. Such rhizoids sometimes arise at a certain distance from the substratum, as shown in fig. 296, where the rhizoid has fixed itself to the mother axis of the pinna and formed an adhesion disc embracing it. The tetrasporangia are placed laterally on the pinne, borne on a one- or two-celled stalk. They are larger than those of A. Plumula, a J A | algen, p. 71). On the other hand, the cysto- Antithamnion Petes as is produced from CARPE mentioned fand fisuned Dy J. the basal joint of a pinna. B, tetrasporangium. 200:1. ÅGARDH (1879) as consisting of several lobes. The species has been found only in a few places in the Limfjord and in Katte- gat. It has been gathered in June to November, growing on stones and wood (piers) and on other Algæ. In the harbour of Frederikshavn it usually occurs in the creeping form radicans which may probably under favourable conditions grow out as the typical erect form. Fig. 296. Antithamnion cruciatum. 73—102 uw long, 51 Lower part of plant; a rhi- ==68 u broad. They zoid has fixed itself to the stem. 110: 1. were met with in July. Sexual organs were not observed. They generally seem to be rather rare; Har- vey (Phyc. Brit.) did not know them and Hauck too did not mention them (Meeres- Localities. Ns: 13'/: miles N.E.'/2 E. of Hanstholm light-house, 23m, C. A. J., very small specimen Oct. 1922. — Lf: Off Hanklit, Thisted Bredning, on Fucus; MK, Holmtunge Hage, c. 2 meters’ depth. — Kn: Harbour of Skagen (November 1911, Kramp); harbour of Frederikshavn, berths on the end of the moles and in other places on piers. — Ks: aU off Lumbsaas, 13 met. 2. Antithamnion Plumula (Ellis) Thuret. Thuret in Le Jolis, Algues mar. de Cherbourg, 1864 p. 112; R. W. Phillips 1897 p. 356, Pl. 18 Figs. 11— 12; A. Nestler 1899, p. 1, Taf. I Figs. 1—10; Killian, Über die Entwickl. einiger Florideen. Zeitschr. f. Bot. 6. 1914, p. 215; B. Schussnig 1914 p.1; Kylin, 1915 p.11; id., Über die Keimung der Florideensporen. Arkiv f. Botanik Bd.14, No. 22, 1915, p. 15; id. 1923 p. 61. Conferva Plumula Ellis, Philos. Transact. Vol. 57 1, 1768 p. 424 Tab. 18. Callithamnion Plumula Lyngbye, 1819, p. 127; J. Agardh, 1851 p. 29; Harvey, Phyc. Brit. III 1851, PI. 242; Kützing, Tab. phyc. Bd. 11, 1861, Taf. 83 I. Pterothamnion Plumula Nägeli in Nägeli u. Cramer, Pflanzenphys. Unters. 1. Heft 1855 p. 54, Taf. VI, Figs. 11—13, Taf. VII; Berthold 1882, p. 614, Taf. XX Figs. 1—2, Taf. XIX Fig. 11—17; id., Ver- theil. d. Alg. im Golf von Neapel; Mittheil. a. d. zool. Stat. zu Neapel 1882, Heft. III; Schmitz, Unters. üb. die Befrucht. d. Florid., Sitzber. d. k. Akad. d. Wiss. zu Berlin, 1883, p. 236, Fig. 35. In the Danish waters this species reaches a height of 9 cm, but usually it does not exceed 5cm. The fixation of the primary shoot is strengthened by free N Fig. 298. Antithamnion Plumula. See text. 70:1. rhizoids springing from the lower end of the cells of the main axes and the lower part of the lateral axes, while intramatrical rhizoids do not occur. It happens, how- ever, that several of the downward growing filaments do not reach the substratum. Some of them may take the character of runners which give rise to upright shoots; they then consist of shorter, thicker cells. Intermediate stages between assimilative shoots and root-like filaments, showing unstable polarity, may occur too. The long shoot to the right in the fig. 298, for instance, is essentially an assimilatory shoot; the filament issuing from its second joint is, however, a branched rhizine though it has been produced at the upper (distal) end of the cell. The Sth cell of the same shoot has also produced at its upper end a filament having if anything the char- — nn 363 acter of a rhizine though it is directed upwards, but from the lower part of the same cell a typical assimilative shoot is given off. The ramification has been carefully described by NÂGezr and Berruorn, The frond is usually flat, the long shoots being contained in one plane, issuing alter- nately to the right and to the left, and the two ranks of opposed pinnæ are given Fig, 299. Antithamnion Plumula. Shoots with tetrasporangia, from Herthas Flak. A, a normal pinna. B, pinnæ mostly un- branched. 95:1. off in the same plane. Each joint usually bears a pair of pinnæ, but the long shoots take the place of a pinna, and the joint which bears a long shoot usually bears no pinna on the opposite side, and in the following joint (or joints) the pinnæ are often wanting over the long shoot (Fig. 299 B). On the other hand, the joint which bears a long shoot often produces two unbranched pinnule issuing in a plane perpendic- ular to the plane of the frond (Fig. 299 B). Similar pinnulæ sometimes occur on other joints than those situated immediately under the branchings, thus in several 364 specimens from the Kattegat. Such specimens form a transition to others which have normally 3 or 4 ranks of pinnæ, as most of the specimens found in the Skagerak. 3 ranks were most frequently met with. When the number of pinnæ in the whorls is constant, they are usually superposed, though not regularly. In these specimens the long shoots are not contained in one plane but issue in different directions. Accord- ing to BERTHOLD (1882 p. 614), the ramification is dependent on the light, so that plants growing in unilateral light branch in one plane, while plants illuminated equally from all sides bear branches on all sides. This, however, cannot be the sole determining factor, for in all the specimens examined by me from eight localities in the North Sea and the Skagerak the pinnæ were arranged in 3 or 4 rows, while the specimens from all the localities within Skagen were branched in one plane and at most bore unbranched pinnulæ on the face of the frond at the angle of the branches, or rarely on a few adjacent joints too. Only in specimens from the south side of Skagens Gren and in one specimen from Groves Flak (Ke, 26 m) the pinnæ were arranged in 3 or 4 rows. These specimens were all growing in water of comparatively high salinity. In the latter specimen the pinnæ were arranged in 4 rows, those on the flat side were, however, Fig. 300. feebler than the others, and in many Antithamnion Plumula. Tetraspore-bearing shoot with un- 5 2 usually numerous gland cells, from Lille Belt. August. Re- CASSER Pınn® occurred on the flat side. duced pinnæ. 380: 1. The pinnæ only bear pinnulæ on the upper side, and these may be un- branched or they bear pinnulæ of the second order on their upper side. More rarely the pinnæ are unbranched or very little branched, as in some specimens from Herthas Flak in more than 20 meters depth (fig. 299 B), which, however, bore typical branched pinnæ in the lower part of the plants. The pinne are at first directed upwards, later usually divaricate, or some of them may even be recurved. Only in specimens from Skagerak off Lonstrup (8 m) a great number of the pinne were recurved. The pinnæ and pinnulæ are finally pointed, the ultimate cell ending in a thin point consisting only of the cell-wall. This pointing takes place at the end of the period of growth; in the later part of July and in August acuminate pinnæ may occur, even near the growing point, while in the first part of July specimens without acuminate pinnæ may be met with. , | — 365 The cells contain one nucleus and nu- merous ribbon-shaped or irregular chromato- phores (Fig. 301 B, comp. NESTLER fig. 1). For the nuclei see SCHILLER (1911). The gland cells are borne on the inner (upper) side of the pinne, resting on a single cell. Their number is rather variable, owing to unknown causes. They are normally present; in single cases, however, I have sought them in vain. In the Skagerak they were never missing, and they were met with, partly even abundantly, in specimens growing near the southern limit of the species (fig. 300); they further occurred in numbers in slight and in great depths (e. g. Groves Flak, 32 m). The function of the gland cells is unknown. NEST- | LER is inclined to suppose them to be absorb- Fig. 301. ing organs; SCHUSSNIG supposes that they Antithamnion Plumula. Antheridial bushes. 390 : 1. function in the same manner as air-bladders. The tetrasporangia are borne on the upper side of the pinnæ usually in small elusters. Often a single sporangium is found terminal on a short stalk-cell, but this cell usually bears further one or two or three younger sporangia or rudiments of sporangia, and the stalk may sometimes consist of two or three cells (figs. 299, 300). Besides the sporangia borne in clusters sessile sporangia may occur too, princip- ally on the outer part of the pinnule. Sporangial clusters opposed to a pinna may sometimes be met with; they re- present a pinna reduced to a cluster of sporangia (figs. 299, 300). At the end of the period of growth the sporangia may even become terminal on the long shools, when their growth is ceasing (fig. 300). The ripe sporangia were 42—45,5 w long, 29—40 w broad in specimens from the Ska- gerak; in a specimen from the Little Belt they were only 35—38 w long, 27—30 u broad. They open by a slit. The antheridia (fig. 301) have a similar Fig. 302: Antithamnion Plumula. Procarps. In A the carpogonial Woke > — branches are shaded. A 300 :1. B 390 : 1. position to the tetrasporangia. They are D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd, VII. 3. 47 366 borne on small bushes, seriate on the upper side of the pinnæ, reminding one of those in Callithamnion Furcellarie, but often a little bigger. These bushes may also occur on the long shoots, taking the place of a pinna. The antheridial clusters may be sessile but are usually provided with a one- or two-celled stalk, their shape is irregularly roundish or more or less lobed, ovate, or more or less elongated with a distinct 4- or 5-celled main axis, and the antheridia may then be most nume- rous on the acroscopic side. The carpogonial branches are, as described by SCHMITZ and PHILLIPS, and recently by Kyrın, 4-celled and borne laterally on the undermost cell of the pinnulæ and con- nected with it. The content of the basal cell and of the next cell of the pinnula is different from that of the vegetative cells and resemb- les that of the cells of the carpogonial filament. The nucleus of the three under- most cells of the carpogonial branch often divide in two before the fertilisation. After Fig. 303. fertilisation an auxiliary cell Antithamnion Plumula. A and B young cystocarps showing the first goni- molobe on the upper face of the auxiliary cell; in B the carpogonial branch is cut off upwards from the is shown behind the filament. C, nearly ripe cystocarp seen from below; basal cell, and it fuses the carpogonial branch is still visible. D, cystocarp seen from above. E, 2 sporeling found on a cystocarp-bearing plant. 350: 1. shortly afterwards with a little sporogenous cell from the fertilised carpogonium (comp. PHiLiips 1897 fig. 12; Kyrın 1923 fig.40h); it then divides, according to Kyrın in a smaller lower and a greater upper cell, the first gonimoblast cell which successively produces the gonimolobes. There are at least four gonimolobes. During this development, according to PHiLuies (1. c. p. 357), the cells immediately above and below the auxiliary cell become fused with it. The first gonimolobe is given off from the upper side, others downwards in an oblique direction (fig. 303). The particular gonimolobes are borne on an unicellular stalk and are globular or reniform. Their size is very different, the first formed being fully developed while the youngest one only consists of a small number of cells and perhaps never reaches full development. Stalk-cells without fertile cells may Son occur 100. The trichogyne decays quickly while the rest of the carpogonium may be kept for a longer time (fig. 303). Antheridia, carpogonia and tetrasporangia as a rule occur on distinct individuals; in two cases, however, tetrasporangia were found on cystocarp-bearing plants. Paraspores in Anthithamnion Plumula have been found in the Mediterranean by Scumirz and SCHILLER (1913 p. 3, Plate V). Such organs have never been met with in the Danish specimens. The germination begins, as in Callithamnion, by the division of the spore-cell by a transversal wall into two cells, one of which gives rise to the first rhizoid, the other to the primary axis (comp. Kırrıan and Kyrın 1915). Young seedlings were met with on the surface of and in the neighbourhood of the cystocarps (fig. 303). The species has been met with in several localities in the Danish waters with salinity of 2 p.c. or higher, but it does not occur in the Limfjord or in other fjords. The best developed specimens were found at Skagen, south of Grenen, where it reached a length of over 8 cm, and where it was found as the predominating species in 13 to 15 meters depth in a locality with clayey sand with molluses. In the Kattegat it otherwise reaches a length of 6 cm, and at Hellebæk in the northern part of the Sound 3 cm; but in the Samso water and the Little Belt it was only 1,5 cm high at most. The relation of this species to A. boreale will be dealt with under the last named species. Only specimens from one locality in the Little Belt (EE) could be said to approach A. boreale by having longer cells in the lower part of the main axis and by the pinnæ bearing, though rarely, pinnulæ on the under side. The species has been met with in depths of 9 to 32 meters, and furthermore slightly below the surface on vertical granitic walls in the harbour ot Frederikshayn. It grows principally on mollusc shells and therefore often occurs on soft bottom, further on the tubes of Tubularia and on various Algæ, e. g. Rhodomela, Furcellaria, Phyllophora. It has only been gathered in the months April to October. The tetra- sporangia have been met with in July to October, the sexual organs in July and August and ripe cystocarps in July to October; the latter, however, more rarely than the sporangia. Localities. Ns: aF, off Thyborøn, 31m. — Sk: eX, north of Bragerne, 16 m; SY, north of Løkken, 13 m; ZK, off Lønstrup, c. 8 m; YL, XO and other localities off Hirshals, 11—15 m (Borge- sen, !). — Kn: Skagen, south side of Grenen, e. 5—15 m; FG and XJ, Herthas Flak, c. 20 m; YS?, north of Hirsholmene, 15 m; YX, east of Nordostrev, Hirsholm, 23—28 m; on shells of Ostrea, Frederikshavn (Ørsted 1840); off Frederikshavn, east of Marens Rev, c. 20 m (!, Ostenfeld), 11 m (Kramp); harbour of Frederikshavn; TP, Tonneberg Banke, 16 m; near Læso Trindel, 11—26 m; 3 miles W. of Læso Trindel light-ship 15 m. — Ke: FC, east of Læsø, 17 m; fH and fl, 1 and 3 miles W. by N. of Fladen light-ship, 17 and 30 m; ZH, ZI, Groves Flak, 32 and 26 m, soft bottom; EQ, east of Anholt; 14'/: miles S.S.E. of Anholt Knob light-ship, 10 m (C. A. J.). — Sa: MS, west of Endelave, 15 m. — Lb: North side of Fænø; EE, west of Feng, 15 m; Feng Sund, 10—15 m, — Su: Hellebæk (Schmidt 1873), 368 3. Antithamnion boreale (Gobi) Kjellman. Kjellman, Norra Ish. algfl. 1883 p. 226, PI. 16 figs. 2—3 (Alg. Artc. Sea p. 180); Reinke, Algenfl. westl. Ostsee 1889, p. 23 (f. baltica), Atlas deutsch. Meeresalg. I 1889 Taf. 22; Kylin 1907, p. 173. Antithamnion Plumula var. boreale Gobi, Algenfl. des weissen Meeres. St. Petersbourg 1878, p. 47. While in a former paper (Gronlands Havalger, 1893, p. 787; Ann. sc. nat. 7° ser. t. 19, 1894, p. 64) I have regarded this species as a variety of A. Plumula, in ac- cordance with Gost, my later investigations of the Danish specimens have led me to agree with KJELLMAN’s view that it must be considered as a distinct species. Ac- N \ \ | cording to KJELLMAN | \ À and other authors it (| N) differs from A. Plu- \\ N i mula by being more \ : NS A slender, by ionger cells N NS Lee 4 in the long shoots, by i W i the pinnæ in great \ X part bearing pinnulæ \ /] on two sides and then N opposed or alternate, N V4 t while the pinnæ of / A. Plumula bear only [ Ye pinnul on the upper \ side, and by the spor- À / angia being always i sessile. KyLIN adds the Fig. 304. character that A. bore- Antithamnion boreale. Lower part of plant. 2 2 B Ya | msi. ale is sporangia-bear- ing early in June while in A. Plumula the sporangia appear only in July. I can confirm these statements and add a little more. eo The base of the plant resembles that of A. Plumula, i as shown in fig. 304 where free descending filaments are i given off from the cells of the main axis and the ( N proximal part of the pinnæ. Fig. 305 shows the lower l) part of a plant gathered in April. The lowermost part Rp which is short-celled and had a darker colour had un- AN doubtedly been formed in the foregoing year while the \\ upper, brighter and more long-celled part of the shoot À had grown out in spring. The first pinnæ are unbranched Fig. 305. and the next following ones bear only one or two pin- uAntithamnion boreale. Specimens nulæ on the upper side. gathered in April. The lowermost z part (shaded) is a survival from the The shoots usually bear two rows of pinnæ; how- foregoing year. 95:1. EE ever, a certain number of joints occur which bear only one pinna. On the other hand, joints which bear three pinnæ may also occur, though rarely. The pinnæ Fig. 306. Antilhamnion boreale. Tetraspore- and antheridia-bearing specimen from the Baltic Sea (UL), May. 70:1. bear not only pinnulæ along their upper face but also on the under face or on the flanks; in the first case the pinnulæ are very often opposite. The pinnæ are more 370 slender and often longer than in A. Plumula. Gland-cells (fig. 307) similar to those of À. Plumula may be present or wanting. They were present in all the examined specimens from the eastern Kattegat and further in some of the specimens from the Samsø waters, though in some cases only in small number, while they were wanting in other specimens, and they were also wanting in all the examined specimens from the Øresund and from the Baltic Sea. The latter specimens can be referred to f. baltica Reinke (1. c.) which is chiefly distinct by this character. The specimen re- presented by Kuckuck in Atlas deutsch. Meeresalg. Taf. 22 has in great part unbranched pinnulæ, which occurs more rarely in the specimens from the Danish waters. The tetrasporangia are sessile on the upper face of the pinnulæ or on their flanks, usually singly on the joints but sometimes in pairs and the second being inserted at a lower level but at the same time beside the first. The sporangia are bigger than in A. Plumula, usually 60— 85 w long, 35—50 w broad. In the specimens from Feng Sund, however, I found them a little smaller, only 46—49 w long, 35 u broad, thus almost of the same size as those in A. Plumula. In some specimens from the Little Belt and the Baltic Sea antheridia were met Be u with. They were borne on the upper end Antithamnion boreale. Pinnulæ bearing antheridia at 5 i å the top, and sporangia, s. g gland cells. In Athe*chrom. Of short pinnulæ which in several cases atophores are shown. A—C 390:1. D 230:1. bore sporangia too (figs. 306, 307). These pinnulæ usually consist of 3—6 cells the uppermost one or two of which bear a small number of closely placed nearly glob- ular antheridia. The pinnula may sometimes bear a small branch which likewise bears antheridia at its top (fig. 306 above), but antheridial clusters like those in A. Plumula never occur. Female sexual organs and cystocarps have never been observed in this species. The presence of antheridia-bearing pinnulæ in tetraspore-bearing specimens and the different shape of these branchlets corroborate the view that A. boreale is specifically distinct from A. Plumula. As stated by previous authors, A. boreale is nearly related to A. americanum (Callithamnion americanum Harvey, Nereis bor. amer. II, 1853 p. 238 pl. 36 A). In a specimen of this communicated in Phykotheka univers. No. 501 I found gland-cells and sporangia 56—60 w long, 35—37 w broad. A. boreale occurs in the Danish waters almost exclusively south of Anholt, in 7 to 40 meters depths, most frequently in 13 to 30 meters depths. The innermost local- ities known are Davids Banke north of Bornholm and a place east of Bornholm 371 where only very small specimens were met with which were much reduced, many of the joints bearing only one branchlet. The specimens from the Kattegat were up to 5 cm high while those from the southern waters reached only a length of 2,5 cm. It usually grows on other Algæ e. g. Delesseria sinuosa, Furcellaria fastigiata and Co- rallina offinalis and on Hydroids. It has been met with in the months April to August and bore sporangia in the same months. Antheridia were met with in May and June. — In the western part of the Baltic Sea it has been found by REINKE in four localities, at the west coast of Sweden it has not been found north of La- holms Bugt (Kyrın). Localities. Kn: Harbour of Frederikshavn. — Ke: ER, Fyrbanken, east of Anholt, 28 meters. — Ks: EO, north of Lysegrund, 26 m. — Sa: PJ, Ebeltoft Vig, 13 m; PL, Wulffs Flak; DK, Bolsaxen, 14 m. — Lb: Fæno Sund, 15 m; dQ, bank south of Lyø, 22 m; dH’, east of Hesteskoen, 18—19 m. — Sb: DL, south of Refsnæs, 7 m; cN, south-west of Musholm, 18 m; cL, north-east of Sprogø, 25—27 m; Z, off Skagbo Huse, 19 m; UH and UT, Langelandsbelt, 19—22 m; US, Langelandsbelt, c. 40 m; US}, near the former, 20 m. — Su: Off Aalsgaarde, shelly bottom (Boye Petersen); north of Lappegrund, 19—26 m (Henn. Petersen); bM, south of Hveen, 23 m. — Bw: Trindelen, west side of Kegnæs, Als; UL, Øjet, 20 m. — Bb: SN, Davids Banke, 15—17 m; 3 miles S.S.E. of Nexo, 21 m (C. A. J.). Maenus (Bot. Erg. Nordseefahrt p. 67) has reported Callithamnion Plumula Lyngb. from “N.W. von Roesnäs 28 Faden” and “N.W. von Fænû 16—10 Faden”. Without examining the specimens in question it is impossible to decide whether they must be referred to A. Plumula or A. boreale. Ceramium (Roth) Lyngbye. In 1908 Dr. HENNING PETERSEN published a monograph on the Danish species of the genus Ceramium, based principally on the material contained in my collections, and in a later paper (1911) he has again mentioned some of the species. Since the publication of these papers I have made further collections of Ceramia in the Danish waters, and Dr. PETERSEN has then readily complied with my request to examine these new collections together with his own later gatherings, and he has at the same time made a revision of his earlier determinations. These investig- ations have in several cases led Dr. PETERSEN to another limitation of the species, and as the new collections have brought species to light which were formerly not known from the Danish coasts, the number of Danish species has been increased from 10 to 18. Dr. PETERSEN has communicated to me descriptions and remarks on several of the species, which are given below, partly with Dr. PETERSEN’s own words. further some drawings and a new key to the species, while I contribute the account of the occurrence and fructification of the species and give some drawings and a few general remarks on the morphology. The vegetative morphology and development has been treated by Cramer (1863). The germination has been repeatedly studied by various authors, (comp. KYLIN 1917, where further literature is quoted). I have examined the germination of the tetraspores of C. rubrum and of the paraspores of C. strictum which take place in essentially the same manner, but I have nothing to add to the earlier descriptions. m _ In more developed plantlets several multicellular rhizoids are developed from the corticating bands near the base of the plant, giving rise to adhesive discs (holdfasts) at their tip. In fig, 308 is represented a long rhizoid showing narrow cortical bands at the nodes like the upright fronds. The hyaline hairs have been mentioned by Henn. PE- TERSEN (1908) and by me (1911). They have been met with in almost all the species and may perhaps occur in all of them. However, in one species they have not been observed, namely in C. cimbricum, which has only been found in the Limfjord in rather deep water of slight transparency. These hairs may be very numerous and vigorous (K. R. 1911, fig. 3) and remain alive long; in other cases they reach only an inconsiderable size and decay early (fig. 314). They appear early in the plantlets a few days after the beginning of the germ- ination. According to PETERSEN the hairs are wanting in winter. Gland cells occur in C. fenuissimum and C. Areschougii, as shown by PETER- SEN (1908 and 1911). The antheridia were briefly described and pictured by BuFFHAM (1884 p. 342 pl. XII figs. 2—5, 1888 p. 260, Fig. 308. Ceramium diaphanum. Base of plant with downward grow- pl. XOXG fig. 4), and ing branches produeing finally terminal hapters. 48 : 1. HENN. PETERSEN de- scribed their develop- ment (1908 p. 50); they were recorded in several Danish species, as a rule in particular male plants, in C. fruticulosum in the same plants as the carpogonia. The development of the cystocarps was described by JanczEwskı (1876), PHILLIPS (1897) and Kyrın (1923). In the species ex- amined by the two first-named authors two carpogonial branches were found, one on each side of the auxiliary mother-cell, while Kyrın found only one in C. rubrum. In C. fruticulosum I found two (fig. 309). In the same species I found numerous spermatia loosely adhering Fig. 309. 2 el 5 R Ceramium fruticulosum. A, young carpogonial to sterile hairs in the neighbourhood of the branches, partly still tricellular. B, carpogonial procarps (fig. 309 B). branch with still infertilised trichogyne ; numer- ee SELER ous spermatia adhere loosely by a sterile hair. C, The division of the tetrasporangia in the fertilised carpogonium. 4, B 625:1. C 390:1. 373 genus Ceramium is said in the systematical works (Kür- ZING, J. AGARDH, Hauck) to be tetrahedral (triangular) and most of the pictures of Ktrzinc and Harvey are in accordance with this statement. In Kiitzing’s figure of C. rubrum (Tab. phyc. XIII pl. 4), however, the oblong \ / sporangia are shown divided by a transversal and a vert- ical wall. HENN. PETERSEN does not mention the mode of am D pins division, but his picture of C. strictum (1908 fig. IV, 1) tetrasporangium seen from three shows very clearly a similar rectangular division, while nie Zu the mode of division is not quite clear in his fig. III, 2 of C. tenuissimum. CoLLıns and Hervey! describe a new species C. cruciatum in 1917, the sporangia of which are “cruciate, sometimes regularly, sometimes decuss- ately”. And recently Mrs. WEBER-van BOSSE” describes another new species C. cingulatum with a similar division of the sporangia. As I have myself found sporangia Fig. 311. with rectangular division in C. vertebrale (figs. 310, Ceramium diaphanum. Tetraspore 322), C. septentrionale a. o. species but on the other mother-cells, dividing. Only two, resp. hand have also ascertained the occurrence of tetra- three nuclei were present in the sect- Er 2 I 5 ER ions. In A tetrahedrical division. 390:1. hedral division in Danish species (e. gr. C. tenuissi- Fig. 312. Ceramium rubrum. Tetrasporangia in division. A—C after the division of the nuclei but before the division of the cell. F two sections of the same sporangium. 340 :1. ! The Algae of Bermuda. Proceed. Amer. Acad. Vol. LIIL No. 1. Cambridge 1917, p. 144. ? Liste des Algues du Siboga. III Rhodophyceae. 2° partie. Leiden 1923, p. 332. D.K.D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 48 mum, fig. 314) I judged it convenient to examine the division process itself in im- bedded proofs of C. diaphanum and C. rubrum, and in both species tetrahedral and rectangular division was ascertained in different sporangia of the same plant. In every case the division of the nuclei was accomplished before the division began (fig. 312 A —C). The division of the cell takes place by walls growing gradually from the periphery towards the centre of the cell, but the orientation of the walls is variable. In figs. 311 A and 312E are represented typical tetrahedral divisions. In other cases a transversal wall is first formed as an annular list while two other walls, perpendicular to the first are formed a little later but before the first wall is finished (figs. 311 B, 312 D, F, H). The division seems thus in all cases to be a division in four of one cell and not a bipartition of the spore-mothercell into two cells which afterwards divide into two. Fig. 313. Paraspores occur in C. diaphanum, C. strictum (comp. HEnn. Ceramium diapha- PETERSEN 1908 pp. 51, 85) and C. Deslongchampsii, and I have found an SEA a couple of sori of paraspores in a specimen of C. vertebrale which 390 : 1. bore at the same time tetrasporangia (fig. 323). These paraspores were remarkable by peculiar pseudopodia from the protoplast to the membrane. The paraspores, as shown by HENN. PETERSEN, develop from a superficial cortical cell (fig. 313), often from à marginal cell of a cortical band. They never occur in the sexual plants but often in tetrasporiferous plants. HENN. PETERSEN states briefly that he has met with a sort of monospores in C. diaphanum (1908 p. 14).* Key to the Danish species of Ceramium. (By HENNING E. PETERSEN). 1. Cortication only at the nodes; distinct cortical bands. 2. Gland cells present, outer edge of apex dentate.................... 1. C. tenuissimum. 2*. Gland cells wanting, outer edge of apex usually even. 3. Cortical bands usually over 100 4 high, lower border-cells irreg- ularly shaped; frond not creeping. 4. Apices always curved inward. 5. Cells in the lower edge of the lower bands usually not over 13 u in transversal diameter; cortication often much developed, bands sometimes upward growing............. 2. C. diaphanum. 5*. The named cells usually 17—20 u in transversal diameter .... 3. C. strictum. 4*. Apices always straight. 5. Bands of about equal height and breadth ........... 5. C. Deslongchampsii. 5”. Bands usually broader than high; often up to 30—40 axial cells between the bifurcations; only in the inner waters ... 6. C. vertebrale. ' Dr. PETERSEN refers to Gogrs fig. 8 in Die Rothtange des Finn. Meerbusens. Mém. Acad. St. Pétersb. XXV No. 7, 1877; but the bodies alluded to in this figure according to the author represent tetrasporangia (“Tetrasporen’”) the division of which is not shown. 375 3". Bands very narrow, usually c. 50 #, rarely over 100 « high, con- sisting of 1—3 (usually 2) transversal rows of cells; cells in the lower edge of the bands often with parallel upper and lower sides; frond sometimes creeping........................ ENTER ft. C. eimbrieum. 1*. Cortication partly or entirely continuous. 2. Cortication with distinct bands in the upper part or in a greater part of the frond. 3. The outer cortical cells very small, 7—10 « in diameter, usually loneitudinallyzeloneated ers ee 12. C. Boergesenii. 3*. Not so. 4. Bands with sharply limited lower border occur; bands at least thrice higher than the diameter. 5. Ramification biseriate alternate or dichotomous; in the latter case the apices are incurved ..................... 16. C. fruliculosum. 5*. Branches not biseriate, apices straight, at least in older specimens. 6. Bands often over 2 mm high, usually distinct below, though often approaching each other .............. 17. €. seplentrionale. 6*. Bands not 10 high. Cortication usually continuous below. Zapicesithinun.n a EE TARA te a 15. C. Areschougii. 4*. Bands with sharply limited lower border do not occur; bands not so high, increasing downwards in various degree. 5. Cells of the bands, in particular of the upper ones, are arranged in distinct longitudinal rows; distinct bands only in the upper parts of the frond ...................... 13. C. scandinavicum. 5*. Cells not in distinct longitudinal rows; distinct bands in the upper parts or in greater parts of the frond. 6. Bands slightly increasing downwards, cells in the lower border often broad Au... u. ek era ele cet co 14. C. abyssale. 6*. Bands much increasing downwards; altogether slight difference between upper and lower border of the band. 7. Cortication usually continuous over more than two thirds of the length. 8. Apices very thin, often capillary, much branched. 9. Main axes much developed, with secondary branches ray. cece acura a REE ne og naan ae 9. C. arborescens. 9*. Ramification usually pronouncedly dichotom- ous, secondary branches not much developed. 8. C. rubriforme. 8*. Apices vigorous, slightly branched near the top. 9. Colour dark, often much developed main stems and secondary branches; cortication continuous over the greater part of the frond 11. C. atlanticum. 9=. Colour light; vigorous main stems without secondary branches.......... SE Sie ob 10. C. Rosenvingii. 7*. Bands distinct in the upper third of the frond; SA COL OUT ER ee er 7. C. danicum. 2*. Cortication continuous over the whole frond ......... DEE RSR ET SU TU DURE 48° 376 1. Ceramium tenuissimum (Lyngb.) J. Agardh. Agardh, 1851, p. 120: Henn. Petersen 1908, pp. 54, 49 pl. I Fig. 1, 190, p. 97; idem 1911, p. 97. i C. diaphanum var. tenuissima Lyngbye Tent. p. 120. As shown by Henn. PETERSEN, the species is easily distinguished by the dent- iculate outline of the young incurved branches, by the presence of gland cells and by the extruding tetrasporangia usually single in the cortical zones. It reaches a length of 8—10 cm: in the Little Belt and the South Fyn Waters, however, spec- imens higher than 3 cm were not met with. It occurs in all seasons; in winter, however, it is only 1—2 cm high. It is spread in all the Danish waters from the Skagerak to the south Fyn waters, but has not been met with in the Great Belt, the Sound and the Baltic Sea; it thrives well in the fjords (Lim- fjord, Isefjord, Odensefjord). It occurs from a little under low-water mark downwards; in the eastern Kattegat it has been met with in 22,5 m depth. It has been found with tetrasporangia in July and August, with cystocarps in July and September. Antheridia were met with in July 1923; they covered the surfaces of the joints in longer stretches of the frond. Epiphytic on various Alge and on Zostera. Fig. 314. Ceramium ienuissimum. A. upper end of filament Localities. Sk: YN®, E. of Bragerne; SY, N. of with hairs, partly decayed. B, band with tetra- Lokken, 13 m; XO off Hirshals; Hirshals mole (Børgesen) SED LSU eb 5 EURE and near land. — Lf: Nissum Bredning; ZS, ZY; Thisted Bredning: MH; Sallingsund: Nykøbing; Løgstør Bredning: LS, 7 m, bT; off Feggeklit, 4m. — Kn: Off Hulsig, 8 m (B. Petersen); N.E. of Hirsholm (Ostenfeld); TP, Tønneberg Banke, 16 m; Brune Rev by Frederikshavn (H. E. P.); ZP, UC, N. of Nordre Rønner. — Ke: Fladen: ZG, ZF, VY. 18—22,5 m: Gilleleje (Lyngbye). — Km: Læsø Rende: Dana St. 2919 (C. A. J.); BO off Stensnæs; ZC* within Kobbergrund; VL south of Tangen; BH off Gjerrild Klint. — Ks: Isefjord: EH off Lynæs, near Rørvig (Joh. Lange), Lammefjord. — Sa: Reef by Kalø; BB, Søby Rev: Korshavn, reef; Odensefjord, Hofmansgave (Lyngbye, C. Rosenberg). — Lh: Helnæs Hoved Flak; CC, Hornenæs. — Sf: Shoals off Nakkebølle Fjord. 2. Ceramium diaphanum Harv. et J. Agardh. Henn. Petersen 1908 pp. 56, 87 figs. I,1, II and IV,1,4, pl. I figs. 2—5, pl. IL figs. 3—4, 1911 p. 98, fig. 1,1, 4, pl. I fig. 2. This species is common in the inner Danish waters where it usually grows near the low-water mark on piers in harbours and in stony reefs in about one meter's depth, more rarely descending to 4—5 meters depth or even to 13 m. It grows on stones and wood, Chorda Filum, Zostera, Fucus vesiculosus a. o. Algæ. It reaches a length of Scm. It has been met with from April to November but is 377 most developed in the summer months. The most frequent fructifications are tetra- spores and paraspores, often occurring in one individual. Tetraspores have been met with in May to Sept., paraspores in July to Sept., anther- idia and cystocarps each once in September. Dr. PETERSEN has in 1908 distinguished 5 forms to which he has now added the f. umbellifera here described. 1. F. typica. 2. F. strictoides, subf. «, subf. 8, corticatula Kylin (Cer. corticatum Kylin 1907 p- 176). F. modificata. F. radieulosa. F. zostericola. -c zZ a Fig. 315. 3 Ceramium diaphanum. F. umbellifera H. Prtsn. n.f. — Much branched towards the young _ pseudodichoto- a oN apex, with short internodes and somewhat divaricate branches. my- In both branches the last segment is on Form from protected water, analogous to C. rubrum f. radians and C. the point of branching. strictum f. stricto-tenuissima. Related to f. strictoides. (Henn.Petersen). © apical cell; s, new branches, c, central cell. Localities. F. typica. Ks: Harbours of Anholt and Lynæs. — Sa: Har- 390 : 1. bours of Koldby Kaas and Horsens. — Lb: Harbour of Rosenvold. — Sf: Svendborg. — Sa: Hofmansgave (Hofm. Bg.). — Sf: Svendborg. — Su: Harbour of Sletten. — Bw: Harbour of Gedser. — Bm: Rodvig; Faxe Ladeplads. F. strictoides. Ks: 3 localities in Isefjord. — Sa: Hofmansgave (Hofm. Bg.). — Sf: UV, 13 m. — Sb: 3 loc.; Nakskov Fjord (Th. Mortensen). — Sm: Venegrund. — Su: 5 loc.; harb. of Helsingor; Kalvebod Strand (M. L. Mortensen). — Bm: 1 loc. : F. modificata. Ke: Gilleleje (Lyngbye). — Ks: Harbour of Grenaa; near Rorvig. — Sa: 4 local. — Lb: 3 loc. — Sf: Svendborg Sund (E. Rostrup). — Sb: 4 loc. — Sm: 6 loc. — Su: 6 loc. — Bw: Near Sonderborg. — Bm: Stevns, Rodvig, harbour of Hesnæs. — Bb: 6 loc. around Bornholm, Chri- stianso, That. F. radiculosa. Bb: Allinge, Gudhjem, Christiansø. F. zostericola. Lf: LR, E. of Livø. — Sb: GY, 5,5 m. — Sm: HI; Stubbekøbing; Guldborgsund. — Su: Knollen. ; F. umbellifera. Ke: Gilleleje, E. of the harbour. — Su; Bay of Hornbek. 3. Ceramium strictum Greville et Harvey. Harvey, Phyc. Brit. III Plate 334. Henn. Petersen 1908 pp. 61, 89, Figs. IV,2, 3. Tab. I Figs. 6, 7, Tab. Il Fig. 1; idem 1911, p. 98, Fig. 12, 3. With regard to the relation of Ceramium strictum to C. diaphanum reference may be made to the quoted papers by Dr. PETERSEN. C. strictum in the Danish waters reaches a length of 10 cm. Paraspores are the most frequent organs of reproduction; they were met with in almost all the waters where the species occurs, in May to Sep- tember. The tetrasporangia are much less common (once in Sm and some places in Bb, July and September); they occur partly in paraspore-bearing specimens, 378 Sexual reproduction seems to take place much more rarely than the asexual. An- theridia have been met with only in a few places (Su, Bw and Bb, July, August); they covered completely globular joints. Cystocarps have only been observed in one place (Bh, August); they were subtended by up to six involucral ramuli. A spec- imen collected by dr. O. PAULSEN in Krie- gers Flak (Bm) in 15 meters depth, showed witches’ broom-like bushes of dark-red, much branched, short straight branches with short articles and with monopodial, lateral Fig. 316. branching. The species has only been met Ceramium strictum, from Bornholm. 4, upper end of within April to October. shoot with hairs. B, upper end of shock of female Baron Seo plant. pe procarpial branch. 390: 1. occurs in all the Danish waters within Skagen, most frequently in the inner waters, from low-water mark to c. 10 meters depth, more rarely deeper; it has been met with in the greatest depth at Bornholm (29 m). Dr. Petersen distinguishes forma vera and f. stricto-tenuissima, characterised by more divaricate branches and more elegant habit. F. vera H. Ptrsn. Localities. Lf: 5 localities. Oddesund, S. side of Jegindø Tap. — Kn: FF, Læsø Trindel, 15 m (?). — Ke: East end of Anholt; IC, Store Middelgrund, 10,5 m: about same place (Dana St. 2925 C. A. J.); Gilleleje, 1—5 m. — Ks: EH, West of Lynæs; GG, Sjællands Rev. — Sa: GE near Sejerø; PG, west of Hatter Rev: Begtrup Vig, stony reef. — Lb: Off Ivernæs; Aarosund; DB, Lillegrund. — Sf: CU: CV. — Sb: LK, Elefantgrund; Kerteminde; Nyborg: UF, N. of Langeland; Snøde Rev; Smerstakken; Nakskov Fjord (Th. Mortensen). Fig. 317. | 3 Ceramium strictum, from { — Sm: CL, Raago Sund (+); CO: Holsteinborg Nor; Karebæk Fjord (War- sen Te, Get ! ming); Petersværft; Grønsund, 4 m.— Su: Off Aalsgaarde (3, Aug.) (H. E. P.); part of the wall of the N. of Julebækshusene; the point at Hvidøre; Copenhagen; SA, SB, Flinteren- internodial cell was more den. — Bw: bV, N.E. of Kobbel Skov; bZ and dO, S. of Als; DU, off Dimes (deeply stained by hem- MA atoxylin than the lower- | Odde: KY, Femerbelt, 12,5 m; KZ, off Kramnisse; Gedser Rev, 8,5 m, (3, July). most part; the latter was — Bm: KS, E. of Falster; VH, S. of Moen; Præstø Fjord; Faxe Ladeplads; off probably younger. 230:1. | Mandehoved, Stevns; QF, S. of Saltholm; QH, Falsterbo Rev; bP. Kriegers h Flak (0. Paulsen). — Bb: N.W. of Sandvig on rock: Allinge (3 ©); Davids Banke, 15—29 m; YF, within Arnager Rev; YE, off Øleaa; near Salthammer Rev (+, p). F. stricto-tenuissima H. Ptrsn. New localities. Sa: Hofmansgave (Hofm. Bang). — Sb: DN, Vengeance Grund, 12 m. 4. Ceramium eimbrieum Henn. Petersen n. sp. C. interdum repens, subdichotome ramosum, apicibus rectis, longis, sæpe in- æqualibus: zonis semper distantibus, marginibus non crescentibus, e cellulis paueis Fig. 318. Ceramium cimbricum. A, young pseudodichotomy. B—D, adult cortical bands. Henn. E. Petersen del. 330 : 1. compositis, plerumque 2—3 cellulis altis, maximis 60 w altis, 100 w latis, aliis 1—2 cellulis altis, c. 25 w altis, 50 w latis, cellulis inferioribus sæpe usque ad 32 w latis; internodiis maximis zonis 5—7-plo longioribus. — Color rubro-violaceus. — Pili, tetrasporangia et organa sexualia non observata (figs. 318, 319). Habitat in Limfjorden. Affine C. stricto sed differt zonis angustissimis et ramificatione. Apices juveniles sæpe curvatura characteristica supra nodos instructi sunt (fig. 318 A). (Henn. Petersen). This small Ceramium, which has only been met with in two localities in the Limfjord, was first referred to C. strictum. However, as it differs by the habit, the branches of the pseudo- dichotomies being often of unequal size, and by the very narrow cortical bands, Dr. PETERSEN has distinguished it later as a distinct species and given me the diagnosis above. C. cimbricum (LO | = Fig. 319. Ceramium cimbricum. A, end of shoot. B, branching. C, D, bands and internodial cells. 345 : 1. 380 is found growing on Laomedea and on various alge, partly creeping with rhizoids, reaching a length of 1—3 cm. It has only been found sterile. Localities. Lf: near Jegindø Tap, 5,5 m; IT, West of Ejerslev Ron, 7 m. 5. Ceramium Deslongchampsii Chauvin. J. Agardh, 1851 p. 122; Henn. Petersen”1908 p. 83 (89). This species which is principally characterized by the cortical bands being of almost equal height and breadth, and by the straight ends of the branches, has only been recorded with certainty from one locality, viz. the harbour of Frederikshavn, where it occurs constantly at the ends of the northern outer mole and of the northern trans- verse mole. It grows at low-water Fig. 320. Ceramium Deslongchampsi. mark and reaches a length of Part of frond with two bands. 4 cm. All the specimens collected Henn. Petersen det. 270: I. : 3 . were sterile till July 1923 when Fig. 321. specimens up to 6 cm high were met with, partly with Ceramium Deslongchampsi. Heap = É = of paraspores. 200 :1. tetrasporangia or paraspores. The sporangia were vert- icillate, the fertile joints much swollen. The heaps of para- spores are solitary or several on the same joint (fig. 321, comp. __ Harvey Phye. Brit. pl. 219). | Localities. Lf: Nykebing Mors (Bergesen), referred with doubt to this i species. — Kn: Harbour of Frederikshavn (April—August). 6. Ceramium vertebrale Henn. Petersen. Henning Petersen, 1908 p. 63, 90 Fig. V. Tab. II Fig. 2. As shown by Dr. PETERSEN, this species is on the one hand related to C. diaphanum and C. strictum, on the other hand to C. Deslongchampsü. It is distinguished in particular by the last branches becoming straight, by the great number of articles in the internodes and by the thick cell-membranes. It reaches a length of 4 to 6 cm. Dr. PETERSEN did not find hairs in this species. I observed these organs in specimens gathered in August: the rare oc- Fig. 322. currence of hairs probably depends on the fact that the species Ceramium vertebrale. Part has only been recorded in July and August. Tetrasporangia of frond with tetraspor- 2 2 ks angia. 230:1. were observed in specimens collected in August at Bornholm; 381 I found them cruciately divided (or better perpendic- ularly divided). The tetrasporangiferous bands which contain one or a small number of sporangia are consi- derably swollen (figs. 322). In a tetrasporangiferous specimen a few sori of paraspores were observed, developed from superficial cortical cells (fig. 323). C. vertebrale occurs in 5,5 to 15 meters’ depth. It has only been recorded from localities around Bornholm and from one locality at the boundary between the Sound and the Baltic Sea. Fig. 323. Ceramium vertebrale. Zone with aheap Localities. Bm: RH, at Knollen west of Saltholm. — Bb: of paraspores. From a dried spec- SN, Davids Grund, 15—17 m; SL, off Allinge; SO, off Gudhjem; RUE EN M URI SK, Hojbratterne; SH, South of Broens Rev; YF, within Arnager ee as al i Rev; SF, Adler Grund. — (The locality Nyborg Havn recorded by Dr. Petersen (1908 p. 64) must be omitted, the specimens being now referred by Dr. Petersen to C. strictum f. radiculosa). 7. Ceramium danieum Henn. Petersen n. sp. C. Rosenvingii H. Petersen f. tenuis et f. intermedia H. Petersen 1908, pp. 66, 90, pl. II figs. 5, 6. Frons dichotoma, apicibus incurvatis teretibus, in partibus superioribus et intermediis zonis discretis, in partibus inferioribus cortice continuo instructa. Zonæ juveniles marginibus non crescentibus, adultiores ab utroque margine crescunt ut in C. Rosenvingü. Interstitia pellucida interdum zonis 5—7-plo longiora. — Cysto- carpia in ramis primariis. — Color subruber. — Individua minus corticata habitum Cer. stricti offerunt. Ceramium Rosenvingü as described by me in 1908, comprises partly forms with feebly developed cortex, with the habit of C. diaphanum and C. strictum, partly forms with somewhat more developed cortex and finally forms approaching to C. rubrum. As such a variation must be considered too great, even when taking the species in a wide sense, I have found it correct to divide the species into two. It would perhaps be most correct to distinguish three species corresponding to the three forms which were described in 1908; however, I am not satisfied whether there is so distinct a limit between f. tenuis and f. intermedia that they ought to be regarded as distinct species. On the other hand f. transgrediens is so distinct from the two just named forms that it seems warranted to draw a specific limit between them. I describe therefore a new species comprising the forms fenuis and intermedia, while the name C. Rosen- vingii is retained for the f. transgrediens. C. danicum comprises forms with continuous cortex at the base or reaching a little over the middle of the frond and with the habit of C. diaphanum or C. strictum in the upper parts of the frond, while C. Rosenvingii comprises more robust forms with continuous cortex reaching to the apex or near the apex, with rubroid branches and without any habit of C. strictum. HENN. PETERSEN. D. K. D, Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 49 382 C. danicum has been met with in May to July, in 4—13 meters’ depth. It reaches a length of 15 cm and has been found with antheridia in May, with cystocarps and tetraspores in July. Localities. Sa: GC, north of Fyn. — Lb: DF, E. of Bogø; DC, Aakrog Bugt; DB, Lillegrund; DX, Vodrups Flak. — Sf: UX, Skjoldnæs; CV, Billes Grunde. — Sb: UE, Vresens Puller; UU, Snode Rev. — Bw: DU, off Dimes Odde. — Bm: KT, Gedser Rev; at Stevns Klint (Joh. Lange). 8. Ceramium rubriforme Kylin. Kylin 1907 p. 183, pl. 7 fig. 7. After having examined recently original speeimens of C. rubriforme Kylin Dr. PETERSEN refers to this species two specimens from one locality in the northern Kattegat and with doubt one from the South Fyn Waters, formerly referred to C. Rosenvingü f. intermedia. The former are 15 cm long and bear ripe tetrasporangia (May). Localities. Kn: Krageskovs Rev, 4—5 m. — Sf: (?) CU, at the N. end of Flæskholms Flak, 5,5 m. 9. Ceramium arborescens J. Agardh. J. Agardh 1894 p. 33; Henn. Petersen 1908 p. 67 and 91, pl. III figs. 1—2; 1911 pl. II fig. 6. The species is rather extensively spread in the Danish waters from the North Sea to the Baltic Sea around Møen. It seems to be only little influenced by the salinity of the water, for the maximal length, 17—18 cm, is reached in the North Sea and the Baltic Sea as well. It occurs mostly near low-water mark, but has been met with in depths down to 12 meters. It is most frequent in spring (May) but has been observed in the months of April to September, with cystocarps and tetrasporangia in May to July. Localities Ns: Thyboron, pier. — Sk: Hirshals, E. side of mole and stony reef near land. — Lf: Glyngore. — Kn: Frederikshavn, harbour; boulder at Jegens Odde. — Ke: GI, Ostindiefarer Grund. — Ks: OP, Lysegrund. — Sa: KL, Bjarkes Grund; Kalo reef; Korshavn, reef; Hofmansgave (Hofm. Bang); Odense Fjord (C. Rosenberg). — Lb: Knudshoved, S. of Anslet Hage. — Sf: Svendborg. — Sb: Korsor (Hornemann); DN, Vengeance Grund, 12 m; UF, near Hov Sand; DQ, off Nakskov Fjord; UR, S. of Albuen. — Su: Dragør. — Bw: UQ, off Tillitse; UP, off Kramnisse Gab. — Bm: Stevns Klint, washed ashore (Joh. Lange); Rødvig, reef E. of the harbour; Klintholm harbour. 10. Ceramium Rosenvingii Henn. Petersen emend. auct. C. Rosenvingii Henn. Petersen f. fransgrediens Henn. Petersen 1908, pp. 66, 91, figs. VI,2, VII,1, pl. II fig. 7. Frons dichotoma, apicibus rectis vel curvatis. Corticatio confluens, exceptis apicibus ramisque superioribus. Zone corticales discrete ab utroque margine crescentes. Tetrasporangia verticillata non erumpentia. Color subruber. HENN. PETERSEN. With regard to the present circumscription of the species comp. above p. 381. It has been collected in April to July, most frequently in May, in 1 to 9,5 meters’ depth. 383 The frond reaches a length of up to 14 cm. Tetrasporangia have been met with repeatedly in May to July, antheridia once in May, cystocarps only once in a dubious specimen from the southern Kattegat, gathered in July. The tetrasporangia were at any rate often cruciately divided. Localities. Kn; Skagen, south side of Grenen. — Ks: (?)EJ, Lysegrund; OT, Hastens Grund. — Sa: PG, W. of Hatterrev; Hofmansgave (Lyngbye). — Lb: FZ, Kasserodde; Baaring, harbour; Dyre- borg. — Sf: CV, Billes Grunde; DZ, Egholms Flak. — Sb: UU, Snode Rev. 11. Ceramium atlantieum Henn. Petersen. Henning Petersen 1911 p. 112. Dr. Petersen refers to this species a specimen collected in April 1906 in the harbour of Skagen then unfinished. It has formerly (1908) been referred to C. fru- ticulosum f. rubroides. It was 13 cm high, but still sterile. C. atlanticum has till now been recorded from Iceland and the Feerées. Locality: Kn: Harbour of Skagen. 12. Ceramium Boergesenii Henn. Petersen. Henning Petersen 1911, p. 108, fig. I, pl. II fig. 8. C. fruticulosum f. rubroides Henn. Petersen 1908 pp. 73, 93 ex parte, pl. IV fig. 1. Dr. PETERSEN has found that some specimens from the Limfjord, formerly referred to C. fruticulosum f. rubroides, must be referred to C. Boergesenii which was described on the basis of specimens from the Fxröes, and which is easily recognis- able by the characteristic small-celled cortication. The species was met with near low-water mark in July and September, in all the places with tetrasporangia, in one place with cystocarps in July. The collected specimens are 7—9 cm long. Localities. Lf: Thisted; Nykøbing; Hals. — Kn: Two specimens from Nordre Ronner must probably, according to Dr. Petersen, be referred to this species though the cortication is not quite typical. 13. Ceramium scandinavieum Henn. Petersen. n. sp, C. fronde regulariter dichotoma + corymbosa fastigiata apicibus incurvatis, in partibus basalibus et intermediis cortice continuo, in partibus superioribus interstitiis pellu- cidis semper brevibus instructa. Zonæ superiores ab initio adproximatæ, marginibus vix crescentibus, deinde ab utroque margine inprimis a superiori crescentes. Cellulæ marginis inferioris semper latæ in seriebus longitudinalibus ordinatæ. Cystocarpia in ramis principalibus; antheridia in soris; tetrasporangia verticillata in partibus nodalibus parum erumpentia. — Color in individuis danicis subruber, in indi- Fig. 324. Ceramium scandinavicum. Cortical viduis ex regionibus borealibus fusco-rubiginosus. (Fig. 324). band. H. Ptrsn. del. 330 : 1. 19* ne This species comes near to C. atlanticum, C. Rosenvingt and C. rubriforme, from which it differs by cortical bands more resembling those in C. Areschougü, with cells arranged in characteristic rows in the lower part of the zones. In contradistinction to C. atlanticum the ramification is distinctly dichotomo-corymbose with slight form- ation of secondary shoots. The specimens from the Baltic Sea have formerly been referred to C. Rosenvingü f. transgrediens. (HENNING PETERSEN). In the Northern Kattegat it has been found with antheridia, cystocarps and tetrasporangia in June. The Danish specimens reach a length of 8,5 cm. Localities. Km: Several places in the neighbourhood of Frederikshavn, e. g. Degets Nordostrev. — Bw: KU, Schünheyders Pulle. 11m. — Bm: VH, Böchers Banke. 14. Ceramium abyssale Henn. Petersen n. sp. C. rubrum f. decurrentoides Henn. Petersen 1908, pp. 82, 96. C. fronde dichotoma vel subdichotoma, apicibus excl. juvenilibus = rectis, cortice continuo vel zonis juxappositis difficile distinguendis instructa. Zonz discrete solo- modo in basibus ramorum occurrunt, typo C. fruticulosi vel C. Areschougii, in mar- ginibus superioribus magis quam in inferioribus crescentes. Cystocarpia in ramis principalibus vel secundariis. Tetrasporangia verticillata vel sparsa parum erumpentia. Color subruber. Hab. in regione abyssale. On closer examination of the specimens which in 1908 were referred to C. rubrum f. decurrentoides I have found that these specimens, owing to the structure of the cortication, must rather be considered as related to C. fruticulosum than as a form of C. rubrum. It differs from C. fruticulosum in particular by the presence of distinct bands at the base of the branches. HENNING PETERSEN. C. abyssale has only been met with in considerable depths, (8,5—31 m) in water of high salinity. It has been collected only in summer (July, August), with cystocarps and tetraspores; it reaches a length of 11,5 cm. Localities. Ns: aF, Jydske Rev, 31 m. — Sk: ZK", off Lønstrup, 8,5 m; off Hirshals, 15 m. — Kn: FG, Herthas Flak, 21 m. — Ke: VY, Fladen, 18 m. 15. Ceramium Areschougii Kylin. Kylin 1907, p. 179, Taf. 7 Fig. 6; Henn. Petersen 1908 p. 69, Figs. VI, 1 and VII, 2, 1911 p. 100 Fig. II. The species has only been met with in summer, May to August, most frequently in June and July. It seems to thrive best in the inner western waters where it reaches a length of 15—16 cm. It has been found with tetraspores in May to August, with cystocarps in June and July, and both modes of fructification occur in all the waters where the species has been met with. It grows in all the waters in various depths from 1/2 m to 15 m; in the Little Belt it has once been found in a depth of 19 m or deeper. 389 Localities. Kn: Various localities at Frederikshavn and Hirsholmene (C. M. Poulsen. H. E. På K. R.); VT, VU, ZL, North of Læsø; FE, FF, Læsø Trindel, 10—15 m. — Ke: EU, Lille Middelgrund. — Km: FA and XC south of Læsø. — Ks: D, off the entrance to Isefjord. — Sa: FT, north of Samsø: bay of Nexelo (Th. Mortensen); BD, north of Tunø; AH’, Lillegrund at Fyns Hoved. — Lb: W. side of Æbelø; cV, off Røgle church; Snoghøj; Fænø Sund; Linderum; Aarøsund; Augustenborg Fjord. — Sf: UV, north of Ærø, 13 m; Nakke Odde, Avernak Ø. — Bw: Several places south of Als (bV, bY, bZ, cE, cG, near land at Kegnæs light-house, dK, Pøls Rev); LE, Vejsnæs Flak; LC, south of Gulstav. 16. Ceramium fruticulosum (Kützing) J. Agardh. J. Agardh 1894 p. 31; Henning Petersen 1908 p. 70, 1911 p. 101. Hormoceras fruticulosum Kützing, Linnæa 1841 p. 734, Spec. Algar. 1849, p. 676, Tab. phyc. 12 1862, pl. 73. Dr. PETERSEN distinguishes the following forms: a, dichotoma H. Ptrsn. 1911 p. 71, H. Ptrsn. 1908, Tab. IV Fig. 2). Branches dichotomous or main stems may be developed. 8, penicillata (Aresch.) H. Ptrsn. 1908 Tab. IV Fig. 3; 1911 Plate I Fig. 4. (Hormoceras fruticulosum Kitz. sensu stricto et Ceramium penicillatum Aresch.; C. penicillatum f. fasciculata Kylin 1907 p. 177). Very distinct main axes with lateral distichous shorter bushels. The third form described in 1908, f. rubroides H. Ptrsn., has been withdrawn by Dr. PETERSEN as, on closer examination, it turned out to comprise two distinct species, most of the specimens belonging to C. Boergesenü, one to C. atlanticum. C. fruticulosum occurs in the Northern Danish waters with comparatively high salinity. It has been met with in all seasons but most frequently in summer. It reaches a length of 9 to 13 cm. It was found sterile in winter (December), and spring (April), with tetrasporangia in May to October, with cystocarps in June to August; antheridia were met with in July. Antheridia may occur in the same in- dividuals as the cystocarps; they cover completely the joints of the upper part of the branches. In female plants spermatia may be found adhering in great number to sterile hairs in their whole extent (fig. 309). Sexual specimens are at least just as common as tetrasporiferous ones. The species occurs always near the low-water mark where it may be rather abundant, in particular in exposed localities, in the Skagerak often in company with Polysiphonia Brodiei. The two varieties have much the same distribution (Skagerak, northern Kattegat) and occur often in the same locality connected with intermediate forms. Localities. Ns: Thyboron harbour, outside of W. mole (3). — Sk: Hanstholm, 2 m (3); Bra- gerne, 2m (8); Lønstrup (8); Hirshals, mole and stones («, 8): Højen («). — Kn: Harbour of Skagen (&, B); harbour of Hirsholm («); Deget («) (Boye Petersen); Rønnerne N. of Frederikshavn; Busserey, in Ascophyllum nodosum (8); harbour of Frederikshavn («, 8, outside of S. mole); off Frederikshavn (©) (A. Otterstrom); Østerby harbour, Læsø («); harbour of Sæby («). 386 17. Ceramium septentrionale Henn. Petersen. Henn. Petersen 1911 p. 110, figs. II—IV.' C. circinnatum Kützing f. borealis Foslie, The norweg. forms of Ceramium. D. kgl. norske Vidensk. Selsk. Skrifter 1893, Trondhjem 1894 p. 9. Having examined Fostte’s original specimens of the above named form I must consider this form as belonging to C. septentrionale described by me in 1911. It differs much from C. circinnatum which is characterised by downward growing zones. C. septentrionale is characterised by very high cortical bands, often reaching a height of 1—2 mm. (HENN. PETERSEN). The Danish specimens referred to this species are all older specimens reaching a length of 13 cm, collected in July and August, with tetrasporangia and cystocarps. The tetrasporangia are cruciately divided. A specimen still in growth, with cystocarps, collected by A. OTTERSTROM off Frederikshavn in Aug. 1902, formerly referred to C. fruticulosum f. dichotoma and represented under this name in Ceram. Stud. 1911 pl. I fig. 1 is now referred with some doubt by Dr. PETERSEN to C. rescissum Kylin. Localities. Kn: Near Hjellen 6—7 m (H. E. P.), Københavner Rev (Boye Petersen) and Borre- bjergs Rev (H. E. P.) near Frederikshavn. 18. Ceramium rubrum (Huds.) Agardh. Henning Petersen 1908 pp- 73 and 93, Plate IV Figs. 5, 6, Plates V—VII: id. 1911 p.113, Plates III, IV, V Figs. 25, 27—30. Whereas in 1908 I referred certain forms with partly separate cortical bands to this species, I now judge it better to exclude such forms. Distinct bands have been met with in certain forms from deeper water, which in 1908 were named f. decurrentoides, and further in f. irregularis subf. subcorticata. As to the latter I am at present in doubt but I hope to contribute later to the question of its systematical position. On the other hand I do not doubt that f. decurrentoides cannot be referred to C. rubrum, and I have therefore described it as a new species, C. abyssale (p. 384). As a new form is distinguished f. furcata which seems to be a f. irregularis developed from f. prolifera; it has a similar occurrence to this. It is characterised by robust branches and often straight apices with long forcipes. In certain cases it resembles C. rubrum f. linearis H. Ptrsn. 1911, p. 116 fig. VI, pl. IV fig. 21. Another form new in the Danish flora is f. fasciculata. HENN. PETERSEN. The numerous forms occurring in the Danish waters of this widely spread species have been treated at length by Dr. PETERSEN (1908 pp. 73 et seq.). All the forms now distinguished by this author are named below. The forms prolifera, secundata and pedicellata (virgata) have only been met with from Ns and SK except f. prolifera, which has also been found in the Limfjord (N. side of Fur). * In Cer. Stud. 1911, the pl. V fig. 26 is given as representing C. septentrionale, but this is er- roneous; the figure in question represents either a new species or a particular form of C. rubrum (H. Ptrsn.) 387 Forma fasciculata H. Ptrsn. 1911 pp. 114, 116, pl. IV fig. 23. Habit of €. fruti- culosum f. penicillata. Localities. Ns: Thyborøn, groin. — Kn: Østerby harbour, Læsø. Forma modificata H. Ptrsn. Localities. Sk: Hirshals. — Lf: Common. — Kn: Common along the east coast of Jutland from Skagen to Sæby; Læsø Trindel. — Km: Asaa. Forma subtypica H. Ptrsn. New localities. Sk: Off Hojen. — Ke: Gilleleje. Km. Ks. Sa. Lb: Bogense, har- bour. — Sf. Sb: Lundeborg, harbour. — Sm: Nykøbing F. — Su: SB, Flinterenden, 8,5 m. Forma furcata H. Ptrsn. n. f., a vigorous f. irregularis with long straight ends of branches. The plant represented 1908 pl. 7 fig. 3 approaches to this form. (Henn. Petersen). Localities. Sk: Off Hirshals, 14 m. — Lf: Nykobing Mors. — Kn: Hirsholm, E. side of Tyskerens Rev (18 cm long). Forma irregularis H. Ptrsn. Localities. Lf: MD, off Doverodde. — Kn S. of Hirsholm. — Ke: Off Gilleleje. — Ks: RL, Isefjord. — Sa: Kyholm, Korshavn, Hofmansgave. — Lb: Off Stenderup; CC, Hornenæs. — Sf: Birkholm. — Sb: MN, N. of Asnæs; Lerchenborg (O. Smith), Kerteminde. — Sm: Guldborgsund; Petersværft. — Su: Hellebæk (Joh. Lange); RH, Knollen; SB, Flinterenden. — Bw: S. side of Als; cE, S. of Als, 13 m; UP, off Kramnisse Gab; Gedser. — Bm: Hesnæs; QZ, off Moens light-house; Stevns; QF, S. of Saltholm; RG. Forma irregularis subcorticata H. Ptrsn. Localities. Km: Boels Rev off Randers Fjord. — Su: BQ, off Ellekilde; PS, off Charlottenlund. — Bm: QG, off Bredegrund; QP, Kalkgrund; QR, Gyldenloves Flak; RB, within Hollænder Grund. — Bb: SQ, S. of Broens Rev, 9 m. Forma baltica H. Ptrsn. Localities. Bw: UL, Ojet, 20 m. — Bm: QY, Bjelkes Flak; RC, within Danneskiold; QG, off Bredgrund. — Bb: Rønne; SH, Rønne Banke; SK, Hojbratterne, 11m; YG, Arnager Rev; SQ, S. of Broens Rev, 9 m; off Allinge, off Gudhjem; Christianso; That. Forma radians H. Ptrsn. New localities. Lf. — Sa: Hofmansgave. — Lb: E. side of Aarosund. — Sf. — Bw: bv, N.E. of Kobbel Skov. Forma divaricata H. Ptrsn. New localities. Lb: Near Fæno Kalv; Augustenborg Fjord.' ‘19. C. rescissum Kylin. The above (p. 386) named specimen collected by Mr. A. OTTERSTROM at Frederikshavn, earlier referred by me to C. fruliculosum f. dichotoma (1911 Tab. I fig. 1) must probably be referred to C. rescissum Kylin (1907, p. 182). This species is in my opinion nearly allied to C. seplen- trionale H. Ptrsn., but the latter differs from it by another habit, caused in particular by the straight or little branched apices. HENNING PETERSEN (Note added during printing). 388 Rhodochorton Nägeli. The systematical position of the genus Rhodochorton is undecided owing to the fact that cystocarps are unknown, and it is even uncertain whether its place is rightly within the Ceramiaceæ. There is much resemblance to certain species of Acrochetium (Chantransia’) of the family Helminthocladiaceæ, and transfers have in reality taken place between the two genera. Thus, Rhodochorton chantransioides has been transferred to the genus Chantransia by Kyrın in 1906, I have judged it ne- cessary to transfer Rh. seiriolanum Gibs. to the same genus (see below, p. 390), and I think that it may be necessary also with Rh. endophyticum Kylin (1907, p. 188) which has only monosporangia, no tetrasporangia. The cell structure usually gives good distinctive characters between the two genera, most of the species of Acrochetium having one chromatophore with a py- renoid, while Rhodochorton has several band-like chromatophores. However, as shown by Kuckuck (1897, p. 21), Rh. floridulum has several stellate chromatophores con- taining a central pyrenoid, which organ is otherwise only known within the Hel- minthocladiaceæ. On the other hand, the species of Acrochetium subg. Grania have several ribbon-shaped, more or less spiral-shaped chromatophores without pyrenoids in each cell. Antheridia have hitherto not been observed in the genus Rhodochorton. As mentioned below, they have now been detected in Rh. penicilliforme; these organs give no indication of the systematic position of the genus as they are in accordance with the antheridia of other Ceramiaceæ and of Acrochætium as well. The discovery of the antheridia raises the hope that cystocarps may also be found. The sporangia are always first divided by a transversal wall and afterwards by two vertical ones. The same mode of division occurs in Acrochetium and in Anti- thamnion as well. 1. Rhodochorton penicilliforme (Kjellm.) K. Rosenv. L. Kolderup Rosenvinge, Les Algues marines du Groenland. Ann. d. sc. nat. Bot. 7° série tome 19, 1894, p- 66; id., Deuxième Mém. Alg. mar. Groenl. 1898, p. 23; F. Borgesen, Mar. Alg. Fer. 1902, p. 389. Thamnidium mesocarpum f. penicilliformis Kjellman, Spetsb. Thallof. I, Bih. K. Sv. Vet. Akad. Handl. Bd. 3 No. 7, 1875, p. 30. Rhodochorton mesocarpum f. penicilliformis Kjellman, N. Isl. Algfl., 1883, p. 235 (Alg. Arct. Sea p. 187), tab. 16 figs. 6—7; Kolderup Rosenvinge, Gronlands Havalger, 1893, p. 792. The species is easily recognisable by its basal system composed of regularly radiating connate. filaments; it has been figured by myself (1893, fig.9 A) and BORGESEN (1. c.). Transverse fusions between cells belonging to different rows were repeatedly observed (fig. 325). The free filaments project in dense tufts or more scattered. In several cases they were unbranched and sterile; they are 9—12 (—14) x * Though I do not see the necessity of exchanging the old name Chantransia, which has been autorized by long spending, with the later Acrochetium, I here follow the modern authors in using the latter name. 389 thick. The cells are usually 11/,—3 times as long as broad; they contain one nucleus and several more or less elongated disc-shaped or ribbon-shaped chromatophores (fig. 326). The sporangia are usually, as figured by KJELLMAN (N. I. Alsfl. 1883, fig. 6—7), terminal on short lateral branches mostly C « given off from the upper part of the otherwise unbranched erect CAD filaments. But they may also be terminal on these filaments or, ici more rarely, terminal on longer lateral branches. The spor- DE Rhodochorton penicilliforme. angiferous branchlets may be branched; KJELLMAN has figured pasal layer showing cell- such a case (I. c. fig. 7). In specimens from the Little Belt AOQEL LUE near Feng Kalv (no. 1365) I found several cases of branched branchlets, the branchlets of the second order terminating also with a sporangium (fig. 327). The sporangia are first divided by a transversal wall and afterwards by two vertical ones which are never in the same plain. The sporangia are (25—) 29—32 (—35) u = long, (21—) 23— 25 (—27) u broad. After evacuation of the spores a new sporangium may arise within the empty spor- angial wall by budding from the next cell (fig. 326). In the nam- ed specimens from the Little Belt (no. 1365), growing on Fig. 326. Phyllophora mem- pee ror Dent: branifolia gather- cilliforme. Young 5 sporangium growing ed in 13 meters’ out within the wall å of an emptied spor- depth In June angium. 625 : 1. 1891, antheridia were found besides tetrasporangia. They occurred in small clusters in the same specimens which bore tetrasporangia and in the neighbourhood of these, sometimes even on the same lateral branch. The antheridial clusters are usually lateral, more rarely terminal on the Fig. 327. Rhodochorton penicilliforme. Upper ends of upright filaments with tetrasporangia and antheridia. B 230 :1, the others $90: 1. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VIL. 3. 50 390 erect filaments (fig. 327) or on lateral branches. The lateral branches bearing an- theridial clusters are short-celled. The antheridial clusters consist of short, recurved filaments composed of short, rounded cells and bearing on their convex side a small number of one- or two-celled short branches bearing together with the main axis of the cluster anumber of antheridia on the upper side and giving to the cluster a corymbose appearance. The antheridia are ovate, 6—7 w long, 4—5,5 w broad; they contain a rather large nucleus. As these organs have only been observed in specimens conserved in alcohol, their colour could not be ascertained, but they seem to contain no chromatophores. | Female sex organs have not been observed. The species has been found growing on Phyllophora membranifolia, Ph. Brodiei and Ph. rubens, further on the chitinous membranes of Tubularia sp. and Abielaria abielina, in 5 to 25 meters’ depth. A membrane agreeing exactly with the basal layer of this species, but without erect filaments, was found growing on a specimen of Cladophora rupestris gathered near Kerteminde. — The species was found with sporangia in May, June, September (unripe) and November. Localities. Kn: Near Hirsholm, 11 met.; Nordostrev by Hirsholm. — Ke: IT and EV, Groves Flak, 23—25 met.; IQ, Fladen. — Ks: Nakkehoved, 22. Nov. 1827, (Lyngbye). — Sa: MS, south of Klophagen, 15 m. — Lb: North of Fæno Kalv, 13 m; off Stenderup; dQ, bank south of Lyo, 22 m. — Sb: LL, off Brolykke by Kerteminde, on Cladophora rupestris, without free filaments; determination uncertain; UH, east of Langeland. — Bw: cE, Middelgrund south of Als, 13—15 m. Rhodochorton seiriolanum Gibs., described in 1890 by Harvey Gipson (Journ. Linn. Soc. Bot. Vol. 28, p. 204) has a monostromatical layer resembling that of Rh. penicilliforme. In a specimen of the same species from the Fsröes kindly communicated to me by Dr. F. BORGESEN I found that the cells contain one single chromatophore with a thick central portion in- cluding a pyrenoid. The species must certainly be referred to the genus Chantransia (Acro- chetium). 2. Rhodochorton Rothii (Turton) Nägeli. Nägeli, 1861, p. 356, Taf. I Figs. 1, 3; Reinke, Algenfl. westl. Ostsee, 1889, p. 22; H. Gibson, Developm. of the sporang. in Rhodochorton Rothii. Journ. Linn. Soc. Bot. Vol. 28, 1891, p. 201; Kuckuck, 1897, p. 20, fig. 5 (cell contents); Børgesen, Mar. Alg. Fzerées, 1902, p. 390. Conferva Rothii Turton, System of Nature VI, p. 1806 (teste Dillwyn); Dillwyn, Brit. Conf., 1809, plate 73. Callithamnion Rothii Lyngbye, Tent., p. 129, Tab. 41 A; Hornemann, Flor. Dan. tab. 2261, 2—3; Harvey, Phye. Brit. Vol. I, 1846, Plate 120 B; J. Agardh, 1851, p. 17; Kützing, Tab. phye. Vol. XI, 1861, pl. 62 I. Thamnidium Rothi Thuret, in Le Jolis, Alg. mar. de Cherbourg, 1861, p. 111, Pl. V. This species occurs frequently in the littoral zone where it forms purple velvety patches e. g. under the Fucus bushes. These patches consist of creeping filaments from which arise erect filaments which are usually without branches below. The creeping filaments may be composed of short inflated cells (fig. 328) or they may be thinner, composed of rather long cells (fig. 330). The erect filaments are usually given 391 off from the middlemost part of the cells of the creeping filaments. Descending filaments are sometimes given off from the lower part of the erect filaments; they have the same appearance as the creeping ones and usually issue from the lower end of the cells while the erect branches are pro- duced at their upper end. Exceptions from this rule and transitional forms between the erect and the descending or creeping filaments may sometimes occur. Thus, creeping filaments may arise from the upper end of a cell, and erect filaments may change into a creep- ing one (fig. 330 A). The erect filaments are usually 10—15 w thick (6—17 w), and the thickness is essentially the same in all the Danish waters; at Bornholm, however, the thickness is on an average a little smaller, 6—12 w. The cells contain a single nucleus and a number of small parietal chromatophores without pyrenoid (Kuckuck, |. c.). In the older transversal walls a refringent ring like that described by me in Rho- dochorton islandicum K. Rosenv.! may sometimes appear. A vegetative propagation is some- times realised by fragments of the thallus consisting of a branched fila- ment loosening from the mother plant and producing at the surface of frac- ture a downward growing filament (figs. 329, 330 E), becoming thus “‘cutt- ings” such as those described by me in Rhodochorton islandicum, |. c. p. 67. The middlemost cell in fig. 330 D is perhaps preparing the formation of Fig. 328. Rhodochorton Ro- thii, from Born- holm. Creeping filament giving off two erect filaments. The latter have been regenerated after the apical part has died. 270 :1. such a cutting, giving rise to a small rhizoid penetrat- ing into the subjacent cell. These cuttings were principally found in specimens collected at Copen- hagen (Frederiksholms Kanal) in September.” The sporangia are usually clustered at the ends Fig. 329. Rhodochorton Rothü. Plant probably arisen by regeneration of an isolated part of the frond. 200 :1. ! Note sur une Floridée aérienne. Bot. Tidsskr. Vol. 23, 1900, p. 67. of the erect filaments, as admirably represented in LE Jorıs Liste, pl. V, but they may also be more scattered in the upper end of these filaments. They ? SvEDELIUS (Östersj. Algflora, 1901, p. 129) mentions the “cuttings” described by me in Rh. is- landieum as stolons; they are, however, no stolons, but fragments of ordinary filaments loosening by splitting of a transversal wall, and germinating by giving rise to creeping filaments. 50 392. are usually 25—28 w long, 14—19 w broad. The longest sporangium which was met with (Middelfart, April) measured 36 w in length. The sporangium is first divided Fig. 330. Rhodochorton Rothii. Parts of upright filaments with upright and descending or creeping branches. In E regeneration of loosened filament by formation of descending filaments. 270 : 1. by a transversal wall, afterwards by two longitudinal ones. The spor- angia are probably produced in autumn; they were found ripe in the months January to May, empty in June. In specimens collected at Bornholm as late as August a few sporangia were still present, while the greater part had emptied and were fallen off. And specimens found by LYNGBYE near Hesselg in the southern Kattegat in July 1832, growing on Phyllophora Brodiei, still bore ripe sporangia. During and after the fructification new long erect branches may be produced from the sporangial cluster, between and under the sporangia, growing out to a bundle of long filaments. The erect filaments attain only a length of 6mm. Mr. Boye PE- TERSEN has, however, given me a specimen gathered at Middelfart in the beginning of July, measuring 17 mm. It reminds one very much of Rh.intermedium KJELLMAN (Spetsb. mar. klorof. Thallof. I, 1875, p. 28, Nor. Ish. Algfl. 1883, p. 231 pl. 15 fig. 8), which possibly is not speci- fically distinct from Rh. Rothü. As the specimen in question is sterile, a closer comparison with KJELL- MAN'S plant cannot be made. R. Rothü is perennial. It occurs principally in the littoral zone be- tween middle and low-water mark, but it has also been found in the sublittoral zone to a depth of 36 m; in this zone, however, it does not occur so abundantly as in the littoral zone. In exposed places on the rocky coast of Bornholm and the neighbouring Christiansø it may ascend 2 or 3 meters above the sea level, usually associated with Verrucaria maura and SAS Hildenbrandia prototypus. Here it forms velvety patches of the usual aspect, but the erect filaments are short, about 1 mm, simple or little branched, thin, usually 7—10 u broad, the cells being about twice as long as broad (fig. 328). The lower part of the filaments are sometimes moniliform, consisting of short inflated cells scarcely longer than broad. These supralittoral specimens thus show no resemblance to Rhodochorton islandicum. — The species is usually found growing on rocks and stones, further on wood (in harbours), more rarely on Mytilus and the hapters and stipe of Laminaria hyperborea and L. digitata, further on Phyllophora Brodiwi, partly on a Bryozoan on this. — In three localities in the North Sea, W. of the Limfjord, very small specimens of a Rhodochorton were found growing on Flustra foliacea, forming small tufts reaching only a height of 180 «. They were supposed to be much reduced specimens of Rh. Rothü. The creeping filaments were often more or less densely united into a pseudoparenchymatic layer reminding one somewhat of that in Rh. membranaceum, but they were creeping on the surface of the skeleton of the Bryozoan, not penetrating it as in the last-named species, and the free, erect filaments were thicker (6—9 «, most frequently 7—8 w). Sporangia were not present, only stipes of shed scattered sporangia (Sept.—Oct.). — The species has been met with in almost all the Danish waters and is probably widely spread except in the Limfjord (and other fjords). Localities. Ns: eE, 12 miles N.W. by N. of Bovbjerg light-house, 16 m; dZ, 17 miles W. °/s N. of Lodbjerg light-house, 36 m; eQ, 8 miles NW. by W. ‘/2 W. of Lodbjerg light-house, 27 m, in all lo- calities on Flustra foliacea. — Sk: Hirshals, reef, under Fucus. — Kn: Tyskerens reef and N.E. reef by Hirsholm, Frederikshavn, moles; Busserev; off Laurs Rev, c. 10 m, on Laminaria digitata; Osterby harbour, Læso; fG, Tonneberg Banke, 15 m. — Ks: Grenaa, harbour; Nordvest-Renden by Hesselo, on Phylloph. Brodiæi (Lyngbye). — Sa: PG, west of Hatterrev, c. 8m; north side of Refsnæs, 19 m, on Mytilus (C. H. Ostenfeld). — Lb: Baaring, harbour; Bogense, harbour; Fredericia (Hofm. Bang); Middel- fart, harbour; Kongebro; Snoghøj, harbour; dH’, east of Hesteskoen, 18—19 m, on Phyllophora. — Sb: Kjerteminde, harbour; near Sprogø, 10—28 m (C. H. Ostenfeld); near Vresen, on Mytilus, 8—9 m (C. H. Ostenfeld); US’, Langelandsbelt, 20 m. — Su: København, Frederiksholms Kanal. — Bm: Køge, harbour. — Bb: Davids Banke, 29 m; near Hammershus, up to 2m above the sea level; Ro, “den vaade Ovn”, at the entrance to “den sorte Gryde” up to 3 m, Helligdomsklipperne (Liebman, J. Hartz, !); Græsholm at Christiansø, up to 2 m above sea level. 3. Khodochorton membranaceum Magnus. Callithamnion (Rhodochorton) membranaceum Magnus, Die botan. Ergebnisse der Nordseefahrt 1872. II. Jahresber. d. Komm. z. Unters. d. deutsch. Meere in Kiel. Berlin 1874, p. 67, Taf. II figs. 7—15; Collins, Notes on New England Marine Algæ II, 1883, p. 56 (Bull. Torr. Bot. Club, Vol. X); Ström- felt, Botaniska Notiser 1887, p. 109; Kolderup Rosenvinge, Gronlands Havalger 1893. Meddel. om Gronland III. 3, p. 794; Kuckuck, Beitr. 1897, p. 13. As shown by CoLLıns, STRÖMFELT and Kuckuck (ll. cc.), the vegetative fila- ments live in the chitinous walls of various Hydroids. In the Danish waters the species is most frequently found in Sertularia pumila, further in Abietaria abielina (North Sea, Skagerak and Kattegat), Tubularia, Hydrallmania falcata (North Sea), 394 Laomedea, Thujaria Thuja. When growing in Sertularia, the filaments to a great extent fuse together into the membranes first described by Macnus. In the tubes of -Tubularia they may for long stretches remain separate, consisting of long cylindrical cells and giving rise to numerous, often opposite, divaricate branches (fig. 331). Specimens growing in the test of Laomedea never fus- ed into membranes; the filaments growing in the soft substance between the outer and the inner membrane of the wall were curled and consisting of long narrow cells, while the filaments situated near the surface were usually composed of broader and shorter cells (fig. 332). In these specimens foldings of the membrane were not observed probably owing to the soft consistence of the medium, while they are frequently met with in the filaments growing in the firmer tubes of Sertularia Fig. 331. and Tubularia. MAGNus (l. c. p. 67) explains these fold- OOH OT 2 RAD CEE ings as caused by the surrounding cells of the same Growing in the tube-wall of Tubu- 5 ag N s x Jaria, 310.:1. species hindering the extension of the membranes in the places where the filaments are densely crowded. The foldings are, however, also produced when the filaments are growing separately, as f. inst. in the tubes of Tubularia (fig. 331), in which case the fold- ings must be caused by the re- sistance of the chitinous membrane in which they grow. As empha- sised by Kuckuck (1. c. p. 23), the penetration of the filaments into the membrane of the Hydroid must take place by means of an en- zyme dissolving the chitine, but this enzyme is probably only se- creted by the young cells, and the older cells are therefore only able to realise their growth by folding their walls when imbedded in chitine on all sides. As shown by Kuckuck (1897) the cells contain several ribbon-shaped chromato- phores (comp. fig. 333). The free fertile filaments are always short in the specimens Fig. 332. \ = 2 å 5 = Rhodochorton membranaceum, growing in the test of Laomedea at growing in Sertularia pumila, 7-84 Hirsholm. On the right a tuft of sporangiferous filaments, 310 :1. Fig. 333. Rhodochorton membrana- ceum. Living cell showing chromatophores and nu- cleus (nj. 675 : 1. thick, frequently extremely short and unbranched, AN . . SRE consisting of one = N or a small num- 5 ber of short cells EN: SRE FE CRD £ Øg Rhodochorton membranaceum. Fromthe North Rhodochorton membranaceum, grow- and terminating Sea, aF, growing in Abietaria abietina. A, port- ing in Abietaria abietina off Refsnæs. with a sporangium. ion of basal layer with a fertile branch: B; sect- A, free filament with sporangia. Band ion of the wall of Abietaria showing the intra- C, cells showing chromatophores. A Or they may be matrical growth of the Rhodochorton. 390 : 1. 230 : 1. B, C 625: 1. branched, but the primary filament then always bears a terminal sporangium, and the branches also end with a sporangium (fig. 334, comp. Kuckuck, I. c. p. 16—17, fig. 2). The free filaments may behave in the same manner when the species is growing in other Hydroids; but in the plants infesting Abietaria abietina, the free filaments are sometimes much longer, ending in a long sterile apical cell, while the sporangia are terminal on short lateral branches or sometimes also on branches of the second order. Kuckuck has described such specimens found growing in the same Hydroid (1. c. p. 17—19, fig. 3); he concludes, in accordance with me, that they must be referred to Rhodochorton membranaceum, not to a special form of it. Hav- ing found similar specimens in an Abietaria abielina dredged at PF off Refsnæs (Sa)! (fig. 335), I have recently been in doubt. The sum of characters found in ! Similar specimens have been recently found in cL, N.E. of Sprogø. these specimens, the free filaments emerging singly, not in bunches, the cells of these filaments being longer, the chromatophores of the long cells being sometimes: partly spiral, the sporangia never being terminal on the principal filaments, give these specimens an appearance so different from those growing in Sertularia pumila that one is tempted to regard them as a distinct form. On the other hand, it must be admitted that the said Abietaria abietina covered with numerous free filaments of the described appearance bore also shorter and very short filaments with terminal sporangia, agreeing perfectly with those typical of the species. It must therefore be assumed that the species under particularly favourable conditions, which are some- times realised when it is growing in Abietaria abietina, produces longer fertile fil- aments with longer cells and without terminal sporangia. These filaments remind one rather of Rhodochorton chantransioides Rke. which, as shown by Kyrın (Z. Kenntnis ein. schwed. Chantransia-Arten, Botan. Stud. tilägn. Kjellman, Upsala 1906, p. 118) must be regarded as the asexual form of Chantransia efflorescens, an opinion which I have supported in 1909 (Mar. Alg. D. I, p. 137). Monosporangia were, how- ever, not found in the form growing in Abietaria abietina, and the free filaments of this plant differed otherwise by greater thickness (6,5—8 u), by the shape of the chromatophores being only exceptionally and partly spiral and by the tetrasporangia being larger, 25—30 w long, 12—17 w broad. The sporangia in the specimens growing in Sertularia pumila were 17—-21 (25) u long, (11) 13—15,5 w broad; in those growing in Sertularia pumila and Tubularia they were 17—30 (31) w long, 12—19 (20) u broad. The fact that the size of the sporangia is rather variable in the same specimen suggests that the sporangia in- crease in size after division. Kuckuck found as a rare case a hyaline hair, like those common in Acroche- lium (l. c. p. 17, fig. 2E). I never observed these organs. The great resemblance with Acrochetium efflorescens suggests that the species might perhaps be referred to the genus Acrochætium. A sponge dredged in Skagerak off Hirshals (possibly Chalina oculata) showed some purple spots, the largest abt. 11/2 cm long. These spots are due to an alga growing in the chitinous skeleton in a similar manner to Rhodochorton in the hy- droids, and probably identical with this species. They consist of branched filaments, mostly running immediately under the surface, but also deeper, partly distinct, partly fusing together in parenchymatous plates. Some cells showed foldings of the walls. Free filaments were not found, only numerous short round protuberances, prob- ably checked rudiments of free filaments. For want of fructification a conclusive determination is not possible. The species has been found in all the Danish waters with the exception of the inner parts of the Baltic, from low-water mark to 38 meters’ depth. It has been found with sporangia in all depths and in all seasons: in the specimens growing in Abie- taria collected in September and October in the North Sea and Skagerak, the spor- 397 angia were, however, thrown off. In small depth it occurs only in shaded places, particularly in Sertularia growing on the older parts of Fucus (serralus). © Localities. NS: aF, off Thyborøn 14/2 miles, 31 met. in Abietaria abietina'; aG, off Thyborøn 19'/2 miles, 38 met., in Hydrallmania falcata; dZ, 17 miles W. */« N. of Lodbjerg light-house, 36 m; eQ, 27m; eO, 23 m, in Abietaria abiet. and Hydrallmania fale.; aD, off Lodbjerg, 23,5 m; XR, off Orhage. — Sk: eV, 6 miles N. by E. of Hanstholm light-house, 22 m, in Thujaria Thuja; off Hirshals in Abiet. ab. (Børgesen, !). — Lf: ZS, off Kobberod; XU, W. of Oddesund. — Kn: Various places near Hirsholm, partly in Laomedea; KC, Krageskovs Rev; Frederikshavn; Marens Rey. — Ke: IQ, Fladen, in Abiet. ab.; : EV, Groves Flak; ER, Fyrbanken, east of Anholt, 28m; HY, store Middelgrund. — Km: XF, Læsø Rende; bK, N.W. of Auholt, 15 m, in Tubularia; BK, Tangen; BH, off Gjerrild Klint, in Tubularia. Ks: OU, Schultz’s Grund; GF, Sjællands Rev; D, gronne Revle; El, entrance to Isefjord: Lammefjord. — Sa: Bjarkes Grund; PC, between Sejero and Ordrups Nes; PF, off Refsnæs, 18—21 m, on Abiet. abiet. (long free filaments); MP, Falske Bolsax. — Lb: Bjornsknude by Vejlefjord; near Damgaard, 13 m, in Tubularia; Linderum, dG, Hesteskoen, N.E. of Als. — Sb: GS, Lysegrundene; LK, Elefantgrund; Kjerteminde; between Korsor and Sprogo, “22—32 fathoms” (Magnus 1872); cL, N.E, of Sprogo, 25—27 m, in Abietaria abietina; DN, Vengeance Grund; UF, Hov Sand; Lohals; Spodsbjerg. — Su: BQ, off Elle- kilde; SB, Flinterenden. — Bw: LE and UY, Vejsnæs Flak. General remarks on the Ceramiaceæ. Referring the reader to the quoted works of Scumirz and HAUPTFLEISCH and ÖLTMANNS for the general morphology and biology of the Ceramiaceæ, I shall here only advance some remarks on some special subjects, based upon observations of the Danish species. 1. Number of nuelei. The cells in the majority of the species contain a single nucleus. In Callithamnion corymbosum the young cells contain a single nucleus, but at a certain distance from the top the nuclei divide without a subsequent cell-division, and by continued divisions of the nuclei the old cells become multinucleate, the nuclei being uniformly distributed over the cell. The same takes place in Callitham- nion tetragonum, but the said division of the nuclei begins earlier and may occur already in the apical cell, which often contains two nuclei in a resting stage before any sign of cell-division is to be seen. In both species the downward growing cortical filaments consist from the first of multinucleate cells. In Spermothamnion repens all the cells contain several nuclei, also the apical cells and the mother-cells of the branches. On the other hand the reproductive cells contain from the first one nucleus only. As far as I have ascertained, this is not realized by degeneration of nuclei in an originally multinucleate cell but so that the divisions of the nuclei do not keep pace with the cell-divisions at the transition from the vegetative to the fertile phase, in consequence of which the number of nuclei in the cells diminishes and is finally one in the young fertile cells. “When no host is indicated the plant was found in Sertularia pumila. D. K, D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII, 3. 51 398 2. Cell-fusions. Secondary pits in the cell-walls have not been observed in any of the Danish species of Ceramiaceæ. Cell-fusions like those occurring in many Cryptonemiales (comp. part II p.279) have only been met with in Rhodochorton penicilliforme, where they take place between cells belonging to different rows it the basal disc. I have further in a single specimen of Callithamnion Furcellarie met with a few cases of fusion between two contiguous cells of the same filament, consequently between cells which were before connected by a central pit in the transversal wall (fig. 264). As this sort of fusion was only observed in one specimen, it must certainly be regarded as an abnormal process. 3. Hyaline unicellular hairs (comp. K. R. 1911) occur normally in almost all the species of Ceramium, in Callithamnion Brodiæi and C. corymbosum; they are only wanting in winter when the growth has ceased. They occur often in Plumaria elegans, sometimes in Spermothamnion repens and Callithamnion Furcellariæ, rarely in C. roseum and Seirospora Griffithsiana, never in Trailliella intrieata, Callithamnion Hookeri and C. tetragonum, further in the species of Antithamnion and Rhodochorton.' In Ptilota plumosa they occur only at the ends of the branches which surround the procarps. 4. The number of the auxiliary cells is usually constant. In Callithamnion there are normally two. one on each side of the carpogonial branch. In C. Fur- cellariæ and C. roseum, however, there is often only one auxiliary mother-cell, namely that which gives rise to the carpogonial branch. 5. The sporangia are lateral, sessile, or terminal on short branchlets. In C. Hookeri only have I as a rare exception found intercalary sporangia. In Trailliella intricata the sporangia are cut off by longitudinal division of the ordinary cells, a mode of formation which is not known in any other filamentous Ceramiacez; it is, however, doubtful, whether Trailliella belongs really to this family. The sporangia are usually 4-parted. 2-parted sporangia occur in Callithamnion Furcellarie and Seirospora Griffithsiana besides 4-parted, but in different plants. In the last-named species, however, a small number of tetrasporangia were met with on a plant with disporangia. The division of the tetrasporangia is either rectangular or tetrahedrical (“tri- angular”). In Antithamnion, Rhodochorton and Trailliella the sporangium is first divided by a transversal wall in two cells which afterwards are divided by vertical walls, perpendicular to the first wall. In the greater part of the Danish Ceramiaceæ (Spermothamnion, Callithamnion, Seirospora, Plumaria, Ptilota) the division is tetra- hedrical, the sporangium after the quadripartition of the nucleus being divided by six walls meeting in the centre of the sporangium. In Ceramium the division is variable, now triangular, now rectangular, and the two modes of division may occur in one and the same species: but, as shown above, the division of the cell begins only after the accomplishment of the nuclear division, and the rectangular division in Ceramium is thus a true quadripartition, while that in the three first-named genera is established by two consecutive bipartitions. * Kuckuck once met with a hyaline hair in Rhodochorton membranaceum (1897, p. 17). Re ee menden nn mn 399 Sporangia containing more than four spores were met with as rare exceptions in Spermothamnion repens and Seirospora Griffithsiana. 6. Paraspores have been met with in the following species occurring in the Danish waters: Callithamnion Hookeri, Plumaria elegans, Seirospora Griffithsiana, Ce- ramium diaphanum, C. strictum, C. Deslongchampsü, C. vertebrale. According to Schmitz and SCHILLER (1913) they occur in the Mediterranean also in Antitham- nion Plumula. Paraspores are never produced in sexual plants. The paraspore-bearing plants often bear only these organs, but in all the species in question tetrasporangia are sometimes produced by the same plants, most frequently in the Ceramium-species. In Antithamnion Plumula SCHILLER found at Triest paraspores in numerous plants which all bore tetrasporangia too. This author tries to show that the paraspores in the Ceramiaceæ must be interpreted as modified tetrasporangia, relying on the fact that they always occur on tetrasporiferous plants and that they often have the same position as the tetrasporangia. This interpretation is certainly warranted for the polysporangia in Pleonosporium which wants typical tetrasporangia, but it cannot be accepted for the true paraspores here in question. The paraspores are at their first appearance decidedly different from tetrasporangia. Whereas the latter have an especial form and early show a firm two-layered cell-wall, the shape of the young heap of paraspores is more indefinite, they have a homogeneous more soft wall and the content in an early stage is not more coloured than the vegetative cells, in Plu- maria even decidedly less coloured, while the young sporangia are deeper coloured than the vegetative cells. Further, the position of the paraspores is not always the same as that of the tetrasporangia, in particular in Ceramium which is also admitted by SCHILLER (1913 p. 149). According to this author two sorts of “paraspores” occur in Ceramium 1° polyspores and 2° true paraspores. The first named organs are produced in the cortical bands, e.g. in C. strictum and C. Deslongchampsii and according to SCHILLER arise from “eine mit einer Tetrasporangienmutterzelle iden- tische Zelle’ I. c. p. 11). I have not observed these organs that seem to be similar to the polyspores in Pleonosporium. The second sort of paraspores develop in a quite different manner. In C. strictum described by SCHILLER they arise at the tips of the branches, all the young cells, even the central cells, being transformed into paraspores. In C. diaphanum and C. strictum from the Danish waters the paraspores arise, as shown by HENN. PETERSEN, only from the peripheral cells in the cortical bands, most frequently near the upper edge of the bands, often from the marginal cells (HENN. PETERSEN 1908 p. 52, 57, figs. II, IV, comp. my fig. 313). When SCHILLER, in order to show the derivation of the paraspores in C. sirietum from the tetrasporangia, only adduces the facts that they only occur in the tetraspore-bearing plants, and that the tetraspore-formation decreases in the same degree as the paraspore-form- ation increases, it must be said that this proof is quite insufficient. The fact that ? ScHILLER’S C. strictum is certainly not the true C. strictum Grey. et Harvey. Dr. HENN. PETERSEN thinks that it is rather a form of C. diaphanum. o1* 400 the paraspores only arise in the tetraspore-bearing plants is probably connected with their number of chromosomes. Their nuclei are undoubtedly diploid, and it must be expected that they always give rise to tetraspore-bearing plants. It is in that respect interesting that in all the paraspore-producing species sexual individuals are either entirely wanting or extremely rare (Ceramium) in the Danish waters. And the fact that their development is in inverse proportion to that of the tetrasporangia is certainly the expression of a correlation similar to that existing in numerous Hepaticæ, Musci and many other plants between the sexual reproduction and the asexual propagation. 7. The occurrence of sexual organs and tetrasporangia in the same plant has been ascertained in several species in the Danish waters. It is a particularly common appearance in Spermothamnion repens, where the sexual organs almost always occur together with sporangia. In Callithamnion tetragonum too the antheridia and the procarps occur frequently in the tetraspore-bearing plants. In 1864 and 1878 Tuuret described a f. amphicarpa of C. corymbosum presenting the same combination but this form has not been observed in the Danish waters. In C. Furcellariæ I have once met with a procarp in a tetraspore-bearing plant, and in Antithamnion Plumula tetrasporangia were twice met with in a female plant. In Antithamnion boreale and Rhodochorton penicilliforme antheridia were detected, occurring in tetraspore-bearing plants, while female sex organs are still unknown. 8. Occurrence of the various organs of reproduction in the Danish waters. Sexual organs have not been met with in Callithamnion Hookeri, Seirospora Griffith- siana, Plumaria elegans and Antithamnion cruciatum, while sexual plants of these species occur elsewhere. The three first-named species propagate in the Danish waters principally by paraspores, but tetraspores have been met with in all of them. In Antithamnion cruciatum sexual organs seem altogether to be a rare occurrence. Sexual plants of Spermothamnion repens occur only in the North Sea, the Skagerak, the Kattegat and the northern part ofthe Sound while the species in the inner waters only bears tetrasporangia or is sterile. In Ceramium diaphanum, C. strietum, C. Rosen- vingü, C. Boergesenii and Antithamnion Plumula the sexual plants are much rarer than the tetraspore-bearing ones. Of Callithamnion corymbosum only sterile plants have been met with in the inner parts of the area of the species (Sm, Su south of Hveen, Baltic). 9. Vegetative propagation occurs in Rhodochorton Rothii, fragments of the erect shoots loosening and producing from the plane of detachment a downward growing filament which is able to fix the fragment as a cutting to a new substratum. Similar cuttings were observed in a culture of Seirospora Griffithsiana. 401. Fam. 12. Bonnemaisoniacex. Bonnemaisonia C. Agardh. 1. Bonnemaisonia asparagoides (Woodw.) Agardh. C. Agardh, Spee. Algar. 1821, p. 197; Harvey, Phycol. Brit. I, 1846, pl. 51; J. Agardh, Spee. g. o. Alg. II, pars III, 1863, p. 779; Cramer, Physiol.-system. Unters. üb. die Ceramiaceen. Neue Denkschr. d. allg. schweiz. Ges. f. Naturw. 20. Zürich 1864, p. 52, Taf. VIII, figs. 4—11, X, figs. 1—12; Kützing, Tab. phye. 15. Band, Taf. 32, 1865; Wille, Beitr. z. Entwick. d. phys. Gew. b. ein. Florideen. Nova Acta Leop.-Carol. Akad. 1887, p. 73, figs. 44—54; Golenkin, Algologische Notizen. Bull. soc. nat. de Moscou, N. S. VIII, 1894, p. 257; Bruns, Ber. deut. bot. Ges. 12, 1894, p. 179; Phillips, Developm. of the cystocarp in Rhodymeniales. Ann. of Botany, Vol. XI, 1897, p. 348, pl. 17 figs. 1—3; Kylin, Blasenzellen einig. Florid., Arkiv för Botanik. Bd. 14 No. 5, 1915; id., Entwicklungsgesch. u. syst. Stell. von Bonnemaisonia asparagoides. Zeitschr. f. Botanik VIII, 1916, p. 545; id., Über die Keimung der Florideensporen. Arkiv för Botanik, Bd. 14, No. 22, 1817, p. 12. Fucus Asparagoides Woodward, Trans. Linn. Soc. Vol. II p. 29, 1794. The structure and development of the alternately pinnate frond has been de- scribed by CRAMER, WILLE and Kyrın (1916). GoLENKIN, Bruns and Kyrın (1915) have described peculiar gland cells situated among the cortical cells and contain- ing a compound of iodine which is easily decomposed, producing free iodine. I have also observed, many years ago, the power of the species of giving a blue stain to paper. — According to Kyrın (1916, p. 549), rather short unicellular hairs may occur sparingly. Tetrasporangia are wanting; all specimens are monoecious sexual plants. The sexual branchlets are alternate, opposite to the alternate sterile pinnule. The an- theridia are produced on the surface of the oval male branchlets (Kyrın 1916, p. 551). The carpogonial branches develop singly on the female branches. Their development and that of the cystocarps has been followed by Kyrın (1916) who has found that it most resembles that of Wrangelia and Naccaria. OLrMANNs and Ky win think that this group of genera makes transition from the Nemalionales to the Cryptone- miales and the Gigartinales. The germination takes place, as shown by GOLENKIN and Kyrın (1917), by the formation of a basal disc, from the margin of which numerous rhizoids are given off. The formation of the erect shoots were not observed. As emphasised by Kyrın, this mode of germination is very different from that of the Rhodomelaceæ to which the Bonnemaisoniaceæ have been considered related. The species is annual. It has only been found rarely in a few localities in the northern and eastern Kattegat, in 18 to 24,5 meters depth, growing on various Algæ (Delesseria sanguinea, Polysiphonia elongata, Laminaria saccharina). The largest specimen observed (from Herthas Flak) was 13 cm long. Collected with ripe cystocarps in July and September. Localities. Kn: Herthas Flak (!, Børgesen). — Ke: VZ, Groves Flak, VY, Fladen. Fam. 13. Rhodomelacezæ. J. G. AGARDH (1863), Species, genera et ordines Floridearum. Vol. II pars 3. Lity Barren (1923), The Genus Polysiphonia, Grev., a critical revision of the British species based upon anatomy. The Journal of the Linnean Society. Vol. 46 No. 308. P. FALKENBERG (1901), Die Rhodomelaceen des Golfes von Neapel. Fauna und Flora des Golfes von Neapel. 25. Monographie. Berlin. L. Kny (1873), Ueber Axillarknospen bei Florideen. Festschr. z. Feier d. hundertj. Best. d. Ges. d. naturf. Freunde zu Berlin. L. KoLDERUP ROSENVINGE (1884), Bidrag til Polysiphonia’s Morfologi. (Résumé francais). Botan. Tidsskr. Bind 14. —, (1902), Ueber die Spiralstellungen der Rhodomelaceen. Jahrb. für wiss. Bot. Bd. 37. — , (1903), Sur les organes piliformes des Rhodomelacées. Overs. K. Danske Vidensk. Selsk. Forh. Ko- benhavn. C. NÂGELt (1846), Polysiphonia. Zeitschrift für wiss. Botanik von Schleiden und Nägeli. 3. u. 4. Heft. Zürich. R. W. Paizzirs (1896), Development of the Cystocarp in the Rhodomelaceae. II. Annals of Botany X. Fr. Schmitz und P. FALKENBERG (1897), Rhodomelaceae. Engler u. Prantl, Die natürl. Pflanzenfam. I, 2. S. YAMANOUCHI (1906), The life-history of Polysiphonia violacea. Botan. Gazette, Vol. 42 p. 401—449, plates 19—28. See further p. 297. Heterosiphonia Mont. 1. Heterosiphonia plumosa (Ellis) Batters. Batters, Catalogue of Brit. Mar. Algæ. 1902, p. 83. Conferva plumosa Ellis, Philosoph. Transact. Vol. 57, 1768, p. 424, Tab. 18, fig. c, d. Conferva coccinea Hudson, Fl. angl. Ed. 2, 1878, p. 603. Callithamnion coccineum Lyngbye, Tent., 1819, p. 144. Dasay coccinea Agardh, Spec. Alg. II, 1828, p. 119; Flora Danica tab. 2456 (1845) (f tenuis); Harvey, Phye. Brit. III, 1851, pl. 253; Areschoug, 1850, p. 42; J. Agardh, 1863, p. 1185; Kny, 1873, p. 108, Taf. II Fig. 7; Janezewski, Dev. du cystoc. d. 1. Florid: Mém. Cherbourg, Vol. XX, 1877, p. 129, pl. 4, figs. 19—21, pl. V, figs. 1—8; Buffham, Reprod. Organs, espec. Anther., Journ. Queck. micr. Club, Vol. III Ser. II 1888, p. 263, pl. XXII, figs. 19—20; Phillips, 1896, p. 187, pl. XII figs. 1—7. Trichothamnion hirsutum Kütz., Tab. phyc. 14, tab. 90. Heterosiphonia coccinea Falkenberg, 1901, p. 648, Taf. 18 Fig. 21; Kylin, 1907, p. 149. The structure and development of the frond have been described by Kny (1873) who first recognised the sympodial character of the ramification. The cells of the monosiphonous pinnules contain a number of small nuclei and numerous minute chromatophores (fig. 336). Fig. 336. The Danish specimens generally agree with 8, tenuis J. Helerosiphonia plumosa. Cell Agardh, 1. c. The older stems are usually naked, sometimes, showing chromatophores and À Ex HSL, Eli. however, beset with numerous adventitious branchlets. 403 As shown by BATTERS, I. c., the antheridia form a covering on the monosiph- onous branches with the exception of the two or three basal and the four to six term- inal cells which remain undivided. The antheridia (spermatangia) are not produced directly from the central cell, as asserted by BurrHam, but from a layer of small cells surrounding the central cell and budding the spermatangia on their outer face (fig. 337 B). As regards the development and structure of the cystocarps, reference may be made to the papers quoted of JanczEwskı and PhirLıps. The procarps are usually borne on the fourth joint from the sympodial axis (PHILLIPS), from the last joint of the pushed aside main axis which in sterile plants becomes polysiphonous (FALKENBERG). The spores of the gonimoblast are seriate. The tetrasporangia are produced in distinct stichidia arising in the upper part of the sympodia; their structure has been described by FALKENBERG (I. c. p. 649). The Danish specimens only reach a length of 10 cm. They were found growing on stony bottom in 13 to 31 meters’ depth, attached to stones or to Delesseria sinuosa or Furcellaria. It was dredged in July to September. An- theridia and tetrasporangia were found in August, young cystocarps in July. Localities. Ns: aF, off Thyboron, 14,5 miles, 31 meters. — Sk: ZK’, off Lønstrup, 4 miles, 17—19 m; YL, N.W. of Hirshals, 2,5 miles, 13 met. and deeper. — Kn: TO, Tonneberg Banke, north of Trindelen, 18 m; FF, Trindelen, 15 m. — Ke: ZG, Fladen, 18 m. — Su: Øresund, “in the deeper region of Algæ” (Lönnberg, Undersökn. rér. Oresunds djurlif, Uppsala 1898). Laurencia Lamouroux. 2 DE er Heterosiphonia plumosa. À, part of 1. Laureneia pinnatifida (Gmel.) Lamouroux. male plant: EU innansyerss section of antheridial covering. 625 : 1. Lamouroux, Essai des Thalass.. Ann. du Mus. XX, 1813 p. 130; Greville Alg. Brit. 1830 p. 108 tab. 14 figs. 1—5; Harvey Phye. Brit. pl. 55, 1846; J. Agardh 1863 p. 764; Kützing Tab. phyc. XV, 1865 tab. 66; Kolkwitz, Beitr. Biol. Flor., Wiss. Meersunters. N. F. IV Abt. Helgoland Heft 1, 1900, p. 52; Falkenberg 1901 p. 248, Taf. 23 figs. 20—36; Kylin 1907 p. 138; id. 1917 p. 20; id. 1923 p. 123. Fucus pinnatifidus Gmelin Historia Fucorum 1768, p.156 tab. 16 fig. 3; Hornemann, Flora Danica tab. 1478, 1813; Smith, English Botany Vol. VII pl. 1202, 1808. Fucus ramosissimus ete. Oeder Flor. Dan. tab. 276, 1765. Gelidium pinnatifidum Lyngbye Tent. 1819 p. 40 tab. 9 C. As regards the basal part of the frond strange discrepancies exist between the statements of the various authors. SmirH (Engl. Bot. 1808) and J. Acarpn describe it as a branched “root” (“radix fibrosa”). Turner (1808) describes it thus: Root a flat disk throwing out a few creeping fibres. GREVILLE (1830) and Harvey describe u it in a similar way; the figure of Harvey shows cylindrical feebly branched creep- ing organs radiating from the base of the stem while the disc is not distinctly visible. According to LYNGBYE (1819) the basal part is a “callus explanatus, fibris brevibus interdum instructa”. KoLkwırz found at Helgoland an extensive basal dise producing a number of distant erect shoots (1900 p. 52, WWW fig. 6), but he does not mention any creeping shoots. ” In Danish specimens I found no creeping root-like organs but only a flat basal disc becoming thinner towards the border which has an even outline. This dise may sometimes have a considerable extension and produce numerous erect shoots (fig. 338). It is early formed in the sporeling; in the young plant represented in fig. 338 À it has increased considerably in circumfer- ence and has produced four new shoots. These arise from superficial cells. The development of the erect shoots has been thor- oughly studied by FALKENBERG and Kyrın. The growing point sunk in the apical groove of the shoot produces spirally arranged trichoblasts while the lateral branches, according to FALKENBERG arise as axillary shoots of the A trichoblasts, but only of those which are placed in two longitudinal rows whereby the pinnate ramification and the compressed form of the frond arise. FALKENBERG found the trichoblasts well developed only in cystocarp- bearing specimens having ceased to grow in length and to branch. According to Kyrın they are well developed during the development of the organs of reproduction, while they are very small during the vegetative devel- ee opment of the plant. I found them well developed and sathered in September (Frederiks- Visible outside the apical groove in the specimens gath- tte be ered in July to September; they were not visible externally erect shoots (Hirshals June). 3:1. in the specimens collected in winter and spring, and in the specimens collected in May and June they were in several cases long, in other cases not visible outside. The long trichoblasts were found both in sterile and fertile specimens (fig. 338 A). The antheridia are borne on cylindrical fertile trichoblasts closely placed in cup-shaped bodies near the tips of the shoots. These trichoblasts which cover the whole surface of the cup are much more numerous than the trichoblasts produced by the growing point in the centre of the cup and FALKENBERG therefore suggests “dass hier eine verkümmerte und verkannte oder normale Achselspross-Bildung vorliegt”. The development of the antheridia has been recently described by Kyrın. The procarps arise as in the other Rhodomelace® from the second segment of 105 the trichoblasts; they are developed in trichoblasts of various position, and the cystocarps are therefore placed on the edges and on the flat sides of the frond as well. The development of the procarps and the cystocarps has been carefully studied by Kyrın (1923, pp. 125—129). In the ripe cystocarp the wall consists only of three or four cell-layers, the innermost ones being disorganised and transformed into a tough mucilage (FALKENBERG p. 246, pl. 23 figs. 20—21, KyziN p. 128 fig. 80 d). The tetrasporangia are immersed in the cortical layer of the upper ends of the frond; according to Kyrın (1923 p. 130) they arise from young cortical cells by divisions similar to those by which the spor- angia arise in the pericentral cells of Polysiphonia. The germination of the tetraspores has been examined by Kyrın Fig. 339. Laurencia pin- (1917) who showed that a pluricellular basal disc is early developed. AO Moe: The young disc is composed of connate radiating filaments, it increases tion of frond gathered in in diameter by marginal growth and early begins to produce new erect ale ie shoots by budding from the surface. The new shoots resemble the branches have . recommenced primary one (fig. 338 A). rn DL. The species has been met with in all the seasons. It occurs at low-water mark or a little deeper, down to 6,5 meters’ depth. It grows most frequently on Fucus vesiculosus and F. serratus, further on stones and more rarely on Chorda Filum a. 0. alge (Chondrus crispus, Furcellaria, Cystoclonium, and the blade of Laminaria digitata). It usually attains a length of 2 to 5 cm, more rarely up to 7 cm. The fructification takes place in summer. Antheridia have been met with in May and June, cystocarps in May to September, in the last month partly empty, and tetrasporangia in May (unripe) to August. According to GREVILLE and Harvey, the species is annual, and it may certainly frequently be so also at the Danish coasts. Young plants are to be found in summer and autumn, July to September (fig. 338 A); they produce a number of erect shoots Fig. 340. which remain sterile in autumn and winter and at the end of Laurencia pinnatifida. the winter attain a length of 3—5 cm. In winter the growth ceases ee, que but it recommences at the end of the winter. In March and reached its full size; me April the new-formed tips of the frond are easily recognised and old frond is darker, cov- sharply limited against the old frond, but only about 1 mm long ered with epiphytes. = : n 13:1. (fig. 339). In summer the new shoots have reached their full size and are distinguished from the old frond by the colour and by the want of epiphytes (fig. 340). The fertile erect fronds probably die in autumn, but the basal disc seems to be able to continue the development, growing al the margin and producing new erect fronds fructifying next year. Thus, the basal dise shown in fig. 338 B, collected in June, is probably more than one year old. The species occurs in the Danish waters with rather high salinity but requires D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk, og mathem. Afd., VII, 3. . 52 protected localities. It occurs most abundantly and most well developed in the Lim- fjord, undoubtedly owing to the high salinity and the high summer temperature; in some stony reefs in the Logstor Bredning it was found to be the characterising species. The specimens growing in very sunny localities are yellow, owing to yellow cell-sap in the outer cortical cells, while the specimens growing in shady places are red-brown. Localities. — Sk: Norre Lyngby north of Lokken, washed ashore (Ove Paulsen); Hirshals, on stones west of the mole, under Fucus vesic. and serr., and on Fue. serr. (fig. 338 B). — Lf: ZS, Nissum Bredning, off Kobbergd, Ronnen and Sondre Ron by Lemvig; Malle (J. P. Jacobsen) and MG, off Hanklit in Thisted Bredning; Sallingsund, east side of Grodde by Nykøbing and further north and south of Nykøbing; off Gronnerup; Knudshoved, Fur; off Lisehoj north coast of Fur; Ejerslev Ron, Amtoft Rev, Holmtunge Hage and Lendrup Ren in Logstor Bredning. — Kn: Hirsholm (Hornemann, !) Kélpen, Deget and Busserev by Frederikshavn; Nordre Renner; UB and ZL south-east of Nordre Ronner, 6,5 met.; stony reef by Jegens Odde. — Km: ZC, Kobbergrund, 4—4,5 m; Boels Rev between Randers Fjord and Mariager Fjord. — Sa: Ronnen in Begtrup Vig; Kalo Rev; Hofmansgave (Lyngbye, Hofm. Bang, Car. Rosenberg). Chondria Agardh (Harvey). 1. Chondria dasyphylla (Woodw.) Agardh. C. A. Agardh, Spec. Algar. Vol. I pars post. 1822, p. 350; Falkenberg, 1901, p. 197, Taf. 22, figs. 4—18. Fucus dasyphyllus Woodward, Trans. Linn. Soc. Vol. 2, 1794, p. 239 tab. 23. Laurencia dasyphylla Greville, Alg. Brit., 1830, p. 112, pl. 14, figs. 13—17; Harvey Manual, 1841, p. 70, Phye. Brit. II, 1849, pl. 152; Kützing, Phye. gener. 1843, Taf. 55 II, Tab. phye. 15. Band, 1861, Tab. 43. Chondriopsis dasyphylla J. Agardh, 1863, p. 809. The morphology of the frond and of the reproductive organs have been exhaustively treated by FALKENBERG to whose work reference may be made. The plant forms tufts, several erect shoots issuing from the base; these shoots are 10— 11 cm high. It was found growing near land in a depth of 1 meter or a little deeper. All the 29 specimens collected by me in August bore ripe tetrasporangia. One specimen only collected by J. P. JACOBSEN bore cystocarps. Localities. Ns: “Vesterhavet ved Thy” (J. P. Jacobsen). — Sk: Lokken, washed ashore; Hirs- hals, on stones east of the mole, in company with Gracilaria confervoides, Polysiphonia nigrescens, Ceramium rubrum a. 0.; west side of Hirshals, August. Polysiphonia Greville. 1. Polysiphonia ureeolata (Dillw.) Grev. Greville, Flora Edinensis 1824 p. 309; Harvey Phye. Brit. II, 1849 pl. 167; J. Agardh 1863 p. 970; Kützing Tab. phye. Bd. 13 1863 Taf. 92; Kolderup Rosenvinge 1884 p. 24 (rés. p. 4) fig. 32; Buffham 1893 p- 298; Falkenberg 1901 p.150; Kolderup Rosenvinge 1902 p. 347 pl. VI figs. 3—14; id. 1903 p. 449 figs. 2—3; Kylin 1907 p. 139; F. Tobler, Weitere Beitr. z. K. d. Florideenkeimlinge. Beih. z. Bot. Centralbl. Bd. 21 Abt. 1, 1917 Taf. 7 figs. 15 —20. ch Conferva urceolata Dillwyn Brit. Conf. p. 82, plate G (The name is originally due to Lightfoot). Hutchinsia urceolata Lyngbye Hydr. 1819 p. 110 pl. 34. Hulchinsia stricla Ag., Lyngbye Hydr. p, 115 pl. 36 (e specim.) Hutchinsia lepadicola Lyngbye Hydr. p. 113 pl. 35,c; Flora Dan. tab. 2313, 1840. Hulchinsia roseola C. Agardh Sp. Alg. p. 92. Polysiphonia formosa Suhr, Flora 1831; Harvey Phye. Brit. II, pl. 168, 1849; Kützing Tab. phye. Bd. 13 tab. 78, 1. Polysiphonia pulvinata Flora Dan. tab. 2458. 1845 (?). Polysiphonia roseola (Ag.) Areschoug Phye. 1850 p. 59. Polysiphonia lepadicola (Lyngb.) Kützing Sp. Alg. 1849 p. 807; Liebman, Kröy. Tidsskr. II Hefte 5 1839, p. 478; J. Agardh 1863 p. 945. Hutchinsia abyssina Lyngbye Rariora Codana (ed. Warming) 1880, Vidsk. Medd. fra Naturh. Foren. 1879—80 p. 227. The primary shoot of the seedling is erect but a lateral shoot is early produced at its base (fig. 341, comp. Tobler fig. 19) or sometimes two. Creeping branches appear later and form a system of procumbent shoots attached to the substratum by scattered rhizoids and giving rise to a great number of erect shoots forming a dense tuft. The procumbent branches are often very short-celled, the articles being much broader than long (fig. 342) while in other cases the articles are of equal length or a little longer than broad (fig. 343). The growing end of the decumbent branches usually grows upwards at last and becomes an erect shoot, but the pro- cumbent filaments may remain creeping for a long time, in particular in the f. lepadicola, Fig. 341. Fig. 342. Polysiphonia urceolata. Sporelings, 9 days old. In A the tricho- Polysiphonia urceolata. Lower part of an ereel blasts are arranged in a spiral turning to the right. 227 :1. branch issuing from a procumbent branch. 95:1. 52* 408 where erect shoots may be entirely wanting. The procumbent and erect shoots issuing from a procumbent one are always of endogenous origin, budding from the central cell, usually very near to the rhizoids (fig. 343). Endogenous branches also fre- quently arise from the lower part of the erect shoots (fig. 342). The rhizoids which always arise from the pericentral cells, except the first rhizoid of the sporeling, sometimes obviously testify to a shortening, the cuticle being transversely wrinkled (fig. 343). FALKENBERG has maintained that P. urceolala lacks trichoblasts (1901 p. 151). As shown by me (1903, p. 450), this may be true but only in autumn and winter, when the development of the plant has ceased, while the specimens collected in the months of March to June are normally provided with trichoblasts, and these organs may still be present in July and August. In the creeping branches, however, they Fig. 343. Polysiphonia urceolata. Procumbent branch with rhizoids and endogenous branches. 50 : 1. are always wanting. The trichoblasts show the typical structure, having the first branchlet always on the right side (fig. 346); their cells contain one nucleus and small plastids which are usually colourless but may be feebly rose-coloured in early spring or in shaded localities. They are arranged in a spiral turning to the left! but are usually separated from each other by more than one joint. The branches occur in the spirals in the place of the trichoblasts, but the relation of frequency of the two kinds of organs to each other is very variable. The erect shoots often over a long stretch only bear branches arranged in a spiral with a divergence of '/ı separated from each other by 3 to 5 joints, and the trichoblasts appear only at the upper end of the shoot intermingled with branches; but in other cases the trichoblasts appear already in the lower part of the shoots. At the upper end of the shoots in partic- ular of the fertile male and female plants, the trichoblasts may be more densely placed, each joint bearing one trichoblast. The erect filaments issuing from the creeping ones are often without primary lateral organs over a long stretch from the base, but endogenous adventitious shoots may frequently occur here (fig. 342). Trichoblasts have been met with in specimens collected near land and in spec- imens from greater depths as well (f. inst. bM, south of Hveen Su 22,5 m). They are shed in summer, when the growth is sisted. This usually takes place in June or July, but specimens in vegetative development may still be met with in August; these specimens seem, however, always to be young plants produced from spores germinated in the same season. * A rare exception is shown in fig. 341 A, where the spiral turns to the right. 409 1) Te3e5e4e2e3e3e17b3b45b4b4b3b5b10b3 5 9) 8e7e17b6b8b3b3b3b3b4b2b2b2b 3) 10b513b2b413b3b4b3b 4) 10D5D3D2b3b3d3d3182d14141414141814 5) ...b5b5(D483b3b38243d242418714218281(%)24141414 6)... OLM2O02b1O2O2O1O1 O21 M11 M1111 (0112/02 (01911111 11411 Schemes of branches of Polysiphonia urceolata. The figures signify the numbers of joints between the consecutive lateral organs. e endogenous branches; b ordinary exogenous branches; I trichoblasts; (t) basal cells of shed trichoblasts; g male trichoblasts; + tetrasporangia, the sign denotes the joint in which the sporangium is seated. ... designates that the base of the branch was not observed. 1)—3) branches of male plant from Frederikshavn April. In 1) the basal portion of the branch is procumbent; from * the shoot is erect. The endogenous branches were feebly developed. Always a divergence of 1/4. 4) and 5) from Store Middelgrund (Ke) May. 6) from Hirshals July. The young segments of the shoots are lower than in the other Danish species, but the segments producing branches are higher and cut off by more inclined walls (fig. 344). The antheridia cover the greater part of unbranched trichoblasts; these organs have a short two-celled stalk and terminate with a sterile filament composed of a small number of cells, most frequently three. A sterile branch does not occur in the antheridia-bearing trichoblasts, but I have once met with a male trichoblast bearing a fertile SEES 3 Polysiphonia urceo- branch corresponding to the first branch fate. Tip of shoot in the sterile trichoblasts (fig.345). The male ner trichoblasts are densely crowded in corym- segment is higher biform clusters at the tip of the shoots, a an each segment often bearing one trichoblast. auce a branch. The male trichoblasts often appear sudden- SEL ly without foregoing sterile trichoblasts. The procarps arise as in the other species in the second joint of the female trichoblasts, the upper part of which takes the shape of a sterile trichoblast. The third joint remains short and undivided and the first sterile branch is given off from the 4th joint, usually to the right (fig. 346). Of 33 examined female trichoblasts 26 bore the first sterile branch on the right side, 7 on the left. A cystocarp with its ostiole protracted in a cylin- drical neck is shown in fig. 247. A remnant of the sterile part of the trichoblast may sometimes be found on the fully developed cystocarp. Fig. 345. The arrangement of the tetrasporangia differs accord- Polysiphonia urceolata. Male ing to whether the filament bears trichoblasts or not. In trichoblasts, anormal, b branched. 2 2 ~ 124 : 1. the latter case the sporangia are seriate and the filament Fig. 344. Fig. 346. Polysiphonia urceolata. a, portion of female plant. b, young procarp-bearing trichoblast. 220 : 1. ae B 3:1. 410 is usually curved so that the spor- angia are placed in a row at the convex side. When trichoblasts are present, the sporangia are placed to the right of the foregoing trichoblast (fig. 348 A). The sporangia-bearing joints have 6 pericentral cells. In the trichoblast-bearing shoots a small peripherie cell is further cut off at the base of the joint; in the joint next to a trichoblast this cell is situated immediately to the right of the tricho- blast. In spore-bearing shoots without trichoblasts such a small peripheric cell was not cut off (fig. 348 B). In a female plant with fully devel- oped eystocarps containing apparently = IR, I & SC nn Ic ec ie JOO) SOC Q “4 (ea) Fig. 347. Polysiphonia urceolata. cystocarp. 68:1. normal carpospores, sporangia were here and there met with in the filaments. The sporangia were developed in the usual manner (without form- ation of a small peripheral cell) but they were small and undivided and obviously abnormal. A very remarkable case is shown in fig. 349. A trichoblast has produced an aborted procarp in its second joint but has then over it been transformed into a sporangia-bearing shoot, with incompletely developed sporangia. The third joint Fig. 348. Polysiphonia urceolata. A, portion of tetrasporiferous branch with trichoblasts. B, portion of tetrasporiferous branch without trichoblasts. C, transverse sec- tion of tetrasporiferous joint after evacuation of the telraspores. D, transverse section of a sterile joint of the same branch, with five pericentral cells. A, C, D 200 :1. Fig. 349. Polysiphonia urceolata. A female trichoblast has been transformed from the fourth joint into a tetraspore-bearing branch. 150 :1. 411 was undivided as in the normal female trichoblasts, but the following joints had produced 4 pericentral cells, and in the 7th joint the formation of sporangia was beginning. YAMANOUCHI has formerly described abnormal tetrasporangia in female plants of Polysiphonia violacea (1906 p. 425, figs. 168—171). BurrHam found anther- idia in tetrasporic plants of Pol. urceolata (1893 p. 298). Tetraspores sown in July germinated immediately and gave rise to young plants provided with trichoblasts and producing in great part one or two vigorous branches at the base (fig. 341). The sporelings obtained by Tobler (1. c.) from carpospores showed no trichoblasts. P. urceolata has been met with from low-water mark to deep water. The deepest observed localities are 31 meters in the North Sea, 26,5 m in the Eastern Kattegat and 22,5 m in the Oresund (south of Hveen). It occurs near low-water mark in all the waters except the Sound where it has only been met with in 5,7 to 22,5 meters’ depth, without doubt owing to the varying and often very low salinity of the surface water. The species is perennial through its creeping filaments. The erect, fructiferous filaments are thrown off after the evacuation of the spores, but the sterile ones may persist, and the species may be found in every season with erect filaments. The length of these varies from 1 to 15 cm and may even reach 23 cm; it does not diminish towards the limits of the occurrence of the species. — Antheridia have been met with in January to July, procarps in April to June, fully developed cystocarps in May but in particular in June to August and further in September (Skagerak), and as late as January I have met with cystocarps containing ripe carpospores by Frederikshavn. Tetraspores have been met with in May to August and in September (Hirshals). The germination takes place immediately, but the new plants seem only to fructify in the following year. The species is comparatively often found in a sterile state, but there is no general relation between the sterility and the size of the individuals. The species grows in particular on stones and is very common on moles in harbours, but it occurs too on several Algæ, in particular on the stipes of Laminaria hyperborea in the Skagerak, further on Phyllophora membranifolia, Furcellaria fasti- giata, Fucus etc., on Ascidiae and shells of molluses and barnacles. P. urceolata is not very variable. Several specimens from deep localities in the inner waters may be referred to f. roseola, remarkable by slender filaments and long joints. Small, poorly developed specimens. consisting principally of creeping filaments have been described by LYNGBYE as a particular species, Hulchinsia lepa- dicola Lyngb. (Polys. lepadicola Ag.) Localities. Ns: 6 miles S.E. to E. of Vyl light-ship, 17 m on Lam. hyperb., loose (A. C. Johan- sen); aF, off Thyboren, 31 m; Thyboron, on groins; XR, off Orhage. — Sk: Dana 2904 23 m (C. A. J.); YM’, Bragerne, 2,5 m; ZK? and ZK}, off Lønstrup, 1 and c. 9m; XO and other places off Hirshals 11—15 m; mole at Hirshals; Hojen, within the shoals. — Lf: Krik, pier; Lemvig harbour; XY and LV in Nissum Bredning; Oddesund; Thisted harbour; MH, off Skrandrup on firm clay; Nykobing and other places 412 in Sallingsund; Agersund harbour; Nibe, pier; Aalborg; Hals harbour. — Kn: Skagen harbour; Herthas Flak c. 20 m; Hirsholm; Deget; Frederikshavn harbour; off Laurs Rev; off Marens Rev; north of Læso, on Hyas (E. Bay); Trindelen (Borgesen); fG, W. of Læso Trindels light-ship. — Ke: Fladen IM, ZF, ZE, VY, 16—26,5 m; EV, south end of Groves Flak; EU, Lille Middelgrund, 14 m; IA, IB, HY, Store Middelgrund; off Gilleleje, Lyngbye (Hutchinsia lepadicola: 1. Marts 1833 in tergo Cancri Aran., and 26. Mart. 1833 in Lepad. Balano. Hutchinsia abyssina: Juni 1834 in Buccino undato and 31. Marts 1835 in testa Balani e profunditate 16 org. (30 m)); Gilleleje harbour. — Km: FL, south of Læsø Rende, 9,5 m. — Ks: Grenaa harbour; HS, Briseis Grund, 7,5—13 m; Nordvestrev by Hesselo (Lyngbye); Holbæk Fjord, on Mytilus. — Sa: KJ, south of Hjelm, 13 m; PJ, Ebeltoft Vig; PL, Wulffs Flak; Kalo Rev; FS, Vejrø Sund; PA, near Albatros, 7,5 m; PC, between Sejerø and Ordrups Nes; PF, north of Refs- næs; Hoy (O. Paulsen); Hofmansgave (Lyngbye, Hofm. Bang, C. Rosenberg); inlet to Odensefjord (Lyng- bye, Hutch. stricta). — Lb: Bogense harbour; Fredericia harbour (Hofm. Bang, !); Strib harbour; Middelfart; Fæno Sund; off Stenderup; Heilsminde; DF, Remmen; Assens harbour; Aargsund; Aarø; DA, Bojgden; CZ, Hornenæs; dH’, E. of Hesteskoen, 18—19 m; dQ, south of Lyde, 22 m; Sønderborg harbour (10 cm long). — Sf: Soby harbour; UV, north of Ere, 13 m; Aaso, Langeland; Marstal harbour; Ærø (Kjærbølling). — Sb: Kalundborg harbour; eT, Ryggen; Stavreshoved; Kerteminde harbour; Nyborg, harbour and Avernakhage; DN, Vengeance Grund, 12 m; UK, Langelandsbelt, 12 m; Spodsbjerg harbour. — Su: Hellebæk (Ørsted); Blokhus Grund north of Helsingør, 13 cm long (Boye Petersen); Helsingør (Liebman, P. lepadicola); bM, south of Hveen, 22,5 m; Taarbæk Rev, 6m. — Bw: Sonderhav and Brunsnæs in Flensborg Fjord, piers; pier at the East end of Sonderkoy, Als; dP, Bredegrund south of Als; dK, Pols Rev; DU, off Dimesodde, 11m. — Bm: 7,5 miles E. of Hellehayns Nakke, 27 m (C.A. J.). 2. Polysiphonia orthocarpa K. Roseny.n. sp. Cæspitosa, c. 7 cm alta, filis erectis nume- rosis, e filis repentibus exeuntibus, inferne rhizoideis numerosis, partim fasciculatis, sub- strato non adfixis, instructis, sursum paululum attenuatis, articulis tetrasiphoniis non corticatis, in parte inferiori filorum ad geniculas leniter incrassatis. Rami in axillis pilorum (trichobla- storum) oriuntur; rami axillarii secundarii, e cellulis basilaribus pilorum deciduorum orti, desunt. Fila inferne crass. 135—160 y, articulis diametro 1,5—2,5-plo longioribus, in parte media articulis diametro 4—6-plo longioribus, superne crass. 40—60 4. Tetrasporangia in ramulis toru- Fig. 350. Polysiphonia orthocarpa. A, portion of decumbent ” branch and the lowermost part ofan erectbranch losis longe spiraliter seriata. Antheridia ignota. given off from it. 50:1. B, trichoblast with axillary branch. 150:1. Cystocarpia subglobosa, ostiolo apicali, non pro- tracto. — Color fusco-purpureus. (Plate V fig. 1). This species which was found in two localities in the Limfjord in some re- spects resembles P. violacea but it differs from it particularly by the much developed creeping filaments and the caespitose growth and further by the want of cortication and of secondary axillary shoots. By these characters it agrees with P. Rhunensis Lower part of an erect filament with numerous Polysiphonia orthocarpa. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 413 Thur., to which it seems to be nearly related; but as it differs from it by other characters, especially the dimensions of the articles, the presence of rhizoids on the erect filaments, and the shape of the cystocarps, it seems legitimate to consider it as a distinct species. The erect filaments issue in great number from creeping filaments fixed to the substratum by short rhizoids ending in attachment discs. These rhizoids are given off not only from the basal but also from the apic- al end of the pericentral cells, from which they are separated by a cell-wall. The articles of the creeping filaments are two to four times as long as broad. Rhizoids are also given off from the lower part of the erect filaments, but these rhizoids are not fixed to any substratum; they are of equal diameter in their whole length and form no attachment disc. They are always given off from the un- dermost end of the articles, often two or three from the same article. In rare cases I have found them fixed by the end to the same filament from which they had issued. Fig. 353. A young and two ripe cystocarps. 107: 1. Fig. 352. Polysiphonia orthocarpa. Portion of branch with tetrasporangia. 200 : 1. 414 The erect filaments are very slowly attenuated upwards; at the base they are 135 — 160 w thick. The upper end of the shoots has the same aspect as in P. violacea. Each joint bears a trichoblast except the undermost 3 or 4 (or 5) of the branches. The tricho- blasts, which remain rather long, have the usual appearance; their cells contain one nucleus only. The branches arise as axillary buds of the trichoblasts; they are separated by 4 or 5 trichoblasts without branches, but two branches frequently follow one another. Secondary axillary shoots do not occur, or only appear excep- tionally on the lower rhizoid-bearing joints. The first trichoblast of the branches appears on the 4th, 5th or 6th joint. Endogenous branches may occur in the pro- cumbent filaments and in the lower part of the erect ones. The tetraspore-bearing shoots have the same structure as in P. violacea. The joints N have 6 pericentral cells and, under one of them, a short peripheral cell situated to the right of the basal cell of the trichoblast of the foregoing joint (fig. 352). The antheridia are unknown. Fig. 354. The cystocarps are subglobose or slightly Polysiphonia Rhunensis Thuret, from St. Vaast (herb. depressed (fig. 353). The ostiole is not pro- Thuret), an unripe, and a ripe cystocarp. 107:1. tracted, it is situated on the apex of the cystocarp opposite to the point of insertion, not on its ventral side as in P. violacea and in P. Rhunensis, of which I have examined an original specimen from THURET collected at St. Vaast (fig. 354). The series of cells forming the outer layer of the wall run in the same direction as the stipe, and the placenta is perpendicular on this direction (fig. 353), while in P. Rhunensis the cell-rows run towards the ventral side and the placenta has an oblique position to the stipe. In the latter species the ostiole is moreover a little protracted and, according to THURET (1. c. p. 85), often a little sinuous. The cells surrounding the ostiole in P. orthocarpa are low, not prominent. , The specimens from the Limfjord resemble P. Rhunensis so much that I have been inclined to consider them as belonging to the same species. They agree with it by the cespitose growth, numerous erect filaments issuing from a system of creep- ing filaments, by the want of cortication, further, as substantiated by examining original specimens of THURET's, by the branches arising in the axils of the tricho- blasts and by the want of secondary axillary branches. Our species differs, however, from THURET's species by the erect filaments being thinner at the base (1/4 mm in P. rhunensis) and less tapering upwards, by the presence of rhizoids from the erect filaments and by the apical, not protracted ostiole of the cystocarps. By the shape of the cystocarp it is also distinct from P. violacea, in which the ostiole has a more or less ventral position and is surrounded by a prominent border composed of rather large projecting cells. 415 Loc alities. Li: Under Lischoj, N.W. point of Fur, 1—2 m, apparently growing on diatomite (dan. Molér) with ripe sporangia in July; Amtoft reef, from a slight depth to 4 meters (unknown in which depth t has been growing). Sand and clay is retained between the erect filaments, With cystocarps in August. 3. Polysiphonia elongata (Huds.) Harvey. Harvey in Hooker, Brit. Flora 1833 p. 333; Harvey Phye. Brit. IU 1851 pl. 292, 293; Kützing, Phycol. gen. 1843 Taf. 50 V; Tab. phyc. 14, 1864 Taf. 4; J. Agardh, 1863, p. 1004; Kny 1873, p. 107, Taf. II Fig. 5; Kolderup Rosenvinge 1884, p. 24, 1903, p. 405; Falkenberg, 1901, p. 126, Taf. 21, Fig. 6—9; Kylin, 1907, p. 144; L. Batten 1923 pp. 279, 297. Conferva elongata Hudson, F1. angl. II, 1778, p. 599. Ceramium elongatum Lyngbye, Hydr. 1819, p. 117. Ceramium brachygonium Lyngbye Hydr. p. 118, Tab. 36 C. Hutchinsia strictoides Lyngbye Hydr. p. 114, Tab. 35 D. Hutchinsia elongata Flora Danica tab. 1836, 1825. Polysiphonia strictoides Kützing Tab. phyc. 14, 1864, Tab. 10. a, typica. 8, Schuebelerii (Foslie) nob. (Plate V fig. 2). Comp. Borgesen and Jonsson, The distribut. of the Mar. Alg. of the Arctic Sea etc. Appendix to the Botany of the Færåes. 1908 p. XII. P. Schuebelerii Foslie, Nye arct. havalg., Christiania Vidensk. Selsk. Forh. 1881 Nr. 14 p. 3, tab. I fig. 1—3. Kolderup Rosenvinge, Gronl. Havalg. 1883 p. 798, pl. I figs. 1—2. y, baltica nob. (Plate V fig. 3). The morphology of the frond has been described by Kny and FALKENBERG. The trichoblasts are arranged in a regular spiral turning to the left, each joint bearing a trichoblast with the exception of the first 5 or 4, rarely of a greater number of joints in the branches, which bear no lateral organs. The divergence of the trichoblasts in the spiral is a little greater than la. The cells of the trichoblasts contain one nucleus. In f. baltica the trichoblasts are simple or very feebly branched and usually contain well developed rose-coloured chromatophores. The branches appear in the places of trichoblasts in the spiral, and are usually separated by 5 joints, more rarely by 4 or 6. Upwards the branches often become rarer, in particular in the tetrasporiferous and the pyspnonta elongata antheridia-bearing shoots, which in their upper parts are entirely £ Schuebelerü. Tip of branchless. The branches usually appear singly; branches on two ee ma a oak consecutive joints may, however, sometimes occur. segment has been cul Adventitious shoots from the basal cells of the fallen off an hir trichoblasts (secondary axillary shoots) appear not rarely, in particular on the lower part of the shoots. In specimens of f. baltica from Flens- borg Fjord adventitious shoots appeared abundantly and early, before the tricho- blast had been shed (fig. 364). The adventitious branches, however, usually reach only a slight degree of development in the first season. On the other hand, =q do AIG adventitious shools appear normally in the shoots of wintering plants. When the growth ceases at the end of summer, a number of shoots and tips of shoots are thrown off, and next spring numerous new shoots are produced, partly from the surfaces of the wounds, partly from the basal cells. Frequently a shoot is produced from each joint. When the new shoots are principally given off from the upper part of the wintering ones the form appears which J. AGARDH has named f. microdendron (1. e.). This form I have only found once (Klorgrund South of Hjelm in May). In the usual form with short joints the branches are to a considerable extent connate with the following joint (fig. 356). In this form the branches are as a rule thin at the base and become thicker upwards. In f. baltica this is not so or c only in a slight degree. The cortication begins early, espec- ially in the typical form. The primary cortical cells are here often of the same length as the pericentral cells, being cut off by a longitudinal wall (fig. 356). In the forms with longer joints, f. Schue- Foly RE So, “Hi belerii and f. baltica, the primary cortical Polysiphonia elongata. A, portion of shoot showing the + formation of the first cortical cells. B, nuclei and chrom- Cells are shorter and cut off by an in- atophores of a pericentral cell. 270: LK C, portion of a clined wall (fig. 361). The pericentral cells branch showing the upper end of a pericentral cell with 3 x MOI om coter co Cha contain numerous nuclei and the primary cortical cells are also plurinucleated (fig. 356), while the central cell contains one large nucleus, at least for a long time. In the typical form, the pericentral cells of the thick main shoots are connected with several secondary pits traversing the transversal walls. In a transverse section one pit is found in the middlemost part of the wall and a number of up to ten in the periphery. The central pit is probably the first, arisen at a very early moment, while the others have only been formed in the following year. The cortical cells may also be connected by several pits in the same wall, in particular in the trans- versal walls. The secondary pits of the pericentral cells are much smaller than those of the central axis, but bigger than the pits between the pericentral cells in the other species of Polysiphonia and bigger than the primary pits connecting the central cells with the pericentral cells in Polysiphonia elongata (fig. 357).! Such multiple pits were not met with in f. baltica. On the other hand, the central cells of this " Dr. Lıry Barren figures three pits connecting two pericentral cells which are erroneously said to be central cells (1923 pl. 22 fig. 1): form were often filled up by hypha-like cells, a phenomenon which, according to FALKENBERG, frequently occurs in the pericentral cells of P. elongata. The attachment organ of the frond is conical, built up of numerous densely crowd- ed descending filaments forming the continuation of the filaments of the cortication, and of rhizoids mostly given off from the latter (comp. L. Barren 1923 pp. 279, 297, fig. 47). Fig. 357. Polysiphonia elongata. A, longitudinal section through the central part of an old stem, showing the central cells and the pericentral ceils connected with multiple secondary pits. 100:1. B, transverse section of a similar stem, at the level of a transverse septum, showing the pits. 290: 1. The antheridia occupy the main axis of the trichoblasts except the two first joints, the upper of which bears a sterile branch on the right side. Sometimes the third cell is also sterile and then bears a sterile branch on the left side. In the first case it happens that the branch becomes fertile and the trichoblast thus bears two antheridial bodies (fig. 358 to the right), and trichoblasts bearing three antheridial bodies were met with too (fig. 358 above). In the branch shown in the same figure an antheridial cushion even occurred on the stem (comp. L. K. R. 1903, p. 465). In the procarp-bearing trichoblasts the first branch is seated on the 4th joint but not always on the right side, frequently on the left side. The ostiole of the cystocarp is fairly broad, not protracted and directed obliquely upwards, but more upwards than forwards (fig. 359, comp. Harv. pl. 292, 293). I have, however, met with cystocarps thicker than those figured by Harvey and me and provided with a short spout. 418 The sporangiferous joints have 6 peri- central cells, 4 of which cover the sporangium. As shown by FALKENBERG (1. c. p. 128, pl. 21 fig. 9), a small peripheral cell situated to the right of the trichoblast of the foregoing joint is usually to be found (fig. 362); it is, how- ever, not always present (fig. 360). When going from one trichoblast to the next two pericentral cells are passed. The sporelings grow out to a vigorous straight primary shoot with early developed cortication, much bigger than the lateral branches. J. AGARDH distinguishes two main forms of the species: I. Lyngbyei and II. Ruchingeri, the first thinner, with flagelliform filaments and the upper branches tapering upwards from RE: a broader base, the latter thicker and more Polysiphonia one male plant, show- fleshy, with straight branches and the upper ing trichoblasts with two or three antheridial bodies ones attenuated upwards and downwards. and a cushion POS the OS Image! is said to be most frequent at the coasts of Sweden and Denmark (“in sinu Codano”), while the other occurs on the shores of the Atlantic Ocean. The characters mentioned seem, however, to be inappropriate as distinctive characters; thus in most specimens from the Danish waters not referable to f. baltica, branches attenuated towards the base may be found. Nor has Kyrın considered this character as con- clusive, having described under the f. Lyngbyei a new subf. gelatinosa with the branches attenuated downwards. This character is most prominent in the specimens from the North Sea, the Skagerak and the Northern Kattegat. Most of the specimens found in the Danish waters have been referred to f. {ypica though they are somewhat variable according to the localities. When growing in slight depth and exposed to light they become brevi- articulate, the joints in the upper part of the plant having only half the length or the same length as the breadth, Fig. 359. Q 0 Polysiphonia elongata. Ripe eystocarp. and the main axes become at least 1 mm thick. In onen greater depths the joints become longer. The typical form is common in the Danish waters from the North Sea to the western Baltic Sea, descending to 19 meters’ depth. The innermost places where it has been met with near low water mark are Svendborg (Sf), Kerteminde (Sb) and Hellebæk (Su). In the Great Belt south of Kerteminde the minimum depth of its occurrence is 6,5 m, in the western Baltic Sea it is 5m and in the Sound south of Helsingør 10 m. In the inner Danish waters P. elongata appears in more slender forms which, however, are closely connected with the typical form by intermediate forms. In the Fig. 360. Fig. 361. Fig. 362. Polysiphonia elongata f. ty- Polysiphonia elongata f. Schuebelerii, from Polysiphonia elongata f. Schuebelerii, from pica (from Frederikshavn). Bolsaxen). A, portion of frond showing peri- Bolsaxen). A, portion of plant with tetra- Portion of tetrasporiferous central cells and cortication. 70:1. B, trans- sporangia. B and C, transverse sections of plant. 75: 1. verse section of stem not yet corticated. 200: 1. tetrasporiferous joints. A 95:1. B, C 200:1. Great Belt (Sb) a form agreeing exactly with P. Schuebelerii Foslie (see above) has been met with in several places in 6,5 to 19 meters’ depth. It differs from the typical form principally in the longer joints, being up to 4 times as long as broad or longer where the cortication begins, and in the feebler cortication which entails a smaller diameter of the main axes (300—660 u). The first cortical cells are comparatively small and cut off by oblique walls. The pericentral cells occupy a great part of the trans- verse section of the old stem; they produce no new pits or a small number of multiple pits in the transverse walls. On the other hand, in some cases I found the central cell filled with hypha-like filaments. The tricho- blasts are branched, in greater depths provided with feebly rose-coloured chromatophores. The frond may be 30 cm long or more. In the Baltic Sea around Moen (Bm) and around Bornholm (Bb), where the salinity is much feebler, the species occurs in a still slenderer form which at first I judged identical with f. expansa (Ag.) which J. Agardh first found at the coast of Blekinge. An examination of the original specimen of Hutchinia expansa Agardh in AGARDH’s herbarium in Lund showed me, however, that AGARDH’s species cannot be referred to P. elongata as its branches arise in the axils of the trichoblasts, but that it is a form of P. violacea. I have therefore given the here described form of P. elongata from the Baltic Sea the name f. baltica. The frond of this form is very slender, up to 20 cm long, and has an intense red colour. The joints are 4—7 times as long as broad wbere the cortic- ation begins. The branches are not attenuated towards the base. The cortication often begins rather late and advances more slowly down- wards so that the pericentral SR; Fig: 96 cells do not be- Polysiphonia elongata f. baltica. A, upper end of 4 shoot; trichoblasts with chromatophores. come entirely covered by the cortical cells. The main axis is only 140—280 w thick. The trichoblasts are unbranched or slightly branched with well developed, feebly rose-coloured chromato- phores; they are usually long kept. When adventitious shoots occur they may arise before the trichoblasts have been shed (fig. 364). This form is confined to localities with feeble salinity and rather feeble light (9—24,5 meters depth). Specimens from the deepest localities in the outer waters with high salinity may resemble f. baltica in some characters, but are so differ- | ent in other respects that they cannot be referred to Fig. 364. it. In the Limfjord, in depths of 7 to 10 meters, where Polusiphonia elongata f. baltica, from 2 3 u ; à Flensborg Fjord. Secondary axillary the light is very feeble, owing to the very turbid water, shoot. 230 : 1. 421 the specimens of P. elongata agree with the typical form in all respects. Spec- imens from the Kattegat collected in 17—19 meters’ depth were certainly a little slenderer than those from higher levels and usually showed longer joints, 1—3 times as long as broad, but the branches tapered downwards and the trichoblasts were branched. P. elongata occurs in all the Danish waters and also enters in the fjords. It descends to 20 meters’ depth but has been recorded in 27 meters’ depth in the eastern Kattegat and in 24,5 meters’ depth near Bornholm (f. baltica). It grows on various substrata, stones, moles, shells of mollusks, various Algæ, as Fucus serratus, Laminaria digitata, etc. and Zostera. It occurs in very different plant associations but usually not as a dominant constituent. In oozy bottom it is frequently met with on mollusk shells. It is remarkable that it may occur rather abundantly in places where the flora is poor in species, f. inst. Fano and Logstor. It often attains a length of 23 cm, more rarely 35 cm, but only in protected localities. In autumn many specimens die but others are only denudated and recommence the growth in winter. New shoots may appear already at the end of December, and in January they are usually present though the growth is slow. Thus, new shoots more than one cm long were found in a specimen gathered on January 25th in the Great Belt; but it must be said that other specimens gathered in other localities in the same water were still in a resting stage. The growth is intense in April and May, it con- tinues in June and July but in the latter month it decreases and usually ceases. The trichoblasts may remain still for some time, but in several specimens they are thrown off already in August. Otherwise this takes place in autumn, and at the same time a number of shoots, principally the fructiferous ones and the ends of the shoots are shed. Antheridia were met with in January (unripe), April, May and July, and once even in August, ripe cystocarps in May to September, most frequently in July and August, unripe in April and May, ripe sporangia in May to August. The sporelings arising from the spores disseminated in summer continue their development, after wintering, the next year; but it is doubtful whether they can winter more than once. Localities. «, typica. NS: Nordby, Fano; Esbjerg; Thyboron, harbour and groins; off Orhage, 5,5—7,5 m. — Sk: YU, Hanstholm, 2 m; within Bragerne, 2—10 m; off Løkken, 13 m; Dana St. 2900, 9m (C. A. J.); FK?, off Lønstrup; Hirshals mole and off Hirshals, 2—11 m; Højen, within first and , second shoals, 2—5 m. — Lf: LV, Nissum Bredning; MH, Thisted Bredning; Oddesund; Nykobing (Th. Mortensen, !); four localities east of Mors; north of Fur, Lendrup Ron, Logstor, Aggersund (Ostenfeld). — Kn: Skagen; fC, S. of Skagen, 15 m; FG, Herthas Flak; off Hulsig (Boye Pet.); Krageskoys Rey (KC and TV); Hirsholmene; Fladstrand (Hornemann); harbour of Frederikshavn and reefs off Frederikshayn, off Marens Rev, 20 m; harbour of Sæby; BP, off Sæby; Nordre Renner; TL, NG, VT, fF, UC, UB, GM, north of Læso; harbour of Osterby; TO (17 m), TP, TQ, NI, FF, FE, fG, Dana St. 3891, near Trindelen. — Ke: FC, FD, XA, east of Læsø; VY, ZE, fH, Fladen; Groves Flak, down to 26,5 m; IK, ET, Lille Middelgrund; HX, Store Middelgrund, 17 m; GI, Ostindiefarer Grund; OO, Soborghoved Grund; Gille- leje, Nakkehoved (Lyngbye). — Km: Læsø Rende; Dana St. 2619, 2884 (C. A. J.); YY, XD, XF south of Læsø; BN; TS; VQ, Svitringen; BM; BL; VP; bK, N.W. of Anholt, 15 m; BK, VM, near Tangen; NC; BI, Gjerrild Flak; Gjerrild bay (Lyngbye). — Ks: EP, Pakhusbugt, Anholt; OP, HQ, EJ, Lysegrund; D. K. D. Vidensk. Selsk., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 54 499 RL, N.W. of Gilleleje; Grenaa harbour; HS, Briseis Grund; OS, Hastens Grund; OU, Schultz’s Grund; FO, NB, Havknudeflak; FP, Jessens Grund; GF, Sjællands Rev; aU; D, Gronne Revle; EJ, entrance to Isefjord; NL and EH, off Lynæs; Lamme Fjord; Holbæk Fjord. — Sa: Very common, found in numer- ous places from 1 to 15 meters’ depth. — Lb: Several places from 2 to 17 m. — Sf: Harbour of Svend- borg, 1m; BY; UV, 13m; DZ. — Sb: 1 to 19 m.: DL; GT; DM; MN; GV; LM; harbour of Kerte- minde; bay of Kerteminde; GQ; NU; AB; NP; NQ; NN, 19 m; UE; DN; Y; LH; LB, 17 m. — Sm; GZ; HA, Agerso Sund, 11 m. — Su: CS, off Aalsgaarde; Hellebæk (Budde Lund); Helsingør (Liebman); HK; PZ, east of Hveen; RZ, 13 m: bM, south of Hveen, 22,5 m; OH, off Vedbæk, 10 m. — Bw: bY, off Sønderskov by Sønderborg, 11 m; cD, dO, 5 m, dK, south of Als; LF, Vodrups Flak, 9,5 m; DV; LC, 11,5 m, south of Langeland. P, Schuebelerii. — Sa: DK, Bolsaxen, 14 m. — Sb: Off Refsnæs, 19 m (Ostenfeld); LK, Elefant- grund (transitional form); UE, near Vresen, 7m; UF, near Hoy Sand, 8,5 m; DN, Vengeance Grund, 11,5 m. — Bm: 11,5 miles S. by E. !/, E. of Mgens light-house, 19 m, (© 6, C. A. J.). y, baltica. — Su: SA, Flinterenden, — Bw: dN, Flensborg Fjord, 9m; KX, Femerbelt, 19 m. — Bm: QY, Bjelkes Flak, 10 m; VG, north of Moens Klint, 17 m; bO, south of Moen. — Bb: SQ, south of Broens Rey, 8,5 m; YE, off Oleaa, 10,5 m; YC, 24,5 m and YD, 19 m, near Salthammer Rey; 3 miles S.S.E. of Nexo harbour (C. A. J.); (12 miles N.!/;E. of Arkona light-house 46 m (© 6, G. A. J.); the specimens much resemble that represented in Lakowitz, Algenfl. Danz. Bucht, Taf. II Fig. 5 under the name of P. violacea forma tenuissima which is perhaps identical with it). 4. Polysiphonia violacea (Roth) Greville, emend. Hooker, Engl. Flora, Vol. II part I. 1833, p. 332; Harvey, Manual, 1841, p. 92; Phye. Brit. II. 1849, plate 209; Areschoug, 1850, p. 51; J. Agardh, 1863, p. 988; Kützing, Tab. phyc. 13, 1863, pl. 97, 98; Kolderup Rosenvinge, 1884, p. 27, pl. 1—2, figs. 33—47; Reinke, Algenfl. d. westl. Osts., 1889, p. 30; Falkenberg, 1901, p. 115, pl. 1, figs. 17—19; S. Yamanouchi, 1906, p. 401—449, plates 19—28; Kylin, 1907, p. 140. Ceramium violaceum Roth, Catal. bot. Vol. I, p. 150. Hutchinsia violacea Ag., Lyngb. Hydr., 1819, p. 112 ex parte (tab. 35, fig. B, 1). Hutchinsia stricta Lyngb. Hydr., 1819, p. 115 ex p. (test. specim.); Fl. Dan. tab. 1666, 1819. Hutchinsia divaricata Fl. Dan. tab. 2312, 1840. a, violacea Aresch. 1. c. p. 53, Alg. sc. exs. Nr. 65. P. violacea 3, sub-Brodiaei Aresch. 1850, p. 52, Exs. Nr. 5 (89). 8, fibrillosa (Dillw.) Aresch. Areschoug, 1850, p. 52. Conferva fibrillosa Dillw., Brit. Conf. 1809, p. 86, pl. G; Flor. Dan. tab. 1545, 1816. Hutchinsia fibrillosa Ag., Lyngb. Hydr. 1819, p. 113. Polysiphonia fibrillosa Grey. Harvey in Hook. Brit. Flora Vol. II p. 334, Phye. Brit. Vol. III pl. 302, 1851. J. Agardh 1863, p. 991; Kny 1873, p. 104; Reinke, Algenfl. p. 31, Kylin, 1907, p. 141. y, tenuis. Ceramium violaceum 3, tenuis Roth Catal. III p. 151 (2). Polysiphonia bulbosa Suhr, Aresch. Alg. se. exs. Ser. I n. 9. Polysiphonia violacea 0, bulbosa Areschoug 1850, p. 53. 423 Polysiphonia violacea €, lenuissima Aresch. 1. c. p. 54, Hauck, Meeresalg. p. 227. Polysiphonia roseola Kützing Tab. phyc. Bd. 13 Taf. 80. 0, aculeata (Ag.) Hutchinsia aculeala Agardh Synopsis Alg. Scand. p. 59. Polysiphonia aculeata J. Agardh, 1863 p. 947, Kützing Tab. phye. Bd. 13 Taf. 71. Polysiphonia aculeifera Kützing Tab. phyc. Bd. 13 Taf. 71. Hutchinsia implicala Lyngbye Hydr. p. 111, Flor. Dan. tab. 1955. Hutchinsia divaricata Ag. Syn. Alg. Scand. 1817 p. 59. Polysiphonia divaricata Kützing Sp. Alg. p. 822, J. Agardh, 1863, p. 947. Polysiphonia violacea is here taken in a larger sense than by earlier authors, not only P. aculeata (Ag.) but also P. fibrillosa (Dillw.) being included in it, while the latter has hitherto been regarded as a distinct species. The morphology and development has been described by Kny (1873, p. 104, P. fibrillosa), my- self (1884) and FALKENBERG (1901). The primary axis is usually very distinct; in the f. {enuis only it is very thin and not easily discernible from the longer branches. The basal disc is composed of numerous densely crowded rhizoids terminating in attachment discs (fig. 365, comp. L. Batten 1923 figs. 55, 59). According to FALKENBERG (1901, p. 116) adventitious, partly creeping branches are later given off from the base of the plant. This may be so, as I have convinced myself, but usually such adventitious shoots are not produced (comp. Harvey Phyc. Brit. Plates 209 and 302). In some cases, how- ever, I found a great number of small adventitious shoots arising from the basal disc, being first creep- ing and then ascending and producing erect branch- es, and I also found erect shoots issuing directly from the basal disc. Such adventitious shoots are perhaps more common in f. fenuis. The trichoblasts are arranged in a regular spiral, with a divergence varying between !/, and I, of the circumference. Each joint of the shoots bears a trichoblast with the exception of the lower- most joints of the primary axis and of the branch- es. The first trichoblast on the branches is most Fig. 365. 0 Ss ES Polysiphonia violacea. A, young plant grow- frequentiy placed on the third joint, the basal joint ing on Polysiphonia elongata, June 15th; included, more rarely on the 4th, very rarely on a procarp is developing in the trichoblast on the 20th joint. B, base of a hardly one the second joint; in a specimen collected at Gjelle- em high plant. 100 :1. 54* 424 grund in the Great Belt in November it was, however, placed on the 5th or 6th joint. The trichoblasts are usually much branched, showing two generations of branches, particularly in the vigorous forms growing in shallow water (fig. 369 A). In other specimens the ramification is feebler, the trichoblasts bearing only one or two simple branches, or they may be entirely unbranched. Such simple trichoblasts are particularly found in slender specimens belonging to or approach- ing to f. {enuis, generally in specimens growing in deeper water or in shaded localities. They were met with in most of the spec- imens collected in November, at a season when the growth is very feeble. They occurred too in several specimens collected by. Bornholm in July and August. The trichoblasts are usually hyaline: Fig. 366. Polysiphonia violacea. Tip of shoot treated with in specimens from deep water, however, they may contain feebly glycerine. I—IV, tricho- - = Has nent een rose-coloured chromatophores. The cells contain one nucleus. The numbered according to trichoblasts may be shed early, in other cases they may persist for age; >» basal en ofte a fairly long time; thus in several specimens from the Baltic Sea they were still present on the 40th to the 42nd joint from the top. The primary branches arise at the base of the trichoblasts and develop simult- aneously with them. They do not, however, occur at all the trichoblasts but are usually separated by 4 or 5 joints; yet, two or even three primary branches often follow immediately after each | jae other. The basal cells of the tricho- blasts which are not accompanied by primary branches generally produce later branches which may be named secondary axillary branches. These branches arise at a considerable distance from the top, usually only when the trichoblast has fallen off, but not rarely before this has taken place; they may attain a considerable length but always remain much feebler than the primary axillary branches. Very often all the basal cells produce branches, though some of them reach only a small size. Asanexampleis here given a diagram ofa shoot, where ¢ signifies trichoblast, ¢ basal Fig. 367. cell of a trichoblast fallen off, b primary Polysiphonia violacea. Portion of ‘central and pericentral m cell showing nuclei, chromatophores (partly) and pits, p, branch and s secondary axillary branch: connecting the central with the pericentral cells. 230:1. ssssbsssssbbissssbssssbbtissbssssbbsstsbssssbbssssbbttlibbitibttttbb (top). 425 These secondary branches can be distinguished in the drawings of Harvey (Phye. brit. Plate 209) and KirzinG (Tab. phye. Vol. 13 Taf. 97 e, 98 e). They are very conspicuous in f. aculeata (fig. 374). As in other species of Polysiphonia, torsions may occur in the long branches with the con- sequence that the primary branches may be placed in a longitudinal row over a long stretch (Plate VI fig. 1). The central cell always contains a single nucleus; in the older cells it is rather large and situated in the middle of the cell. The pericentral cells after the formation of the secondary pits con- tain two nuclei which by continuous bipartitions produce the numerous small nuclei contained in the older pericentral cells. In one case c. 100 nuclei with a diameter of 5—6 4 were counted in one pericentral cell, while the nucleus of the central cell measured c. 30 x in the greatest diameter (fig. Fig. 369. Polysiphonia violacea. A, trichoblast. B, trichoblast with antheridia. 200 : 1, Fig. 368. Polysiphonia violacea. A,cortical cell with three nuclei cut off from a pericentral cell. B, down- ward growing corlical filament on the point of establishing a secondary pit connecting it with another corticating filament. 230: 1. 367). The central cell contains no chromatophores; the protoplasm shows a fine longitudinal striation. Cortical cells are always produc- ed, but the cortication occurs in various degrees; it is most developed in f. fibrillosa, least in f. fenuis. It is usually not more pronounced than that the pericentral cells are visible between the cortical filaments; in the lower part of the main stem, however, the pericentral filaments may be completely covered, in part- icular in f. fibrillosa. The primary cortical cells are cut off from the undermost part of the pericentral cells by oblique wall and originally contain more than one nucleus (fig. 368). They early be- gin to downwards in the outer wall two peri- central cells, dividing by transversal At their upper end they may also grow upwards segmentation. The descending bark- an grow between walls. under 426 filaments become connected with each other and with the pericentral cells by secondary pits (fig. 368 B). Two pits in the same wall may even occur. The antheridia occupy the main axis of the male trichoblasts except the two lowermost cells. and the second cell bears a sterile branch on its right side. A torsion takes place. however, in the second joint with the con- Fig. 370. Polysiphonia violacea. Ripe # 5 cystocarp. 76:1. sequence thatthe sterile branch issues on the outer side of the trichoblast and thus serves to protect the antheridial body (fig. 369). As regards the development and the structure of the cystocarps reference may be made to Yamanoucut (1906). A ripe cystocarp is shown in fig. 370. In the tetrasporiferous shoots a considerable number of joints, usually without interruption, contain each one sporangium. As the sporangia always arise to the left of the trichoblast of the same joint, the sporangia are thus arranged Fig. 371. in a spiral. The fertile joints have 6 pericentral cells, two of Polysiphonia violacea. Branch which are cut off from the cell which gives rise to the spor- “ifh !etrasporangia. 20:1. angium and which corresponds to the second pericentral cell in the sterile joints (figs. 372, 373. comp. fig. 366). One of these secondary peri- central cells does not reach the base of the joint, and a small peripheral cell (p) is here later cut off from the inner cell which is thereafter divided by a horizontal wall in a short stalk-cell (s) and the mother-cell of the sporangium. The stalk-cell is then connected through pits with the central cell, the sporangium, the two secondary pericentral cells and the small peripheral cell, p. P. violacea which is one of the most common species of Algæ in the Danish waters is very variable. The single characters distinguishing the different forms, as the length of the joints, the degree of cortication, the degree of branching of the trichoblasts Fig. 372. Polysiphonia violacea, A, tetrasporiferous joint; b basal cell of and the frequency of the secondary trichoblast; Ps small peripheral cell. B, transverse section of axillarv shoots are evidently depend- tetrasporiferous joint. 390:1. C, similar after evacuation; s, 5 aoe = A split through which the tetraspores have escaped. 230 : 1. ent on the outer conditions. P. fibrillosa has hitherto been regarded as a distinct species though in its morphology il exactly agrees with P. violacea and only differs by very variable characters such as those men- tioned. Harvey indeed observes of P. fibrillosa (Phye. Brit. Pl. 302, 1851): “It is most nearly related to P. violacea, with which alone can it well be confounded, and from which it chiefly differs in its shorter and less multified ramuli, duller colour, and shorter articulations; but there are specimens occasionally found which seem almost to connect these two species together”. J. AGARDH, REINKE and Kyrın admit too the relation of the two species but nevertheless consider them as distinct. After having examined a great number of spec- imens from numerous localities in the Danish waters I have arrived at the apprehension that it is im- possible to draw a natural line of demarkation between them. In too many cases it depends on an arbi- trary estimate whether a specimen may be referred to the one or the other of the two species, and I have therefore arrived at the con- clusion that LP. fibrillosa must be mic CFA regarded as a form of P. violacea Polysiphonia violacea. Division of tetrasporiferous joints. b, basal distinguished principally by shorter el! of trichoblast; p, small peripheral cell; s, stalk cell of spor- aS 2 4 angium; X small cell establishing the secondary pit between the joints and stronger cortication. The pericentral cells. 636 : 1. trichoblasts are strongly developed and much branched, at the base up to 28 « thick. The straw-colour of the frond emphasised by REINKE is entirely due to an intense light. It grows only in slight depths and in rather light places, and usually also in more agitated water, and these conditions undoubtedly produce the characters mentioned. In f. fibrillosa the joints in the upper part of the frond are about 11/2 (1—2) times as long as the diameter. In f. fypica they are longer, usually 3—5 times as long as broad. In this form the main axis is distinct as is the case also with f. fibrillosa. But the thickness of this axis is variable, and in the finer forms it is scarcely thicker than the principal branches. In f. fenuis the principal axis is thin and not discernible from the branches; the joints are longer, c. 6—9 times as long as broad, the cortication almost wanting, the secondary axillary shoots are scarce, and the trichoblasts simple or feebly branched, often with rose-coloured chrom- atophores. This form grows in localities with feebler light and less agitated water, principally in fjords and in great depths. F. aculeata is a loose sterile form characteristic by its squarrose branches and by wanting cortication. It has usually numerous secondary axillary branches which in spreading at tight angles give to the plant a characteristic appearance (fig. 374). Sometimes, however, the secondary branches occur only rather sparsely, and the 428° plant might then be referred to P. divaricata Ag. which is otherwise not sufficiently different from f. aculeata to be distinguished from it as a different form. F. aculeata occurs in shallow water. It must be assumed that loose individuals of P. violacea drifted in shallow water may go on growing there and by the altered condition, in particular the stronger light, assume the appearance characteristic to this form. Spec- imens of f. fibrillsa growing in very sunny localities, e.g. the stony reef in Kalo Vig, may take an appearance reminding one of f. aculeata by squarrose branchlets. P. violacea may complete its develop- ment in a short period. Most of the in- dividuals probably only reach an age of a few months. This is at least the case with the specimens which grow on annual species of Algæ, e. g. Chorda Filum; they must have germinated in spring (May) or later, are fully developed in summer, and perish with the host plant in autumn. In favourable localities more than one generation may probably be produced in one summer. In the plant shown in fig. 365, collected June 15th, which was cert- ainly only a few weeks old, a young procarp was already discernible in the trichoblast of the 20th joint of the plant, and another young plant of about the i J | Fig. 374. RL same size bore almost ripe antheridia. Polyphony ace f aut, Portion of shoo! With Most Of the specimens certainly perish in autumn after fructification, but other individuals endure the winter and recommence in spring the growth arrested during the winter. The growth ceases or is at least much diminished in August, and several in- dividuals then begin to lose the trichoblasts. In the following months the growth is likewise stopped or extremely feeble. In November all or most of the trichoblasts are thrown off, and that is also the case with the tips of many of the shoots. In December and January the species appears in the same stage (fig. 375). In the last part of December 1890, however, I found on the bottom of Holbek Fjord, which at that time had been covered with ice during a month, specimens with well preserved growing points and trichoblasts. The growth recommences in the last part of the winter. In the wintering specimens new shoots are found in spring growing out from the basal cells of the decayed trichoblasts, while the tips of the wintering shoots have fallen off. It seems, however, to be only a small number of specimens which endure the winter in a more advanced stage of development. In the northern part of the Kattegat, in the neighbourhood of Frederikshavn, I did not find any specimen of this species when collecting Algæ in December 1894 and Januar 1895, while it is very common there in summer. On the other hand full-grown specimens more frequently endure the winter in the inner waters, for I found such specimens in several places in the Little Belt and in the Great Belt in December and January. In the northern Kattegat it probably passes the winter in very small specimens arising from spores germinated in autumn. P. violacea fructifies in summer. Ripe sporangia occur in May to September; in May the sporangia are frequently unripe. Ripe antheridia were met with in May to September and in No- vember. Ripe cystocarps occur in July to September. The spores germinate immediately; sporelings are frequently met with on various Algæ in summer. Three days old sporelings from tetra- spores and carpospores sown in vessels with sea-water showed about 10 tiers of cells. The frond usually reaches a length of 7—14 cm, not un- frequently up to 20 cm, more rarely up to 30 cm. 8, fibrillosa Fig. 375. does not reach the same length as «, violacea, it scarcely grows Polysiphonia violacea. over 13 cm in length. The longest specimens have been found in FP eer ae ER the following localities: Knollen, Øresund, 11—14 meters’ depth, been shed; only the July, over 30 cm; Øresund east of Hveen, 10—19 met., July, En ER OR 25 cm; N.E. of Sejero light-house, 11—14 met., July, 22 cm; Lille most ones are perhaps Belt off Stenderup wood, 13—15 met., July, 20 em. The maximal "menu Ehe size is not very different in the various waters. Outside Skagen, however, the species does not reach the same size as in the more protected waters. It grows on all kind of firm substrata, stones, wood, but prineipally on various Algæ e. g. Chorda Filum, Fucus, Furcellaria, Polysiphonia nigrescens, P. elongata etc., further on Zostera. It occurs in depths of 0—19 meters, rarely deeper. 8, /ibrillosa grows principally on stony reefs in 0—7,5 meters’ depth. Localities. Ns: Does not occur at Fano and Esbjerg. ZQ, jydske Rey, 24,5 meters («). — Sk: «: Lønstrup, near land; 8: Hanstholm; Bragerne; Hirshals mole. — Lf: Very common in all parts of the fjord, most frequently «, in deeper water y; 2 at Ronnen by Lemvig, Oddesund and Nykøbing (Th. Mortensen). — Kn: « and § very common near land; wanting on Herthas Flak. Trindelen, FE, NI and dT, 9,5—11 m (a). — Ke: «, common to a depth of 28 m (ER east of Læsø. y: ZE, Fladen, 15 m. — Km: « and § common. bK, N.W. of Anholt, 15 m, approaching to y; d: BO, BM, BL east of Jutland, 5,5—9,5 m, with Zostera. — Ks: & common, also in Isefjord: Holbæk Fjord, Frederikssund, PQ, near Boserup. 8, several places. 0, Lammefjord. — Sa: « common to 14 meters’ depth; § on stony reefs near land; d Hofmansgave (Hofm. Bg., C. Rosenberg). — Lb: Principally &. § off Langore near ‘land. — Sf: & most frequent. 8: CT and Skaarup Or (Rostrup). y UX, Skjoldnæs, 9,5 m. — Sb: « common. J: AC, off Knuds Hoved, 17 m. — Sm: & common. d common: off Orenæsgaard, Petersværft, Kragevig, Guldborgsund. — Su: & common. 8: Kronborg (C. Rosenberg); QD, south of Saltholm; Dragør D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 55 150 (not typical). d Kronborg (f. divaricata, C. Rosenberg). — Bw: « Egernsund; Pols Rev; LC, off Gulstav. — Bm: « common. y Præstø Fjord, Tromnæs, Falster (O. Paulsen). — Bb: «: 0—11 m depth, up to 8,5 cm long; in several places with tetrasporangia, sexual organs and cystocarps not observed. 5. Polysiphonia Brodiæi (Dillw.) Grev. Harvey in Hooker, Brit. Flora Vol. II part I, 1833, p. 328; Harvey, Phyc. Brit. Vol. II, 1849, Pl. 195; J. Agardh, 1863, p. 993; Kützing, Tab. phyc. 14. Bd., 1864, Taf. 1; Kny, 1873, p. 103; Schwendener, Monatsber. d. Ak. Wiss. Berlin 1880, p. 333; Falkenberg, 1901 p. 34 Taf. 21 Fig. 12; Kolderup Ro- senvinge 1902, p. 342, Taf. VI Figs. 1—2; id., 1903, p. 444 and p. 457; L. Batten, 1923, p. 303, figs. 61—63. Conferva Brodiei Dillw. Brit. Conf. 1809, pl. 107. Hutchinsia Brodiwi Lyngb. Hydr. 1819, p. 109, pl. 33 B; Flora Dan. 1840, tab. 2312 (?). Polysiphonia penicillata (Ag.) Kützing, Tab. phye, 14. Bd., Taf. 1. The erect shoots, with the exception of the primary shoot, issue from a system of creeping filaments with short articles, partly as continuations of these, partly as endogenous branches of them. The creeping shoots bear no trichoblasts but numer- ous rhizoids, and such organs may also be produced in abundance from the lower part of the erect shoots. These shoots, which are very flexible, on the Danish coasts attain a length of more than 20 cm; in almost their whole extent they bear a number of penicilliform shoots which are mostly much shorter than the main shoots. Long shoots are principally given off from the lowermost part of the prim- ary axis; they are usually shorter than this, and transitional stages between the long and the short shoots frequently occur. The trichoblasts of the erect shoots are arranged in a spiral almost always turning to the left. As shown by me (1902, p. 342), the spiral in 165 sporelings in 160 cases turned to the left, in 4 or perhaps 5 cases to the right (2,5 and 3 per cent respectively), and in the numerous full- grown plants examined I have met with one shoot only with a spiral turning to the right. According to Kny, the angle of divergence was, in plants from Cherbourg, '/, of the circum- ference, between the first trichoblasts of the shoots, however, 1/4. In the Danish specimens I found the divergences varying about !/,, from a little greater than !/, to a little smaller than !/;, most frequently nearly 1/4, and that not only at the base of the shoots. In the sporelings the divergence was !/;. The first trichoblast appeared on the 5th to the 8th joint, and hence- forth each joint bears a trichoblast (fig. 384). The trichoblasts show the usual structure; they are well developed and are kept comparatively long. The primary branch- Fig. 376. es (II) are alternate in two lateral series converging towards the. ROBIN ROUE axis, the branches of the second order (III) are likewise alternate Trichoblast seen from the ÿ x x à à É: back. 200 : 1. in two series converging towards the primary axis of the tricho- 431 blast; the first branch of the second order III! is a — AD directed towards the stem (fig. 376). Each cell of the GS SS CT trichoblasts contains one nucleus. For a transitional Aim Be C stage between a trichoblast and a stem comp. K. R. 1903, p. 457. The number of pericentral cells is, as shown 2 [) by J. AGARDH, 7— 8, more rarely 6, in the full-grown > Co plant. The first pericentral cell is cut off exactly D E under the first leaf or, more frequently under its Fig. 377. right side (fig. 377). The cortication begins rather polysiphonia Brodiei. A—C, segregate young early, the primary cortical cells being cut off at the s¢éments of sporeling seen from the face, 4 2 showing the successive divisions. D, E, lower angles of the pericentral cells and growing similar segments, from older plant, the downwards and dividing. A cortex of considerable fourth from the top, showing the relation ; wa gg of the first pericentral cell to the tricho- thickness, consisting for a great part of hypha-like plast; D seen from above, E from below. filaments, early covering the pericentral cells, is then —% Youns segments seen from the side. 626:1. formed. At the same time a plexus of hypha-like filaments appears between the central cell and the pericentral cells (fig. 378). It was detected by J. AGARDH (1863, p. 993), who thought that it arose by division of the central cell. Later on it was figured by FALKENBERG who rightly shows (1901, p. 34, Taf. 21 Fig. 12) that the hyphæ arise from the pericentral cells, which I can confirm. Secondary pits are produced in considerable number through the longitudinal walls between the cortical cells mutually and between these and the pericentral cells. The branches arise, as shown by Kny (1873), in the axils of the trichoblasts, however, not exactly in the median plane, but they are somewhat displaced to the left. The joint common to 5) ORs VÆK A HX > < i i : the trichoblast and the Fig. 378. branch has 3 pericentral Polysiphonia Brodiei. Transverse sections of stem. A rather young. 200: 1. B older with hypha-like filaments in the interior of the stem. x the central cell. 63:1. situated to the left and one to the right of the median plane of the trichoblast, as shown by Kny. The pit connecting the second cell of the trichoblast with the central cell of the basal joint appears at the upper end of the longitudinal wall between the middlemost pericentral cell and that to the right (fig. 379). The ordinary (primary) branches do not arise in the axils of all the trichoblasts. In the lower part of the long shoots none or only few are present, upwards 55* cells, two of which are 432 they increase in number but decrease again in the fertile region, in particular in the tetrasporiferous and male plants. In the upper part of the plant two or three or even more branch-bearing joints may follow consecutively; on the other hand, the number of fieneent branchless joints may vary from one to many. The basal cell of the Ve originally branchless trichoblasts frequently later on gives rise . to a secondary shoot which, however, as a rule attains only a small size. As examples some diagrams of shoots may here be presented: ¢ signifies a trichoblast without primary branch, r a primary branch, s a secondary branch, (é) a basal cell of a shed trichoblast, ¢ a male trichoblast. long shoot: sssssssss((Orrsrsr@OOrt@Orttrttrrrrir tetrasporiferous plant: rsrrHOrOOrOrOrOrOOrOoOMrt similar: ...f¢rtttrtttttttt male plant: .. {trtttrttértété à Fig. 379 similar: ...{trtté gr Polysiphonia Brodiei. Basal . 2 Horton ot branch “showing The first lateral organ (trichoblast) of the branches is the pil connectingthecentral usually in the Danish specimens placed on the second joint; cell ofthe basal joint with the vest of the trichoblast. 390:1 in Specimens from Cherbourg, Kny found it on the second to the fifth joint. As in most other species of the genus the antheridia are produced in the main axis of the trichoblasts except the two lowermost joints. At the right hand the upper of these cells bears a sterile branch which projects more than the antheridial body and may thus protect it. A sterile cell does not occur at the top of the full-grown antheridial body. The carpogoniferous trichoblasts frequently show a curious aberration, some of the cells of their primary axis bearing two branchlets each (cp. K. R. 1903 p. 444). The fertile trichoblast shown in fig. 380 bears two branchlets on the fourth joint to the right and two on the fifth joint to the left. In other cases one joint only (the fourth) bears two branchlets, and in one case the 3rd joint, which normally bears no branch, bore one branch on the left side, the 4th two branchlets on the right side, the 5th one branchlet on the left side. The second joint of the female trichoblasts may even in rare cases bear a branch; such cases are shown in fig. 381. In fig. A the second, fertile, joint and the fourth bear each a branch to the right, the third bears no branch. In fig. Bthe second joint bears a branch to the right, the third one to the left and the fourth one to the right. In the latter case the first joint of branch 2 bears no branch as if it were a basal cell of a trichoblast; its second joint bears two branchlets. Branch 3 bears two branchlets on its first joint. In all cases where a joint bears two branchlets, the last-formed branchlet is placed NG 7 Ve Fig. 380. Polysiphonia Brodiei. Young female tricho- blast. 220:1. under the first and feebler than it. Accessory branchlets do not occur in all the female trichoblasts, and in some specimens (f. inst. from Thybo- ron) they were not met with at all. In the ripe cystocarps the orifice is enlarged and funnel-shaped, con- sisting of large cells (fig. 382). The tetrasporangia arise at the left side of the trichoblast borne on i the same joint; they are produc- ed by the second pericentral cell (comp. fig. 377). Two secondary this cell and the Fig. 382. th © : e sporangium. ] Il Polysiphonia Brodiwi. 1 2 This small ce Ripe cystocarp. 63:1. may, however, be wanting, the second secondary pericentral cell continuing to the base of the article (fig. 383). Germination is easily realised in cultures (comp. K. R. 1902 p. 342). In August sporelings consisting of 6 joints or more and bearing trichoblasts were produced in two days. The lowermost article or the two first joints produced no pericentral cells but only feebly coloured rhizoids. The following one to four joints had 4 pericentral cells, the following 5, and shortly afterwards joints with 6 or 7 pericentral cells appear, the same number which is found in a trans- verse section of the lower part of the stem of a full- grown plant. As mentioned above, the angle of divergence in the sporelings is 1/; of the circum- ference. — Abnormal sporelings, showing two op- posite rhizoids or two opposite vegetative poles were not unfrequently met with in my cultures. z Polysiphonia Brodiæi. Female trichoblasts with supernumerary pericentral cells branchlets. The figures indicate the branches of the first order according to the joints of the primary axis of the trichoblast. are cut off from (See texte). À 560 : 1. B 350 : 1. most remote of them is usually a little shorter than the other, a small peripheric cell being later cut off from the basal cell of Fig. 383. Polysiphonia Brodiei. Portion of tetra- sporiferous plant with branch. 350:1. This species has only been collected in the months of May to September. It has the appearance of being annual on the Danish shores. In May small specimens only were met with at Hirshals, and in April I did not find it at all in the same locality. Further it was not contained in the samples of Algæ from the groins of Thyborøn collected and sent to me in March. It therefore seems probable that the plants die in au- tumn or in winter, leaving only the young plants produced by the germinating spores and the basal parts of some of the older plants, which pass the winter in a resting stage and again take up the N Wy VE 2) ÿ = Fig. 384. Fig. 385. Polysiphonia Brodiei. Sporeling. The Polysiphonia atrorubescens. A, portion of plant near the base; numerous figures denote the number of pericentral rhizoids and endogenous branches. B, decumbent branch. C, joint of cells in the joints. stem. A, B 26:1. C 68:1. growth in spring. Antheridia were met with in all the months mentioned, cystocarps and tetrasporangia only in July—September. It grows in exposed places on moles, stones and wrecks at middle sea level. In moles and groins it forms a continuous vegetation at the ordinary limit of the sea. Localities. Ns: Groins at Harboøre and Thyborøn; harbour of Thyborøn, outside. — Sk: Hanst- holm, Roshage, stone on the shore; Lanstrup, stones on the shore, Hirshals, mole and reef; wreck by Skiveren; Hojen, on pebbles within the innermost shoal and between the first and the second shoal, 1—4 meters. — Kn: Harbour of Skagen, outside eastern mole. 6. Polysiphonia atrorubescens (Dillw.) Grey. Greville, Flora Edinensis, 1824, p. 308; Harvey, Phye. Brit. Vol. 2, 1849, pl. 172; Kützing, Tab. phye. 13. Band, 1863, Taf. 82; J. Agardh, 1863, p. 1035; Farlow, Mar. Alg. N. Engl. 1881, p. 174; Kuckuck, Bemerk. I, 1894. Wiss. Meeresuntersuch. N. Folge I. Bd., p. 253, Fig. 21; L. Batten, 1923 p. 289 fig. 26—29. Conferva atrorubescens Dillwyn, Brit. Conf. 1809, pl. 70. Polysiphonia Agardhiana Greville, Scottish Cryptog. Flora Vol. IV, 1826, plate 210; Kiitzing Tab. phye. 13. Band, 1863, Taf. 49. A number of vigorous endogenous creeping shoots are given off from the base of the primary shoot and from the long branches issuing from its base (fig. 385).1 These shoots produce numer- ous rhizoids (comp. Kuckuck, BATTEN) and such organs are also given off in number from the lowermost part of the erect shoots. The rhizoids are se- parated from the pericentral cell by a wall and contain numerous nuclei. The creeping shoots bear no trichoblasts but produce endogenous shoots; they are not much branched, most of the branches issuing from their proximal part. Some of these shoots, arising from the upper side, become erect, others, given off from the flanks or from the under side of the shoots grow out in a hori- : : Fig. 386. zontal direction. The branches p Se - ae UE : Polysiphonia atrorubescens. A, tip of tetraspore-bearing shoot with tricho- arising at a greater distance blasts. B, trichoblast. 200 : 1. from the base of the creeping shoots attain only a small size. The creeping shoots are usually somewhat incurved at the top, but not always upwards; they seem not to change from the horizontal to the vertical direction of growth, being transformed into erect shoot. The long erect shoots are densely tufted, issuing endogenously partly from the lowermost part of the erect filaments, partly from the innermost part of the creep- ing shoots. They bear no trichoblasts from the base to a comparatively great distance upwards; often more than the first twenty joints are without trichoblasts, but en- dogenous branches may occur in this part of the shoots. The trichoblasts are as a rule separated from each other by more than one joint, frequently by two or three 7 Harvey incorrectly ascribes a scutate root to this species (Phye. Brit. 1. c.). 436 joints, sometimes even more. In the upper parts of the plants, however, in partic- ular of the sex plants, the trichoblasts may follow immediately after each other on Fig. 387. Polysiphonia atrorubescens. Basal portion of trichoblast with axillary shoot. 200 : 1. the consecutive joints. In the male plants, the fertile tricho- blasts are usually densely crowded at the upper end of the shoots, each joint bearing a trichoblast. The angle of divergence of the trichoblasts must be de- termined at the upper end of the shoots, for torsions take place later. It is usually !/; or nearly so. In a male shoot I found it 1/,. On the other hand, in short branches I found a divergence of 4/5. The spiral always turns to the left; in one short shoot only I found a spiral turning to the right. The trichoblasts have the same structure as in the other species; they are much branched. The cells of the fully devel- oped trichoblasts contain two or more nuclei; two nuclei most frequently occur (fig. 386), but four were repeatedly met with. The branches arise as axillary buds to the trichoblasts, but only part of the trichoblasts, mostly those of the lowermost part of the shoots, are accompanied by shoots; these are placed at the left side of the trichoblasts. The first joint of the branches common to the branch and the trichoblast has three or four pericentral cells. The pit connecting (the second joint of) the trichoblast with the central cell in the basal joint is situated in the longitudinal wall between the outermost pericentral cell to the right and the cell next to it (fig. 388 A). The branches are given off from the axes under a rather acute angle, and they are often connate with the joint above to some extent. It may even rarely occur that the second joint of the branch is entirely connate with the mother shoot. The first trichoblast of the branch is always situated on the left side of the 3rd to the 6th joint (fig. 388 B). The basal cells of the shed trichoblasts often produce secondary axillary shoots, Fig. 388. z Polysiphonia atrorubescens. A, portion of branch showing the pitx connecting the central cell of the basal joint with (the rest of) the trichoblast fallen off. B, portion of branch showing the basal cells (X) of the three first trichoblasts. 150 : 1. developing into short shoots, sometimes fructiferous but often reaching only a very slight degree of development. In these shoots, as in the primary ones, the first tri- choblast arises on the left side. As mentioned above, endogenous adventitious shoots, EAST produced from the central cells, further occur on the creeping shoots and the under- most part of the long upright shoots, but they may also arise at the base of the normal branches in the upper part of the plant. They usually appear on the inner side of the branch, most frequently between the 2nd and the 3rd or between the 3rd and the 4th joint. The upper trichoblast-bearing end of the shoots is curved, each trichoblast causing the axis to change direction. Later on, when the longitudinal growth takes place, the shoots are strengthened and each trace of bending is effaced. The number of pericentral cells is 11—13 in the long shoots, lower in the short shoots (about 9). ( The older joints, in particular of the longer shoots, usually show a more or less marked torsion, the pericentral cells being spirally curved, an appearance already observed by the first observers of the species. The torsion is undoubtedly caused by the pericentral cells growing more in length than the central cell. The coherence between the first and latter and between the ends of the pericentral cells in consecutive joints must, however, oppose resistance to this torsion, and this resistance may sometimes cause that the pericentral cells have a sigmoid curvature Be = 5 5 Polysiphonia atrorubescens. Male trichoblasts with ste- (fig. 385 C). The torsion may go to the rile branches. 200 : 1. right or to the left, and the direction may change in various joints of the same shoot. — Cortication does not occur. The antheridia have been met with only once in a specimen from Hirshals (July 1914). The male trichoblasts may have the same appearance as in most other species, the antheridial body occupying the main axis of the trichoblast except the two first joints, the upper of which bears a sterile branched branch to the right.” But the fertile part of the trichoblast, which is always curved inwards, often bears sterile branches on the flanks in varying number (1 to 3 or more), issuing from the inner central axial cell-row (fig. 389). The antheridial bodies may then be a little irregular in shape and sometimes slightly branched. It also happens that the lower sterile branch is transformed into an antheridial body. The sterile branches of the antheridial bodies occurred in so great a number that they seemed to be a normal appearance. The ripe cystocarps are nearly globular, about 400 « in diameter, with a short stalk, the ostiole is small, situated in a slight depression and surrounded by small cells. The outer cells of the cystocarpial wall are connected with secondary pits, the formation of which is easily studied in this object. 1 According to THURET (Et. phyc. p. 86) the male trichoblast in this species bears no sterile branch on the coast of France. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 56 438 The tetrasporangia occur in the upper ends of the long shoots and in the fusiform short shoots. They are situated to the right of the trichoblast in the tri- choblast-bearing segments, in the foregoing trichoblast-less joints the sporangia are situ- ated under the sporangium in the trichoblast- bearing joint. The sporangia are covered by two secondary pericentral cells. A small peri- pheric cell is never found under one of these.! P. atrorubescens occurs only in waters with a high salinity. It grows on stones and shells of mollusks at from one to 23 meters’ depth or deeper. In the Skagerak it has mostly been found near land in 1 to 4 meters’ depth growing on stones, in the northern Kattegat in 11,5 to 23 meters’ depth or deeper in soft bottom growing on Aporrhais, Turritella a. o. mollusks. Its non-occurrence in the upper regions of this water is probably due to the slighter and more variable salinity. It has only been collected in the summer months (June—August) and thus it cannot be stated whether the species is annual or perennial on the Danish shores. In October it was - only met with once in a denudate state. GREVILLE and HARVEY mention it as annual, while BATTERS states that it is to be found “all the year”. In the Skagerak and the A Limfjord it attains a length of 18 cm, in the Kattegat 13 cm. RUN Fig. 391. N er, In the Danish waters it has 0 ysip honia atrorubescens. A, transverse section of stem. > , transverse sections of tetrasporiferous joints, C emptied. 200 : 1. been found with cystocarps and tetrasporangia in June to August, with antheridia in July. It must be supposed that the spores germinate in summer and that the plants pass the winter in a feebly developed state. Fig. 390. Polysiphonia atrorubescens. Ripe cystocarp. 150 : 1. Localities. Sk: YT? and YT%, Hanstholm 5,5 and 13 meters and YM, Roshage, near land, 2 m; Bragerne, YM’, 1,5—2 m; Grønhøj Strand, Miss Ellen Möller; Lønstrup, on stones near land, 1m; 1 J. Acarpn states (1. c. p. 1037) that he has found two sporangia in each joint in a densely branched specimen from Tanger collected by SCHOUSBOE. As this species has not been found near Tanger (comp. BORNET, Les Algues de Schousboe. Mém. soc. sc. nat. Cherbourg 1892 p. 315) it must be supposed that it has been confounded with another species, f. i. Ophidocladus Schousboei (Thuret). (Comp. DE- Toni Syll. Alg. IV, p. 1073). 139 Hirshals, on stones near land, 1—2 m; off Højen, on pebbles within the first shoal and between the first and the second shoal. — Lf: XY, at Mullerne, Thisted Bredning, 6,5 m; XV, north of Ronnen at Lem Vig; Oddesund, 6,5 to 10 m or deeper. — Kn: South of Skagens Gren, 13—15 m (Kramp); fC, 3 miles S.W. by S. of Skagen light-house, 15 m, denudate in October; YS?, north of Græsholm, Hirsholm, 15 m; YX, east of Nordostrev, Hirsholm, 23—28 m; south of Hirsholm, 13 m; XH and XL, east of Marens Rev, 11,5 —15 m. — Ke: FC, east of Flyndergrund, east of Læsø 17—18 m. 7. Polysiphonia nigrescens (Engl. Bot.) Grey. Harvey in Hooker, Brit. Flora II, 1833, p. 332; Phyc. Brit. III, 1851, Plate 277; J. Agardh, 1863, p. 1057; Kolderup Rosenvinge, 1884, p. 13 (Re- sume p. 2), plates I—II figs. 15—29; Hauck, Meeresalg. 1884, p. 2445 Falkenberg, 1901, p. 129; Svedelius, Östersj. Hafsalg., 1901, p. 121; Kylin, 1907, p. 143; Lakowitz, Alg. Danz., 1907, p. 20; Kylin, 1923, p. 116; L. Batten, 1923, p. 306. Conferva nigrescens Smith, Engl. Bot. 1806 Plate 1717. Hutchinsia nigrescens Lyngb. Tent. 1819, p. 109 Tab. 33. Hutchinsia violacea Lyngb. Tent. 1819, p. 112 ex parte, tab. 35 A.1—2. B.2. f. pectinata J. Agardh, I. c., p. 1058; Aresch. Exsice. No. 63 and 57 (Polys. Brodici). f. fucoides J. Ag., 1. c. f. flaccida Aresch., 1850, p. 49; Kylin, 1907, p. 143, Taf. 5 Fig. 1. f. reducta Svedelius, 1901, p. 121. The morphology of this very common species has been described at length by me (1884) and later by FALKENBERG (1901). The trichoblasts are arranged in a spiral with rather Fig. 392. large angles of divergence, about ?/;. They may occupy all NR the consecutive joints, including those bearing branches which 3ı1st. Tip of shoot without may take the place of some of the trichoblasts in the spiral te EES KJOLE (comp. K. R. 1884 fig. 24). But it also happens that “sterile” joints occur between the trichoblast- or branch-bearing ones, e. g. that every second joint only bears a lateral organ, or the sterile joints may occur more sparsely and more irregularly. In other cases the shoots are entirely or almost entirely devoid of tricho- blasts; the branches are then placed in a spiral or they are biseriate, alternate, separated by a varying number of joints bearing no lateral organs. The latter occurs particularly in the f. pectinata J. Ag. but also in the other forms (fig. 392, comp. FALKENBERG, p. 129). The main branches often begin by bearing only branches, no trichoblasts. Endogenous branches normally arise at the base of the primary axis and of the main branches (fig. 396), and at the base of almost all later well developed branches, mostly at their inner face (fig. 393, K. R. 1884, figs. 25—28); these 56* endogenous branches may reach a considerable length. Secondary axillary shoots developed from the basal cell of trichoblasts also frequently occur, but these shoots Fig. 393. Polysiphonia nigrescens. Endogenous adventitious shoot at the limit between the second and the third joint of the branch. Small cortical cells have been cut off from the lower end of the pericentral cells. 220 :1. usually reach only a small size (K. R. 1884 fig. 29); they some- times arise before the trichoblast has been shed (fig. 395 A). The trichoblasts show the usual structure; they have at least three generations of branchlets. The older cells contain a number of nuclei each (fig. 395 B). In specimens collected in April the trichoblasts had in a living stage a feeble rose tinge due to the cell sap, but the small round chromatophores were also feebly coloured. Later in the year the cell sap may have a brownish tinge. The first joint of the branches is short and has only peri- central cells on its outer side, in a number of 4—6, the second ‘joint of the branch being at the base in connection with the following joint in the mother axis. It may happen, however, that the first transversal wall of the branch does not reach the mother axis, but the first joint of the branch is at all events shorter than the following ones (fig. 394 A). A peculiar case is shown in fig. 394 B, where the third joint bears at the back the basal cell of a trichoblast whereafter follows a bifurcation, the two branches being of equal strength and diverging equally from the original direction of the axis. This must probably be because the apical cell, after having produced a tricho- blast-bearing segment, has been divided by a vertical wall in two equal parts, each giving rise to a branch, a true dichotomy thus occurring here. In the upper part of the plants the first lateral organ on the branches usually occurs on the 3rd to the 5th joint, in the season of vegetation. The basal joint of the trichoblasts may sometimes pro- duce pericentral cells, as if it were the basal joint of a branch (fig. 395 B). These trichoblasts must be apprehended as transitional forms approaching to the branches. A further transitional stage is shown in fig. 295C, where the two lower- most joints are provided with pericentral cells and the upper of these has produced a tetrasporangium, while the upper part IE Fig. 394. A, pseudodichotomy; the first Polysiphonia nigrescens. joint of the branch (to the left) is long, with pericentral cells all round, though shorter than the following joints. 50:1. B, portion of young plant; probably true dicho- tomy (see text). of the lateral organ has the character of a trichoblast, though it is unbranched. In winter (January) the plants as a rule bear no trichoblasts (fig. 392). The growth seems to begin slowly in February. In April, specimens with corymbi- form shoots and well developed trichoblasts are met with, in May the trichoblasts have in great part attained their definitive size and in the two following months the growth gradually ceases. As the fully developed trichoblasts are shed early, hairless specimens may be found already in July; in Sep- tember such specimens become more frequent, and in the following months they are almost exclusively met with. The number of pericentral cells varies from 10 to 20, or more fre- quently between 12 and 17, but the average number is different in the different parts of the Danish waters as may be seen in the Fig. 395. following table showing the numbers Holusiphonia nigrescens: from Seborshoved Grand off Gilleleje: € 4 A, a shoot has developed from the basal joint of the tricho- of pericentral cells found in cross last. B, the basal cells of the trichoblasts have produced sections of primary axes or prin- pericentral cells but no shoot. C, the two lowermost joints £ A ofan unbranched trichoblast have produced pericentral cells; cipal long branches below the middle. the second joint a tetrasporangium. 200: 1. Number of pericentral cells. {| Localities over 11 meters’ depth Localities deeper than 11 meters Fi | average |numbers vary- numberof || average | numbers vary- | number of number ing between observations | number | ing between | observalions North Sea and Skagerak . 15,1 12—18 26 55 a 5,5 Northern Kattegat ....... 15,3 1120 21 | 12—17 6 Southern Kattegat ....... 14 I 19 13 HET 2 Samsø Waters, the Belts and Sydfyn Waters... . 14,2 10—19 30 13,3 10—16 12 Smaaland Sea and Sound. 13,7 12—15 17 Western Baltic and Baltic around Meen.......... ahi 11—16 16 11229) 11—14 5 Baltic around Bornholm. . 12,1 10—14 9 11 10—13 3 The table shows that the average number gradually decreases on going from the North Sea to Bornholm, and it is also a little smaller in deeper than in 442 shallow water. In a specimen from the deepest locality where the species has been met with, US, Store Belt, in 33—45 meters’ depth, 9—10 pericentral cells were found. € E 56 DB ehe Denkt Fan Fig. 396. Polysiphonia nigrescens. Young plant. The lowermost cell of the primary axis is the short primary rhizoid-cell fixed to the substratum ; the second has produced no pericentral cells but several rhizoids. The following joints have produced peri- central cells, the numbers of which are indicated by the respective joints. A vigorous branch of endogenous origin is given off from the lower end of the “third joint. 70:1. cells, but are sometimes confluent and show some resemblance to cells (fig. 398). The older parts of the long shoots are usually covered by a continuous cortex. The cortical cells arise as small cells cut off from the lower end of the pericentral cells. The antheridia, as in the other species, usually occupy the prineipal axis of the fertile trichoblast except the two first The number of the pericentral cells is for the rest rather variable in different parts of the same plant. In the sporelings the first joint after the primary rhizoid-cell has no pericentral cells but gives rise to numerous rhizoids; the following two or perhaps more have 4, and in the next following the number gradually rises to the number normal to the species (fig. 396). In the branches of the latest order, the num- ber may be much lower; in a tetraspore-bearing spec- imen I found it reduced to 6 (fig. 401 C). The pericentral cells usually contain numerous large starch grains. The nuclei were found situated at the inner and radial walls, not at the outer wall. The pericentral cells often contain peculiar star- shaped bodies with curved rays which are probably a sort of crystalloids (fig. 397 B). They take a brown tinge when treated with iodine. They are very resist- ent to chemical reagents; they were not dissolved by KOH, HCl and Eau de Javelle, nor by boiling water. They seem to disappear at a later moment, for in older pericentral cells they were not met with. The inner and radial walls of older pericentral cells are transversely striped. In a tetrasporiferous branch I found two nuclei in the central cells (fig. 401). At the level of the transversal walls between the joints, intercellular bodies like those described by me in Polysiphonia fastigiata as inter- cellular cuticular bodies (1884, p-10 (2), figs.11—14) occur; they occupy the angles between the central cell and the pericentral a” Fig. 397. Polysiphonia nigrescens. A, pericentral cell showing chromatophores {lying at the outer wall, January. 435 : 1. B, star-shaped bodies, probably crystal- loids in pericentralZ cells. 300 : 1. After living plants. 443 _ joints; the antheridial bodies are usually pointed (comp. Harvey |. c. and BurrHam) and terminate in a short row of sterile cells, but that is not always the case (comp. Kyrın 1923 p. 122). A sterile branch given off from the second joint is in many spec- imens normally present, in other specimens it is normally wanting, and the trichoblast is then unbranched. For the rest various arrangements may occur, as shown in fig. 399. As regards the development of the spermatia see KyLiN (1. c.). The development of the cystocarp from the second joint of the female trichoblasts and the position of the branches of the upper sterile part of these trichoblasts in relation to that of the sterile trichoblasts have been mentioned by me in 1884. The development of the procarp and the cystocarp has recently been very carefully studied by Kyrın (1923 pp. 118—121). The ripe cystocarps have a conical upper part, tapering towards the orifice (fig. 400). The tetrasporangia are, in the shoots Fig. 398. Polysiphonia nigrescens. Transverse section of stem, at the level of the transverse wall between two central cells. p, callus plate of the pit between the central cells. c, intercellular “euticular” bodies. 200 :1. bearing a trichoblast on each joint, seated to the right of the trichoblast (or branch) borne on the same joint. When the internodia consist of more than one joint, the D Fig. 399. position of the one following next to a trichoblast seems usually to be determined by the position of the follow- ing trichoblast. The tetra- sporangia are covered in the front with two peri- (a) = central cells between which m 5 Sra split is formed through a eZ NAG which the spores escape at [ E Of F maturity. On the flanks the sporangium is coyered by two other pericentral cells. Polysiphonia nigrescens. Male trichoblasts, differing from the ordinary type, No short peripheral cell is dorsal view. A without branches, B—F with one or two branches, sterile or fertile. A 230:1. produced as in several other species. A cruciately divided sporangium was once observed amongst numerous sporangia divided in the ordin- ary tetrahedrical way. 444 The species is very common in all the Danish waters. It is perennial and may be found in well developed and large specimens in all the seasons. In winter there Fig. 400. Polysiphonia nigrescens. Ripe cystocarp. 130 : 1. is no or almost no growth, and the wintering shoots have no trichoblasts. In spring the plants are in full vegetative development with numerous hairs, and sexual organs occur. Thus antheridia and carpogonia were met with in April to June. Ripe cystocarps were met with in (May) June to September. Young tetrasporangia were found in April and May, ripe in May to September. The fructiferous branches seem to be thrown off in August and September, for in the follow- ing months the species was always found sterile. The denudate plants may produce new shoots in the following year as well as the young plants produced by the germinat- ing spores in summer. The plants arising from early germinating spores may without doubt produce ripe spores in the same season while those germinating in the later part of the summer probably pass the winter in a sterile state. The denudate specimens bearing short remnants of the fruc- tiferous shoots, may be referable to f. senticosa. Most of the specimens may be referred to f. fucoides. F. pectinata was met with in exposed localities in the North Sea and the Skagerak. In deeper localities in the inner waters slender specimens occur which may in part be referred to f. flaccida Aresch.! Other specimens from deeper localities were slightly branched and ought there- fore to be referred to f. reducta Svedelius, described from the inner Baltic Sea. — The species thrives best in depths smaller than 15 meters, where it is very common, even in very light local- ities. Under that level it occurs rather rarely and only in small quantities. 1 When ÅRESCHOUG (1. c. p. 49) says that the branches änd branchlets in this form are subhorizontal, it does not seem to be justified. Fig. 401. Polysiphonia nigrescens. A, portion of tetrasporiferous branch ; b, basal cell of trichoblast; c, central cell; s, stalk cell; sp, sporangium. B, similar in longitudinal section. C, D, trans- verse sections of sterile joints, E, F, of fertile joints of tetrasporiferous branches. A 95:1. B—F 200: 1. 445 Thus in the North Sea it has only been found from low-water mark to 13 meters’ depth, although several dredgings have been made in localities in deeper water. Further it was wanting in all the dredgings on Herthas Flak in the Northern Katte- gat (19—22,5 meters), and in almost all the numerous dredgings made in the Eastern Kattegat. The species reaches a length of at least 20 cm; the largest specimens collected were 30 cm (Skagerak) and 35 cm (Lille Belt) long. Localities. As the species is very common in shallow water, only localities deeper than 15 meters are recorded. In these specimens the joints were thrice as long as broad in the middlemost part of the frond. — Ns: From Esbjerg to Hanstholm, down to 13 m. — Sk: Down to 13 m. — Lf: — Kn: IX, near Trindelen, 19 m; YX, east of Nordest-Rev, Hirsholm, 23—28 m. — Ke: Only in IN, Fladen, 15 m; EX, Groves Flak, 26,5 m; ET, Lille Middelgrund, 12 m; IA, Store Middelgrund, 16,5 m (f. reducta); GJ, Ostindiefarer Grund, 8,5 m and Soborghoved Grund, 8,5 m. — Ks: Hastens Grund, 16 m. — Sa: YV, 15m. — Lb: Rogle Klint S. by E. 19—30 m; between Strib and Nederballe, 35 —44 m; Fæno Sund, 28 m; dH!, east of Hesteskoen, 18—19 m (f. flaccida); dQ, south of Lyø, 22 m. — Sf: — Sb: eN, 18 m; Z, off Skagbo Huse, 19 m; AA, north of Nyborg, 22,5—26,5 m (f. reducta); NN, S.W. of Sprogø, 19 m; US, Langelandsbelt 37,5—45 m (f. flaccida); LB, Langelandsbelt, 17 m.— Sm: — Su: bM, south of Hveen, 22,5 m (f. reducta). — Bw: KX, Femerbelt, deeper than 19 m. — Bm: VG, 17 m and QS, 20,5 m, North of Moens Klint. — Bb: SR, 15—16 m and ST, 18 m, Rønne Banke (f. reducta); YC, Salthammer Rev, 24,5 m. Brongniartella Bory. 1. Brongniartella byssoides (Good. et Woodw.) Schmitz. Fr. Schmitz, Die Gattung Lophothalia. Ber. deut. bot. Ges. 11, 1893, p. 217; P. Falkenberg 1901, p. 542, Taf. 19 Fig. 8—10; Kolderup Rosenvinge, 1903, p. 469. Fucus byssoides Goodenough et Woodward, Trans. Linn. Soc. III 1797, p. 229. Hutchinsia byssoides C. Agardh, Synops. Alg. Scand. 1817, p. 60; Lyngbye, Tent. 1819, p. 110, Tab. 34 B, C; Flora Danica Tab. 1905,2, 1827. Polysiphonia byssoides Greville, Flora Edin. 1824, p. 309; Areschoug, Phyc. Scand. mar. 1850, p. 56; Harvey, Phye. Brit. III, 1851, Plate 284; J. Agardh, 1863, p. 1042; P. Magnus, Bot. Zeit. 1872, p- 253; L. Kny 1873, p. 106; G. Thuret et E. Bornet, Etudes phyc. 1878, p. 86; L. Kolderup Ro- senvinge, 1884, p. 25 (4), PI. 2 Fig. 30; Hauck Meeresalg. p. 238; Buffham, 1888, p. 263; Reinke, Algenflora 1889, p. 31. Polysiphonia Dillwynii Kützing, Phyc. gen. 1843, p. 430; Tab. phyc. 14, 1864, Tab. 23 (&). Polysiphonia vaga Kützing, Phye. gen. 1843, p. 431; Tab. phyc. 14, 1864, Tab. 24. Polysiphonia asperula Kütz., Spec. Alg., p. 835, Tab. phyc. 14, Tab. 25. Polysiphonia Lyngbyei Kützing, Phyc. gen. 1843, p. 431 (Hofmansgave). Polysiphonia Bangii Kützing, Spec. Alg. p. 1849, p. 835; Tab. phyc. 14, Tab. 25 (Hofman Bang). Lophothalia byssoides J. Agardh, Till Algernas Systematik, 6. Afdel. 1890, p, 59 (Lunds Univ. Ärsskr. 26). As first shown by Kny and confirmed by the writer and by FALKENBERG, the trichoblasts are arranged in a spiral turning to the left with an angle of divergence of ?/; or nearly so. In luxuriantly growing shoots, the upper end of the axis is straight and overreaches the young trichoblasts which are curved upwards but not appressed to the axis (comp. FALKENBERG |. c. fig. 8). The trichoblasts have usually not more than two branches (FALKENBERG p. 544) but three branches are not un- frequently met with (comp. KOLDERUP ROSENVINGE 1884 fig. 30). On the other hand D. K. D. Vidensk. Selsk. Skr., 7, Række, naturvidensk. og mathem. Afd. VII. 3. 57 Fig. 402. Brongniartella byssoides. Store Belt, May. Procumbent shoot giving off an erect shoot. The upper figure is the continuation of the lower, but eight joints without tricho- blasts have been omitted; the lowermost joint in the upper figure is the 17th from the base. 50:1. unbranched trichoblasts also occur, f. inst. on the lower part of the erect shoots (fig. 402). The cells of the full-grown trichoblasts contain a number of nuclei. The long shoots have 7 pericentral cells but in the shoots of higher order the number is frequently only 6 or even 5, and in the creeping shoots, too, only 5 or 6 pericentral cells were found. Cor- tication is wanting. In the long erect shoots an axillary shoot is usually given off from the basal cell of all the trichoblasts; the lowermost trichoblasts, however, are often not ac- companied by axillary shoots, and the same may sometimes be the case with single trichoblasts among the usual ones. The first joint of the axillary shoot, common to this and the trichoblast, has usually 4 pericentral cells, as stated by FALKENBERG (1901 p.545), but the number may be smaller, e. g. 2, as described by Kny (1873, p. 106, comp. our fig. 404, 405 A). The normal axillary shoots arise comparatively late, on the kathodic side of the basal cell, according to FALKEN- BERG at the 20th to the 30th segment of the mother shoot; they may, however, arise earlier, e. g. at the 8th to the 10th joint. The pericentral cells of the basal joint are cut off shortly after the form- ation of the axillary branch. The direction of these cells is usually very different from that of the pericentral cells of the follow- ing joints, coinciding with the direction of the trichoblast, while the direction of the axillary branch diverges almost at right angles from the trichoblast (fig. 405). As shown by FALKENBERG, it happens that no axillary shoots are produced in feebler branches, but notwithstanding that four pericentral cells are cut off from the basal cells of the trichoblasts. The same has been found by me in Polysiphonia nigrescens Fig. 403. Brongniartella byssoides. A, transverse section of stem. B and C, transverse sections of tetrasporiferous branch. B, fertile joint after evacuation; C, sterile joint of tetra- sporiferous branch. 200 : 1. 447 (see above p. 440). In normal axillary shoots the first tricho- blast appears on the 3rd or 4th, more rarely on the 5th joint, the basal joint included. At the base of the plants endogenous creeping fila- ments are to be found which bear no trichoblasts; they may bend upwards and become erect, tricho- blast-bearing shoots (fig. Fig. 404. 410). Endogenous shoots Brongniartella byssoides. Communication arise from the creeping of the second joint of the trichoblast with the central cell of the basal joint. 220 : 1. and the lowermost part of the erect shoots, emerg- ing at the limit between two joints. Their first joint has pericentral cells on all sides. In these shoots a great number of joints is often without trichoblasts; but when the tricho- blasts appear they occur on all the joints (figs. 402, 410). FALKENBERG under the designation stolons describes certain shoots which bear no trichoblasts but are provided with rhizoids and have a long conical point. Such shoots are frequently met LY with in the Danish waters but they have not the char- acter of stolons. They occur often indeed, mostly in the lower part ofthe plants, but they are not creeping, the numerous rhizoids are directed forward and not fixed to any substratum and Fig. 405. therefore without Brongniartella byssoides. Lower part of trichoblasts ttach t di with axillary shoots. The pericentral cells of the attachmen ISG; basal joint parallel with the longitudinal axis of and such shoots the trichoblast, the axillary shoot nearly perpendic- Al à 5 ular to this direction. 350 : 1. may also occur In the upper part of Fig. 406. Brongniartella byssoides. Spiny shoot without trichoblasts but with rhizoids or hairs. 30:1. the plants. Their appearance is in correlation with a weakening of the growing power. In certain long shoots the trichoblasts become gradually feebler, finally their 7% 5 us production ceases and then the rhizoids appear and the shoot becomes pointed. Such spiny shoots have been met with in specimens from the different Danish waters from the North Sea to the Belts, gathered in July to November. The form described and figured by Kürzıng under the name of Polysiphonia asperula (l. c.) shows these spinous shoots in great number also in the upper part of the plant. The rhizoids mentioned ought perhaps rather to be compared with the unicellular hyaline hairs occurring in other Florideæ; they are like these separated Fig. 407. Brongniartella byssoides. Shoot with antheridia- g R bearing trichoblasts. June. 350: 1. from the pericentral cell by a wall. As I have had no occasion of examining them in a living state, it cannot be said with certainty whether they contain chromatophores or not. The antheridia-bearing trichoblasts are simple with a two-celled stipe without sterile branch (comp. Kürzıng Tab. phyc. 14, Pl. 23 and THuRET 1878). They are borne on short branches which also bear sterile trichoblasts but are usually unbranched (fig. 407). I always found them on particular individuals, but BurrHam found them intermixed with eystocarps on different branches of the same plant, and in another plant he found antheridia combined with tetrasporangia (1888, p. 263). LyNGBYE found these organs in specimens gathered at Gjerrild 1825 and men- tions them in his herbarium as corpuscula antheræformia. The procarps arise as usual in the second joint of a trichoblast. The third joint remains short and the fourth bears a branch on the right side. The ripe cystocarp has a cylindrical spout consisting of parallel cell-rows. The sterile part of the trichoblast is kept till the maturity of the cystocarp. (fig. 408). The tetrasporangia arise in shoots with more or less limited growth of the two last orders of ramification. In transversal sections of tetraspore-bearing joints I found 7 pericentral cells whereas sterile joints of the same shoot often showed only 6 or 5 (fig. 403). A small peri- pheral cell under one of the secondary pericentral cells was not met with. The sporangia apparently always arise Fig. 408. Brongniartella byssoides. Ripe to the right of the trichoblast borne on the same joint. cystocarp. July. 130: 1. The different organs of fructification were always found in distinct individuals. Antheridia were met with in June to September, carpogonia in June to July and even later, cystocarps in August to October and tetraspor- 449 angia in July to November; as late as December sporangia, partly emptied, were met with. The principal season for the production of ripe spores is August to September. The spores are able to germinate immediately after dissemination. I have not myself observed the germination, but Mr. BoyE PETERSEN has kindly at my request sowed carpospores in vessels with sea-water and brought me slides with the sporelings raised in the cultures. After one day the globular spore-cell showed a feeble proeminence, the first step of the arising rhizoid. The following day an elongated rhizoid-cell was formed and the still glob- ular spore-cell was divided by parallel walls perpendic- ular to the direction of the rhizoid. The sixth day a number of (5—9) segments were formed, the upper end of the lengthened sporeling had taken a shape reminding one of that of the full-grown plants, but lateral organs had not Fig. 409. Brongniartella byssoides. Spore- lings, 6 days old. 200: 1. yet appeared. Most of the segments had formed pericentral cells, but the division of the first segments was somewhat irregular and the number of pericentral cells Fig. 410. Plants gathered January 3rd. Brongniartella byssoides. A 200:1. B 95:1. could not be deter- mined with certainty (fig. 409). As the cul- tures had to be discon- tinued after 6 days, the further development is unknown, but itis pro- bable that the spore- lings produce early creeping filaments. Young sporelings were not met with in Na- ture, but in winter and spring I found only creeping filaments giv- ing off short erect shoots (fig. 410). It has to be decided whether these creeping fila- ments originate from sporelings produced the last year or from older plants, or from both. In the first case the species would be annual like our winter-crops, in the second case it would be perennial. Brongniartella byssoides develops later as the species of Polysiphonia. In April the erect shoots are only 1 cm high, in May 1—3 cm, in June it is in active growth 450 and in July it usually attains the maximal size (23 cm). The growth seems to cease towards the end of July or in the beginning of August, in September the trichoblasts begin to fall off, but as late as November specimens with well preserved tricho- blasts may be met with. At the end of the year the plants die, in many cases with the exception of the creeping filaments from which new shoots are given off next spring. The new sboots in winter bear at the top a tuft of simple or feebly branched trichoblasts which are incurved over the upper end of the stem (fig. 410). In the Danish waters from the Skagerak to the Belts the species reached a length of 20 cm or a little more. In the western Baltic Sea the greatest length observed was 12 cm and in the Sound south of Helsingør only 5 cm. It does not usually occur in the fjords; in the Limfjord it has only been met with once, and in the Isefjord only in the entrance. It occurs in the sublittoral region. At Hirshals it was found near land in about 1 meters’ depth, and in the harbour of Frederikshavn it was found in the same depth, but otherwise it has not been met with over 4 meters’ level, in the Great Belt and the western Baltic Sea not over 6 meters’ level, and in the Sound south of Helsingor only in 10 meters’ depth. It has been found most frequently in 7,5 to 15 meters’ depth and descends to 38 meters’ depth. It grows most frequently on various Algæ, in particular Furcellaria, but also occurs on shells of Molluses and barnacles and on stones. Localities. Ns: ZQ, jydske Rev, 24,5 m; aF, off Thyborøn, 31 m; aE, 16 m. — Sk: YN!, YN? within Bragerne, 6,5—10 m; SY, off Løkken; ZK?*, off Lønstrup; off Hirshals, several places 11—15 m, near land, 1 m. — Lf: bU, Ejerslev Næse, 3—8 m, one specimen. — Kn: Off Skagen, 9,5 m; off Hulsig (Boye Petersen); Herthas Flak (Borgesen); around Hirsholmene, 5,5—7,5 m; Frederikshavn; off Frede- rikshavn; several places near Nordre Ronner; GM, Engelskmands Banke; TO, TP, ZA, Tonneberg Banke, 16—18 m; NI, FE, dS, a. o. pl., Trindelen, 8—16 m. — Ke: 4*/, miles S.W.°/, W. of Fladen light-ship, 30 m (C. A. J.); FD, east of Leso; VY, Fladen; ZJ, EX, EV, Groves Flak; XA; EU, Lille Middelgrund, 14m; ER, Fyrbanken, 28 m; Store Middelgrund, 10m (C. A. J.); Ostindiefarer Grund; OO, Soborg Hoved Grund; bR, Vesterlands Grund off Gilleleje, 7,5 m. — Km: 6 miles S.S.W.!/; W. of Læsø Rende light-ship (C. A. J.); 54/2 miles N. by E.*/, E. of Østre Flak light-ship (C. A. J.); XD, XC, south of Læsø; VP, south of Leso; ND, NC, BH, off Gjerrild Klint; Gjerrild Bugt (Lyngbye). — Ks: FO, NB, off Hav- knude; EM, Lysegrund; RL, west of Ostindiefarer Grund; near Hesselo (Lyngbye); D, north of Grenne Revle, 11,5 m; Tisvilde (Lyngbye); GG, GF, Sjællands Rev; EJ, entrance to Isefjord; EH, west of Lynæs. — Sa: FU, Begtrup Vig; MY, FT, north of Samsø; BE, off Sletterhage, 10 m; FS, Vejro Sund; GD, GE, north of Sejerø; MP, Falske Bolsax; AS, Mejlgrund; FX, west of Tunø; AT, Syanegrund, 5 m; MQ, south of Paludans Flak, 11,5 m; Hofmansgave (Lyngbye, Hofman Bang, C. Rosenberg); AJ‘, north of Æbelø, 4m; AY, Ashoved; AX, Bjornsknude, 9,5 m. — Lb: FZ, Kasserodde, 6m; cX, between Strib and Neder- balle, 35—44 m; Fænø Sund; north of Fænø Kalv; off Stenderup Skov, 13—15 m; Aarø Sund (Reinke); Lillegrund (Reinke); CD, Helnæs Hoved Flak, 4m; CC, south side of Hornenzs, 7,5 m; dH}, east of Hesteskoen, 18—19 m; CF, west of Lyø; dQ, south of Lyø, 22 m. — Sf: UV, north of re, 13 m. — Sb: Off Refsnæs; MN, north of Asnæs, 11 m; GS> south of Asnæs; LH, Elefantgrund; eN, S.W. of Mus- holm, 18 m; AA, north of Sprogø, 23—26 m; XS, Kleverhage; GZ, north of Egholm; DP, UJ, north of Onsevig; US, Langelandsbelt, 38 m. — Su: Off Ellekilde, 5,5 m, cast ashore north of Helsingor and at Hellebæk (C. Rosenberg, Ørsted, Joh. Lange); PZ, east of Hveen, 10—19 m. — Bw: LG, off Vidso, Ærø, 9,5 m; bV, bX, off Kobbel Skov, 6—13 m; cG, west of Kegnæs; south of Als (Reinke); cE, Middelgrund, south of Als, 13 m; dK, Pols Rev, 6—7 m; Vodrups Flak, 9,5 m; DU, off Dimesodde, Langeland, 11 m; KX, Femerbelt, 19 m or deeper. 451 Rhodomela Agardh. 1. Rhodomela subfusea (Woodw.) Agardh. C. A. Agardh, Sp. Ale. I, 1821, p. 378, emend.; Harvey, Phyc. Brit. Vol. III 1851 pl. 264; J. Agardh, 1863 p- 883; Areschoug, Obs. phyc. III 1875, p. 6. N. Act. R. Soc. Ups. Ser. III Vol. X; Kjellman, N. Ish. Algfl. 1883 p. 146 (113); Kolderup Rosenvinge 1884, p. 33; 1902 p. 360; 1903 p. 459; Falkenberg 1901, p. 593 Taf. 11 Figs. 2—17; Kylin 1907, p. 145; id. 1923 p. 114. Fucus subfuscus Woodward, Linn. Transact. I, 1791, p. 131, tab. 12; Hornemann, Flor. Dan. tab. 1543, 1816. Gigartina subfusca (Woodw.) Lamx.; Lyngbye Tent. 1819, p. 47, Tab. 10, 11. Lophura gracilis Kützing Phyc. gen. 1843, p. 435, Taf. 53 IV. Lophura cymosa Kützing Phyc. gen. p. 435; Tab. phyc. XV Tab. 36. @, genuina. Rh. subfusca Kjellm. I. c.; Kylin, 1. c. 8, lycopodioides (L.) Gobi. C. Gobi, Alg. weiss. Meeres. Mem. Acad. Imp. St. Petersbourg VII® ser. t. 26, 1878, p. 24. Fucus lycopodioides Lin. Syst. Nat. ed. 12, tom. II p. 717. Rhodomela lycopodioides Agardh Sp. Alg. I 1822 p. 377; J. Agardh, 1863, p. 885. Gigartina lycopodioides Lyngbye Tent. p. 45. Conferva squarrosa Oeder Flor. Dan. tab. 357, 1767. y, virgata (Kjellm.) nob. Rhodomela virgata Kjellman N. I. Algfl. 1883 p. 143 (110) tafl. 7; Kylin, 1907 p. 147; id., Stud. üb. die Entw. v. Rhod. virg. Sv. bot. Tids. Bd. 8 1914 p. 33. 0, tenuior (C. Agardh) Svedelius. C. Agardh, Synops. Alg. sc. 1817 p. 32; Svedelius 1901, p. 124. Rh. subfusca f. gracilior J. Ag. Gobi, Rothtange Finn. Meerbus. 1877 p. 11. e, abyssicola nob. Plate VI figs. 2—4. From old time the Rhodomelas occurring at the shores of Northern Europe have been referred to the two species Rh. subfusca and Rh. lycopodioides, the near relation of which to one another has been emphasised by several authors. In 1883 KieLr- MAN tried to show that the first of these species must be divided into two corres- ponding with the forms extratæniensis and intratæniensis distinguished by ARESCHOUG in 1875. The latter, to which he gave the name Rh. virgata, is distinguished by the following characters: The vernal plant of the first year does not become black by dry- ing and is flattened while Rh. subfusca becomes black and keeps cylindrical. The main axes are distinctly thickest in the middle and in their whole length bear branches gradually decreasing in length upwards, while Rh. subfusca has pronounced branch- lets with limited growth. All these branches are shed in summer, the main axes only remaining. The organs of reproduction arise in winter on the branchlets which grow out on the long shoots from the previous winter, and which are shed after 452 the fructification, while the corresponding branchlets in Rh. subfusca after fructific- ation may develop as vegetative shoots, and the fructification in this species takes place later, in spring. KJELLMAN also found anatomical differences between the two species, the cells in the main axes of Rh. virgata decreasing gradually in size towards the periphery, while Rh. subfusca has a small-celled cortex rich in “endochrome”, distinctly bounded towards the inner parenchyma consisting of large cells. Rh. lyco- podioides is considered as a distinct species though nearly related to Rh. subfusca. Kjellman emphasises as distinctive characters the numerous curved branchlets hay- ing their greatest thickness a little below the middle; they are arranged without any distinct order and are supposed to be adventitious. While REINKE and FALKENBERG do not adopt Rh. virgata as a distinct species, KyLın follows KJELLMAN, laying particular stress on the different season of fructification (Nov. to Jan. for Rh. virgata, April and May for Rh. subfusca) and on Fig. 411. the fact that the new shoots which Rhodomela subfusca. A (f. virgata) adventitious shoots near the in Rh. subfusca develop in the last base of a primary branch. 64:1. B transverse section of stem à 3 2 with a young adventitious shoot. 206 : 1. part of the winter and in spring, are at first both vegetative and fertile but after fructification remain as vegetative, while the organs of reproduction in Rh. virgala are seated in particular shoots which are thrown off after fructification. As to the branchlets of Rh. lycopodioides 1 have convinced myself, by examin- ation of specimens from Iceland and Greenland, that numerous adventitious branch- lets really occur in this species, arising from a single superficial cell growing out and dividing by a transversal wall, whereupon the outer cell becomes the apical cell of a branchlet. A similar formation of adventitious shoots has not only been met with in specimens from the Danish coasts otherwise fairly agreeing with Rh. lycopodioides, but also in specimens of Rh. subfusca and Rh. virgata (figs. 411 A). In the latter they were produced in particular near the base of the primary shoots. The occurrence of adventitious branchlets has thus no absolute value as distinctive character, and the same is, according to my experience, the case with the alleged shape of the branchlet and other characters, and I must therefore agree with the authors who have more or less distinctly suggested that Rh. lycopodioides might be considered a form of Rh. subfusca. As to the two species Rh. subfusca and Rh. virgata as distinguished by KJELL- MAN, to which most of the Danish species can be referred, it must be confessed, that in their typical shape they are so distinct as to habit and anatomical structure that they have the appearance of being distinct species. The examination of a great number of specimens, how- ever, has led me to the conclusion that they are only marked types of a very variable species produced by the influence of the outer conditions. The first occurs in particular near the low- water mark, where it is ex- posed to the movement of the waves, whereas Rh. vir- gata grows in greater depth, in particular in streaming water but not exposed to the waves. In localities which are intermediary as to the outer conditions specimens intermediary as to the distinctive characters are also met with. In the outer characters it appears that e. g. individuals which 453 == 000 ST eu LUZ sin? Fig. 412. Rhodomela subfusca. Transverse sections of stems. A, & genuina. B, y virgata. 160 : 1. if anything agree with Rh. virgata keep some branchlets which are not shed at the end of the period of vegetation, and do not show the above mentioned distinction : Fig. 413. Rhodomela subfusca f. virgata. Transverse sec- tion of stem. 80:1. between vegetative and fertile shoots. Further, the above-mentioned greater thickness on the middle of the long shoots is often wanting. When in doubtful cases the anatomical structure, which according to KJELLMAN seems to offer a very good distinction, is taken into consideration one finds that this also is not reliable. As a rule the anatomical structure in Rh. virgata is as described by KJELLMAN (fig. 412 B), but not rarely a more or less developed small-celled cortex is to be found in the lower part of the long shoots in specimens otherwise agreeing with typical Rh. virgata. Such a cortex may be found on one side of the branch but not of the other (fig. 413), or several more or less confluent proeminences with similar structure or even a continuous cortex all round may be met with. Usually then some long shoots are provided with cortex, others not. D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 58 454 Further, in some cases a feebly differentiated cortex may occur. Neither does the differ- ence in the season of fructification emphasised by KyLın seem to give a decisive mark, for both species were found with sex ofgans in January and were frequently found with ripe sporangia in April and May in the Danish Waters. In the inner waters, particularly the Baltic Sea, a fine form appears which in its extreme shape is very marked but which on the other hand is nearly related to the typical Rh. subfusca and to Rh. virgata as well. It is remarkable by its very thin and slender shoots and may be referred to f. tenuior Agardh, especially as it is characterised by SVEDELIUS (1. c.). In the ramification it usually resembles Rh. subfusca, the long branches bear- ing a considerable number of branchlets which Fig. 414. are not shed, whereas in the anatomical structure ln NOS ee DE it agrees better with Rh. virgata (comp. SVEDELIUS 1901 p. 125). Another thin and slender form &, abyssicola nob. was gathered in the southern Little Belt south of Lyo in 22 meters’ depth. Some of the specimens resembled Rh. vir- gata in habit (Plate VI fig. 2), others had a very thin principal axis and very distant thin and slender branches which were only slightly branched, in particular towards the top (Plate VI fig. 4). The trichoblasts were kept at least 4 cm below the top. These plants were still fructiferous on June 20th and bore sporangia and cystocarps in elongated branchlets not different from the vegetative ones, thus behaving much as Rh. subfusca. A section of the main stem shows the same structure as in Rh. virgata, but the cells are smaller. The diameter of the stem was 320 w (fig. 414). The plants are red and keep the colour when drying. All the forms mentioned are thus here considered as forms of Rh. subfusca which may be divided in the following principal forms: &, genuina. 8, lycopodioides (L.) Gobi. Fig. 415. > virgata (Kjellman) nob. Rhodomela subfusca growing on Portunus. Basal dise . . 2 : with primary and secondary shoots. 38:1. 0, tenuior (C. Agardh) Svedelius. ep: 2 e, abyssicola nob. F. axi primario distincto tenui, ramis remotis longis, parce præcipue apicem versus ramosis, trichoblastibus diu persistentibus. 455 The structure and development of the frond have been treated at length by FALKENBERG and Kyrın. Some supplementary remarks may be given here. Fig. 416. Rhodomela subfusca. Fæno Sund February. Trichoblast. 150 : 1. The fronds issue from a parenchymatous dise from which new shoots arise as adventitious buds without any order (fig. 415). Ac- cording to FALKENBERG the lateral organs produced by the branching of the fronds are only branches except at the tips of the shoots which are closing their growth, where numerous hair-leaves are produced, on long stretches one on each joint, and above this region of hair- leaves a formation of branches never takes place. The latter assertion, however, does not always hold good, for in the upper part of the branched shoots basal cells of shed trichoblasts are frequently found and single branches frequently occur between the trichoblasts still in function. The branches of the last order bear only tricho- blasts. The trichoblasts and the branches are placed in a spiral with a divergence varying between !/, and ?/, (often nearly ?/;). When occurring between the trichoblasts the branches take the place of the latter in the spiral without a change of the angle of divergence. The spiral may be turning to the right or to the left, but there is no regular antidromy as stated by me in 1884 (p.33 (5)). It seems that the spiral turns more frequently to the left than to the right, but my observations are not sufficient to ascertain that with certainty. The trichoblasts have the same structure as in Polysiphonia and other Rhodome- lacex. The first branchlet of the tricho- blast, however, is often given off from the third joint instead of from the second (fig. 416), or, though rarely, from the 4th, and unbranched tricho- blasts may occur, e. g. in f. fenuior. The second joint is often shorter than the following ones whether it bear a Fig. 417. Rhodomela subfusca. Upper end of male plant. 124: 1. branchlet or not. The cells contain a single nucleus and numerous chromatophores which are distinctly red. FALKENBERG lays much stress upon this fact which he alleges 58* 456 as supporting the opinion that “Die Blätter von Rh. subfusca stellen ein eigenartiges Mittelglied dar, über dessen Benennung man zweifelhaft sein kann” (I. c. p. 597). I cannot agree with the said author in this as there is only a slight gradual difference in the colour of the chromatophores in Rhodomela and in several species of Polysiphonia which have also rose-coloured chromatophores in spring and in deep localities. On the other hand the chromatophores of the trichoblasts in Rhodomela are often more or less decoloured during the spring, even in April." The trichoblasts begin to develop in winter (January) and are fully developed in spring (March to May). In June they are shed at the same time as the growth ceases, and in the follow- ing months no trichoblasts are met with except the uppermost ones which are apparently without function. Vigorous trichoblasts with red chromatophores have been met with only exceptionally in mid-summer, in the beginning of August in a specimen found in great depth in the North Sea (31 m), and in specimens of the f. Rhodomela nn ee tricho- tenuior found at Bornholm (8,5—15 m). blasts. a—c of var. virgata. 220: 1. As mentioned above, adventitious shoots may arise from superficial cortical cells of the stem in f. lycopo- dioides and other forms. The fasciculate branches occurring frequently in the long shoots of various forms of Rhodomela are probably. due to the production of such adventitious buds. The antheridia, as I have shown (1903 p. 462), arise on the stems and on the tricho- blasts (fig. 417). The fertile organs form corymbiform tufts at the ends of the shoots, or lateral on the long shoots in f. virgata. In some cases the fertile organs are appa- rently only branches, in others they are principally trichoblasts, but in both cases the main axis is usually covered with antheridia, and the formation of antheridia may extend to three generations of branches 1 Further it must be remembered that the assimilating trichoblasts in Brongniartella are just as distinct from Fig. 419. the stem as those in Polysiphonia. Rhodomela subfusca f. virgata. Cystocarp. May. 95:1. 457 (fig. 417, comp. FALKENBERG p. 597). As regards the development of the spermatia reference may be made to Kyrın’s paper (1914, p. 55 pl. 3 figs. 13—18). The procarps arise in the second joint of the trichoblasts (fig. 418, comp. K. R. 1903 p. 459, Kyrın 1914 p. 42). The sterile upper part of the latter remains for a shorter or longer time at the upper end of the developing cystocarp; it may still be found sometimes in the ripe cystocarp (fig. 419). It may be simple or branched. The development of the procarp and the cystocarp has been described at length in the important papers of Kyrın (1914 pp.41—54 and 1993 p.114). N The tetrasporangia arise in \. AW short branches forming small tufts AS EA at the ends or on the sides of the long shoots, the latter principally in the f. virgata, two in the same joint, in a number of consecutive joints. In the lower part of the branch, under the first lateral or- gan, they are arranged laterally, to the right and to the left of the median plane. The first trichoblast is inserted over one of them. In the joint following after a tricho- 3 blast (or a branch) the sporangia Rhodomela subfusca f. REN N, section of tetra- are arranged ina similar way to sporiferous joint before division of the sporangia. B, tetrasporiferous “ie Night eral ee i the orientation of the sporangia is thus constantly changing in the trichoblast-bearing region. The pericentral cells, from which the sporangia are produced, are first divided by two oblique walls by which two cover-cells are cut off (comp. KyziN 1914 fig. 11). These cells are shorter than the mother-cell, the lower part of which therefore is free outwards and which after- wards is divided by a horizontal wall into two cells, the upper of which becomes the sporangium. The lower cell, the stalk-cell, is then divided by one or two peri- clinal walls cutting off one or two shorter peripheric cells that cover the stalk-cell. The other pericentral cells divide in the usual manner by horizontal walls in such a manner that the upper cell remains in pit-connection with the central cell while the cover-cells of the sporangia are connected with the stalk-cell (fig. 420 A, Kyrın p- 61). The pits connecting the central cell with the sterile pericentral cells are situ- ated at a much higher level than that connecting it with the stalk-cell (fig. 420). At the stage of maturation the central cell, the stalk-cell and the pericentral cells contain several nuclei. For further details in the development of the sporangia see Kylin 1914. The germination has not been observed by me, but I have once found a spore- ling on Callithamnion Hookeri, which is shown in fig. 421. The basal part was | disc-shaped, as in the adult plant, but it was only developed on one side. Rhodomela subfusca is widely distributed in the Danish waters, growing on | stones and various Algæ (Fucus, Laminaria). It usually descends only to a depth | of 20 meters, but it has been found once in the North Sea in 31 meters’ depth | (Jydske Rev, f. «), and f. tenuior has been repeatedly recorded in depths from 25 | to 38 meters near Bornholm. The forma « occurs from low-water | mark to a depth of about 15 m or a little more, but it is most typical near low-water mark. F. lycopodioides has only been met with rarely in the Skagerak, washed ashore or by dredging in slight depths near land. F. virgata has been met with in all the waters | within Skagen in depths from 4 to 20 meters, most typical in the Belts. F. tenuior has been found in the Baltic Sea and particularly round Bornholm, in depths from 8,5 to 38 meters. F. abyssicola has only been met with once in the Little Belt in 22 meters’ depth. | — The vegetative development begins in winter (January) and is | usually arrested in May or June whereupon the trichoblasts and fertile shoots are shed. The organs of fructification begin to develop in winter and the spores are evacuated in spring. Localities. Ns: a: Jydske Rev 31 m and some other loc. off Lodbjerg | light-house and off Orhage, very sparsely. 8: washed ashore by Klitmøller (Hor- | fl | nemann). — Sk: Several places from Hanstholm to Hirshals, from low-water mark (Hirshals) to 15 m, mostly «, more or less approaching to ß, Iycopodioides | at Bragerne, Løkken and Hirshals. — Lf: Several places from Rennen by Lem | N Vig to Løgstør Bredning, but not well developed, usually intermediary between & | Fig. 421. . 4 2 : | and ?, virgata. — Kattegat: « very common, y very common, also in the Isefjord; Rhodomela subfusca. 2 M > 5 à | Plantlet growing on here also f. tenuior. — Sa: & and £ very common down to 17 meters’ depth. — | Callithamnion Hoo- Lb: @ and in particular y very common, « from low-water mark to 15 m, y from | keri. 210:1. 7—30 m; €, abyssicola: dQ, south of Lyø, 22 m. — Sf: «, y. — Sb: «: LK, Ele- | fantgrund; Kerteminde; GY, south of Sprogø; NN, 19 m. y: in numerous places, I 5—19 m. — Sm: y in numerous places 4—12 m. — Su: «, off Aalsgaarde, Charlottenlund. y, in several | places, 5—10,5 m. — Bw: «, UP off Kramnisse Gab 8,5 m; KU, Schonheyders Pulle 7,5 m; KR, near | Korselitze Grund. y several places 7—20 m.— Bm: «, HG, Prestebjergs Rev. y, several places from 7 to 20,5 m. d SD, north-east of Moen, 23,5 m, loose. — Bb: The species is common at Bornholm in depths from 5,5 to 25 m, but descending to 40 meters’ depth, more rarely near low-water mark, e. g. at Ronne (!) and at Ro (C. A. J.) in 1—2 meters’ depth. Some specimens have been referred to f. genu- ina; their stem was provided with cortex. These specimens were found near land in 1—10 meters’ depth. But also in great depth specimens were found which, though small and slender, most resembled f. genuina (Dana St. 3116, 5,5 miles N.N.E.1/. W. of Hammershus light-house, 35—40 m, C. A. J.); their stem had a well developed cortex. Most of the specimens from the waters around Bornholm may be referred to f. tenuis though they not rarely approach to f. genuina or to f. virgata. They are rather small; their height does not usually exceed 15 cm and the shoots are slender. The awl-shaped branch- I lets emphasised by SvepeErıius as characteristic to f. fenuior are not always present; in other cases | they are very numerous. A small-celled cortex is wanting as in SVEDELIUS’ specimens. On all sides of Bornholm. 459 Odonthalia Lyngbye. 1. Odonthalia dentata (L.) Lyngbye. Lyngbye Hydr. 1819, p. 9 tab. 3 A; Orsted De reg. mar. 1844 p. 52; Harvey Phye. brit. I 1846 PI. 34; J. Agardh, 1863, p. 899; Wille, 1885, pp. 30, 50, Tab. IV figs. 48—49; id. 1887, p. 69 figs. 32—37; Buffham 1893, p. 297, Pl. XIV figs. 33—36; Falkenberg 1901, p. 604, Taf. X figs. 6—22. Fucus dentatus Lin. Syst. nat. ed. 12, vol. II, p. 718. Fucus pinnatifidus Oeder Fl. Dan. Tab. 354, 1767. Rhodomela dentata Lyngb., Rar. cod. 1880 p. 225. The morphology of this species shall only be mentioned here rather shortly as it has been treated at length by FALKENBERG (1901). As mentioned by this author, p. 605, the two-edged shape of the frond is caused partly by the formation of a wing on each side of the frond, partly by the congenital coalescence of the lower parts of the shoots The branch-bearing segments are, in the sterile parts of the frond, separated by 2—4 segments bearing no branch (fig. 422). The ectoblastesis (L. K. R. 1920 p. 20) is very prominent. As emphasised by FALKENBERG, there are no trichoblasts. The pericentral cells divide early and thus become covered by a layer of smaller cells which divide further and the outermost of which are so arranged that four transversal rows correspond to the height of a primary segment (comp. FALKENBERG p. 606, our fig. 422 B). It deserves further notice that triangular initial cells are to be found in the edge of the frond, in particular where the outline is convex, one for each secondary segment (fig. 422 B). There is thus resemblance with the edge of Delesseria. but with the difference that the initial cell is seated in the lower (basiscopic) corner of the segment while in Delesseria it is to be found in the upper corner. In Apoglossum ruscifolium, however, I also found marginal initial cells with the same orientation as in Odonthalia (comp. p. 459). FALKENBERG has delineated these initial cells in Odonthalia (1. c. Pl. 10 Fig. 12), but he has not shown the pro- duces of their divisions. The frond of the last year has a slightly projecting mid-rib which contains the central cell in the centre. This cell is com- paratively narrow but becomes very long and is connected with the contiguous central cells through a large primary pit; it contains several nuclei but pro- duces no starch. The other cells of the inner tissue have a larger Fig. 422. . Odonthalia dentata. Tips of growing plant. J—III the successive diameter (fig. 423 A) but are generations of branches. 350 :1. sus ul ne Fig. 423. Odonthalia dentata. A, transverse section of frond from the last year. B, longitudinal section of cells of the inner tissue (pericentral cells or inner cortical cells), connected by three secondary pits. 150:1. 460 shorter and are connected with each other by one to three, mostly secondary pits in the transversal walls (fig. 423 B). They contain several nuclei and produce many starch grains when the growing period has ceased. The cells surrounding the central cell are longer and constitute together with it a conducting system (comp. Wille 1. c.). The older, at least one year old parts of the frond are provided with a more distinet mid-rib projecting on both faces of the frond. Its appearance may be somewhat irregular, the rib being present on a certain stretch, disappearing further downwards and then reappearing definitely, and the two ribs are not always exactly opposite to each other. This rib is composed of cell-rows directed outwards and then in a bow obliquely downwards and united into a compact tissue, the surface of which is even. Wırre’s fig. 48 (1885) evidently represents a transverse section of such a mid-rib. He regards this tissue as belonging to the assimilating system; it has in my opinion rather a mechanical function. The germination has not been observed, but young plants, about 3 mm high, were found in the northern part ofthe Sound off Aalsgaarde, on a shell of Cyprina islandica in a depth of 19 meters (fig. 424). The smallest one (A) which did not reach 2 mm in length was entirely un- branched. It had a terete stipe continuing in a nar- row lanceolate lamina, the upper part of which is shown in fig. D. Numerous marginal initial cells sim- ilar to those shown in fig. 422 B are to be found in Odonthalia dentata. Fig. 494. A—C, plantlets found growing on Cyprina islandica, B and C, with an adventitious hranch. D, upper end of À more highly mag- the edge. A couple of some- nified. E, young adventitious branch. 4A 50:1. B,€ 18:1. D, E 30:1. what more developed plants showed an adventitious shoot issuing from the stipe, produced from a super- ficial cell (fig. 424 B, C, E). The normal branching at the apex seems only to begin when the plants have attained a size of about 3 mm. In a young 7 mm high plant the pri- mary shoot was terete at the base but a short distance upwards flattened and at a higher level branched in the usual way. The young fronds are fixed to the sub- stratum by a circular basal disc composed of densely united radiat- ing cell-filaments. In a more ad- Fig. 425. Female sexual shoots. partly in the third joint of the branches. probably arise subterminally in the main axis *. The procarps arise In B a procarp will 200 : 1. Odonthalia dentata. vanced stage the basal disc is a flat expansion having a circular or lobed outline; the regularly radiating filaments are united to the margin. The organs of reproduction are as a rule confined to small adventitious shoots + Fig. 426. Odonthalia dentata. Female sexual branchlets with ripe and aborted cystocarps. See text. At :* procarps are apparently developing in the last segment cut off from the apical cell. 4"95':1. B 50:1: borne on the margin of the frond. The antheridial shoots are according to BurFHAM (1893) and FALKENBERG (1901, p. 607) pale simple or bifid leaflets, the surfaces of which are covered with antheridia. They have hitherto not been observed in the Danish waters. The female shoots are much branched, slightly winged or quite cylindrical. Accord- ing to FALKENBERG (1901, p. 606) the pro- carps constantly arise in the second joint of the fertile shoot. That is, however, not always the case, for I not unfrequently found them in the third joint (fig. 425 A, C), and it seems that they may also arise in higher situated joints (fig. 426 B, to the right). The sterile upper part of the procarp-bearing shoots (the calcar) is as a rule unbranched, incurved, but it not unfrequently happens that it is branch- ed and produces new procarps (fig. 426). It seems that the end of the shoot may also produce a procarp arising from the last seg- ment cell (figs. 425, 426*). The tetraspore-bearing shoots are cylindrical, D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 59 462 much branched, forming small fascicles of stichidia each containing two series of sporangia. O. dentata is perennial; it attains a length of up to 20 cm, thus in the most southern locality recorded in the Sound. It has only been met with in the months of April to September. The new shoots must arise in winter; in spring they are of a fresh red colour in contrast to the shoots of the foregoing year. The organs of fructification must develop in winter. According to ARESCHOUG the species is fructi- ferous in winter (Dec. to March) at the west coast of Sweden, and that is probably also the case in the Danish waters, but tetraspore-bearing specimens have been met with as late as May, and cystocarp-bearing ones were collected in April and even in June (Store Belt). On the other hand, specimens were found in May with adventitious shoots having shed the outer fructiferous part. The species is confined to the waters with high salinity and slightly varying temperature; it has therefore principally been met with in the deeper parts of the eastern Kattegat in 15 meters’ depth and deeper. In slighter depth it has only been collected in one place in the northern Kattegat on the north side of Hirsholmene. In the Great Belt it has only been found in one place in 19 meters’ depth, and in the Sound south of Helsingör only in one place in 22,5 meters’ depth in the deep channel. It grows on stony or gravelly bottom and may be fixed to Litothamnia, barnacles or mollusks, has also been found on Fucus serratus and Polysiphonia elongata. Localities. Kn: East of Tyskerens Rev, Hirsholmene, c. 11 m; VX, Böchers Banke, 29 m. — Ke: IL!, IM, ZE!, ZE?, ZF, IP, IQ, Dana St. 2922 (C. A. J.), Fladen, 15—30 m; Groves Flak, 24,5 m; IK, Lille Middelgrund, c. 18 m; RU, 26,5 m; IA, Store Middelgrund, 17 m. — Ks: Lysegrund (Lyngbye, Rhodomela dentata, Rariora codana, p. 225); near Hesselo (Lyngbye); off Isefjord, buoy at Gronne Revle in S. 3 miles, 15 m (Biolog. Station). — Sa: The Herbarium of the Bot. Mus. of Copenhagen contains a denudate specimen of Polysiphonia elongata bearing in Hornemann’s handwriting the follow- ing labelling: “hab. ad littus Hofmansgave saxis adnascens ded. Lyngbye”. This bears some small spec- imens of O. dentata, c. 1 cm long. — Sb: Off Refsnes, 19 m (C. H. Ostenfeld). — Su: Off Aalsgaarde (Th. Mortensen), off Hellebæk (Orsted); frequently cast ashore at Julebæk and Hellebæk; bM, south of Hveen, 22,5 m. General Remarks on the Morphology of the Danish Rhodomelaceæ. The following remarks deal particularly with the genus Polysiphonia which has been most thoroughly studied as to the morphology. Further information on the morphology of this interesting family must be sought in the quoted papers of FALKENBERG, KYLIN a. 0. 1. The hair-shaped organs which were named leaves by NAGELI (1846) were repeatedly studied by various authors. I treated them in 1903 and gave them the name trichoblasts; they might also be named hair-leaves. Vegetative trichoblasts occur in all the Danish species of Rhodomelaceæ except Odonthalia and Heterosiphonia. In Polysiphonia they occur only in the erect shoots, not in the creeping ones. In this genus they are usually hyaline though provided with small colourless plastids. 463 In most of the Danish species, however, I have observed that in specimens gathered in spring or in great depths these bodies were true chromatophores giving to the trichoblasts a light rose colour. This phenomenon is particularly conspieuous in Polysiphonia elongata f. baltica which just occurs in deep water. In Rhodomela the chromatophores of the trichoblasts are distinctly rose-coloured, but they are finally decoloured in the adult trichoblasts which are shed at the beginning of the summer. In Brongniartella byssoides they are persistent and remain coloured during the life of the plant. In Polysiphonia nigrescens the cell-sap of the trichoblasts may be rose-coloured in April, later brownish. The ramification of the primary axis of the trichoblasts is regularly alternate, biseriate. The first branchlet is always given off on the anodie side (to the right when the spiral turns to the left), from the second joint, in Rhodomela often from the third. In the female trichoblasts the first branch is given off from the fourth joint and most frequently on the anodic side. In female trichoblasts of Pol. Brodiæi two branches were found on the same joint, one above the other (p. 381). 2. Unicellular hyaline hairs do not occur in the Rhodomelaceæ. Only in Brong- niartella byssoides such organs may sometimes be met with in peculiar pointed shoots without trichoblasts (comp. p. 406); but they might perhaps better be interpreted as a sort of rhizoids. 3. The branches arise in different manners. a) In Polysiphonia urceolata, P. elongata, P. nigrescens and Rhodomela they are produced directly from the youngest segment under the apical cell, usually in the place of a trichoblast in the spiral. In some species, at any rate, the branch- producing segments are higher than those which give rise to the trichoblasts or do not produce any sort of lateral organs (P. urceolata, fig. 344, P. elongata). To this group belongs Odonthalia, which is destitute of trichoblasts, and Heterosiphonia which has a sympodial growth. b) In the other species of Polysiphonia, in Brongniartella byssoides, Chondria dasyphylla and Laurencia pinnatifida the normal branches arise as axillary buds of the trichoblasts. In Brongniartella they arise rather late when the trichoblast has reached a pluricellular stage. In Polysiphonia they arise much earlier, simultaneously with the trichoblast or nearly so, and it seems that the branch-producing trichoblasts are, at their first appearance, bigger than the sterile ones (comp. K. R. 1884 p. 29, rés. p. 5, figs. 34—40). The branches in Polysiphonia are thus not branches of the trichoblasts as OLTMANNS thinks (Morph. u. Biol. d. Alg. 1904 p. 609). The basal cell common to the trichoblast and the branch belongs as to its lowermost part to the stem. The first joint of the branch, common with the trichoblast, cuts off peri- central cells on its outer surface, but the central cell of this joint keeps the proto- plasma continuity with the trichoblast through a longitudinal wall between the peri- central cells or the segmental wall between the first and the second joint (figs. 379, 388, comp. K. R. 1903, p. 468). 464 c) Secondary axillary shoots arise from the basal cells of shed trichoblasts. They occur normally in P. violacea, giving rise to the shorter branches characteristic to this species, appearing between the longer primary branches, further in P. elon- gata, particularly in older, wintering plants, and in P. Brodiæi, more rarely in P. nigres- cens (K. R. 1884, p. 19, rés. p. 3) while they have not been met with in P. urceolata and in P. orthocarpa. Thus they occur also in species having no primary axillary shoots. In some cases they appear before the trichoblasts have been shed (figs. 364, 394). d) Endogenous branches produced from the central cell of older joints occur in particular in the species of Polysiphonia with creeping shoots and in Brongniar- lella. The creeping shoots always arise endogenously and produce new endogenous shoots; they issue normally near the base of the principal stems in P. urceolata, P. orthocarpa, P. atrorubescens and P. nigrescens. In the latter species an endogenous shoot often appears in the axil of the longer branches, near the base of the branch (fig. 393). e) Adventitious branches arising from peripheric cortical cells occur in Rho- domela and Odonthalia; they have not been met with in Polysiphonia. 4. The rhizoids are unicellular. In Polysiphonia and Brongniartella they are produced from the pericentral cells or in the corticated species also from the cort- ical cells. In the sporelings, however, the first rhizoid originates from the lowermost cell of the plant and the next following from the first joints which do not produce pericentral cells (figs. 384, 396). The rhizoids are separated from the pericentral cells by a wall (comp. Derick 1899 p. 251). Dr. Lizy BATTEN did not observe a wall at the base of a rhizoid in any species of Polysiphonia that she had observed (1923 p. 276). Such a wall is, however, really present in all of the Danish species. In P. urceolala only I found rhizoids in open connection with the pericentral cell. A shortening of the rhizoids was stated in P. urceolata. Rhizoids are wanting in Lau- rencia pinnatifida, Rhodomela subfusca and Odonthalia dentata, the organ of attach- ment of which is a continuous pseudoparenchymatous disc. 5. Torsion of the stems in Polysiphonia and Rhodomela frequently occurs. In P. atrorubescens it is a constant feature, but the direction of the torsion varies. The twisting may cause that the branches become uniseriate for a longer stretch (P. vio- lacea, P. Brodiei, Rhodomela). 6. In most of the species the central cell contains one nucleus which remains undivided, while the pericentral cells are always polynucleate. In Polysiphonia ni- grescens and Rhodomela subfusca, however, it becomes plurinucleate by division of the primary nucleus. 7. By the germination of the spores (of Polysiphonia and Brongniartella) the cell is first divided by a transversal wall whereby a cell is cut off that becomes the first rhizoid cell. In Brongniartella the rhizoid was perceivable before the ap- pearance of the wall. The sporeling is then divided by parallel walls into segments, the first one or two of which (in Polysiphonia) do not produce pericentral cells, 465 which only appear in the second or third and following joints. In P. Brodiawi and P. nigrescens, which have 7—8 and 12—17 pericentral cells respectively, the next following one to four joints had 4 pericentral cells (figs. 384, 396), an interesting fact when we remember that a great number of the species of this genus have con- stantly 4 pericentral cells. The normal number of pericentral cells in the said species is gradually reached in the following joints. 8. Secondary pits are produced not only between pericentral cells but also between the cortical cells and between these and the pericentral cells (Pol. violacea, P. Brodiwi). Cells connected with more than one secondary pit in the same wall occur in Pol. elongata, Rhodomela and Odonthalia. In Pol. elongata the pericentral cells are first connected by one secondary pit, but later on, in the following year, a circle of further secondary pits arises in the same wall (fig. 357). 9. The tetrasporangia arise in a pericentral cell. According to FALKENBERG (1901 p. 88) they always originate in the Polysiphoniæ from the oldest pericentral cell in the segment. This is, howewer, not in accordance with my observations. As early as in 1884 I have ascertained that the sporangia in P. fastigiata take their rise in a lateral pericentral cell separated from the oldest one by two or three sterile peri- central cells (1884 p. 10, rés. p. 2, figs. 1—3). In P. violacea and LP. Brodiei I found that the first pericentral cell is cut off to the right of the trichoblast, while the fertile pericentral cell is always situated to the left of the trichoblast borne on the same joint, and is probably the second pericentral cell. The fertile cell cuts off two secondary pericentral cells, and the inner cell is then divided by a horizontal wall into a stalk cell and a spore-mother-cell or tetrasporangium. In the species of Poly- siphonia with 4 pericentral cells a small peripheric cell is further cut off under one of the secondary pericentral cells which is a little shorter than the other, and this little cell is always situated beside the basal cell of the trichoblast of the fore- going joint, on its right side. This cell is always present in P. violacea and P. or- thocarpa. In P. urceolata and P. elongata it may be present or wanting; in the first named species it was present in the trichoblast-bearing stems, while it was wanting in the stems without trichoblasts. It is further usually present in P. Brodiei which has 7—8 pericentral cells, but it is wanting in P. atrorubescens and P. nigrescens where the number of pericentral cells is greater. In the species with 4 pericentral cells in the sterile joints the number of pericentral cells in the fertile joints is always 6, though there are always only two secondary pericentral cells. Fam. 14. Delesseriaceæ. J. G. AGARDH, 1852, Species genera et ordines Algarum. Vol. II pars 2. Lunde. — , 1898, — Vol. III pars 3. R. Korkwırz, (1900), Beiträge zur Biologie der Florideen. Wissensch. Meeresuntersuch. Neue Folge. IV. Band. Abt. Helgoland Heft 1. Kiel und Leipzig. 466 P. Kuckuck, 1894, Bemerkungen zur marinen Algenvegetation von Helgoland. (I). Wissensch. Meeres- untersuch. Neue Folge. I. Band. W. NIENBURG, 1908, Zur Keimungs- und Wachstumsgeschichte der Delesseriaceen. Botan. Zeitung 1908, p. 183, Taf. VII. R. W. Paırrıps 1898, The Development of the Cystocarp in Rhodymeniales: II. Delesseriaceae. Annals of Botany, Vol. 12. N. WILLE, 1885, Bidrag til Algernes physiologiske Anatomi. K. Sv. Vet. Akad. Handl. Bd. 21 No. 12. Stockholm. — , 1887, Beiträge z. Entwickelungsgeschichte der physiolog. Gewebesysteme bei einiger Florideen. N. A Leop. Car. Ak. Bd. LII Nr. 2. Halle. See further p. 297 and p. 402. My investigations on the Danish Delesseriaceæ, which have been directed to the structure and development of the frond, were almost finished when I received Kyrın’s important paper (1923) which contributes so much to the morphology of this family. My observations are in full accordance with those of Kyrın to which I can, however, give some additions. Two matters only must here be emphasized. 1. The presence of secondary pits, first pointed out by me (1888) in Mem- branoptera alata, was ascertained in all the species in question, both in the ribs and in the monostromatic frond. In the mid-ribs of the fronds multiple pits occur in the transverse walls of most of the long cells. These pits are in most cases all of secondary kind, arising at different moments between two pericentral or similar cells that were not before-hand connected by pits. In Phycodrys rubens, however, secondary pits are alsc formed between the cells of the axial cell-row, though these cells are from the first connected by a primary pit. The secondary pits are here formed in the periphery of the wall while the primary pit is central (figs. 429, 430). 2. The germination has only been observed in Apoglossum ruscifolium by TOBLER, but young specimens of the other species were found in nature. In Apoglossum rus- cifolium, Delesseria sanguinea and Membranoptera alata the primary axis of the plantlet becomes a typical frond provided with a mid-rib. In Delesseria sanguinea this prim- ary frond seems to obtain only a moderate length, but in Membranoptera alata and probably also in Apoglossum ruscifolium it becomes the main axis of the frond, and in Membranoptera it early begins branching. In Phycodrys rubens, on the other hand, the primary axis of the young plant develops into a thorough monostromatic frond without mid-rib, reaching only a length of half a cm or a little more; the typical fronds arise as adventitious shoots from the stalk of the primary shoot. The accord- ance of this primary frond with the normal frond in Nitophyllum corroborates the opinion put forth by earlier authors, in particular by Kyrın, that this species must be referred to the Nitophyllee. 467. Subfam. Nitophyllez. Phycodrys Kützing. 1. Phycodrys rubens (Huds.) Batters. Batters, Cat. Brit. Mar. Algæ. 1902 p. 76. Fucus rubens Hudson F1. Angl. 1762 p. 475 (not seen). Fucus roseus O. Fr. Müller, Flora Danica tab. 652, 1775. Fucus sinuosis Gooden. & Woodw., Linn. Transact. III 1797 p. 111. Delesseria sinuosa (G. & W.) Lamour. Essai, 1813 p. 124, Lyngbye Hydr. 1819 p. 7 Tab. 2B; Harvey, Phye. Brit. III pl. 259, 1851; J. Agardh, 1852 p. 691; Magnus, Bot. Erg. d. Pommerania Exp. Kiel 1873 p. 75; Nägeli u. Schwendener, Das Mikroskop, 2. Aufl. 1877 p. 563; Wille, 1885 pp. 30, 51, fig. 51, 1887 pp. 65—69 figs. 21—31; Kuckuck, 1894 p. 255; Phillips, 1898, p. 189. Phycodrys sinuosa (Huds.) Kützing. Phye. gen. 1843 p. 444 Taf. 68 II; Tab. phyc. XVI 1866 pl. 20; Kylin, 1923 p. 64. The apical growth of the frond has been studied repeatedly (NAGELI and SCHWENDENER, WILLE, NIENBURG, KYLIN). NIENBURG has stated the occurrence of intercalary cell-divisions!, but the succession of the divisions and the genetic con- nection of the cells has only been correctly described by Kyrın (1923) who payed especial attention to the pits connecting the cells. In my figures 427 and 428 the pits connecting the cells have not been drawn. The sequence of the division walls can, however, to a certain degree be concluded from a comparison of the consecutive segments cut off from the apical cell, but the fact stated by Kyrın, that the prim- ary cell-row of the segment issues from the lowermost cell produced by intercalary division of the primary cell in the axial cell-row, cannot be recognized. Intercalary divisions occur early in the axial cell-row; they appear already in the second seg- ment from the top (Kyun figs. 44, 45) or a little later, in particular in narrow fronds (figs. 427, 428), where the primary segments do not become so much deepened as in Kyrın’s fig. 44. The secondary initial cells situated in the upper edges of the primary segments are able to grow out into lobes, and as the two initial segments of a segment always behaye in the same manner, the lobes are always opposed. In the frond shown in fig. 427 the three con- D secutive segments produced each a lobe on 2 3 Fig. 427. each side, and it seems to be normally so that Phycodrys rubens. Tip of frond. April. 260 :1. the number of lobes in a normal leaf corre- sponds to an equal number of consecutive segments. The distance between two consecutive lobes or between the nerves belonging to them in an adult leaf thus in- dicates the height obtained by the primary segments which may be 3-—6 mm. * SCHMITZ has undoubtedly observed these cell-divisions in Del. sinuosa, but he has not expressly cited this species in this connection. 468 The border of an older frond shows numerous triangular initial cells (fig. 431) which are the end-cells of cell-rows of the third or fourth order, which really exist in and the cortication proceeds at both sides of it. A transverse section of the mid-rib shows a row of large cells with rather thick walls traversing the mid- rib (fig. 429). These cells are lengthened in the longitud- inal direction of the frond and Fig. 428. show multiple pits in the trans- PR Arve AED versal walls. The cells situat- frond. 260:1. ed on both sides of the median row have a similar character to these, but they have a smaller diameter and are shorter (comp. WiLLE 1887 fig. 28, KyLiN 1923 p. 70 fig. 45); they are also provided with (secondary) pits in the transversal walls. The spite of NIENBURG's assertion (comp. 1908 pp. 195, 206). These ini- tial cells do not grow out except by producing adventitious shoots. The structure and development of the mid-rib has been de- scribed by WILLE and Kyrın. The development begins with longi- tudinal divisions of the primary cell-row in the middle of the frond, Fig. 429. Phycodrys rubens. Transverse section of mid- rib. c, central cell with a central primary pit and four secondary pits. 150: 1. middlemost cell of the transversal cell-row must be designated as the central cell; its transverse walls contain the primary pit of the primary segment walls or of the Fig. 430. Phycodrys rubens. Longitudinal sections of inner cells in the mid-rib. A in the living state, B and C fixed and stained, showing the pits and the nuclei. A 200:1. B, C 450: 1. intercalary walls; it is shown in the middle of the middle- most cell-wall (c) in fig. 429, but the same wall shows four secondary pits in the periphery of the wall by which the cell is connected with the next following central cell. The transverse walls of the other cells in the transverse cell-row are only provided with second- ary pits, usually four, all situ- ated near the periphery of the wall. Fig. 430 shows longitud- inal sections of the inner cells in a mid-rib; C is a central cell showing at the upper end 469 a primary and two secondary pits, B a transverse wall with four secondary pits. As pointed out by WILLE the inner cells of the rib have, a mechanical and a conductive function as well. This tissue is covered on both sides by an assimilatory system composed of radiating filaments of short cells (fig. 429, comp. WiLLE 1885, fig. 51, Kyuin I. c.). The lateral veins are opposed, in accordance with their origin from the primary cell-rows of the consecutive segments, and run out in the lobes. Lateral veins of the Fig. 431. Phycodrys rubens. A, marginal part of frond showing formation of secondary pits (#). i interealary division wall. 450:1. B, group of cells showing secondary pits. In the middlemost cell the inner contour is the outline of the cell at high level; the outer contour showing the pits is at a lower level. 380: 1. second order may also occur, but they are much feebler. The later arising marginal shoots give further rise to lateral veins in the leaves. By treatment with iodine the veins take a darker stain owing to their richer contents of starch (July). Secondary pits are also produced in great numbers in the monostromatic part of the frond; but they arise only at a considerable distance from the top. In the liy- ing plant it is impossible to observe their formation, as it takes place only in the middlemost part of the walls while the parts of the cells situated at the surfaces of the frond do not participate in the process. The formation of the secondary pits seems to continue rather long; their number increases downwards and inwards from the border. In a leaf examined by me the cells situated near the border (not includ- ing the marginal cells) had averagely 2,5 pits, while the cells in some distance from the border had averagely 3,6 pits, a difference due to the greater frequency of the secondary pits. The secondary pits are recognizable by the transmigrating cell being not completely incorporated in the receiving cell but remaining at all events for a D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd, VII. 3. 60 470 long time as a triangular projection, after the entrance of the nucleus in the receiy- ing cell (fig. 431). No wall separating two cells in the monostromatic part of the leaf contains more than one pit. The shape of the frond is rather variable according to the different length and breadth of the lobes and to the differ- ent manner in which the growth recommences after the rest of the winter. In some cases a number of the lobes resume the growth from a broad base and form new leaves as prolong- ations of the lobes of the old leaf. In other cases the apical cells of the lobes give rise to a leafy shoot with a narrow stipe, and it has then a similar character to the other mar- ginal shoots arising from single marginal cells, probably prin- Fig. 432. cipally from initial cells of the third order. Most of these shoots, Phycodrys rubens. Multicell- SL a 2 asien ED which may be very numerous, reach only a small size and become fertile. Adventitious shoots may also arise, in older leaves, from the middle-rib and from the side-ribs. KyLiN found tetrasporiferous leaflets projecting from the veins (1923 p. 65); I found the same. Long narrow shoots are frequently produced, mostly at the base of the plants, but sometimes also from the upper end of the shoots. They often bear multicellular papillæ (fig. 432) which take the function of hapters when meeting a firm substratum, f. inst. other Algæ. Such papillæ, which have first been described by P. Mac- Nus (l.c. p. 75), occur frequently in this species, also in the broader forms of the frond and frequently cause the fronds to be entangled with each other and with other Algæ. Germinating spores have not been observed in cultures, but young plants have repeatedly been found in nature, principally in hydroids. The small plant shown in fig. 433 A is most pro- bably a sporeling of Phycodrys rubens, as it has been found by dredging in April in company with adult specimens of this species while other species of Delesseriaceæ were not present. This Fig. 433. young plant shows much resemblance Pfycodrys rubens. A sporeling found in April off Refsnæs 2 ae (Store Belt). 270: 1. B plantlet found in July in the Little Belt to the sporelings of Nitophyllum punct- on Sertularia. 63 : 1. = ERA mA ETA atum described and figured by NıengurG (1908 Taf. VII). Like these it lacks the regular apical cell-divisions characteristic of the older shoots of the Phycodrys-plants; the monostromatic frond is composed of uniform cells which are rather irregularly divided, intercalary divisions being very frequent, and no mid-rib is present. Our sporeling differs, however, from those described by NIENBURG in being erect, while the latter, according to the said author, are decumbent, growing along the sub- stratum (l. c. p. 185). This primary. shoot has been found again in a number of older plantlets collected in July; it had reached a considerable size, up to 6 mm long and 2 mm broad or more, and had a broadly lanceolate shape, but otherwise showed the same character as before. It was thor- oughly monostromatic, com- posed of uniform, irregularly disposed cells becoming small- er upwards, and terminated in an apical cell divided by transversal walls, but showed no trace of a mid-rib. The base of the primary shoot was contracted in a short stalk fixed to the substratum by a basal disc. From the stalk one Fig. 434. or more adventitious shoots Phycodrys rubens. A, plantlet found in July in the Little Bell on Sertu- ae? 5 R laria, with lobed primary frond; atthe base a young adventitious shoot. showing the typical apical 20:1. B, tip of the primary frond in A, showing the apical cell. 260 :1. growth and a well developed mid-rib were given off; the mid-rib could be traced to the very base (fig. 433 B). The primary frond in an advanced stage terminates in an apical cell dividing like that of the typical fronds, and the first divisions of the primary segments are similar to those mentioned above of the normal fronds, but intercalary divisions occur early and continue in still greater number than in the ordinary leaves and cause the arrangement of the cells to become much more irregular than in these (fig. 434 B). The cells in the middle of the frond do not show any tendency to longi- tudinal arrangement and no divisions parallel to the surface of the frond occur. Secondary apical cells appear and may give rise to slight sinuosities of the outline (fig. 434 A above) but normally they do not occasion branching. Primary fronds with one lateral lobe such as that represented in fig. 434 may, however, sometimes be met with. Even in these fronds no rudiment of a mid-rib was discernible. The prim- ary fronds thus agree perfectly well with the normal fronds in Nilophyllum (comp. NIENBURG 1908). The discovery of the primary frond in Phycodrys rubens is in good 60* accordance with the opinion pronounced by earlier authors (Scamirz, PHILLIPS, NIENBURG), and recently more precisely by Kyrın, that this species must be referred to the Nitophyllee. Antheridia have been met with in one specimen collected in November in the Great Belt; it was well developed, 5 cm long, while Kuckuck only found antheridia on dwarfy specimens at Helgoland. The antheridia were borne on marginal lobes and leaflets on the upper part of the plant, about 1 mm long. The antheridial patches are usually surrounded by a narrow sterile border (fig. 435 A). In young leaves Kyrıy found the antheridial sori forming bands parallel to the margin (1923 p. 65). The development of the antheridia has been described by the same author (p. 77). The procarps arise in great num- bers in the upper part of the fronds without any relation to the veins. The development and structure of ER the procarps and the cystocarps has a > been studied by PhıtLıps and re- cently most carefully by Kyrın (1923 p.71) whose description may Fig. 435. here be referred to. The cystocarps Phycodrys rubens. A, part of male frond with antheridia in part- were, in the Danish waters, only icular leaflets, November. B, ae ae in particular leaflets. met with in a few specimens dredged in the Little Belt; they were almost all placed in special marginal leaflets usually containing one cystocarp only (fig. 435 B), otherwise near the margin in the larger leaves. The tetrasporangia arise in the Danish specimens only in small marginal ad- ventitious folioles, never in larger leaves. The folioles, as shown also by Ky Lin, may arise from the face of the frond, and sometimes even from old mid-ribs without membrane, much as in Del. sanguinea. They contain two layers of tetrasporangia which are only separated by one median layer of cells. Their development has been described by Kyrın (1923, p. 73) who emphasises that the mother-cells of the spor- angia arise in the inner cortical layer, whereas in Del. sanguinea they are super- ficial cells. Ph. rubens is rather variable in the size and shape of the frond, but the forms are connected with each other by intermediate forms. It is widely spread in all the Danish waters except the fjords, usually in the ordinary, rather broad form. In the North Sea and the Skagerak, however, it reaches only a moderate length (about 4 cm). In the northern Kattegat, too, it does not reach the full size (7 cm). In the inner waters it becomes larger, it not unfrequently attains a length of 10 cm and more. The largest specimens were found in the Great Belt and the Sound, in depths of 15 to 23 m, where they reach a length of up to 18 cm and a breadth of 1—2 cm & pa % 473 excluding the lobes. These, the most well developed specimens can be referred to f. quercifolia Turn., distinguished by the outline of the frond resembling an oak-leaf and by the rounded lobes. In smaller depths the size of the frond is smaller; that appears very plainly when comparing the rather numerous specimens collected in the Great Belt. In those dredged in depths of 1 to 17 meters the length was at most 8 cm, the breadth at most 1 cm, while the specimens collected in greater depths, where the salinity is higher and the conditions less vari- able, reached a length of 10—18 em and a breadth of 1,3—2 cm and analogous differences were found in the Sound. A much branched loose form (f. egagropila) was found in fast flowing water in Svendborgsund at 5,5 meters’ depth. As a noticeable form may be named f. lingulata Ag., characterized by its narrow frond with stalked lingulate almost entire marginal shoots. This form is, however, closely connected with the typical form through intermediate specimens. The smaller breadth of the frond is evidently an effect of the unfavourable conditions in the water with feebler salinity and great variations in temperature and salinity. In the Western Baltic Sea the frond still reaches a length of 10 cm and a breadth of up to 1 cm, but in Bm and Bb the frond is only 0,5— 1,5 mm broad. The frond is then almost linear or lineari- Fig 0 å Phycodrys rubensf. sublinearis. From lanceolate and reminds one of Membranoptera alata from Bornholm, castofDueodde, 38m. 2:1. which it is, however, distinct by the more or less lan- ceolate segments of the frond. The margin is for long stretches even or only provided with few feeble teeth (fig. 436). These specimens which may be named f. sublinearis usually seem to be loose; they occur together with Furcellaria and Mytilus and attached to these, but apparently only by lateral hapters, and it is doubtful whether they have arisen directly from spores. Tetrasporiferous specimens occur more frequently than sexual ones. Antheridia have been met with once only in November and cystocarps in two or three local- ities in March, while tetrasporangia have been found in numerous specimens collected in the months December to May. In the last-named month the sporangia were, how- ever, usually entirely or partly emptied. The species occurs in depths from i to 40 meters. In the southern parts of the Belts and the Sound and in the southern waters it has, however, not been met with in smaller depths than 5,5 m, and at Bornholm only in 19 to 38 meters” depth. It grows partly on stones, partly and principally on other Algæ as Furcellaria, Laminaria, Halidrys and many others, further on shells of mollusks, hydroids, Hyas etc. 474 Localities. Ns: ZQ, jydske Rev, 24,5 m; aF, off Thyboron, 31 m; XR, off Klitmoller, 12 m; YT, Hanstholm, 15 m. — Sk: eV; Dana 2902; eY; eZ: several places off Lonstrup, off Hirshals, mole at Hirshals, everywhere were scarce. — Lf: Wanting. — Kn: Skagen harbour; Herthas Flak; Krageskovs Rev; around Hirsholmene; Frederikshavn, harbour and environs; UC, TL and ZP, at Nordre Ronner; several places near Læsø Trindel, 11-~21 m. — Ke: Fladen, 16—30 m; Groves Flak, 19—32 m; Lille Middel- grund; ER, Fyrbanken, 28 m; IE; RU; RV; Store Middelgrund; Gilleleje. — Km: Læsø Rende: BN, off Asaa; Dana St. 2884 (C. A. J.). — Ks: Grenaa harbour; PF, Jessens Grund, 4 m; EJ, EM, Lysegrund; at Hesselo (Lyngbye); RL, 15 m; D, north of Grønne Revle, 11 m; aU, off Lumbsaas, 13 m; GF, GG, Sjællands Rev, 4—8,5 m. — Sa: GD, north of Sejerø; PC, MY, north of Samsø; stony reef in Begtrup Vig; Aarhus harbour; FV; FX; FY; GC, east of Æbelø; Hofmansgave (Lyngb., Hofm. Bang); AH!, Lille- grund at Fyns Hoved, 13 m; Korshavn; MP; DK, Bolsaxen; PF, off Refsnes. — Lb: AX; OB; AL (Baaring Vig); AN; Middelfart harbour; common in the belt at Middelfart; Fæno Sund; cX; DG; dC; DF; DD; DE; DA; CC; CY; dQ; dE; dH, east of Hesteskoen. — Sf: CU; UV; Svendborgsund several places, f. egagropila at 5,5 m depth. — Sb. Very common: GT, off Asnæs; GU; GS; AG; GV; cN; Kerte- minde harbour; NU; cL; GP; NN; Z; AB; AC; BS; BT; between Sprogø and Korsør (Magnus); UE; DN; UF; UH; UT; DP; UI; Spodsbjerg; LH; DQ; DR; US, over 38m; US!; DS; DT; LB; UR. — Sm: HA, HB, Agersosund; CK; Q. — Bw: bX, off Kobbel Skov; CD, CE, Middelgrund south of Als; dO; dP; dK, Pols Rev; DX, Vodrups Flak; UY, Vejsnæs Flak; DV; DU; UL, Øjet, 20 m; LA; KX; KU; UM, 25 m. — Bm: HG, Præstebjergs Rev; VH, south of Moen; VG, n. of Mogens Klint; QS; SD; QO; QM; PR, off Dragor. — Bb: F. sublinearis: Ronne; XZ!, Davids Banke; SP, off Svaneke, 28m; YD; YA, east of Dueodde, 38 m. Subfam. Delesseriez. Apoglossum J. Agardh. 1. Apoglossum ruscifolium (Turner) J. Agardh, 1898 p. 194; Kylin 1923 p. 83. Fucus ruscifolius Turner, Trans. Linn. Soc. t. 6 p. 127, tab. 8 figs. 1—2, 1801. Delesseria ruscifolia (Turn.) Lamouroux, Essai 1813 p. 124; Harvey Phyc. Brit. II pl. 26, 1846; J. Agardh 1852 p. 695; Kützing Tab. phye. XVI tab. 12, 1866; Buffham 1893 p. 296 pl. 14; Kuckuck 1894 p. 256 (antheridia); Phillips 1898 p. 188; Kolkwitz 1900 pp. 45, 46; Nienburg, Z. Entwickl. d. Florideenkeimlinge, Hedwigia Bd. 51, 1912, p. 299; Kylin, Keimung der Florideensporen, Arkiv f. Botanik 1917 p. 21. U Two specimens only of this prett (} OD P y pretty Ol Is lo little Alga have been met with in the N ” Danish waters, I must therefore refer the reader for the structure and D development of the frond and of the ¢ organs of fructification to the recent paper of Kyrın (1923). It must only be noted that, according to my observations many years ago at Biarritz, the adven- titious branches do not arise from any Fig. 437. A, Apoglossum ruscifolium (Biarritz), part of mid-rib in super- a 2 i 3 ficial view. e endogenous branch budding from the central Superficial cell of the mid-rib, as main- cell which, is) not visible. 700:1. B and C, Hypoglossum tained by KyLin (1923 p- 85), but by Woodwardii, similar views; the central cells are shown be- 5 i hind the cortical cells. ‘240 : 1. endogenous budding from the central 475 cell. I have found the same in Hypoglossum Woodwardii Kitz. (Delesseria Hypo- glossum (Woodw.)) (fig. 437). The first stages of the germination have been observed by Kyrın (1917 p. 21). NIENBURG, who studied the further development, found that the sporeling is early divided by parallel walls into four cells. By irregular divisions of the two middle- most and partly of the lowermost and the upper of these cells, a flat body without mid-rib is produced which corresponds to the primary frond in Nitophyllum and continues in the primary frond, showing the typical structure. Apoglossum ruscifolium has been met with in two localities in the northern and eastern Kattegat in great depths with salt water, 20—22,5 m, in July, in each place only in one specimen. They were both provided with tetraspores. The largest specimen was 2 cm high, 4 mm broad. According to Kuckuck it accomplishes its course of life in scarcely more than four weeks. ARESCHOUG states, however, that it has been found fructiferous at the western coast of Sweden in July to September. Localities. Kn: XJ, Herthas Flak, c. 20 m. — Ke: ZF, near Fladens light-ship, 22,5 m. Delesseria Lamouroux. 1. Delesseria sanguinea (L.) Lamouroux. Lamouroux, Essai 1813 p. 124; Lyngbye, 1819 p.7 pl. 2; Flora Danica tab. 2198,2 1836 (f. lanceolata Ag.); Kützing, Phyc. gen. 1843 p. 445 pl. 67; Harvey, Phye. Brit. II pl. 151, 1849; Buffham, 1893, p. 296 pl. XIV figs. 28—30; Kuckuck, 1894 p. 255; Kolkwitz, 1900 p. 41; Kylin, 1907 p. 136; Svedelius, Svensk Botan. Tidskr. Bd. 5, 1911 p.200, Bd. 6, 1912 p. 239, Bd. 8 1914 p. 1; Kylin, 1923 p. 92. Fucus sanguineus Linne Mantissa 1767 p. 136; Oeder Fl. Dan. tab. 349 1767. Hydrolapathum sanguineum Stackhouse Tent. 1809 p. 67 (not seen); J. Agardh, Sp. g. ord. Vol. III 1876 p. 370; Le Jolis, Liste.. Cherbourg 1864 p. 133; Wille, 1887 p. 57 figs. 1—13; J. Agardh, Analecta alg. cont. IV 1897 pp. 22, 41. Wormskioldia sanguinea Sprengel, Syst. veg. IV 1827 p. 331; J. Agardh, 1851 p. 408. The cell-divisions in the tip of the frond are very regular (comp. WILLE, KYLIN). As emphasised by Kyrın (1923 p. 93), intercalary cell-divisions do not take place in the primary cell-row but in the cell-rows of the second and third orders. These divisions are marked with an + in my fig. 438 B. The cell-rows of the third order are given off from the lower side of those of the second order, and the cell-rows of the fourth order equally from the lower side of those of the third order (fig. 438, comp. Kyrın 1923 fig. 61). The pericentral cells cut off from the primary cell-row are early divided by a transverse wall (fig. 443). The cells surrounding the central cell-row are therefore of half the length of the central ones. As the central cells never divide by transverse walls they become very long. They are connected with one another by a broad pit in each transversal wall. The nucleus early divides into two, and the divisions continue, in consequence of which the older central cells contain nu- merous nuclei. The first transverse wall dividing the young pericentral cell is situated 476 under the pit connecting it with the central cell (comp. Kyrın 1923 fig. 62 a) and this pit is later to be found near the upper end of the central cell. The lowermost cell resulting from this division is at first not connected with the central cell by a pit, but such a con- nection must lat- er be establish- ed for in a more advanced stage the lower end of the central cell is also connect- ed with the sur- rounding cells by pits (fig. 439 A, C). The pericen- tral cells are con- nected longitudi- nallyby multiple, usually three pits of which all or at least two are secondary. The lateral veins of the first order arise in the upper border of the primary seg- ments. Lateral veins of the se- cond order are given off from’ the lower side of the primary Fig. 438. Delesseria sanguinea. A, growing point of young leaf; the division of the apical cell has begun. B, lateral part of the same leaf; the intercalary division walls are marked with ones; only near an =. C, marginal portion of frond at a longer distance from the top, showing the second- ary pits (=). D, young adventitious shoot given off from a mid-rib. A, B 560:1. D 200:1. the margin of the leaf small veins may also sometimes project from the upper side. Veins of the third order may be met with and anastomoses of the veins may occur near the border. The branching of the veins is wrongly represented in Flora Dan. pl. 349. The leaves do not normally branch, and branched leaves do not seem to have been mentioned in the literature. I have, however, observed some cases of branched leaves; as they have been met with in three different places, branched leaves may 477 perhaps be found to be not quite uncommon. / The branching is caused by a secondary apical cell becoming a primary one. When the branch has arisen at an early moment it may give rise to a pseudodichotomy (fig. 440 A); if it arises later, it becomes feebler and the branching more distinctly monopodial (fig. 440 B, C). Opposite branches have never been observed. Secondary pits are produced in great numbers, not only in the veins but also in the monostromatic frond (438 C). Two pits may exceptionally occur in the same wall be- tween two cells in the latter. The new leaves, as is known, arise as adventitious shoots from the mid-rib. The first stages of development have not been observed, but the new leaves seem to arise from a super- ficial cell. They are at first almost filiform (fig. 438 D) but soon become flat. In the lower A C Bart of the VOTE leaves several cells early Delesseria N oe the mid-rib in grow downward giving rise to rhizine-like longitudinal sections. A, central cell. B, inner filaments that strengthen the connection with (Orlical cells showing secondary pits. C, central (ec) and pericentral (p) cells, the latter showing the mother axis and establish a union of the three secondary pits. A, € 350 :1. B 560 :1. conductive systems of the two axes which does not exist to begin with (comp. fig. 444). A small number of adventitious leaves may arise early, in spring, and grow out in the summer (comp. Harvey |. c.), but most of the leaves arise in autumn (or perhaps early in winter). In January they have only a small size, they grow out in early spring and reach a considerable size already in April and the growth ceases in the beginning of summer, usually in June or perhaps already in May. In the mid-rib the inner cortical cells are segregated by numerous rhizoids or con- ductive hyphæ (WILLE 1887 p. 59; Kyrın 1923 ! As mentioned by Kyrın (1923 p. 92), Schmitz / and HAUPTFLEISCH's fig. 238 B, which shows a ramific- B ation, does not represent Delesseria sanguinea. Fig. A Fig. 440. according to Kyrın is a Hypoglossum, probably H. Wood- Delesseria sanguinea. From the Baltic, south of wardii; fig. B is probably Membranoptera alata. Als. Branched leaves. 1/4:1 D. K. D. Vidensk. Selsk. Skr.. 7. Række, naturvidensk. og mathem. Afd. VII. 3. 61 478 p. 95). As shown by Kozxkwirz (1. c.) starch is deposited in the mid-rib of the new leaves in June, and in summer and autumn they are densely filled with starch Fig. 441. Delesseria sangui- nea. Basal part of frond consisting of several cylindric hapters. Natural size. grains. The lateral veins are also filled with starch and therefore become dark brown by treatment with iodine. The basal portion of the frond is disc-shaped or conical and composed of densely united rhizines (KoLKwitz p. 45). It may, how- ever, also be branched, composed of cylindrical members resembling the hapters of the Laminariæ (fig. 441). The basal portion is, accord- ing to Korkwırz, filled with starch in August and September; it gives rise to new adventitious shoots. The germination has not been observed, but plantlets which could be identified with this species were repeatedly met with in summer, mostly growing on Hydroids, often in company with plant- lets of Phycodrys rubens but easily distinguished from them by the lan- ceolate outline of the primary frond which is provided with a very distinct mid-rib from the base to the top (fig. 442). As shown in fig. 443, the cell- divisions at the top of the frond agree exactly with those of the later fronds and the mid-rib has also the same structure as in these (comp. Kyrin 1923 fig. 61). Near the base, however, the cortication of the mid-rib is less advanced than in the middle of the young frond (fig. 442 B). As in the later fronds, the margin shows a num- ber of secondary apical cells, but while these are otherwise always situated so that the right angle of the cell is directed upward, the marginal apical cells of the primary frond often show the inverse situation, the wall by which they have been cut off being inclined upwards and the right angle of the cell there- fore being directed downward. It not rarely happens that two marginal cells situated be- side one another show different orientation, the one directed upward, the other down- ward (fig. 443 B). The downward directed apical cells remind one of those described above (p. 459) in Odonthalia dentata. Adven- titious shoots early arise in the lowermost Fig. 442. Delesseria sanguinea. A, plantlet from the Little Belt, July, 1,7 mm long. 43:1. B, lower part of the same showing adventitious branch. 200 : 1. part of the primary frond, which has the character of a stipe, probably produced by a superficial cell (figs. 442, 444). The laminæ of the leaves begin to disorganise in September, and this process advances more or less quickly during the autumn and winter and so that only the Mon mid-rib remains. In exposed localities the disorganisation may begin earlier and the mid-rib may be denudated in September, whereas in sheltered localities, e. g. in the belts the laminæ keep till the next spring, having then a brownish colour. W776 SIT Bo) ds So? Do SC Bie ES a SUG CD S \) Fig. 443. Delesseria sanguinea. Parts of 7 mm long plantlet, primary shoot. A, apical part Showing cell-divisions. B, marginal part showing secondary, variously orientated apical cells. C, lateral veins and secondary pits. 560 : 1. The fertile folioles arise in the autumn as adventitious shoots on the mid-ribs of the leaves from the foregoing winter. The development and structure of the or- gans of fructification has been thoroughly described by SvepeLıus and Kyrın and will not therefore be mentioned here. The three kinds of fructification always occur in separate individuals. The antheridia-bearing leaflets were met with in September and October; they reach a length of 5 mm. The procarp-bearing leaflets produce a great number of procarps situated on the mid-rib, but one eystocarp only is devel- oped in each shoot. Ripe cystocarps were met with in January and may certainly 61* 480 also occur in December and in the following months. Still in May numerous cysto- carps may be found. Ripe tetrasporangiferous leaflets were met with in January to May, but the dissemination of the spores apparently takes place mostly in winter. The sporophylls reach a length of 20 mm. The age reached by the individuals of this species is not easy to determine with certainty, not only because the basal disc is able to produce adventitious shoots, as emphasised by Korkwırz (1900, p. 45), but also owing to the fact that new vegetative shoots may be produced not only in the autumn or in winter, but also in spring or early in summer on the new leaves, and there may thus possibly be produced two generations of shoots in one year. When in single cases, in specimens from the Little Belt, I have ascertained the presence of 7 generations of shoots in one specimen, it is therefore not per- mitted to conclude that it was 7 years old, though it is not improbable that it was really so. KoLkwitz thinks that D. sanguinea becomes “kaum Alter als einige Jahre’. I estimate the maximal age to be 4—5, perhaps 7 years. Delesseria sanguinea reaches its greatest frequency Fig. 444. and the best development in comparatively deep Delesseria sanguinea. Adventitious branch ater with fresh flow, as in the eastern channel of of plantlet producing downward growing 2 S 3 Ahrons ef ana Eds Zee iL. the Kattegat and in particular in the Belts and the Sound, where it is often predominant. In such places it often attains a length of 30 cm or a little more. In the open waters as Ns and Sk and in Kn it does not thrive by far so well and only reaches a length of up to 20 cm. Still in the western Baltie (Bw), in the deep channel between Lolland and Fehmern it reaches the maximal length. But in Bm it reaches only 18 cm and at Bornholm only 9 cm in length. The maximal length of the leaves varies about 10 cm in most of the Danish waters, in Kn and Ke between 7 and 18,5 cm, in Sb between 6 and 17 cm, in Su and Bw between 7 and 14 cm. In Bm it is only 5—8 cm and at Bornholm 2—5 cm. The greatest breadth of the leaves is reached in the Northern and Eastern Kattegat where it is 1,5—7,5 cm, most frequently 2,5 —4,5 cm. In Sb the breadth is 1,3—4 cm, in the Sound 1,4—3 cm, in Bw only 0,8—1,5 cm, in Bm 0,3—1,3 cm and in Bb only 0,3 cm (comp. Plate VII figs. 1—4). The breadth of the leaves seems therefore to be more influenced than the length when the salin- ity of the water is diminished. D. sanguinea occurs in all the Danish waters except the Limfjord and other fjords. It does not grow in depths smaller than 4—5 meters and descends to 30 meters’ depth at least; in Sb it has been met with in 40 meters’ depth. It prefers water with a salinity of 20 °/,, or higher and with rather low summer temperature. It is char- acteristic to stony bottom in the deep channels in our inner waters, where it occurs in great specimens with several generations of shoots. si Localities. Ns: ZQ, jydske Rev, 24,5 meters; aF, 31m; XR, off @rhage; eT, 34 m; YT, off Helshage, Hanstholm, 5,5—13 m. — Sk: eX, N.W. of Bragerne, S.E. of Bragerne, 10,5 m; washed ashore at Svinklov; Dana St. 2900, 2899 (C. A. J.); several places off Lonstrup, 7,5—19 m; Bredegrund and Mollegrund off Hirshals; bF, Skagbanken. — Kn: Herthas Flak, e. 22 m; around Hirsholm; Frederiks- havn; VT and GN, near Nordre Ronner; VT; common at Læsø Trindel, 10—24 m. Ke: Fladen, several places, 16—30 m; Groves Flak; several places, 19—30 m; XA; RU, 26,5 m; Store Middelgrund (Borgesen, !); GJ, Ostindiefarer Grund; OO, Soborghoved Grund, 8,5 m; bR, Vesterlands Grund at Gilleleje, 7,5 m. — Km: Læsø Rende, Dana St. 2884 (C. A. J.); XC, south of Læsø, 7m. — Ks: Lyse- grund (Lyngbye, HQ, OP!); OT, Hastens Grund, 9,5 m; near Hesselo (Lyngbye); RL; D; GG, GF, Sjællands Rev; FP, Jessens Grund, 4m. — Sa: PA, GD. GE, PC, near Sejerø; PG, near Hatter Rev; Koldby Kaas, outer side of mole; aV; MP, DK, Bolsaxen; AH!, Lille Grund; Hofmansgave (Hofm. Bang); entrance to Odense Fjord (C. Rosenberg). — Lb: Middelfart; off Kongebro; Fano Sund, 19—34 m; off Stenderup; DA, off Bojgden; dH, dH’, east of Hesteskoen; CF, dQ, south of Lyø, 22 m; LG, off Vidso, Ærø. — Sf: BY, BX, Svendborgsund; UV, north of Ærø. — Sb: GT, off Asnæs; GU; LK, Elefantgrund; CN; NU; cL, 25—27 m, NO, NN, near Sprogø; GP; DN, Vengeance Grund; UE; UF; UG; LH, West Side of Langeland; UH; UT; DQ; US, c. 40 m; US!; DR; LB; UR. — Sm: HA, Agerso Sund; VC; HC; CR; KQ. — Su: Hellebæk; north of Kronborg cast ashore (Liebman, C. Rosenberg a. 0.); bM, south of Hveen, 22,5 m. — Bw: bV, N.E. of Kobbel Skov; cD, cE, dO, 5 m, south of Als; Pols Rev; DX, Vodrups Flak; UL, Ojet, 20 m; LA, UQ, KY, KV, KU, south of Lolland; KT, Gedser Rev; Kadetrenden, 24,5 m. — Bm: KS, KR, HG, east of Falster; bO, 15 m (O. Paulsen); VG, QS, N.E. of Moen; 7,5 miles E. of Hellehavns Nakke (C. A. J.); 20 miles E. by N. of Moens light-house (C. A. J.); 13,5 miles E.S.E. of Moens light-house, 24 m (C. A. J.); QN, QM, Koge Bugt. — Bb: Adler Grund, 20 and 30 meters (C. A. J.); SH, Rønne Banke; YH, off Rønne, 24,5 m; 8 miles S.1/, E. of Rønne harbour, 11—19 m (C. A. J.); XZ!, Da- vids Banke, 29 m; 3 miles S.S.E. of Nexo harbour, 21 m (C. A. J.); YC, near Salthammer Rev, 24,5 m. Membranoptera Stackhouse. 1. Membranoptera alata (L.) Stackhouse. Stackhouse, Tentamen marino-cryptogamicum. Mémoires de la soc. imp. des Natur. de Moscou, Tom. 2, Moskwa 1809 p. 85 (teste Kylin); Kylin 1923 p. 108. Fucus alatus Hudson, Fl. Angl. Ist ed. 1762 p. 578 (not seen); Oeder Fl. Dan. tab. 352, 1767. Delesseria alata (Huds.) Lamour. Essai 1813 p. 124; Lyngbye 1819 p. 8 pl. 2; Hornemann FI. Dan. tab. 2129, 1836; Harvey Phye. Brit. III 1851 pl. 247; J. Agardh 1852 p. 683; Wille 1885 pp. 31, 64, id. 1887 p. 62 figs. 14—20, 79; Kny Wandtaf. Taf. 77. 1886, Erlauterungen p. 334; Buffham 1893 p- 296 figs. 22—24; Phillips 1898 p. 183 figs. 17—19; Kolderup Rosenvinge, Sporeplanterne 1913 p. 112 fig. 158. Hypoglossum alatum Kützing, Phyc. gen. 1843 p. 445, pl. 66; Tab. phyc. Bd. 16 tab. 16, 1866. Pteridium alatum J. Agardh 1898 p. 225. The apical cell-divisions of the frond have been described and figured by Kny (1886), WILLE (1887), myself (1913) and recently by Kyrın (1923). The latter au- thor shows that the structure of the tip of the frond resembles that of Delesseria sanguinea but differs from it 1) in the absence of intercalary divisions, 2) in that the lateral pericentral cells do not divide by transversal walls, and 3) by the branch- ing of the frond by the secondary apical cells transforming into primary ones. After the division of the primary segment cut off from the apical cell by two longitudinal walls, the two lateral cells are divided by inclined walls in a number of segments of the second order, the first of which are included, the outer end meeting the low- er primary segment wall, while the young- er segments of the second order reach the border of the Ce One frond. The number SOS Ve Se f included segment SO OSD ADO at Die ol included segments ID OP CP ESR EOI ESS C of the second order is FES variable, it is great- Fig. 445 est in the broader Membranoptera alata. Tip of frond from Frederikshavn, May. forms (comp. Kny 1. c., K. ROSENVINGE 1913 p. 22 (from Cherbourg) and Kyrın 1923 fig. 70), while in the narrow forms from the Baltic Sea it may be only 1 or 2 (fig. 447). Their number can be recog- nised in the older parts of the frond by the aid of the lateral veins of the second order arising in the upper border of the segment Fig. 447. Membranoptera alata f. baltica, from Bornholm. Tip of frond. 350 : 1. ofthe second order (fig. 446 A), just as the lateral veins of first order arise in the upper border of the primary segments. In the branch - producing segments one seg- ment of the second order only is asa rule included (fig. Fig. 446. 445.1 br I Membranoptera alata. A, tip of frond showing the Dp HOES ONE mid-rib and the lateral veins. B, portion of membrane on the right hand; showing the veins. 19:1. comp. Kny l.c., se- cond branch from the top on the right; K. R. 1913 fig. 158 last branch; Kyrın 1923 fig. 70 a). But it also happens that the first segment of the second order reaches the border of the frond (fig. 445 last branch on the right, comp. Kny L.c. last branch on the right, Kyrın 1923 fig. 70 c). When the first segment of the second order of the branch-producing segment is included the vein situated in its upper border anastomoses with the vein of the foregoing primary segment (fig. 446 A). The primary segment situated immediately over a branch may sometimes be included (fig. 452, segm. 9). The branch- es are as a rule regularly alternate, but superposed branches may occur (fig. 445). 1 The mid-rib arising by tangential divisions, not only of the median cell but also of the adjacent parts of the primary segments, early attains a considerable thick- Kad EL, > = —<—— SE es nessandthelateral veins are also ear- ly developed, the cells in the up- lengthening and Fig. 449. Membranoptera alata. Portion however, not correct, they RP ONE EN re only oven off from the lateral veins and secondary 2 pits. The limits of the primary lower side (fig. 446). Lateral segments are marked with an veins may also spring from arrow. 260 :1. 2 R x the mid-rib between the prim- ary lateral veins (fig. 446). The divisions parallel to the flat of the frond extend from the mid-rib towards the margin, so that the greater part of the frond consists of more than one layer of cells; the margin itself, however, is always monostromatic (fig. 448 B, C, comp. Kyrın 1923 p.111). The veins are rather close owing to the want of growth beyond the apical portion of the frond. Secondary pits are produced in great numbers and, in the membranaceous portion of the frond, in particular in the walls perpendicular to the longi- ==— = Tann Vey DE HONOR u Fig. 448. per border of the Membranoptera alata. A, longitudinal section of young 5 shoot. B, C, transverse sections of shoots. D, longitu- primary segments dinal section of lateral vein. 390: 1. dividing by walls parallel to the flat, in consequence of which the inner conducting cell becomes covered by a short- celled layer on both sides (fig. 448 D). Lateral veins of the second order are also early developed in the upper border of the seg- ments of the second order. According to Harvey (Phye. Brit. pl. 247 fig. 8) the lateral veins of the second order spring up- wards and downwards as well from the primary ones; this is, Fig. 450. Membranoptera alata, Adventitious shoots from an axil. 350: 1. RER tudinal axis of the frond, thus establishing a longitudinal connection between the cells of the flat. A longitudinal arrangement of the cells not agreeing with the distribution corresponding to the succession of the cell-divisions then frequently appears (fig. 449). Adventitious shoots arise in various number from the axils of the branches; they have no fixed position but develop from marginal initial cells or from other cells near the margin (fig. 450). In the Baltic Sea a very narrow form occurs, the frond L, N! of which is only c. 1 mm broad, at Bornholm even only | c. 0,3 mm broad (Plate VII fig. 7). While in the typical Sh form the frond is rounded above with two or three N) branches near the top, the frond from the Baltic is much | less branched; the shoots are pointed, frequently without any branch near the top (fig. 447). The frond is poly- stromatic almost to the margin. Of the segments of the second order only one or two are included; sometimes even the first one reaches the margin of the frond (fig. 447, 7th segment from the top). The mid-rib becomes very convex on both sides. Within a thin assimilatory cortex it is built up by 1) primary longitudinal cell-rows, the cells of which are prineipally jointed by secondary pits, often three in each transversal wall, 2) conducting hyphæ given off from the former (comp. WILLE 1887 p. 62 figs. 14—20, 79). In a cross section a transversal row of primary cells is present, the middlemost of which, the primary axial cell, may have a smaller diameter than the others. All the inner cells of the mid-rib contain several nuclei. St As, Sporelings produced in cultures were not obtained Membranoptera alata. Young plants And very young plantlets were not met with in Nature, growing on Membranipora pilosa. but young plants that could be referred with certainty to een this species were collected in July, e. g. growing on Mem- near the base, 19:1. branipora pilosa at Herthas Flak. They were !/; to !/, cm long, not branched, with a terete stipe continuing in a vigorous mid-rib from which opposed lateral veins were given off (fig. 451). The apical cell-divisions agreed exactly with those of the adult plants (fig. 452). In one of the larger plants the ramification had begun, the first branch hav- ing been formed near the top (fig. 451 A). As shown. in fig. 452, this branch differs from those of the older fronds in that it is more symmetrical, the first segments being equally developed in the anterior and the posterior side; the foll- owing segment of the primary axis is therefore included, and the rib of the branch is not as usual in its outer part situated in the anterior border of the segment of the mother axis from which it has arisen. The primary axis appears to develop LL LL LU 485 into an ordinary branched frond. The stipe is fixed to the substratum by a conical dise united rhizines. Adventitious shoots early appear in the stipe. formed by densely The antheri- dia occur, as shown by BurrHam (1893 p. 296 figs. 22—24) in minute leaflets arising from the apices of the plant and, especially, in groups from the axils (comp. KYLIN 1923 fig. 69a); they cover the whole sur- face except a mar- ginal zone which is sometimes very nar- row, and the lower portion of the leaflet may also be sterile ) COX S MI STE a SS C RS Oo Z TIS TERING to ÉTANG ee Ÿ O DO Pe ee Oa EEE Weta tele Te DS SOEEEN Fig. 452. Membranoptera alata. Tip of the plantlet represented in fig. 451 A. The figures indicate the number of segments from the top. 350: 1. (fig. 453). According to Kyrın, the development and structure of the spermatangia and the spermatia is similar to that in Apoglossum ruscifolium. The procarps arise in the mid-rib in adventitious shoots or in the upper part of the frond; their development has been described by PrırLırs (1898) and Ky in Fig. 453. Membranoptera alata. Male leaflets. (1923). The cystocarps occur singly on the mid- rib in the said parts of the frond. The tetrasporangia occur in sori in adventitious branchlets or in the ultimate branches of the frond. According to Kyrın (1923 p. 113), they develop from superficial cortical cells in the same way as in Delesseria. Membranoptera alata occurs in all the Danish waters except the fjords and perhaps the waters around Bornholm where it has only been met with as washed ashore. It reaches a length of 14 cm in the Northern Danish waters, 12 cm in the Sound and the Belts, 8 em in Bw, 7 em in Bm and 5 cm in Bb. The breadth is rather variable. In the northern waters it usually varies about 2 mm, it frequently amounts to 3 mm more rarely to 4,5 mm. In the Great Belt and the Sound a breadth of 3,5—4 mm may still be reached in deep salt water. In Bw it is rarely more than 2 mm broad, in Bm !/,—1 mm (in one specimen 1,5 mm). A specimen from Bornholm was only 0,3 mm broad (comp. Plate VII figs. 5—7). D. K. D. Vidensk, Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd, VII, 3. 62 486 The narrow Baltic form (fig. 447, Plate VII fig. 7) is much feebler and less branched than the typical form and thereby rather characteristic. It is, however, connected with the typical form by transitional forms. It may be named f. baltica. Some of the specimens of this form were loose on the bottom, especially those found north of Moen. The vegetative growth begins in winter and ceases in summer. Antheridia were met with in October and November, cystocarps and tetrasporangia in January to April. The species has been found growing on stones and on various Algæ (Fur- cellaria, Fucus serratus, Halidrys, Ahnfeltia, Laminaria etc.). It has been met with from low-water mark to 27 meters’ depth. Localities. Ns: Romo, cast ashore (Moller); YT, off Helshage, Hanstholm, 13 m. — Sk: Roshage, Hanstholm, near land, 2 m; Dana 2902 (loose?) (C. A. J.); eY, 15m; Bragerne, 1—2 m; Dana 2900 (loose?) (C. A. J.); off Lonstrup, 7—9 m; off Hirshals, 12—15 m (Borgesen, !); Hirshals mole and stones near land, 1—2 m. — Lf: Wanting. — Kn: Herthas Flak; Hirsholmene; Krageskovs Rev, 5 m; Strandby, 1 m; Frederikshavn, harbour and stony reefs; GM, north of Læso; Trindelen, FE, IX. — Ke: fH, Fladen, 17 m; Store Middelgrund (!, C. A. J.); GI, Ostindiefarer Grund; OO, Soborghoved Grund; Gilleleje (Lyng- bye). — Km: Læsø Rende, Dana 2884, 9m (C. A. J.). — Ks: Grenaa harbour; Jessens Grund, 4 m; OP, EM, HQ, Lysegrund, 6—10 m: RL; near Hesselo (Lyngbye); GF, Sjællands Rev, 8 m. — Sa: GD, GE, north of Sejero; FT; FS; PG; YV, 15 m; MP, Falske Bolsax; DK, Bolsaxen; AH!, AH, Lillegrund north of Fyns Hoved. — Lb: NV, Middelfart; LG, off Vidso, Ærø. — Sf: Ærø, Kjærbølling. — Sb: GT, off Asnæs; CN, S.W. of Musholm; Kerteminde harbour; GP, off Halskov; near Sprogø (Magnus); NN; NO; NP; Nyborg (Hofm. Bang); UE; DN, Vengeance Grund, 12m; UT; US!, 20 m; DR, off Albuen; DT; LB, 17 m; UR. — Sm: HA, Agerso Sund, 11 m; VC; HC, off Knudshoved Odde; Q; KP, 3m; HI and KQ, 4 m, Grønsund. — Su: Hellebæk (Ørsted), washed ashore north of Helsingør (C. Rosenberg a. 0.); bM, south of Hveen, 22,5 m: OG, Taarbæk Rev; TB, off Skovshoved, 5 m; OG!; RH, Knollen; PR, off Dragor. — Bw: cE, south of Als; UY, Vejsnæs Flak; UY; UL, Ojet, 20 m; KY; KX; KU, KV, Schon- heyders Pulle. — Bm: (f. baltica) KR, KS, HG, east of Falster; VH, QY, south of Moen; QZ, RC, VG, east side of Moen; 7,5 miles east of Hellehavns Nakke, 27 m (C. A. J.); QS; QR; VD; SD; QN; QM, off Køge; QF, south end of Flinterenden. — Bb: (f. baltica) washed ashore at Rønne (R. T. Hoff). YU D nm EP Ex E> 9 [= EXPLANATION OF PLATES All figures are photographs of dried specimens, 4/; nat. size. Plate V. . Polysiphonia orthocarpa, from Amtoft Reef, Limfjorden. . Polysiphonia elongata f. Schuebelerii, from the Great Belt north of Langeland (UF). . Polysiphonia elongata f. baltica, from YC, east of Bornholm, 24,5 meters’ depth. Plate VI. . Polysiphonia violacea, from Hirsholm 11 meters’ depth showing secondary axillary shoots and torsion. . Rhodomela subfusca f. abyssicola, from dQ south of Lyø 22 m, June; fig. 3 with tetra- sporangia. Plate VIT. . Delesseria sanguinea, from N.E. Reef by Hirsholm, July. — , from Ojet (Bw) 20 m, May 21st. With cystocarps. — , from VG, north of Moens Klint, 17 m, May 28th. — , from YC, east of Bornholm, 24,5 m, July. . Membranoptera alata, from Læsø Trindel, April, Børgesen. — , from Frederikshavn, outside of harbour, May. , from Præstebjergs Rev, east of Falster, 7,5 m, November. Fr ta _ + CI Ch 3 = i ET ii - à 2 ne U SRE = i = en - LOS, PO 4 rod its) + x foi CAE u ni 7 Qi LUS be Psy , AMK 4 ley oi ER REIN eal) Wants , (VD ke : tua Re 7 i rr x uh P lea" à LE, A så 7 a : så , ii 0 T x 2358-50 Say - 3 - ig 2 = SAT i "it i fr Si 3 5 Nun “4 ‘ +: Pre [L. Kozperur ROSENVINGE] 2 oO AFD., VII. LSK. SKR., 7. R., NATURV. OG MATH. NSK. . VIDE D. K. VI Pr ROSENVINGE 3 [L. KoLperur OG MATH. AFD., VII. D. K. D. VIDENSK. SELSK. Skn., 7. R., NATURV. SER REDET OS re Og BORE / D: K: D: Vinensk. SELSK. SKR., 7. R., NATURV. OG MATH. AFD., VII - 3 [L. KOLDERUP ROSENVINGE Pr. VII ER ne => RN: A THE MARINE ALGÆ OF DENMARK CONTRIBUTIONS TO THEIR NATURAL HISTORY PART IV RHODOPHYCEAE IV. (GIGARTINALES. RHODYMENIALES. NEMASTOMATALES) BY L. KOLDERUP ROSENVINGE WITH ONE PLATE D. KGL. DANSKE VIDENSK. SELSK. SKRIFTER, 7. RÆKKE, NATURVIDENSK. OG MATHEM. AFD., VII. 4. OE KS KOBENHAVN HOVEDKOMMISSIONÆR: ANDR. HOST & SON, KGL. HOF-BOGHANDEL BIANCO LUNOS BOGTRYKKERI A/S 1931 INTRODUCGTION Je a comparativety small number of species, belonging to the Gigarli- nales, Rhodymeniales, and Nemastomatales, are treated in the present part, seven years have been spent in completing it. This is partly due to the fact that some of the species offered problems that demanded thorough investigations. Two of these problems have been treated in particular papers, viz. (1) the question of the reproduction of Phyllophora Brodi@ei and the nature of Actinococcus subeulaneus'), and (2) the question of the reproduction of Ahnfeltia plicata*). In the years elapsed since the publication of the third part of this work, numerous gatherings have been made in several places on the coasts, and dredgings have been made in many new stations which are recorded below. Many new localities have been stated for species recorded in the foregoing parts, but these are not named here; only a few species belonging to the orders treated in the foregoing parts but not named there are mentioned here under Addenda. List of new Dredging Stations arranged according to the different Waters. Kattegat, Northern Part. (Kn) gR. 17/729. Midway between Hirsholm harbour and Kelpen. — 8 m. — Boulders (picked up). On the upper side mostly Halidrys siliqu., on the other sides many others, e. g. Deless. sangu., Polys. viol., Phylloph. membr., Codium toment., (young plants), Rhodym. palm., Bryopsis plum. and many others. gl. ‘/:28. Midway between Hirsholm and Deget. 7.5 m. — Soft bottom with stones. — Scarce vegetation: Desmarestia aculeata, Acrothrix gracilis, Desmar. viridis. gK. ‘/128. Hirsholm light-house in N.W., Frederikshavn Church in W.S. W., 19 m. — Soft bottom, no Alge. gQ. /:29. East end of Hjellens Rev by Frederikshavn. — 4—6 m. — Stones. Abundant vegetation: Halidrys siliqu., the three Laminaria species, Fuc. serralus, Furcellaria, Laurencia pinn., Polyides, Ahnfeltia, Corallina offic. 1) L. Korperup ROSENVINGE: Phyllophora Brodiæi and Actinococeus subeutaneus. K. D. Vid Selsk. Biolog. Meddel. IX, 4, 1929. ?) L. Korperup Rosenvince: The Reproduction of Ahnfeltia plicata. K. D. Vid. Selsk. Biolog. Medd. X, 2, 1931. 63° 492 gL. 7°/7 28, */s 29, 1/029. Off Friis’ Sten W. side of Læsø. 2—3 m. — Sand with stones. — Fucus serratus, Fuc. vesic., Phylloph. Brodiei, further Brongniartella, Zostera, Phylloph. membranifolia. gk’. *°/; 28. Vesterø harbour in S. E. by E. 10—11 m. — Sand. — Acrothrix gracilis, Striaria and others on dead Zostera leaves. Samsø area. (Sa) fN. */s 25. Off Ballen, east side of Samsø. 1) East of the channel, 13 m. — Stony bottom — Laminaria saccharina, Lithothamnion glaciale, Corallina off., Ectocarpus silieul., Brongniartella byss. 2) In the channel, 22.5 m. — Soft bottom with stones. — Lithothamn. glaciale. 3) Within the channel, 13.5 m. — Sand. ST. °'/;30. Paludans Flak, near the broom. — 10-11 m. — Sand with small stones. — Fucus serralus, Lamin. digit., Furcell. fast., Polys. viol., Chondrus crispus. — 6-8 m, further Ahnfeltia plicala, Corallina off. and many others. gH. '/s27. South side of Hesbjerg Grund, near land, 3 m. — Gravel. — Furcellaria fast., Zostera, Ascophyllum nodosum scorpioides, Halidrys sil. loose, Asperococcus echinatus, Eclocarpus conferv., Rhodomela subfusca, Chorda Filum. The South Fyen Waters. (Sf) fX. '°/s25. South side of Svelme. 7,5 m. — Soft bottom. — Broad-leaved Zostera. — Same place, nearer to land, 4 m. — Narrow-leaved Zostera marina, Potamogeton pecti- natus, Cladophora. fV. “/825. At the East side of Avernak ©, near land, 3—4 m. — Stones with Fucus vesicul. and Chorda Filum. Great Belt. (Sb) gU. */5 30. East side of Lille Grund, North of Hindsholm. — 10—11 m. — Sand with stones. — Fucus serratus, Fuc. vesic., Furcellaria, Laminaria digit., Phylloph. Brod. and Ph. mem- branif., Corallina off., Ahnfeltia plic. and many others. gS. 1/129. Elefant Grund, north side and middle. — 6-7.5 m. — Stones and Mytilus edulis abundantly. — Phylloph. Brodiei, Rhodomela subfusca, Ahnfeltia plic. etc. gV. °/5 30. At the broom S. E. of Romsø, 11 m. — Stones. — Laminaria digitata, Furcel- laria fast. (LP) '*/s 27. Off Stavreshoved, 7 m. — Stones. — Fucus serratus, Fuc. vesicul., Laminaria digi- tata, Lam. sacchar., several Floridee. gX *'/s 30. Off Stavreshoved. — 8 m. — Sand with spots of Zostera vegetation. — Fucus ser- ratus, Laminaria sacch., Furcellaria, Halidrys. gY. °/s30. Mollegrund. — 8 m. — Sand with stones. — Laminaria digitata, L. sacch. gG. **/s 27. Off Bovense, 6.5—8 m. — Stones. — Laminaria digitata, Furcellaria fast., Phylloph. membranifolia and many others. gF. **/s 27. Off Teglværksskoven, 7.5—10 m. — Stones. — Laminaria saccharina, Lam. digit., Fucus serratus, several Florideæ e. g. Phycodrys rubens, Cystoclonium purp. fY. “4/1125. Sprogø light-house in N. W. ‘4 W., Halskov Rev light-ship in N.E., 9—10 m. — Stones. — Furcellaria, Fucus serratus, Laminaria digitata, several Florideæ. fY', — near the foregoing place, 12—14 m. — Stones. — Same vegetation. fZ. 4/1 25. Sprogø light-house in N.W. ‘4 W., Halskov Rey light-ship in N. E. */s N. — 20 m. — Soft bottom, stones. — Phyllophora Brodiei, Delesseria sanguinea, Phycodrys rubens, Furcellaria, Phylloph. membranifolia. gA. ”/11 25. Sprogø light-house in N.E. 1/2 N., Gjellegrund light-beacon in S. E. ‘4 E. — Mytilus edulis, few Algæ: Laminaria digitata, Furcellaria fast. 493 gC. (= NS) “/1 and *°/1 25. Between Knudshoved and Slipshavn. 5-6 m. Stones. Fucus serratus, Chorda Filum, Fucus vesic., Phycodrys rubens, Laminaria digitata, Halidrys siliqu. fructiferous. gB. %/11 25. Vresens Puller, the broom in E. by N. '/» N., 04 mile to 0.2 mile. 7 m. Stones. — Fucus serratus, Halidrys siliqu., Laminaria digitata. gD. *“/129. The double broom for Kobberdyb in N. by E. */s E. 1.0 mile. — 9 m. — Soft bottom (?) — Phyllophora Brodiwi f., Furcellaria fastig. gE. ”/1 25. Stokkebæks Flak. 5—7 m. — Stones. — Zoslera, Fucus serratus, Chorda Filum. fP. **/3 25. '/2 mile E. of Hov light-house, 5.5 m. — Coarse sand with scattered stones, and firm clay. — Zostera leaves and abundant, partly loose Algæ: Fucus vesicul., Furcellaria, Rhodomela, Phyllophora Brodiæi and Phyll. Bangii. fO. '*/3 25. S.S.E. of Vresen, E. of Langesand. 7,5 m. — Bottom? with a few stones. — Dead Zostera leaves, Ascophyllum nodosum f. scorpioides, loose Furcellaria. fQ. '*/s25. ON Spodsbjerg, 19 m. — Bottom with stones. — Mostly Delesseria sanguinea, further Laminaria saccharina and digilata, Phycodrys rubens. fR. '*/s25. Off Hjortholm Skov, Kjelsnor light-house in W. by N., °/ mile from land, 21 m. — Stones. — Laminaria digitata, Delesseria sanguinea, Phycodrys rubens, Brongniartella byss., Laminaria saccharina. fS. “/s 25. East of Kjelsnor light-house, °/s mile, 9.5 m. — Sand with stones, gravel. — Mostly Furcellaria, further Laminaria digit., Mylilus edulis abundant. — Same place, 11.5 m. — Stones. — Similar vegetation, mostly Furcellaria, further Rhodo- mela, Deless. sangu., Polysiph. elongata, Brongniartella byss., Phycodrys rubens. The Sound (Øresund). (Su) gM. °°/s29. Taarbæk Rev. One mile W. of the bell buoy. 8—9 m. — Stones and Mytilus. — In particular brown Algæ, Ectocarpus silicul., Chorda Filum, Stictyosiphon lort., Rhodomela subf., Polysiph. nigr., Dumontia incrassata etc. gM!. °°/s29. Just outside the bell buoy. 12 m. — Stones. — Laminaria saccharina, L.-digitata, Rhodymenia palmata, Fucus serratus, etc. as in the foregoing place. sM?. */629. Same place, 500 m N.E. of the bell buoy. 15 m. — S{riaria altenuala, Rhodymenia palmata, Ceramium Areschougii. gN. ”/6 29. Taarbæk Rev, 2'/2 miles N. by W. of Middelgrundsfort. — 7 m. — Sand with scattered stones. — Chorda Filum, Eclocarpus, Polysiph. violacea, P. urceolata, Dumontia incrassala. gP. °°/s29. 22 miles E. of Skovshoved. — 11 m. — Sand with stones. — Mytilus. Desmarestia viridis, Polysiph. nigrescens, Laminaria sacch. etc. gO. >/6 29. Skovshoved in W. by N. 3 miles. 14 m. — Clay-mud. — Mylilus. Laminaria sacchar., Desmarestia aculeata. Baltic, Western Part. (Bw) fT. '*/s25. South of Marstal, Fakkebjerg light-house in S.E. by E. 5'/2 miles. 7.5 and 11 m. - Gravel. — Fucus vesicul., Chorda. Filum, Rhodomela subfusca, Zostera. fU. 4/25. South of Ærø, off Drejet. 7 m. — Gravel with stones. — Fucus vesicul., Fuc. serratus, Furcellaria, Rhodomela subf., Phylloph. Brodiæi and membranifolia, numerous loose forms of Phylloph. Brodiæi, and Phyll. Bangii. V. Gigartinales. Fam. 15. Gigartinacee. T. H. Burraax (1891), On the reproductive organs. especially, the antheridia, of some of the Florideæ: Journal of the Quekett Microscopical Club, Vol. IV. Ser. II, p. 246. — (1893), On the Antheridia eic., of some Florideæ. Ibid. Vol. V, Ser. II, pp. 291—305. — (1896). Notes on some Floridez. Ibid. Vol. VI. Ser. II, pp. 183—190. O. V. D:srBismire (1894), Beitrag zur Anatomie und Entwicklungsgeschichie von Phyllophora. Botan. Centralblatt Bd. 57, p. 361. i — (1895). Die Phyllophora-Arten der Westlichen Ostsee Deutschen Antheils. Wissenschaftl. Meeres- uniersuchungen herausg. y. d. Kommission z. Unters. d. deut. Meere. Neue Folge. I. Band. Heft 2. Kiel 1895. | — (1899), On Actinococcus and Phyllophora. Annals of Botany. Vol. XIM, p. 253, pl. 15. GREVILLE (1830), Alsæ Britanice. Edinburgh. B. Jonsson (1891), Beiträge zur Kenntniss des Dickenwachses der Rhodophycéen. Lunds Univ. Arsskr. Tom. XXVII L. KorLperup ROSENVINGE (1893), Grønlands Havalger. Meddelelser om Grønland III. Kjøbenhavn. (Les Algues marines du Groenland. Ann. d. sc. nat. 7° Serie XIX 1894). — (1898), Deuxième Mémoire sur les Algues marines du Groenland. Meddelelser om Grenland 20. P. Kuckuck (Bemerk. I. 1894): Bemerkungen zur marinen Algenvegeiation von Helgoland. Wissensch. Meeresuntersuch. Neue Folge I. Band. Kiel und Leipzig 1894. — (Bemerk. IL (1897): — II. Ibid. Il. Band, Heft 1. F. T. Körzıng (1843), Phycologia generalis. Leipzig. H. Krrın (1917), Über die Keimung der Florideensporen. Arkiv for Botanik uig. af K. Svenska Vet. Akad. Bd. 14, No. 22 — (1923), Studien über die Entwicklungsgeschichie der Florideen. K. sv. Vetenskapsak. Handl. Bd. 63, No. 11. Stockholm. — (1928), Entwicklungsgeschichtliche Florideenstudien. Lunds Univ. Årsskrift. N.F. Afd. 2. Bd. 24 No.4. H.C. Lynesye (1819), Tentamen hydrophytologiae danicae. Hafniae. R. W. Picuips (1925), On the genera Phyllophora, Gymnogongrus and Ahnfeldtia and their parasites. The New Phytologist. Vol. 24, No. 4. HENRIK Printz (1926). Die Algenvegetation des Trondhjemfjordes. Skrifter utgitt av d. Norske Viden- skaps-Akademi i Oslo. Math. naturv. KL 1926. No. 5. Oslo. Fr. Scumitz (1893), Die Gattung Actinococcus Kütz. Flora 1893. See further pp. 79, 297, 465. Harveyella Schmitz and Reinke. 1. Harveyella mirabilis (Reinsch) Schmitz et Reinke. Reinke Algenfl. wesil. Osis. 1889 p. 28: Buffham (1893), p. 292, Pl. XIII figs. 3, 4, Pl. XIV figs. 4042; Kuckuck, Bemerk. II, 1897, p. 395. H. H. Sturch, Harveyella mirabilis. Annals of Botany, Vol. 13, 1899. p. 84 PL III, IV; id, on the life-history of Harveyella pachyderma and H. mirabilis. Ann. 495 of Botany, Vol. 38, 1924 p. 27. Kylin (1923) p. 134. E. Chemin, Sur le développement des spores et sur le parasitisme d’Harveyella mirabilis Schmitz et Reinke. Comptes rendus d. s. de l'Acad. d. sc. Paris t. 184, p. 1187, 1927. Choreocolax mirabilis Reinsch, Contrib. 1875 p. 63, Taf. 53 et 54. Choreocolax albus Kuckuck, Choreocolax albus n. sp., ein echter Schmarotzer. Sitzungsber. d. K. preuss. Akad. d. Wiss. 1894. Although not described until 1875, this interesting parasitic alga was already observed by Lynesye. In Tent. Hydr. (1819, p. 47 tab. 11 B) he mentions and gives a drawing of some warts seated laterally on the branchlets of Gigartina subfusca y, tenuior (Rhodomela subfusca). The “puncta nigra” mentioned (I. ec. p. 48) which “potius pro massainterna hic illic magis conden- sata, quam pro semini- bus sumenda sunt’’, were probably the large inner cells rich in starch-grains. Specimens in Herb. Lyne- BYE of the named host- plant from Svinger, Nor- way, collected by Lyne- BYE in October 1817, bear several of these warts which are mentioned in Fig. 454. the label in similar terms Harveyella mirabilis. A, end of intramatrical filament(May) ; the last cell in begin- . Kr. ning division (to the right). B and C, longitudinal sections of Rhodomela with as in Tent. Hydr.; they intercellular filaments of Harveyella, pit-connections between the host and the proved on microscopical parasite. A, 560:1, B,C 350 : 1. examination to be sexual specimens of Harveyella mirabilis, one with procarps and a young gonimoblast, an- other perhaps a young male specimen. LIEBMAN also met with this species in December 1838 at Helsingor but referred it to Corynephora marina (Leathesia dif- formis). Our knowledge of the structure and development of this plant is principally due to the researches of Scumirz, Kuckuck and Srurcu cited above. The colour of the plant may be pure white in the living state, in particular in the large tetraspori- ferous specimens collected in May, but other specimens were feebly rosy or yellowish, apparently owing to the isolated cells of the host plant interspersed among the cells of the parasite. As pointed out by Kuckuck, the cells are devoid of chromatophores; it would be of interest to ascertain whether leucoplastids are also wanting. The cells represented in fig. 454 A after treatment with Nawasnın’s mixture’, showed filamentous bodies which are probably leucoplastids. The cells contain one nucleus as shown by Srurcn * See Karpechenko, The production of polyploid gametes. Hereditas IX, 1927, p. 349. 496 (comp. fig. 454 4, B). Floridean starch-grains are often very abundant, in particular in the inner large cells of the globular thallus. The statement of SrurcH that there Fig. 455. Harveyella mirabilis. Cells from the cushion of a male plant connected with pri- mary and secondary pits (May). 350 : 1. The antheridia are no secondary connections between the cells of the gameto- phyte does not agree with my observations as I have repeatedly met with secondary pit-connections between the cells situated a little within the antheridia-producing cells (fig. 455). According to Scumirz (1889, p. 29), the cells of the intra- matrical filaments are here and there connected with the cells of the host-plant through secondary pits. An immigration of a nucleus from the parasite into the host-plant or vice versa probably takes place, as in the ordinary formation of secondary pits, but I have not ascertained this with full certainty, as the nuclei were usually not distinct in the specimens examined when treated after NAWASCHIN. In some cases a nucleus seemed to have penelrated from the parasite into the host-plant. As emphasized by SturcH (1924, p. 39), “the cystocarps, antheridia, and tetraspores are invariably developed on separate individuals”. The three kinds of individuals may attain about the same size, in the Danish waters scarcely exceeding 1 mm. arise by oblique alternate divisions of elongated cells composing the outer layer of the external cushion of the male plants (Sturcn 1924, fig. 20). Numerous procarps arise in the female specimens, but one cystocarp only is produced, which occupies most of the cushion. As to the details of the development of the cystocarp, reference may be made to Sturcu’s papers. It shall only be stated that I found a four-celled carpogonial branch in accordance with STURCH. According to STURCH, the cystocarpial wall is composed of branched cell-filaments consisting of fairly short cells. In a cystocarp collected by LIEBMAN December 1838 I found the filaments feebly branched and consisting of long cells (fig. 456). The tetrasporangia are cruciately divided, as shown by Kuckuck and STURCH. In specimens preserved in spirit the nuclei in the dividing sporangia sometimes showed irregular lobed features that may perhaps be due to the imperfect state of preservation (fig. 457). This picture shows, moreover, that the division of the tetrasporangium does not consist in two consecutive bipartitions but that the transverse and the longitudinal divisions proceed almost simultaneously from the periphery towards the centre of the sporangium. Fig. 456. Harveyella mirabilis. Hel- singer, December. Section through the cystocarpial wall; below, cells of the gonimoblast. 350 : 1. The relationship of the genus Harveyella is doubtful. Schmitz (Engler a. Prantl. I. 2, 1897 p. 344) classed it among the Gelidiacew, whilst Srurcx referred it to the Gigartinacee. As emphasized by Kyrın (1923, p. 124) it is not in accordance 497 with the latter family, from which it differs among other things by a four-celled carpogonial filament and by the first gonimoblast-cell being cut off on the outer side of the auxiliary cell. In these characters it agrees better with the Rhodomelacew, but as, on the other hand, it differs very much from this family in the structure of the frond, it seems impossible to refer it to it!. E. CHEMIN in 1927 made the surprising communication that he had obtained the germination of the tetraspores of Harveyella mirabilis on a glass-plate. The ripe spores were without the slightest trace of pigment; they surrounded themselves with a membrane and were divided in 48 hours by successive bipartitions into a paren- chymatous disc much resembling that of Chondrus crispus. The French author remarks that the germinating spore begins to produce phycoérythrine immediately after the fixation on the substratum, and the cellular disc taking its rise from it is coloured intensely red. This very interesting statement is so unexpected that it requires confirmation. If this can be obtained, a relationship with the Rhodome- laceæ is decidedly excluded’. Harveyella mirabilis has been collected in all seasons in nearly all the inner Danish waters, most frequently in spring, always growing on Rhodomela subfusca (incl. R. vir- gata) at 4—26 metres’ depth. Antheridia have been met with in July (Bm and Bb), September (Kn, Lb), October (Ke, Su) and once in January (Kn). Procarp-bearing speci- Fig. 457. Harveyella mirabilis. Tetraspo- rangia in various stages of divi- once in October (Su) and once in April in one specimen sion. 835 : 1. together with tetrasporiferous ones, probably a retarded abortive specimen. Cystocarps were met with in December and January. Tetra- sporiferous cushions were frequently found in April to June, in July once only in the Northern Kattegat, but several specimens at Bornholm, and finally once in Au- gust in the Great Belt and once in October in the Sound. The species is most frequently met with in spring (May) and then always with tetrasporangia. It would be of interest to compare this occurrence with that on other coasts mens may probably be sought in autumn; I met with them 1 It is remarkable that Srurcn in 1924 described another species, H. pachydermus, parasitic on Gracilaria confervoides; it differs by having a two-celled carpogonial branch and by numerous fusions of the ooblastema with cells of the gametophyte. As the number of cells in the carpogonial branch as a rule is a good systematic character, it ought to be examined 1) whether this number is really constant and 2) whether this species is rightly referred to the genus Harveyella. ? To verify the statement of CHEMIN, I searched for specimens with ripe tetrasporangia in May 1929 and in June 1930, but in vain. In June 1930 the season of fructification seemed to be closed for that year, for although I dredged in several places where I- might reasonably expect to find fructiferous specimens of Harveyella, only few specimens were met with and none with well devel- oped ripe tetrasporangia, and the examination of the germination of the spores could not, there- fore, be made. D.K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. 64 498 of North Europe. The cystocarps have everywhere been met with only in winter (Plymouth December to February, west coast of Sweden December (Kyrın), west coast of Holstein December (REINKE), Færûe Islands November (BORGESEN)). The tetrasporangia were met with only in February and March at Plymouth (Srurch). At the Faröe Islands (BorGESEN), in Kristiania Fjord (GRAN) and at the coast of Bohuslän, Sweden (Kyrın) they were met with in April or May, at Helgoland (Kuckuck) at the end of May, at the coast of Halland sparingly in June and July (Kyrın), and at Gotland in the Baltic Sea at the end of June (Svepezius). The sporangia thus generally develop on the North-European coasts in late spring, at Plymouth earlier, and in the inner Danish waters partly a little later (June, July, once in October). In the Arctic Sea, on the other hand, the biology of the species seems to be very different, for in Scoresby Sound (East Greenland) it was found with cystocarps in April and July, while tetrasporiferous plants were not met with at all. Kyrın (1907 p. 128) has emphasized the fact that the tetrasporiferous specimens found in April grew exclusively on branchlets of the host-plant which had devel- oped later than December and concludes that they must have arisen from the carpospores of the specimens occurring in December. It must really be supposed that the species at the coasts of North Europe offers a rare example of a regular alternance of a sexual generation in winter and a tetraspore-generation in spring (or summer), while in the Arctic Sea one sexual generation only is produced. The fact that Harveyella mirabilis has only been observed with tetrasporangia in the inner Baltic Sea (Bornholm, Gotland) must perhaps be explained by the lack of dredgings during the winter in these waters. Localities. Not observed in Ns, Sk and Lf. — Kn: KA, Aalbæk Bugt, 13m (+ 5'); TX, North of Hirsholm, 9m ($ 1); TL, West of N. Ronner, 7.5 m (8 9); FE, Læsø Trindel 9—11 m (+ 7). — Ke: fH, cast of Fladen light-ship, 17 m (8 10). — Ks: OS”, Hastens Grund, 16 m (+ 4): at Hesselo (+5); aU Lumbsaas mill in South 32° West, 13 m. — Sa: KM, east of Oreflippen, 9—17 m (+ 5); DK, Bolsaxen, 13—15 m (+ 5) — Lb: OB, at Stavrshoved, 9—11 m (unripe + 3); DF, Remmen east of Bogø, 5.5 m (+ 5); DE, by the broom at Thoro Rev, 5.5 m (+ 5); dH, east of Hesteskoen, 15 m (+ 6). — Sf: CC, south side of Hornenæs, 7.5 m (8 9); UV, north of Ærø, 13 m (+ 5). — Sb: gy, Mollegrund, 8 m; cL, NE of Sprogø, 25—27 m (+ 6); NN, Sprogø light-house i NE ‘/: E 3'/s miles 19 m (© 1); AB north of Nyborg, 7.5 m (+ 8); Nyborg (Lyngbye); UE, by the buoy of Vresens Puller, 7 m (+5); UF, by Hov Sand, 8.5 m (+ 5); UT, Langelands Belt, 19 m (+5); UJ, near Onsevig, 7.5 m (+ 5); DR, by the broom of Albu Triller, 8.5 m (+ 5). — Su: Off Hellebæk (+ 4); near Helsingør (Liebman), (QC 12); OJ, Nivaa Flak, 6m (+ 4, one sp. with 2); OG, by Taarbæk Rev, 6m (+4); east of Taarbæk Flak 12.5 m (S. Lund, +4 910); Charlottenlund (Hoffmeyer). — Bw: dM, Flensborg Fjord, east of the broom at Krage Sand, 14 m (+ 6); dK, Pols Rev south of Als, 6—7 m (+ 6); UL, Femer- belt, Øjet, 20 m (+ 5). — Bm: VJ, off Hjelm, Møen, 6 m (+5); VG and QS north of Møen (+ 5 and & 7); VD at Bogestremmen, 7.5 m (+ 5). — Bb: Davids Banke, 15 m (4 7), 19—21 m (+ 7); near Salt- hammer Rev, 24.5 m (+ 7). 1 — designates tetrasporangia, d antheridia, ® carpogonia, ©) cystocarps, the number added being the number of the month. 499 Chondrus Stackh. 1. Chondrus erispus (L.) Stackh. Lyngbye, Hydr., 1819, p. 15, tab. 5, A, B; Greville Alg. Brit. 1830, p. 129, pl. 15 (cystocarp); Kützing, Phycol. gen. 1843, p. 398, tab. 73 III; Harvey Phye. Brit. III, 1846, pl. 63; J. Agardh, Sp. g. ord. Vol. Il, I, 1851, p. 246; Kützing, Tab. phyc. Bd. 17, 1867, tab. 49; Schmitz, Befr. d. Florideen 1883, p. 238; Wille, Beitr. 1887, p. 82, Taf. VII, figs. 70—71; Buffham, Notes 1896, p. 183; Darbishire, Chondrus, Liverpool Marine Biology Committee. Memoirs IX. London 1902; Oltmanns, Morph. u. Biol., I, 1904, p. 549; Kylin, Studien 1907, p. 123; id. Keim. ein. Florid., Arkiv för Botanik, Bd. 14, No. 22, 1917, p. 12; id. Entwickl. 1923, p. 19; Violet Grubb, The Male Organs of the Florideæ, Linn. Soc. Journal. Botany, Vol. 47, 1925, pp. 184—187. Fucus erispus Linné Mantissa plant. 1767, p. 134. Fucus polymorphus Lamour. Diss. sur plus. especes de Fucus. I. Agen et Paris 1805. The fronds arise from a flat expanded dise which originates from the primary cushion-shaped stage of the germling, It is in older plants a nearly orbicular rather thin plate with irregularly lobed margin, densely attached to the substratum up to 1 or 2 cm in diameter. Several upright shoots may be given off from the same dise, e. g. 30—40, and these shoots are of very different age, old and young ones inter- mixed without any distinct order, the youngest, however, for the most part at the periphery. The dise itself may attain an age of several years. In specimens collected in summer upright shoots from the foregoing year or per- haps older are found together with numerous shoots produced after the last winter, and the latter have evidently arisen at various times during the last period of vegetation, for all gradations are to be found from well developed repeatedly branched shoots to quite small ones, a few mm long only. Owing to the fact that the upright shoots produced in the last period of growth are in very different stages of development when the growth is arrested in winter, it is not always easy to distinguish the portion of an older shoot which was produced in the last year from that existing already in the foregoing year. A dif- ference in the colour, however, is often very significant, in particular in spring and the first part of the summer, the new portions of the frond showing a brighter colour. But the difference often becomes more striking by the epiphytes cover- ing more or less densely the portion of the frond produced in the foregoing year, whereas the new segments are destitute of epiphytes or bear only very young specimens of such (comp. fig. 458). b> < j | Fig. 458. Chondrus crispus. Northern Kattegat at Læsø Trindel, about 10m depth, July. Photo, nat. size. 64* 500 The upright fronds ordinarily attain an age of two years, and sometimes they continue growing in the third year. This seems to be the case with the specimen represented in fig. 459 which was gathered in May. This frond has probably in the first year produced the first system of fans, in the second year the branches of these have produced a new system of fans, and in the year when the plant was gathered some of the branches have continued growing but have only caused a slight prolongation of the frond, 1 cm at most: the growing power of this frond was evidently exhausted. In the cases where the frond has arisen late in summer and therefore has only a small size at the end of the firstseason, the chance for a considerable growth in ihe third year may probably be greater. The period of growth begins in spring in the Danish waters and ceases towards the end of summer. The old fronds finally decay and are thrown off, pro- bably as a rule in autumn and winter; they are sepa- rated at the very base, leaving scars that are a \ | little deepened and have a slightly elevated border. Fig. 459. An attachment disc, ga- Chondrus crispus. Krageskovs Rev, 4 m, May. The short streaks above indicate th me HR Shoes the limit between the portions of the frond formed in the foregoing and the ered In Spring, SHOWE present year. Photo, 3/, nat. size. some 30 such scars and . a few upright shoots. Ac- cording to Prinrz the growth of the frond begins in Trondhjem Fjord about February and mostly ceases in August and September. The attachment disc has a parenchymatous structure of firm consistence (comp. DARBISHIRE p. 15, figs. 9—11), being built up of approximately quadrangular cells arranged in more or less vertical rows. The height of the cells is rather vari- able, from half to twice the breadth. The cell-walls are firm, not gelatinous, slaining deeply with hematoxylin. The outer wall is very thick, showing a lamellate struc- ture. The pits in the transverse walls are scarcely discernible except in the neigh- bourhood of the upright shoots. A stratification due to the periodical growth of the crust appears in older crusts, but it is rather irregular, probably depending on the production of the upright shoots. The cells are filled with starch grains. The upright fronds arise as outgrowths from the basal disc. A vertical section 501. of the lowermost portion of the frond issuing from the disc shows a marked differ- ence between the frond and the disc. In the neighbourhood the cell-rows of the disc are bent outwards, the cell-walls, which in the normal dise are firm, swell, the intercellular substance becoming much developed and gelatinous, and numerous transverse secondary pits appear between the cells of the originally vertical cell- rows (Fig. 460). These cell-rows gradually pass into the cortical cell-rows of the upright shoot, where the transverse secondary pits are also numerous and very long. These secondary pits enable a more intense longitudinal conductive power between the frond and the disc. The structure of the upright frond has repeatedly been described and pictured (Kürzıng 1843, WILLE, DARBISHIRE, OLTMANNS, KyLın 1923). The tip of the frond has the structure designed by OLTManns as the fountain type (Springbrunnen- typus) (Kyrın 1823, p. 20, fig. 10 a). The medullar or conducting tissue is built up of elongated cells arranged in longitudinal rows, 7—16 x in inner diameter, connected with small pits in the end- walls and here and there also by transverse pils of secondary origin. The longitudinal cell-rows Fig. 460. may be more or less bent, especially in the older ee parts of the frond. WILLE (1887, p. 83) thought shoot; the latter issued to the right. 350: 1. that this might be explained by the supposition that the ends of the long cells slide past each other much as the bast-cells of the Phanerogams. This view, however, cannot be upheld, for the ends of these cells are connected by (primary) pits which persist and do not permit of such a sliding growth. The cells of the outer longitudinal cell-rows are much shorter than the inner ones, and gradually pass into the cortical layer which consists of branched cell-rows that are outward-directed and not unfrequently connected with secondary pits. The inner part of these cell-rows forms the storage Fig. 461. tissue. The last 2 or 3 cells in the cortical cell- Chondrus crispus- Vertical section of the cortex rows are very narrow and contain no starch, at the base of an upright shoot. 560: 1. : whereas the inner cells are more or less filled with starch-grains. For further details of the anatomy and cytology see the authors quoted, in particular DARBISHIRE. According to this author each cell contains only one chromatophore. In the outermost, assimilating cells it forms a plate lining the cell-wall, in the storage-cells the plate is divided into branched ribbons. Ac- Fig. 462. cording to the same author, the conducting cells of the medulla contain several leucoplastids. In 1911 (Hyaline hairs, p. 205) I have ranged this species among those which are devoid of hyaline hairs. I have, however, re- cently found such hairs in tetrasporiferous specimens collected at Hirlshals, Skagerak, in July 1914 and preserved in alcohol. They oc- curred scattered in the upper part of the frond. J The basal portion of the hair-cell is swollen Chondrus crispus. Section of outer cortex of tetra- and sunk in the frond; this swelling is emptied sporiferous specimen showing hyaline hairs. Hirts- when the hair has grown out. but still con- 3 hals, July. 835: 1. tains a thin layer of protoplasm lining the wall. The supporting cell is shorter and thicker than the surrounding cells and richer in contents (Fig. 462). The hairs attained a length of up to 250 w. The three kinds of reproductive organs are produced in separate individuals. The antheridia have been examined by Burr- HAM, DARBISHIRE and more recently by Gruss. DARBISHIRE found them in particular small and narrow white leaves (spermophores), while Miss Gruss describes them as whitish-pink patches or sori on the upper parts of the thallus of an otherwise normal vegetative plant. BUFFHAM and DARBISHIRE found them ripe in September and October, while Gruss found the material examined fully fertile in the spring, and she suggests that there are two seasons of spermatial production, spring and autumn. The outermost cortical cells, according to this author, give rise to two an- theridial mother-cells from which two antheridia spring. For more details see GRUBB’s paper. The procarp was first described by SCHMITZ (1883, p. 238), later by DARBISHIRE and recently by Ky in (1923, p. 20) who also followed the develop- ment of the gonimoblast. The three-celled carpo- Fig. 463. Chondruscrispus. North of Læso,9,5m,January. With cystocarps (above). Photo, */; nat. size. gonial branch is borne on a large cell rich in protoplasm, which is the auxiliary cell.” After * According to DARBISHIRE, the large basal cell has a small cell cut off that is the auxiliary cell, 1. c. p. 28. fertilisation and fusion of the carpogo- nium with the auxiliary cell the latter gives off several sporogenous filaments penetrating between the vegetative cells of the frond and finally forming a large goni- moblast producing numerous carpo- spores. Theripe gonimoblastis composed ofanumber of more or less distinct glome- ruli separated by shrunken hyphe, as shown by Kirzine (Tab. phyc. 17 Tab. 49 b). The whole cystocarp appears as an oblong or round swelling, up to 2 mm long, prominent on one or some- times on both faces of the frond; in the first case the not swollen face of Fig. 464. Chondrus crispus. West side of Hirtshals, low water, July. With cystocarps. Photo, nat. size. the frond may be concave. The cells of the inner layers of the cystocarpial wall are all connected transversally with secondary pits. In the narrow fronds only one rm wa É Fig. 465. Chondrus crispus. Hirtshals, mole, May. With tetrasporangial sori. Photo, nat size. cystocarp is present at the same level (fig. 463); in the broader ones several cystocarps may occur in the same segment (fig. 464), and it then hap- pens that two are contiguous, but the limit be- tween them is always distinct. No opening is pre- formed in the fruit wall but a hole is formed in the middle of the convex fruit wall by disinte- gration of the cells. The tetrasporangial sori appear as dark-red elongated spots, slightly bulging on both faces of the frond, in particular in a dried condition; they are usually smaller, more irregular in out- line and more numerous than the cystocarps and often confluent, and no limit can then be drawn between the fused sori. They occupy the younger portions of the frond, also the adventitious shoots, but may sometimes, in specimens growing near low-water mark, be met with in most parts of the frond (fig. 465). The production of the sporan- gial sori may persist during a long period and the development then proceeds from the base towards the top. Emptied sori may be met with ‘in the middle of the frond or lower, while young sori are still in development at the top. The sporangia arise in branched cell-rows produced by the medullar cells, not only in the end-cells, but also from the intercalary ones. They are cruciately 504 divided, first by a transverse wall, later by two longitudinal ones (fig. 466). In a specimen gathered in the eastern Kattegat in October I met with a sorus containing only two-parted sporangia. Fructification occurs during the greater part of the year at the Danish coasts. Ripe sporangia and cystocarps were met with in all the months of March to October. In the winter months no well developed fructiferous specimens were met with, but some few with emptied cystocarps; but the species has only been gathered in small quantities at this season, and it is highly probable that it will be found fructiferous also in winter, so much the more as it may occur with ripe and partly emptied cystocarps and sporangial sori in March and April. The antheridia will probably be found on our shores at the same season as on the British coasts viz. spring and autumn, and it is probable that the development of the cystocarps usually begins in the autumn; it then continues through the following year. The production of the tetra- sporangia has apparently a similar course. At the west coast of Sweden the fructification seems to take place at the same seasons as at the Danish Fig. 466. coasts (comp. ARESCHOUG Phyceæ, p. 86, Kyrın Chondrus crispus. Tetrasporangia. Hirtshals Ea one Rg 2 ® RØG 1 dtl, 1D Anne la. 1907, p. 123). On the British coasts it has not, ac cording to BATTERS and DARBISHIRE, been recorded with fruit in the summer months, but that is perhaps only accidental, and will probably not be confirmed by further investigation, for it has been gathered with cystocarps at the Ferées in June and September by BORGESEN (Mar. Alg. Fer. 1902, p. 357). According to Printz the cystocarps and the tetrasporangia begin to appear in August and September in Trondhjem Fjord, and the fructification continues during the winter and mostly ceases in early spring; he adds, however, that the species shows great power of variation as to the incidence of fructification. The germination of the tetraspores has been shortly described and illustrated by DARBISHIRE and Kyrın (1917). I have observed the germination of the tetra- spores and the carpospores in summer (July, August); they present the same features. The spore-cell is first divided by a perpendicular wall and then by rather irregularly orientated walls in a number of cells that are much smaller than the spore-cell. The germling is then hemispherical or cushion-shaped with a fairly regular outline, and increases slowly without changing in shape, or it becomes more flat, the vertical radius increasing less than the transverse ones. Sometimes one or two filaments are given off from the border; these filaments consist of a single cell-row rarely divided by a longitudinal wall (fig. 467, comp. DARBISHIRE, fig. 29, Kyrın, figs.g—i). Most of the sporelings in my cultures, however, were without such filaments. When two sporelings are developing close together, they may fuse together without any distinct limit. The oldest germlings in my cultures, 24 days old, showed no upright shoots. The young plants arising from germinating spores in summer probably only attain a small size before the following winter. The variability of Chondrus crispus is well known, but it is impossible to draw any distinct limits between the numerous forms that may be met with. The most frequent and characteristic forms in the Danish waters are here recorded. A. Forms occurring near low- water mark, down to 2 or 3 metres’ depth. The uppermost specimens growing on stony reefs or moles left dry at low- water. Frond proportionally broad. F. typica. The most common form near low-water mark. Frond regularly dichotomously divided, sometimes with proliferations, up to 14 (18) cm long, 6—10 mm broad, deep brown-red with a blue lustre. (LyNGBYE Tent. Tab. V A, Lamourovx, figs. 2—5, 8). The best devel- oped specimens were found at Hirtshals, Skagerak, where the fronds are usually regularly flabellate and broad without proliferations (figs. 464, 465). 505 Fig. 467. Chondrus crispus. Germination, A—D, germinating carpo- spores, 6 days old (*1/,—°/; 1928). E, germling from carpo- spore /; / 1914. F, G, germlings from tetraspores, Hirts- hals °/,—*/, 1914. 625 : 1 F. abbreviata K3ELLMAN. KYLiN 1907. Only different from the foregoing by smaller dimensions. Frond up to 9 (13) cm long, up to 4 (6) mm broad. Same Fig. 468. Chondrus crispus f. densa. Shal- low water. Frederikshavn, July. Photo, nat. size. occurrence as the foregoing, in particular in the inner waters, on moles and stony reefs. F. densa. The frond short, broad, much branched, often taking a nearly globular form. The ramification may be apical (fig. 468) or, more frequently, chiefly marginal; in the latter case the frond is very broad and bears a very great number of longer or shorter, branched or unbranched marginal shoots. The number of branches and. shoots is so great that the tips of the shoots point in all directions in the globular forms (fig. 468). This form grows on stones in shallow water protected against the waves, for instance at Frederikshavn at the north-side of the harbour. A less dense form with num- erous proliferations is depicted in Flora Danica under the name of Ch. crispus var. ciliatus Suhr. It seems to be common at the isle of FönHr at the west coast of Slesvig, and has also been col- lected at Blaavandshuk. (Specimens with numerous narrow branches or proli- ferations at the upper margin of a short broad thallus may be named f. siellata D.K. D. Vidensk. Selsk. Skr.,7. Række, naturvidensk. ogmathem. Afd.,VII, 4. bo Fig. 469. Chondrus crispus, f. densa (ciliata Suhr). Shallow water, Frederikshavn, July. With tetrasporangial sori. Photo, nat. size. 506 Sracku., LYNGBYE). Similar specimens have been met with in shallow, protected water at Frederikshavn (fig. 469). B. The specimens growingatgreater depths, more than 3 metres, are less variable than those growing near low-water mark. They are proportionally narrow, being usually at most 2—4 mm broad, and fairly long, up to 16 cm. Proliferations do not usually oceur. The colour is more reddish. F. @qualis Lynes., Tent. Tab. 5 B, Lamour., figs. 12, 16, 22, ARESCHOUG Exsicc. no. 156. Figs. 458, 463. Most of the specimens from deeper water may be referred to this form, characterized by the frond having al- most a uniform breadth. The specimens from the greatest depths (13—20 m) are thinner but not otherwise different; they might be named f. membranacea. F. polychotoma KJELLMAN, KyLiN 1907, p- 123, Lamouroux tab. XII, figs. 31, 32. This form is represented by two year old fronds, with numerous branches in the upper part of the frond. Two systems of fan- shaped ramifications from two consecutive years may be found (fig. 459). C. Specimens lying loose on the bottom. Fronds disengaged from the attach- ment disc may maintain life in the loose condition for a shorter or longer time. Such specimens may keep the original form for some time (usually f. equalis); but upon conti- nued life in a loose condition the shape of the frond becomes altered. The specimens that have lived for some length of time lying loose on the bottom and are carried along by the currents often show a swelling at the lower end where they have been loosened, like a feeble callus disc (fig. 470). The loose specimens are always sterile. They are only met with in sheltered localities in the inner waters. F. incurvata LYNG8., Tent. p.16; Chondrus incurvatus KÜTZING, Sp. Alg. p. 735, Phyc. gener. p. 399, Taf. 73 IL, Tab. phyc. Bd.17, tab. 50 ec, d. r Fig. 470. Chondrus crispus, f. incurvata. Off Vesterskovs Flak, north of Falster, 7,5 m. Photo, nat. size. _ EU Frond long, up to 20 cm, narrow, subterete, some- times with proliferations, variously curved, often to one side. This is the most common loose form met with repeatedly at Hofmansgave (North Fyn) and further in Sb, Sf and Sm. Fig. 470, 471. F. uncinata LyNGB. Tent. p. 16. Frond small, cartilaginous, linear, cylindrical, complanated only at the bifurcations, at the ends recurved like the horns of a ram. This very characteristic form has only been found very rarely at Hofmansgave. It is so different from the typical form that an anatomical examination is needed for the identification (fig. 472). F. egagropila. A much branched specimen forming an irregularly rounded clump was found lying loose on the muddy bottom in shallow sheltered water at Frederikshavn in company with f. densa. The base was not visible, it was hidden in the interior of the clump the surface of which consisted on all sides of the irregularly outward Fig. 471. Chondrus crispus, f. incurvala. At Hof- mansgave (Hofman Bang). Photo, ?/, n.s. directed ends of the shoots (fig. 473). In the North Sea and Skagerak Chondrus crispus thrives only near land from a little over low-water mark to 2 metres’ depth and only where the coast is stony, Fig. 472. Chondrus crispus f. uncinata. Hofmans- gave, Car. Rosenberg. Photo, nat. size. and the same can be said of its occurrence in the Limfjord. In the other waters within Skagen it oc- curs most frequently in similar localities (f. fypica and abbreviata), but it also grows at greater depths among other Algæ on stones, down to 15 m, more rarely to 20 metres’ depth. The boundary for its en- trance into the Baltic is at Kriegers Flak and Salt- holm, but in the most southerly part of its area it has only been met with at greater depths. At a higher level, near low-water mark, the southern boundary is more northerly, undoubtedly owing to the lower salinity of the surface water. In the Little Belt the southernmost locality known is at Sonder- balle Hoved, at 2 metres’ depth, but the specimens were very small, only 1—1,5 cm high. In the Great Belt it has not been met with near low-water mark south of Nyborg harbour, and in the Sound it has not been met with at this level south of Helsingborg. Chondrus crispus always grows on stones. Once only have I met with a small specimen growing on the stipe of Laminaria hyperborea in the Skagerak. It is often 65* much overgrown by epi- phytes, especially in Ska- gerak and Kattegat. The older parts of the frond may be totally covered by Bryozoans of the genus Membranipora, and in- crusting Algæ as Epili- thon membranaceum and Melobesia limitata may appear in the same way in the Kattegat, and further a number of other Algæ frequently occur as epiphytes, such as Sphacelaria cirrosa, Ceramia, Polysiphonie, Brongniartella byssoides, germlings of Furcellaria fastigiata a. o. At the coasts of the North Sea, Skagerak and the northern Katlegat the specimens of Chondrus growing in shallow water (1—2 metres’, more rarely at 5,5 metres’ depth) are often infested with the parasitic Pyrenomycete Didymospheria marina (Rostr.) Linp, Danish Fungi as repr. in the herb. of E. Rostrup, 1913, p. 214 (Leptosphæria marina RosTR.), that gives to the sporangial sori and cystocarps a black colour and develops perithecia and pycnidia there. Another parasitic Fungus of the class Phycomycetes, Pleotra- chelus pollagaster HENN. PETERSEN (Phycomycètes marins. Oversigt oy. d. K. D. Vid. Selsk. Forh. 1905), has repeatedly been found infesting the upper portion of fronds of Chondrus crispus growing at various depths in Kattegat and the inner waters. Fig. 473. Chondrus crispus f. ægagropila. Shallow water, Frederikshavn. Photo, nat. size. Localities: Ns: Esbjerg harbour on muddy bottom with Zostera vegetation, f. ciliata; Blaa- vandshuk washed ashore, various forms, f. equalis, f. ciliata, f. incurvata; Thyborøn, on a groin; Klit- møller, within @rhage. — Sk: Hanstholm, Roshage 2 m, mole; Torup Strand, washed ashore (C. M. Poulsen) ; ZK? off Lønstrup, 8—9 m; Hirtshals, on the mole and on boulders, down to 2 m depth; Skagen, washed ashore on the North beach. — Lf: Common near low-water mark: Lemvig harbour; Mulle (J. P. Jacobsen); Thisted; Struer; Nykøbing, harbour and Orodde; Ejerslev Ron; Knudshoved, Fur; off Lisehoj North side of Fur; Løgstør; Agersund (Th. Mortensen); Aalborg, large, very broad specimens with numerous proliferations (Th. Mort.); Hals (Borgesen). — Kn: Skagen harbour; Krageskov Rev; Hirsholmene; reefs and harbour at Frederikshavn; Bangsbostrand; Sæby; several places around Læsø Trindel, 8—19 m; several places North of Læsø; Vesterø. — Ke: IO, ZE, ZG, fH, Fladen, 11—17 m; Lille Middelgrund, 17—19 m; ES, S.W. of Lille Middelgr., 24.5 m; Store Middelgrund, 10—15 m; Gille- leje (Lyngbye); GJ, OO and Vesterlandsgrund north of Gilleleje. — Km: ZC, ZC’ and XB, Kobber- 509 grund; Asaa, mole; Anholt harbour; Gerrild bay (Lyngbye). — Ks: Grenaa harbour; at Hesselo (Lyngbye); RL near Ostindiefarer Grund; aU off Lumbsaas 13 m; Hastens Grund; GG Sjællands Rev; Holbæk harbour; on stones picked up near Roskilde. — Sa: Common on stony ground in 0 to 15 m depth, from KM, east of Oreflippen and the channel east of Sejro to Endelave and DJ North of Fyn. Several specimens of f. incurvala from Hofmansgave (Hofm. Bang, Lyngbye). — Lb: Bogense harbour; Prins Frederiks Grund, Vejlefjord; FZ, Kasserodde; Fredericia harbour; Middelfart, harbour and 15 m; Assens harbour; at Sonderballe Hoved 2 m, 1—1.5 em long specimens. — Sf: Faaborg harbour; UX at the North end of Ærø 9.5 m; CG, Skrams Flak, f. incurvata, loose. — Sb: Off Refsnæs (C. H. Ostenfeld); Kalundborg harbour; gU, east of Lille Grund 10—12 m; Elefantgrund 6—7 m; LP, Stavreshoved, 2—4 m; Kerteminde harbour; bay of Kerteminde; GY and fZ at Sprogo; AB off Teglgaardsskov; Knuds- hoved 5—6 m; Nyborg harbour; Palegrund 7,5 m; XS near Kloverhage; GZ North of Egholm 6,5 m; DN Vengeance Grund 12m; gB, Vresens Puller; gE, Stokkebæks Flak 6 m, f.incurvala; fS, east of Kjelsnor ligthouse, 11.5 m. — Sm: Q, off Vesterskovs Flak, 7.5 m, f.incurvata. — Su: Off Ellekilde and Hellebæk (@Orsted,!); washed ashore at Helsingør (Liebman a. 0.); PX, off Tibberup, 8.5 m, with Zostera; TF", Staffans Flak, 12—13 m; QD, east of the North end of Saltholm. — Bw: bY, off Sonder- borg Nordskov, 11 m, f. incurvata; Sønderborg (Frölich according to Reinke); UL, Øjet, 20 m, attached to the bottom. — Bm: bP, Kriegers Flak, 15 m (O. Paulsen). Gigartina Stackh. 1. Gigartina mamillosa (Good. et Woodw.) J. Agardh. J. Agardh, Alg. mar. mediterr. p. 104 (1842); Sp. g. ord. Alg. Vol. II, pars. 1, p. 273, 1851; Harvey, Phye. Brit. Vol. II, 1849, pl. 199; Buffham 1896, p. 84, plate X, figs. 4—8; Oltmanns, Morph. u. Biol. I, 1904, p. 547. fig. 331. Fucus stellatus Stackhouse in Withering, Bot. Arr. ed. 3, vol. IV, p. 99, excl. syn. omn. (1796), sec. Batters. (Not seen by the author). Fucus mamillosus Good. et Woodw., Trans. Linn. Soc. Vol. III, 1797, p. 174. Spherococcus mamillosus Agardh, Synops. Alg. scand. 1817, p. 25; Lyngbye Tent. 1819, p. 14, tab. 5 C; Flora Danica tab. 2011, Hornemann 1830 (from the Færûes). Mastocarpus mamillosus Kützing, Phycol. gener. 1843, p. 398, Tab. 76 III, Tab. phycol. XVII, pl. 39, 1867. Gigartina stellata Batters Catal. of the Brit. Marine Algæ. Suppl. to the ‘Journ. of Botany’ 1902, p. 64. This Alga reminds one in habit of Chondrus crispus, a tuft of upright fronds of a similar shape as in this species springing from a flat disc. The latter is composed of densely united vertical cell-rows and shows seyeral transverse lines indicating a periodical growth. The upright fronds are placed closely together; they are more or less canaliculate and bear numerous papille on one or on both faces. The papillae seem to: arise in spring (comp. 476 B). The upright fronds haye a cortex built up of outward directed cell-rows con- sisting of small oblong cells becoming smaller towards the surface, the outermost being only 2 w thick. The number of cells in these rows may be 7—10. Within this dense assimilating cortex a few layers of somewhat larger almost isodiametrical cells form an inner cortex. These cells are more distant from each other, being separated by a hyaline intercellular substance, and are connected with primary and secondary pits (fig. 474,475 A). They pass into the inner medullar cells which in a transyerse section show almost the same aspect being only somewhat larger and aller still more distant from each other, while in longitudinal section they appear as long cells having their long axis parallel to the longitudinal axis of the frond. The ES HY ets: LP ap ape © Se FR & æ o EP CB > Ze 2 PE æ Ba, Fig. 474. Gigarlina mamillosa. Transverse section of frond. 560: 1. cells of the inner cortex and of the medullar tissue may produce long thin cell-filaments consisting of long cells, which grow out in a transverse direction downwards between the primary cell-rows and may be con- nected with these through second- ary pits (fig. 475). The sex organs have not been observed by me. The an- theridia were described by Burr- HAM in 1896. The male plant, according to this author, differs much from the female one, “for sometimes it is thickly beset from near the base with flattened leaf-like branches arising just within the edges of the main portions of the frond, and with smaller ones from Fig. 475. Gigartina mamillosa. A, longitudinal section of frond. 560:1. B, longitudinal section of medullar tissue. 350 : 1. the other portions of the thallus”. In some of these leaf-like branches the an- theridia appear. The male plant was found in September; BORGESEN found antheridia bit in June at the Farôes (M. A. Fær. 1902, p. 357). The cystocarps arise in the papillæ covering the flat frond. The procarps seem not to have been described; I have nol observed them, perhaps owing to the fact that I haye only examined specimens gathered in late summer (August, September). Ripe and partly emplied cystocarps were met with in August. According to the authors (J. AGARDH, Scumirz and Haupr- FLEISCH, SJOSTEDT), the gonimoblast is surrounded in the genus Gigarlina by an inner pericarp of medullary hyphæ. This pericarp, however, is not represented, or only feebly developed in Kürzıng’s figures of this species (1843 and 1867) and I have not observed it on the outside of the gonimoblast. As shown by KürziNG (1867), transverse secondary pits are very well developed in the inner part of the cystocarpial wall exactly corresponding to the inner cortical layer of the frond. Ripe and partly emptied cystocarps were met with at Thisted in August. Tetra- sporangia are unknown. As they have been searched for by several phycologists, it seems most probable that they are really wanting. On the other hand one might imagine that they do occur in the papillæ, just like the cystocarps, and that the sori of tetrasporangia might have been confounded with the cystocarps, as has been the case repeatedly with Chondrus crispus. Gigartina mamillosa has up to 1929 only been found in two localities at the shores of Denmark, namely at Thisted in the Limfjord and at Aarhus on the east coast of Jutland, in both places growing on moles of the harbour or on stony slopes near the harbour. As shown in an earlier paper’, it must be supposed that it has been introduced into both localities by vessels. As to Thisted, where the species was first found by J. P. JACOBSEN in 1869, this conclusion is almost certainly correct 1) since the salinity of the Limfjord before 1825, when the isthmus separating the fjord from the North Sea was broken through, was so slight that is was impossible for G. mamillosa to thrive here, 2) since the species has not been found elsewhere in the Limfjord and 3) since the part of the fjord (Thisted Bredning) where Thisted is situated is connected with the other parts of the fjord only by narrow channels with Zostera vegetation. The average salinity in the western part of the Limfjord is now 29 p.m. At Aarhus the species was found on a stony slope north of the harbour in 1911 or 1912. One might imagine that it might here be a relict from a time when the salinity was higher than now, when it varies probably about 20 p.m.; but that is quite improbable as the species has never been found else- where in similar localities in the Samsø waters or in Kattegat (except Skagen). It is therefore highly probable that the species has been introduced to this much frequented harbour by a vessel. Gigartina mamillosa grows at low-water mark, at Thisted under the Porphyra- belt, over the Fucus vesiculosus-belt or partially in the upper part of this. It thrives well at Thisted, where it reaches a length of 5—8 cm, whereas at Aarhus it be- 1 Om nogle i nyere Tid indvandr. Havalger i de danske Farvande. Botan. Tidsskr. Bd. 37, 1921, p. 126 and 133 (English abstract). 512 comes only 3—5 cm high, undoubtedly owing to the slighter salinity; here, how- ever, it still produces ripe cystocarps. In May 1929 I found G. mamillosa in the harbour of Skagen forming a conti- nuous vegetation in the lover part of the tidal region and below the low-water mark. It was very well developed, reaching a length of 8,5 cm. There was a remark- able difference between the specimens growing over | and below the low-water mark; the latter were broad, A B Fig. 476. Gigartina mamillosa. Harbour of Skagen. A in the littoral zone, B at low-water mark. Photo, */, nat. size. of a proportionally bright colour, without or only with very feeble papillæ appearing as low warts, whereas the littoral specimens were much darker, nearly black, and bearing numerous long, partly branched papillæ, mostly near the border (fig. 476). The sublittoral specimens were perhaps a year younger than the littoral ones. Localities. Lf: Thisted, first discovered by J. P. Jacobsen in August 1869, later found by me in Sept. 1890 and August 1893; it grew on the moles and on a stony slope east of the harbour. — Kn: Skagen, harbour, discovered May 1929. (The harbour was built in 1904—1907). — Sa: Aarhus, discovered in 1911 or 1912 by V.Petersson on a stony slope at the bathing-place “Kattegat” north of the harbour. I found it in 1917 and 1927 in the same place and on the outer side of the North mole, but it did not grow on the southern mole (at least 20 years old). Phyllophora Greville. 1. Phyllophora membranifolia (G. & W.) J. Agardh. J. Agardh, Alg. maris medit. (1842) p. 93; Harvey, Phyc. Brit. Vol. II (1849) pl. 163; J. Agardh, Sp. g. o. Vol. II, p. 1 (1851), p. 334; Wille, Bidrag (1885) p. 17, 32, 42, 65, 68, Tab. V, figs. 57, 58; Wille, Beiträge (1887), p. 79, Tab. VII, fig. 65; Buffham, Repr. Org. (1891), p. 248, PI. 16 figs. 10—13 (antheridia); 513 B. Jönsson (1891, p. 19); Schmitz, Actinococcus (1893), p. 367; Darbishire (1895) pp. 5, 10, 20, 27, 31, 34; Kylin, Entwick. Florideenstud. (1928) p. 54, fig. 33. Fucus membranifolius Good. et Woodw., Trans. Lin. Soc. III (1797), p. 120, pl. 16, fig. 1, 2. 5 Fucus crispatus Fl. Dan. tab. 826, fig. 1 (1778). Fucus rubens Fl. Dan. tab. 827, fig. 1 (1778). Spherococcus membranifolius C. Agardh Sy nops. Alg. scand. (1817), p. 26; Lyngbye Tent., p. 10, tab. 3C. Spherococcus Palmetta Lyngbye 1819, p. 11 ex parte. Phyllotylus membranifolius Kützing, (1869) Taf. 75 (c. nemathec.). Phyc. gener. (1843) p. 412, Taf. 62 I (cystoc.), Tab. phyc. XIX The shoots arise in various number from an expanded basal disc, of a similar structure to that in Ph. Brodici (comp. DARBISHIRE |]. c.). It has a very thick outer wall and is built up of densely united vertical rows of cells that are square or higher or lower than broad; the uppermost cells are usually low. The cells contain numerous grains of floridean starch that are stained blue by iodine. The outermost cells, however, contain no starch grains but similar refractive bodies that do not stain with iodine. They give no reaction with osmic acid, and take a feeble red colour with hæma- A B Fig. 477. Phyllophora membranifolia. Small specimens with short stipe Sallingsund, Limfjorden. July. Photo, nat. size. toxylin (Hansen), while the starch grains remain quite colourless. By treatment Fig. 478. Phyllophora membranifolia. Groves eastern Kattegat, April. Photo, */, Flak, n.s. D.K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. with caustic potash they swell somewhat and become less refractive; by the following washing out in water and treatment with iodine they stain feebly yellow; they give no reaction with bichro- mate of potassium nor with nitric acid and with ammonia after treatment with nitric acid. Their chemical quality thus remains unknown. The young shoots that may be met with in summer on the vertical faces of boulders and which have arisen after the last winter, have often a very short terete stipe while the flat part of the frond is broad and repeatedly bifur- cate, and this is especially so in the first erect shoot of young plants; a lateral shoot then often arises from the short stipe (fig. 477 A). In other cases the stipe is long, in particular in older plants, where it may be 4—5 cm or longer. At the end of the first period of vegetation the frond has thus the shape of a well deyeloped fan 66 514 Fig. 479. Fig. 480. Phyllophora membranifolia. Fladen, eastern Phyllophora membranifolia. Limfjorden, at Jegindø. Kattegat. May. Photo, “/; n.s. July. Photo, ‘/; n.s. at the end of a cylindrical stipe. The fan is not plane but convex, turning the convex face upwards, towards the light. The growth of the particular segments of the frond may continue in the be- ginning of the next season (fig. 478), and the primary fan may thus be divided into secondary ones. But all the segments of the frond do not keep the growing power; several of them definitively cease growing at the end of the season, and, at least in older fronds, this may be the case with all the segments of a fan (fig. 479, the lowermost fans). In such cases the renewal of the fronds takes place only by proliferations arising from the cylindrical part or from the lower part of the flat frond. In the plant shown in fig. 478, gathered at the end of April, the difference in colour, and the absence of epiphytes characterized the new-formed portions of the frond. The proliferations arise as long cylindrical outgrowths that later become flattened and forked above. When given off from the flat frond they are usually placed on the border, but they may also frequently arise from the flat surface of the frond. These proliferations give rise to normal fan-shaped shoots that, however, only reach their full fan-shape in the season following their first appearance. Cylindrical proliferations without a blade are frequently met with in summer and autumn (fig. 480, 481). The production of proliferations may be repeated in the new-formed shoots, and 3 (or 4) generations of shoots are therefore easily recognized in the ordinary plants. In full-grown plants collected in summer, the fan-shaped frond from the foregoing year is fully preserved even when its growth has quite ceased (fig. 479), while the flat portion of the foregoing generation is often decayed; only a narrow strip connecting the base of the new shoot with the eylindrical part of the foregoing is kept and strengthened by secondary corti- cal layers. The named 3 (or 4) generations of shoots undoubt- edly represent an equal number of years, and it must there- fore be supposed that the up- right shoots normally reach an age of at least three years. In the plant represented in fig. 488, gathered in April 1906, the first generation is represented by the short stem having a nearly horizontal direction, the second reaches the middle of the picture. The next generation (of 1905) is represented by two long shoots bearing cystocarps on the margin; the lowermost portions of these shoots, covered with Membranipora pilosa, were probably produced already in 1904. On the margins of these shoots a number of narrow proliferations are seen; it is however doubtful whether they I would have been able to pro- duce new fan-shaped segments. Red a. Phyllophora membranifolia. Store Bell, At Kloverhage south of Nyborg, When more than three genera- October. Photo, ‘/; n.s. tions of shoots are produced, a greater total length of the plant is scarcely obtained; the new shoots do not usually overreach those of the third generation. New shoots may, however, arise from older portions of the upright shoots and from the basal disc, and the plants may thus become several years old. The length of the shoots produced in a year is rather variable, varying from a few to 10 cm, and there seem to be no great differences between plants from the different waters in this respect. Only in the true Baltic Sea is it less, scarcely exceeding 5 cm, and at Bornholm 3.5 cm. On the other hand, the total length of 66* the plants exhibits consider- able differences. The maxi- mal total length observed in the North Sea and Skage- rak is only 12 cm while in the Limfjord and most of the other inner waters it is usually 18 cm, and greater maximal lengths are obser- ved in Eastern Kattegat (24 cm), the Little Belt (23 cm), Ole D Fig. 482. the Great Belt (28cm) and the OS Phyllophora membranifolia. A, cortical : € cells, transverse section of frond. B, me- western Baltic Sea (21 cm). Fig. 483. dullar cell. 840 : 1. Only in the true Baltic is the Phyllophora membranifolia. Hya- La i line hairs on carpophores. Prins maximal length much less, Frederiks Grund, Vejle Fjord. Bm (12 cm) and Bb (5.5cm). The specimens occurring in Sb are 835 : 1. often very long and narrow with fairly slender stems (fig. 481). The anatomical structure of the thallus has been treated at length by Darsi- SHIRE, Whose description (1895) may here be referred to. WILLE has pictured a longitudinal section of the end of a frond showing the structure of the “Spring- brunnentypus” (1887, pl. 5, fig. 65). The cortical cells contain, according to DARBISHIRE, each one chromatophore that may easily be observed in the outermost cells where it lines the outer and lateral walls. In the inner cortical cells it is much branched and appears as much bent ribbons that perhaps partly are sepa- rate chromatophores. In the inner cells a great number of rod-shaped or ribbon-like plastids are present which stain intensively with hematoxylin. A single nucleus in the vegetative cells may also be ascertained by this reagent (fig. 482). Hyaline hairs have only been observed in carpophores from a specimen gathered in Vejle Fjord in August (fig. 483). Secondary pits are produced in consider- able number between the elongated cells of Fig. 484. the medullary tissue with the effect that Phyllophora membranifolia, Longitudinal section of several pits are to be found in the same wall medullar cells Dreh Pi pits. (fig. 484). A plug Re Gale de geen fim the middle of each pit. As shown by Jønsson (1891, p. 19) and DARBISHIRE (1895), the lower portion of the stem has a thick cortex produced by secondary growth in thickness. The 517 layers are, however, not regularly concentrical, the separate layers not usually continuing round the stem, for which reason the number of layers may be much greater on one side than on the other. The boundary of a layer may meet that of the fore- going layer or it may gradually disappear (fig. 485). The antheridia are produced in particular yellowish or nearly colourless folioles borne on the border of the upper part of the flat fronds of the male plants. The androphores are up to 2 mm long, totally covered with spermatia- producing cells, sometimes with the exception of the outmost tip that remains sterile. The antheridia were first described by BurrHam (1891), later by DARBISHIRE (1895, p.30) who showed that the spermatia are produced in conceptacles that are provided with an orifice in the roof. Kyrın (1928, p. 54) did not observe these orifices, but Fig. 485. Phyllophora membranifolia. Transverse section of stem near the base. 86: 1. I can confirm their existence; they arise by dissolution of a distinct area of the on the margin of the flat frond at a considerable distance from Fig. 486. Phyllophora mem- branifolia. Male the cylindrical base. The carpo- plant with andro- phores. Nat. size, Pores arise in July. The carpo- gonial branch is three-celled (comp. SCHMITZ u. HAUPTFLEISCH p. 253, KYLIN 1928, p. 55, K. RosENVINGE 1929, p. 12"). Fig. 491 shows carpogonial branches isolated by outer wall. I found the conceptacles close together, not separated by sterile cells (fig. 487). The spermatia are about 6 w long, 3 w broad. Antheridia were observed from June to October. The procarps arise in considerable number in particular oblong or nearly globular short-stalked carpophores borne on the upper part of the cylindrical and the lower part of the flat thallus of the female plants (fig. 488). In the latter case the carpophores are mostly placed on the border but often on the flat side too. In a short-stemmed specimen from the North-Sea (fig. 490) the carpophores were borne pressure and separated from the supporting cell Fig. 487. which later functions as auxiliary cell. The Phyllophora membranifolia. Transverse section of ins 3 4 androphore showing fourantheridial crypts. 625 : 1. carposonium gives off downwards a prolonga- fo) Oo Oo tion that is connected with the second cell of the carpogonial branch through a lateral ! According to DARBISHIRE 1895, p. 31 the carpogonial branch is four-celled; the first cell, how- ever, does not belong to the carpogonial branch but is the supporting cell, the later auxiliary cell. Fig. 488. Phyllophora membranifolia. Specimen with ripe cystocarps. Hirtshals, April. 4/; n.s. 518 pit. The continuity of the protoplasm of the pro- longation with that of the carpogonium was in all cases interrupted. The pit connection of the second cell with the first cell of the carpogonial branch is situated at the lower end ofthe second cell. Abranch is frequently given off from the first cell; in fig. 491 G it has produced a com- plex of 7 cells. In fig. 492 similar stages are shown from sections through car- pophores; the carpogonial branch is here seen borne on the auxiliary cell (a). In fig. 492 B a vegetative branch is given off from the auxiliary cell besides the carpogonial one, and Fig. 489. Phyllophora membranifolia. Spe- cimen with nemathecia. Veno Bugt, Limfjord. September. */, n.s. this appears to be frequently the case (comp. Kyrın 1928, p. 55). In fig. 492 D the auxiliary cell has given off a prolongation apparently functioning by the transfer of the sporogenous nucleus. It appears that a great number of the procarps in a + Fig. 490. Phyllophora membranifolia. Plant with short stem bearing carpophores on the border of the flat branched frond. North Sea, off Agger, 24 m, October. */; n.s. carpophore do not reach normal development (fig. 493 A,B); in many carpophores only few carpogonia are to be found, though there may be numerous supporting cells, but many of these bear only incompletely developed carpogonial branches or even no fertile branches at all. To begin with the auxiliary cell contains one nucleus. In fig. 493 C is shown an auxiliary cell containing several small nuclei and four small protuberances at the lower face. It must be supposed that a sporogenous nucleus has entered into the cell, though a normal carpogonial branch could not be observed in this case. At all events the protuberances may be interpreted as the first stage of the gonimoblast. A similar stage is shown in fig. 494 A where a connection of the auxiliary cell with a normal carpogonial branch is not longer Fig. 491. Phyllophora membranifolia. Carpogonial branches isolated by pressure, August. D, the same branch as C seen from another side. F the same branch as E. G, carpogonial branch in connection with the auxiliary cell. 390 : 1. visible either. Later stages are shown in fig.494 B—D, where the gonimoblast has arisen as several outgrowths from the lower and lateral sides of the auxiliary cell. The long cell or cell-complex at the upper face of the auxiliary cell probably derives from the carpogonial branch. It must be admitted that the fertilisation and the connection of the auxiliary cell with the carpogonium has not been ascertained. As to the first point reference may, however, be made to fig. 491 A where a pit in the wall of the trichogyne is undoubtedly the trace of a fusion with a spermatium. Kyrın (1928, p. 54) has emphasized the accord- ance that exists in several respects between this species and Stenogramme interrupta; the develop- ment of the gonimoblast here pointed out is in good agreement with this conception. The carpo- gonium reminds one of that in Jridwa cordata Fig. 492. Fig. 493. Phyllophora membranifolia Procarps from transverse sections Phyllophora membranifolia. À and B, supporting of carpophores. In B—D the lower portion of the carpogo- cells with apparently not normally developed nium is hidden behind the second cell of the carpogonial carpogonial branches. C, auxiliary cell con- branch. In D the auxiliary cell has given off a prolongation taining several nuclei and producing four pro- towards the lower end of the carpogonium. A, B, Hanstholm, tuberances at the lower face. A 6235 :1. B,C August. C, D Gilleleje, September. 390 : 1. 390 : 1. (Kyun l.c. p.47), being in both cases inserted laterally on the second cell of the carpogonial branch. The gonimoblast filaments penetrate into the medullary tissue of cells rich in Floridean starch and produce numerous small carpospores. In the ripe cystocarps cell filaments consisting of long narrow cells are Fig. 494. seen traversing the Phyllophora membranifolia. Auxiliary cells producing gonimoblast filaments in various mass of carpospores stages of development. B—D isolated by squeezing. 390 : 1. (fig. 495, comp. KyLın 1928, fig. 33 B). The cystocarps ripen in winter; they may still be met with in March to May, more or less empty. The nemathecia arise in July, sometimes already in June (Lf, Lb) as deep-red wedge-shaped spots on both faces of the lower part of the flat frond (fig. 489). They are built up of parallel filaments, the cells of which develop slowly into tetrasporangia except the outermost cells (comp. Darsi- SHIRE 1895, p. 27). The division takes place in winter (De- cember, January); in October I always found them undi- vided. The sporangium is first divided by a transverse wall, afterwards by two vertical walls perpendicular to the first. Phyllophora membranifolia occurs in all the Danish waters, from low-water mark or a little lower to at least 20 metres’ depth. The greatest observed depths are 41 m (Ns) and 25.5 m (Ke). It grows on stones, in particular on the sides of boulders, more rarely on shells (Astarte). As mentioned above, it only attains a small size in the Baltic Sea proper (east of Gedser), and around Bornholm it is dwarfish, at most 5.5 cm in height (fig. 496); the specimens from this section of the Baltic were all sterile though they were collected in July, August (mostly) and November. The species has otherwise been recorded in the Batic Sea from Gotland Fig. 495. (Krox, SvVEDELIUS) and from the east coasts of Smäland Phyllophora membranifolia. Portion à 2 å of a transverse seclion of a ripe cysto- and Skåne, but also here it was always sterile. LAKOWITZ carp. November. 390 : 1. did not meet with it in the Bay of Danzig. The species may be met with lying loose on the bottom in the inner Danish waters, but it is much less common in this state than Ph. Brodiei and the loose specimens areslightly differ- ent from the normal ones. Localities. Ns: Jydske Rev ZQ, 24.5 m, several typical specimens but much overgrown with Hydroids and Bryozoa; eD, 41 m; aF, 31 m; eP, 24 m, (fig. 490); eQ, 27 m; eR, 27 m; eT, 34m; XR, off Örhage 5.5—13 m, small spec. In all localities except ZQ and aF only few and small specimens were met with. — Sk: Hanstholm, off Helshage, 5—13 m, on limestone, and off Roshage; eX north of Bragerne 16m; eY, 15 m; YM, YN’, Bragerne 2—10 m; Dana St. 2899, 14 m; SZ off Lokken 11 m; off Lonstrup, 7.3—13 m; Hirtshals, mole, Mollegrund 11—15 m and reef at Kjul, 5.5 m. — Lf: Nissum Bredning, XV Ronnen at Lemvig, ZY within Mullerne, 4.5 m; I, Vene Bugt; XT south of Jegind ©, 6 m; MY Thisted Bredning; Sallingsund; Logster Bredning, Ejerslev Næse, Ejerslev Ron, off Fegge Klit, Amtoft Rev, Len- drup Ren. — Kn: Common everywhere on stony ground from Herthas Flak, 20—22 m, on the stony reefs from 1 m’s depth. — Ke: Fladen, 16—18 m; Groves Flak, 19 m (F. Borgesen); Store Middelgrund, 25,5 m; Soborghoved Grund (00); Vesterlands Grund; Gilleleje harbour. — Km: Sæby harbour; Several å Fig. 496. Phyllophora membranifolia. From the Baltic Sea. A, Gedser Rey 8.5m; B and C off Gudhjem, Bornholm. 5.5—11 m. August. Nat. size. places south of Læsø; Gerrild Bay (Lyngbye). — Ks: Lysegrund; Hesselø (Lyngbye); RL, 15 m; NB, Havknude Flak; Briseis Grund; OS, Hastens Grund. — Sa: PA, near Albatros; KM, east of Øreflippen; PG near Hatterrev; Kyholm; PK, Norsminde Flak; Aarhus harbour. AH'; Korshavn; Hofmansgave (Hofm. Bang, Lgb. a. 0.); aY; AY, Ashoved. — Lb: Bogense; Prins Frederiks Grund, Vejlefjord; Kasserodde; OB, Stavrshoved; Fredericia harbour (C. M. Poulsen); Middelfart, Snoghøj; Fænø Sund; off Stenderup; DC, Aakrog Bugt; Linderum, 1 m. — Sf: CC, Hornenæs; UX; Svendborg Sund. — Sb: Elefant Grund; AG W. of Romsø; Kerteminde, bay and harbour; several places around Sprogø; Halskov, Korsør; between Knudshoved and Slipshavn; Kløverhage (XS);. GZ near Egholm; UE and gB, Vresens Puller; gE Stokke- bæks Flak; Lohals; fR off Hjortholm Skov, 21 m; DP N. of Onsevig; DT, off Magleby; fS east of Kjelsnor lighthouse. — Sm: CK near Staalgrund. — Su: BQ,CS, Ellekilde; Hellebæk; PX off Tibberup; off Skovs- hoved, 5 m; QC east of Saltholms Flak. — Bw: bY near Sønderborg; bV, near Sundeved; cD, cE, cF, dO south of Als; fT south of Ærø; UY, Vejsnæs Flak; DU south of Langeland; KU Schönheyders Pulle; KT, Gedser Rev. — Bm: QT, QG south of Flinterenden; QH, Falsterbo Rev; SD; QS, VG, QZ east of Møen. — Bb: Bay of Arnager; SQ, Broens Rev; SL off Allinge; off Gudhjem; Christiansø (C. Rosenberg). 2. Phyllophora Brodiæi (Turn.) J. Agardh. J. Agardh, Alg. maris medit. 1842 p. 93, Sp. g. ord. Alg. Vol. II, 1. 1851, p. 330; Harvey, Phye. Brit. Vol. I, 1846; pl. 20 (excl. var. 8); Wille (1887) p. 79, figs. 66—69; Schmitz Actin. 1893; Darbishire D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. 67 O1 ID 1 1894, p. 361; id. 1895 pp. 6, 13, 15, 23, 29, 34; id. 1899. Gomont Actinoc., Journ. de Bot. 1894, p- 2; R. H. Phillips 1925, p. 244; H. Printz 1926, p. 60; L. Kolderup Rosenvinge, Phyllophora Brodiæi and Actinococcus subcutaneus. D. K. Vid. Selsk. Biol. Meddel. VIII, 4. 1929; Hugo Claus- sen, zur Entwicklungsgesch. v. Phylloph. Brodizi. Ber. deut. b. Ges., Bd. 47, 1929, p. 544; Kylin 1930, p. 26. Fucus Brodiei Turn. Hist. Fue. II. 1809, p. 1, tab. 72 (good pictures), Hornemann, Flora Danica, tab. 1476 (1813) (good pieture with numerous nemathecia on narrow sexual shoots). Spherococcus Brodiwi Agardh Syn. Alg. Scand. 1817, p. 27; Lyngbye Tent. 1819, p. 11, tab. 3. Chondrus Brodici Greville (1830), p. 133. Coccotylus Brodiei Kützing Phyc. gener. (1843), p. 412, Tab. phyc. Bd. 19, Taf. 74. (1869). For the nemathecia: Chetophora membranifolii Lyngb. ms. (Tent. 1819, p. 11). Chetophora subcutanea Lyngb., Flora Danica, tab. 2135, 2 (1834). Rivularia rosea Suhr mscr. (according to Kützing). Actinococcus roseus Kützing, Phyc. gen. 1843, p. 177, Schmitz, Flora 1889, Flora 1893. Actinococcus subcutaneus (Lyngb.) K. Roseny. (1893), p. 822, Schmitz Flora 1893. The fronds arise from the basal disc the development and structure of which are described at length by DARBISHIRE (1895, pp. 15—20). In young plants a single frond is given off from the disc, later several fronds may spring from the same disc. As shown by this author, hapters may be produced from the under face of the disc and penetrate into the substratum, for instance shells of bivalves. The A young fronds are to begin with cylindrical À but early become flattened above. The flatten- { | ing may begin near the base or there may be a long cylindrical stem before the flatten- ing begins. Some of the fronds represented in fig. 497 show narrowings, often occurring in the species but in this case probably not ) due to the influence of the winter. The rami- fication by dichotomy may begin in the first year, but often the first branching does not take place till the second year (fig. 498 c). Lateral ramification of the flat frond as in fig. 497 c only rarely-occurs in the first year. Only one or two dichotomies are produced Fig. 497. in one season. Adventitious shoots or proli- Phyllophora Brodiei young fronds, a—cfrom Holsts | ferations are later offen produced from the Banke north of Als, June; d—h from fR, Lange- lands Belt, August. 8 : 1. cylindrical stem or from the flat frond. The growth is arrested in winter (No- vember to January). The young flat frond has then a growing zone in the upper margin of the frond or of each section of the frond. After the winter rest the growing zones resume their activity, and the difference between the old and the new frond is then very conspicuous, the first being darker, somewhat brownish, while the new segments are bright red. The growing margin may be long, and IN R e 523 there is then only a feeble or no narrowing at the boundary between the old and the new frond (fig. 498 b, c); but when the segments are pointed at the end of the season, the growing zone is very short; the new segments are connected with the old ones by a narrow stalk (fig. 498 a). In both cases the periodicity of the growth is connected with a periodicity of the breadth of the frond, the latter be- coming greatest in the middle of the growing period. The apical growth and dicho- tomy of the frond is usually not continued during more than two or three years. The growth then ceases and the upper portion of the flat frond is very often disorganised. fi This mode of growth occurs in particular in broad speci- mens reminding one of the arc- tic f. interrupta (fig. 488 b). In some cases new leaves arise as adventitious shoots from the cicatrized upper border of a flat frond (fig. 498 b, above in the middle, comp. Harvey Phyc. Brit. pl. 20, fig. 3). Besides the apical growth and dichotomy, a branching by adventitious shoots or proli- ferations arising at a lower level are very characteristic of the species. The prolifera- tions become long shoots terete below, upwards gradually flat- Fig. 498. lened and more or less divided Phyllophora Brodiei, fronds branched by dichotomy. a from Lille Belt, 1 . ] March. b, Fæno Sund, April. c, from UK, Langelands Belt, May. d, Store ‘4 7 EJ by og they arise from Belt, November. e, Busserev at Frederikshavn, December. a, b,e ?/, nat. the margin or, not rarely, from size; c 2:1. d */, nat. size. the flat side of the frond (figs. 499, 502). Their number is less than in Phyll. membranifolia, sometimes only one, and they may be entirely wanting. When the branching by proliferations is much pronounced, the apical ramification is often feeble; the growth of the upper border ceases at an early period. The growth of the single proliferations sometimes endures only one year; the growth is then taken up again by the new prolifera- tions that may cease to grow in the next year, and so on, and a series of genera- tions of proliferations may thus be produced. This takes place particularly in specimens growing in the inner waters in deep localities where the water is agitated by the current but not by the waves. In the specimen pictured in fig. 499 at least 67% 1916 Fig. 499. Phyllophora Brodiei. Frond col- lected in June 1922 east of Heste- skoen NE of Als at 18—19 metres’ depth. The oldest part of the frond has probably arisen in ?/, nat. size. 1916. 524 7 generations of shoots could be ascertained, undoubtedly re- presenting an equal number of years. The specimens growing here attached to stones attained a length of 33 cm but had a very narrow frond, undivided orscarcely divided by dichotomy. A particular kind of shoots are the folioles, flat or nearly Fig. 500. terete small shoots which arise Phyllophora Brodiæi Transverse at the upper margin of the leafy section of the stem near the hold- > à fast. frond and which usually produce Fra the sex organs (fig. 502). These shoots, however, are not always fertile, and in a loose form (f. stellata) similar shoots but sterile and often branched give to this form a charac- teristic habit (figs. 517 D, 518). The anatomical structure will not be mentioned here, as it has been treated by WırrE (1887) and DARBISHIRE (1895). A transverse section of the stem of an older frond near the attachment disc is shown in fig. 500. There are a number of concentric cortical layers, partly incomplete, the limits between them often vanishing or merging. The central tissue has an elliptical out- line. As shown by DARBISHIRE (1895, p- 20, fig. 25,1), secondary cortical layers (sekundäre Verdickungsschichten) may also be produced at the base of branches, but they may further arise sometimes as local formations in the sexual shoots, as I, too, have observed. According to () DARBISHIRE, the young cells contain a single chromatophore. In the large cells in the inte- rior of the frond several long ribbon-shaped chromatophores can be distinguished. According to H. CLAUSSEN the vegeta- Fig: 501. | tive cells contain several small nuclei (1929, anal, p- 546); the smaller cells of the cortex seem, Jar tissue of leafy however, to contain a single nucleus. frond QUES The reproduction of Phyllophora Brodiæi has been much disputed for more than a century. TURNER, who described the species in 1809, interpreted the globular bodies . situated on the upper border of the frond, or on particular small shoots, as the fructi- fication of the species, but LYNGBYE as early as 1819 was in doubt whether this was really so. He suggested that they might possibly be some parasite, and since then these bodies, which were later named nemathecia, have been the subject of various inter- pretations and much dis- cussion. I have recently published a special paper on this question (1929), in which I have shown that the nemathecium does not belong to a particular para- site (Actinococcus), but that it is the nemathecium of the much reduced sporophyte ty NÅ L L QUI a y Pr 7 “qj À Fig. 502. Phyllophora Brodiei. A, from a dredging south of Als in June, 8.5 m's depth, nemathecia in leaflets, terminal or marginal. B, from 12 metres’ depth off Ballen, Samso in August; with nemathecia and new sexual leaflets. 1.8 : 1. of Phyllophora Brodiæi growing on the gametophyte. I shall therefore refer the reader to Fig. 503. Phyllophora Brodiei. Lille Belt, 18—19 metres’ depth, June. of frond with undulated fertile margin. B, similar with young nematheeia. @ Hy pale the historical survey given in that paper and here give only a shortaccount of my own researches. The sex organs occur in particular sexual leaflets situated on the upper border of the flat frond (fig. 502) or in a marginal zone of the upper segments of the frond (fig. 503 A). Dar- BISHIRE, Who observed the sexual shoots, main- tained that the species is dioecious, and it may perhaps sometimes be so, but the two sexes usually occur in the same plant and often in the same organ. When the upper border of the frond is fertile, it is much 526 undulated and finally lobed owing to increased transversal growth, and it also becomes incrassated. The small fertile shoots are narrow, nearly terete, angu- Fig. 504. Phyllophora Brodiei, from Store Belt, near Ny- Fig. 505. - borg. May. Fertile lobe of frond with a group Phyllophora Brodiei. Two antheridial crypts. A, not of procarps made distinct by staining with hema- fully developed, June. B, ripe, partly emptied, Au- toxylin. 47:1. gust. 625: 1. late, flattened or canaliculate (fig. 502). The sex organs are irregularly distributed in the fertile portions of the frond, and it may happen that some of the small shoots are sterile. In fig. 504 is shown a lobe of an undulated margin of a frond containing numerous procarps, while most of the other lobes of the same margin were without procarps. The antheridia are similar to those of Phyll. membranifolia (comp. Dargt- SHIRE 1895, p. 29, 1899, p. 257, K. RosENvINGE 1929, p. 14). They are developed in small globular cavities in the sexual shoots and, when ripe, communicate with the exterior by an ostiole. Each cavity probably derives from one superficial cell (fig. 505 A). The crypts contain a number of short, often converging cell- filaments the end-cells of which become spermatia, but the spermatia-producing cells may also be situated at the Fig. 506. surface of the shoot (comp. Phyllophora Brodiei, from Lille Belt, east of Hesteskoen, June 1922, from Kyrın 1929, fis. 16 E) The frond with crenulated border. 4, procarp; a two-celled branch issues from 3 5 = er i 3 the first cell of the carpogonial branch; a, the auxiliary cell, 1,2, c, the cells antheridia were met with in of the carpogonial branch. B, two procarps, that to the left without tricho- the months of March and May gyne. C, carpogonial branch isolated by pressure. D, protruding tricho- 5 Sy gyne, the base of which cannot be distinguished. 560 : 1. to November. The procarps are situated in the inner cortex. When fully developed they are composed of a tricellular carpo- gonial branch and a large supporting cell (Tragzelle KyLin) which becomes an 527 auxiliary cell, but it may happen that two carpogonial branches are borne on the same supporting cell (fig. 508 D). DARBISHIRE (1895, p. 33) describes the carpogonial branch as four-celled, but he considers the supporting cell as the first cell of the carpogonial branch. — Numerous procarps were examined in specimens from various localities and gathered at different seasons; they showed considerable differences and the great majority of the procarps were not completely devel- oped. The procarps are easily recognizable by their abundant proto- plasmic contents and their staining power with hematoxylin. The supporting cell is larger than the cells of the carpogonial branch; it must be Fig. 508. Phyllophora Brodiei, collected by Dr. Henning Pelersen at Ellekilde Hage, Ore- sund June 1910 and treated with Juel’s solution. A, procarp; the carpogonium is attenuated towards the trichogyne channel but the trichogyne itself is wanting. Fig. 507. B, the last cell has not the character of a carpogonium; the supporting cell seems Phyllophora Brodiei, from to be uninuclear. C, the same, the supporting cell is plurinuclear. D, the supporting the same specimen as fig. cell is multinuclear; it bears two carpogonial branches, but no carpogonium is 506. Tvo-celled carpogonial developed. E, procarp showing more than the ordinary number of cells, without branch. 560 : 1. carpogonium. F, similar group to the left. A, B, 870 : 1. C—F, 480 : 1. regarded as the auxiliary cell. In referring for details to my paper of 1929 and to the figures from there reproduced here, I shall only mention the principal facts. The carpogonial branches are often only two-celled (fig. 507), and the last cell is most frequently not developed as a carpogonium but roundish like the other cells of the branch, also in the three-celled carpogonial branches. The best developed carpo- gonial branches were met with in May and June, when long, projecting trichogynes were often observed (fig. 506). But most of the carpogonia observed had an abortive A Fig. 509. Phyllophora Brodiei. From a specimen collected in Store Belt in May, fixed with formol-sublimate. A. Three cells only are to be seen in the procarp, the supporting cell seemed to be wanting in the section. B, procarp the interpretation of which was doubtful; no transverse wall was visible at the narrowing of the carpogonium. C. At least two nuclei were present in the supporting cell that is still round. D. The supporting cell is angular, plurinuclear. E. Three auxiliary cells, the two showing numerous nuclei, two producing prolongations foreing their way between the surrounding cells. A, 1000 : 1. B—E, 560 : 1. Fig 510. Phyllophora Brodiei. From Ellekilde Hage, Juel's solution. (Compare fig.508). Auxiliary cells with protuberances. A, The protuberances penetrate between the surrounding cells. 625:1. B, more advanced stage. The protuberances have produced cells and cell-rows at their ends; some of these have begun to form a low tubercle, a young nemathecium. 390: 1. character (fig. 508). No spermatia were found adhering to the tricho- gynes and no other signs of a fertilization were observed. Furthermore, a transferring of a sporo- genous, diploid nucleus from the carpogonium to the auxiliary cell could not be ascertained and I therefore concluded (1929) that it was uncer- tain whether or not a fertilization takes place in this species. The auxi- liary cell, which originally seems to be uninucleate (comp. figs. 506 B, 508 B), later contains numerous nuclei (fig. 508 D). Such cells may increase in size and, at a certain stage of development, shoot out several pro- tuberances (figs.509, 510) which grow out to long branched radiating cell- rows forcing their way between the cells of the gametophyte and ending in nemathecial filaments. A globular body is then produced composed of radiating nemathecial filaments issuing from a system of more irre- gular cell-rows and con- taining in the middle a large central cell, the original auxiliary cell, from which they have all originated (Plate VIII 529 figs. 1 3). These globular bodies have formerly by several authors (LYNGBYE, SuHR, KüTziNG, SCHMITZ, DARBISHIRE (1899)) been considered as a parasite (Actinococcus subcu- taneus (LynGB.) K. Rosenv., Act. roseus (Svar) Kürz.), but have now turned out to be the much reduced sporophytic genera- tion of Phyllophora Brodiwi growing as a parasite on the gametophyte. The greater part of the globular bodies consists of nemathecial filaments and they can therefore be designated as nemathecia. They are placed either on particular sexual leaflets and are therefore often described as stipitate, or they are placed in great number in the undulated upper margin of flat frond segments (fig. 503 B). In the first case the fertile shoot usually remains short, but it may happen that it develops into a foliole of considerable size (fig. 502 A). The nemathecia can be met with at Fig. 511. Phyllophora Brodiei. A, specimen from Middelfart, April; radial section of young nemathecium, showing the outer sterile cells and the fertile ones, the latter connected by primary pits and partly by secondary pits with cells of the contiguous filaments. B, fertile filaments from specimen gathered in Store Belt. No- vember 24th with sporangia in division 625 : 1. all seasons; they usually arise in the spring and may early attain a considerable Fig. 512. Germlings from tetraspores of Phyllophora Brodiæi sown in the beginning of De- that some nemathecia cember 1925. A—B, 3/, months old, 22/3 1926. C—F, 6*/. months old, *°/, 1926. G, 7 i months old, /, 1926. E, optical vertical section. 4, C—F, 350:1. B, 410:1. G, 560:1. (Sporophytes) which are D.K.D. Vidensk. Selsk. Skr.,7. Riekke, naturvidensk. og mathem.Afd., VII, 4. 68 size. The maximal size is 2 to 3.5 mm in dia- meter; it is reached al- ready in June and July, while the nemathecia are only fully developed in winter. The sporangia begin to ripen at the close of November, and ripe sporangia are met with in December to February. As the ne- mathecia occurring in winter are of different sizes and as nemathecia of considerable size are to be found in early spring, it is probable 530 small in December may be retained without producing tetrasporangia and continue their life in the following season, whereas most nemathecia perish in winter after the Fig. 513. Phyllophora Brodiei. Germlings from tetraspores sown in the beginning of December 1925. A, spores newly liberated. B, por- tion of filament from germling. C, eight months old germling, 14/, 1926. D, 14 months old germling with upright shoot springing near the border !°/, 1927, E and F, 20 months old germlings, 15/, 1927. A—C, 625:: 1... D; 70:1. E—F, 9:1. production of tetraspores. The 3 or 4 outermost cells in the nemathecial cell-rows are narrower than the other and remain sterile. It is remarkable that the young sporangial cells are sometimes connected with cells in the contiguous cell-rows by secondary pits (fig. 511 A). The fate of the nuclei transferred by the formation of these pits could not be followed. The sporangia are first divided by a transverse wall and later by two vertical or slightly inclined walls (fig. 511 B). The germination of the tetra- spores was first observed by DARBI- SHIRE (1895); he found that the germlings were deep red bodies of various shape, filamentous, disc- or cushion-shaped, but they attained only a small size in his cultures. The germlings in my cultures from the end of November 1925 were kept alive for several months, up to more than two years and a half, and partly reached a much better development than in DARBISHIRE’S cultures. In the best cultures orbicular, flat or more or less cushion- shaped discs, thickest in the middle, were produced, which after half a year began to give off an upright shoot, usually in the middle. The upright shoot is first terete but later becomes flattened, and in the older cul- tures ramification could be ascertained, partly by dicho- tomy, partly by lateral branching (figs. 513, 515). Owing to the unfavourable conditions in the old cultures, the germlings figured are not quite normal, but there can 4 B € be no doubt of their identity with Phyll. Brodiei. It Fig. 514. must further be supposed that the germlings would Phyllophora Brodiei. Germlings from the bottom ofa glass vessel in which have developed into gametophytes, as all fronds of this a fructiferous plant was deposited at species are sexual plants, as far as we know. the close of November 1925, picked up *°/, 1927 (18 months old). After the publication of my paper (1929) two authors have confirmed the general conclusions there advanced as to the relationship of Actinococcus subculaneus, but they have both pointed out facts which suggest that 531 a fertilization really takes place. Huco Craussen (1929) studied the behaviour of the nuclei and found that the vegetative cells of Phyll. Brodiei contain numerous small nuclei, about 2 w in diameter, containing 4 chromosomes, whereas “In den Zellen des Karpogons [?] und im Gewebe des Parasiten” nuclei with 8 chromosomes are frequently to be found, which makes it probable that the formation of the sporo- phytic generation is preceded by a fertilization. This process however was not observed. Nor has Kyrın (1930, p. 26) observed the fertilization process, but he has found a carpogonium fusing together with an auxiliary cell, N and he thinks that such a process only takes place when / VÆR) the carpogonium is fertilized. | Phyllophora Brodiæi is spread in all the Danish waters from the North Sea to Bornholm, from 1 to 36 metres” depth, attached to stones and sometimes to shells of bivalves. In the North Sea and Skagerak there are only few places where it thrives well (Bragerne); the frond is here fairly broad but only attains a height of 10 cm. It scarcely becomes higher in the northern Kattegat where it is much less common than Ph. mem- branifolia. In the inner waters it attains its best develop- ment and is often abundant. Its maximal height increases considerably, as will be seen from the following figures indicating the maximal heights observed in the respec- tive waters: Ke 15 cm, Ks 17.5 cm, Sa 24 cm, Lb 34 cm, Sb 29 cm, Su 23. In the Baltie it is much smaller: Bw 11 cm, Bb 8 cm. Its appearance varies not only as to the size but also otherwise, according to the different none ee Dre mode of ramification and the varying breadth of the sermlings from the walls and the frond. There is, however, no reason to describe special bottom of ea te an varieties because the differences seem to depend on outer conditions, and I am not able to point out types that might be supposed to be genotypically distinct. As mentioned above, there are two modes of ramification: dichotomy and proliferation, which are usually both in function; but it may happen that one of them is predominant. When the ramification is chiefly or exclusively dichotomous, which happens particularly with broad fronds (fig. 498), the shape may come near to the arctic f. interrupta, characterized by the frond being alternately broad and narrow, but the typical f. interrupta hardly occurs in the Danish waters; the specimen most resembling it was met with in a bank south of Lyo, Lille Belt, in 22 metres’ depth. Specimens of the type nearly exclusively branched by proliferations so extreme as that represented in fig. 499 are rare; they occur too in deep water; the great majority of individuals are intermediary between the two extremes. The specimens growing in exposed localities in shallow water have a firmer texture than those growing in deep water. In specimens growing in 68° Fig. 515. 532 light localities the upper, exposed portions of the frond are green in summer. In the Baltic around Bornholm the dimensions are small, the individuals often dwarfish (fig. 516). They are usually sterile; specimens with small sexual shoots, however, sometimes occur. In a specimen from Ronne Banke imperfectly developed procarps were met with, and once I found, in a specimen collected in August, what seemed to me to be a young nemathecium. Localities: Ns: Not met with in a fixed state south of 56°48’ lat. N. aF, 31 m; dZ, 36 m; eS 25 m, scarce in all the localities. — Sk: Helshage and Roshage, Hanstholm 2—13 m; eX, north of Bragerne, 16 m; YN°, S.E. of Bragerne 10.5 m, several broad specimens, 10 cm high, partly with nemathecia and new marginal leaflets; eY, 15 m; a small specimen; Hirtshals, near land ec. 2 m, with Actinococcus 2 mm in diam.; August. — Lf: Found in several localities in the western Lim- fjord, but always without the basal part, so in most cases it must remain uncertain whether the species was growing on the locality in Fig. 516. question. In most cases the specimens have certainly been lying loose Phyllophora Brodiei from Born- U the bottom; they were usually found on soft bottom and bore no holm. A, B off Ronne 24.5 m. C, D sexual leaflets. In two cases only did such leaflets occur and in one off Gudhjem 5-11 m. Nat. size. case Actinococcus. ZT, LX, LY and XV by Lemvig; LU, Thisted Bred- ning; XT; I; Sallingsund, several places, Th. Mortensen,!; MJ and LR, Løgstør Bredning; F, Skive Fjord. — Kn: Hirsholmene; Deget, Busserev, Frederikshavn, not abundant in the neighbourhood of Frederikshavn; Kummel Banke, (loose?) 38 m; several places near Læsø Trindel, 8—19 m; near Nordre Ronner; gL at Friis’ Sten, south of Nordre Ronner, 2—3 m, abundant. — Ke: Inner side of Kobbergrund; several places 1—4'/2 miles of Fladens lightship, 15—30 m; Groves Flak (F. Borgesen,!), with Actin. April; GJ, Ostindiefarer Grund; OO, Soborghoved Grund and Vesterlandsgrund N. of Gilleleje; Gilleleje harbour; washed ashore by Gilleleje (Lyngbye). — Km: Usually loose; fixed on stones; N by E */s E of Østre Flaks light-ship 5’/2 miles (C. A. Jorgensen); ZC, XB and KF south of Læsø; Gjerrild Bay; Rygaard Strand (Lyngbye); KG near Anholt.— Ks: Grenaa harbour; FO, off Havknude; Jessens Grund; Hastens Grund; EJ, Lysegrund 4—5 m; D near Gronne Revle, 11 m: GF, Sjællands Rev; EH, Isefjord off Lynæs. — Sa: Common on stony ground at 1 to 15 m’s depth from KM east of @re- flippen and PA, Albatros 7.5 m to Hofmansgave (ripe tetrasporangia in February (C. Rosenberg), aZ and OA, 7.5m North of Fyn. — Lb: More than 20 localities, usually at depths from 6 to 15 m; off Stenderup and East of Hesteskoen (dH’) at 19 m and at dQ south of Lyo at 22 m depth; at Linderum at 1m depth. — Sf: Mostly loose; attached to stones at Hornenæs, 15 m; CV, Billes Grunde, 5.5 m; UV and UX North of Ærø; Svendborgsund, 7.5 m. — Sb: Numerous localities from Refsnæs to fS off the South end of Langeland at depths from 1 m (Kerteminde harbour) to 20 m. — Sm: CK, 9.5 m and HF West of Farø, 12 m. — Su: Common from BQ and CS near Ellekilde to QC and QD North of Salt- holm, down to 13 m’s depth, frequently with nemathecia. — Bw: Common from dL in Flensborg Fjord to KT, Gedser Rev and UM, Kadetrenden, at depths down to 25 m; deepest localities: UL, Øjet, 20 m; KX, more than 20 m, and UM, Kadetrenden, 25 m (small specimens). — Bm: Numerous localities. KS South of Falster, with nem.; VH South of Møen; several places East of Moen; VD, entrance to Boge- strom, with nem.; several places along the East coast of Sealand, partly with nem. — Bb: 14 miles SW */s S of Adler Grund light-ship, 30 m (C. A. Jorgensen); SF, Adler Grund c. 10 m (loose); SR, Rønne Banke, 15—16 m, on gravel and stones, with sexual shoots; YH, off Ronne 24.5 m; XZ, Davids Banke 10—29 m; off Gudhjem 5.5—11 m; off Svaneke; 3 miles SSE of Nexo, 21m; Dueodde light-house in W 5°/: miles, 38 m; 5.5 miles NNE ‘/2 W of Hammeren light-house, 35—40 m (C. A. J.); SV, North West Ground at Christiansø, 30—32 m, 533 Loose forms. Phyllophora Brodiæi very often occurs lying loose on the bottom in the inner Danish waters. It is able to keep living in this condition for a long time, growing continually in a sterile state, and it then usually takes a shape different from that of the typical species. Loose specimens occur in particular in the Zosiera-associations and in other localities where the water is not too agitated by waves or by currents. They sometimes occur in great quantities in company with other loose Algæ. The loose forms are very variable, and distinct limits between the different forms cannot be drawn. In some cases they are only slightly different from the typical form, for instance those occurring in the Limfjord, in others they have a characteristic shape. The following types may here be distinguished. f. concatenata LyYNGB. (1819), p. 11. Areschoug, Phyceae, 1850, p. 83, tab. III A. B, elongata Hauck Meeresalg., p. 141. Elongated often intricate frond repeatedly branched by dichotomy or by proliferations, the leafy portions lanceolate or bifurcate, above and below attenuated in cylindrical parts (fig. 517 A). The breadth is variable, the narrowest specimens merge imperceptibly into the following form. This form has usually few or no marginal shoots, but such shoots may sometimes occur, and may even be more numerous than in AREscHOUG’s figure. Very common in the inner waters, but also met with in the North Sea at Blaavandshuk, in the inner waters in particular in Sa (numerous specimens collected at Hofmansgave by HOFMAN-BANG, LYNGBYE and CAROLINE ROSENBERG), Ib, Sf, Sb, Sm and Su. f. filiformis. Frond cylindrical or here and there a little flattened, mostly branched by proliferations. It occurs in a robuster form, the cylindrical part of which is about 0.5 mm in diameter while the flat expansions are usually only 1 mm broad (fig. 517 B), and in a thinner form with a threadlike frond. The finest specimens are sometimes so thin that they are only '/; mm thick and almost without flat expansions, and one would therefore be inclined to doubt that they belong to the form-cyclus of Phyllophora Brodiei if other specimens from the same gathering did not offer intermediate forms connecting them with less aberrant forms. Moreover, even the finest specimens may be infested by Ceratocolax Hartzii, which is a specific parasite of Phyllophora Brodiwi (fig. 517 C). In its typical form it is only found in Sf and Bw. Localities: Sf: Hojen at Faaborg, between broad-leaved Zostera, very thin; DZ, Egholms Flak at Morke Dyb, with Zostera. — Bw: cF south of Kegnæs lighthouse. f. stellata. Phyllophora parvula Darbishire ex p. (1895) fig. 10, 6—8. The proportionally small flat frond bears at the top a bunch of radiating small, narrow, undivided or forked shoots. These shoots are similar to the sexual 534 shoots in the normal plants but are sterile. They remain for the most part short, but some of the shoots in a bundle may grow out and develop into a long shoot like the mother shoot and bear a similar bunch of short shoots at the top (figs. Fig. 517. Phyllophora Brodiæi loose forms. A, f. concatenata, Store Belt. °/, nat. size. B, f. filiformis, at Kegnæs south side of Als, */; nat. size. C, f. filiformis very thin, infested by Ceratocolax Hartzii, dredged near Faaborg. Nat.size. D, f. stellata, from ZC south of Lieso. Nat. size. 517 D, 518). This form is analogous to the f. stellata of Chondrus crispus, (comp. p- 505). The radiating shoots are sometimes repeatedly forked, and when, as will some- times happen, they are partly reflexed, the plants may remind one of f. uncinata of the said species. Some of the specimens referred by DARBISHIRE to Phyllophora par- vula (see above), belong to this form, while the other figured specimens probably represent other reduced loose forms of Phyllophora Brodiei. 535 Localities: Kn: Kummel Banke 38 m. — Km: ZC and EZ south of Læsø; 6 miles SSW !/a W of Læso Rendes lightship Sm (C. A. J.); BK, Tangen. — Sa: East side of Wulff’s Flak; AO; Endelaves SE Flak, 7.5 m; Fyns Hoved in E Y4 N 57/2 miles. — Sf: fV, south side of Svelmo, 4 m; — Sh: fP, E of Hov light-house, 5.5 m. — Bw: fU, south side of Æro, 7 m. Fig. 518. Phyllophora Brodi«i f. stellata. South of Ærø. 2:1. 3. Phyllophora epiphylla (Fl. Dan.) BATTERS. Batters, A Catalogue of the British Marine Algæ, 1902, p. 65. Fucus epiphyllus O. F. Müller, Flora Danica, Tab. 705. 1777. (from Norway). Fucus prolifer Lightfoot, Fl. Scot. II, p. 949, tab. 30. 1777. Fucus rubens Good. et Woodw. Trans. Lin. Soc. Ill, 1797, p. 165. Chondrus rubens Lyngb. Tent. p. 18. Phyllophora rubens (G.& W.) Greville Algæ Brit. p. 135, pl. 15; Harvey Phye. Brit. II, Pl. 131, (1849); J. Agardh, Sp. g. o. II, I p. 331, (1851); Kützing Tab. phyc. IX, tab. 76, (1869); Buffham, Antherid. (1893), p. 292, pl. XII, fig. 5; Schmitz, Actinoc. 1893, p.399 ff.; Darbishire (1894), p. 369, id. (1895), pp. 4, 7, 12, 21, 28, 30, 33, 34, 36). The fronds arise from a basal disc that, according to DARBISHIRE, may be 5—15 mm in diameter and up to 1.5 mm thick. The lowermost portion of the frond is cylindrical, but this stemlike portion may be extremely short; when it is more developed it may give rise to a considerable number of branches that take a similar appearance as the primary Fig. 519. Phyllophora epiphylla. A,frond dredged off Lonstrup, frond (fig.519 B). The shoots gradually expand Skagerak. B, lower portion of frond from the same o . . locality. C, upper portion of frond dredged in the ea membranaceous linear frond w hich North Sea 15 miles off Hanstholm lighthouse. A, C */; grows by the activity of an apical meristeme natural size. B natural size. 536 and may remain simple or branch by dichotomy. Sometimes the ramification is lateral as in fig. 519 A, C, which may perhaps be due to the checking of one of the pro- ducts of the dichotomy. Besides this apical ramification a branching by prolifera- tions regularly takes place. The latter, one or more, arise from the plane surface of the frond, usually near the end, and a series of generations of proliferations is con- sequently produced, representing probably an equal number of years (fig. 520). At least 5 or 6 generations are normally produced in the Danish individuals. The growth of the shoots normally ceases when a proliferation arises near its end. The ramification by proliferations is usually more pronounced than the apical forking in the specimens from the Danish waters, where the proliferations are very often simple, in par- ticular from the waters within Skagen. The membrana- ceous frond reaches a breadth of 10 mm; in the southern Kattegat and the Sound it only becomes 5 mm broad at most. The thickness diminishes gradually from the middle towards the margin. As to the anatomical struc- ture of the frond reference may be made to DARBISHIRE’S paper (1895, p. 12). As shown by this author, small interstitial cells are wanting between the medullary cells. The shoots are often furnished with a midrib in their lower part. It is formed by local thickening of the cortex, produced by activity of the outer cortical layer on both sides (comp. DARBISHIRE ].c. p. 12). The antheridia are produced in small andro- phores on particular male specimens. The androphores are spherical or subspherical bodies, about 0.5 mm in Fig. 520. diameter or a little more, borne on a short pedicel on Phyllophora epiphylla. Fromthe9re- the plane surface of the frond near the border (fig. 521). sund; north of Kronborg. Sept. 1848. 5 ~ ‘rc Caroline Rosenberg. 2:1. They were first pictured by DERBÈS et SoLIER' in the nearly related Ph. nervosa which is probably not specific- ally distinct from Ph. epiphylla, later on they were briefly mentioned by THURET (Et. phye. 1878, p. 82) who found that “les corpuscules males sont contenus dans des cryptes tapissées d’anthéridies fort semblables à celles du Gracilaria confervoides’. In 1883 they were described and figured by BurrHam (1883, p. 292, pl. XIII, figs. 5—7). This author observed the cavities, from the walls of which numerous tufts of thin fila- ments spring which produce at their extremities the spermatia, and he presumed that these bodies escape through one common issue at the top of the androphore (comp. l.c. fig. 7). My observations on the structure of the androphores however, are, not in accordance with those of BurrHam. A vertical section of an androphore shows a layer of cavities or crypts covering the whole surface of the globular body " Ann. sc. nat. III: S. tome 14 p. 278, pl. 37 figs. 10—11, 1850. 537 and surrounding a globular parenchymatous medullary tissue (fig. 521). This parenchy- matous columella seems not to have been observed by Burruam, but it has been distinctly represented by DERBÈS et Souter (i. c. fig. 10—11). The crypts are deep, 120—150 w, nearly pris- matic but somewhat irregular in a transverse section, and with rounded ends, 45—63 w in diameter. The separating walls between these cavities are built up of very thin filaments from which the spermatia producing filaments spring. When the cavities are more irregular in transverse section, the separating walls may form folds in the cavity like incomplete septa, or the cavities may be partly confluent. The ostioles of the crypts were not observed by me but there is no doubt that the latter have each their particular opening, not a common one as supposed by BUFFHAM, and this species is therefore in better accordance with the other species of the genus than must be supposed from Burr- Fig. 521. HAM’s representation. The spermatia are very small, a en about 4 w long, 2 w broad; one nucleus was easily section of androphore. 30 : 1. recognisable in the dried material. The antheridia were met with in September (Kn and Su). According to Kyrın (1907, p. 125) antheridia-bearing specimens collected in May are present in the Riksmuseum at Stockholm. The procarps are developed in particular globular carpophores which have a similar position to that of the androphores. To begin with they are like these globular, sessile or furnished with a very short stalk but early become beset with anastomosing crests (comp. Harvey, l.c. and DARBISHIRE 1895, p. 33). The procarps arise in the inner cortex in considerable number in each carpophore. The carpogonial branch is, as in the other species of the genus, three-celled and borne on a large cell that probably becomes the auxiliary cell (fig. 522). The trichogyne was observed to protrude through the surface in some cases; the narrowing between the ventral part of the carpogone and the trichogyne was very distinct at the level Fig. 522. of the surface of the carpophore. The development of the Phyllophora epiphylla. Pro- cystocarp was not examined. A great number of the pro- IR ee carps observed in a carpophore collected in October were pogonium. 390 : 1. not fully developed and many of them would probably never have reached maturity. Carpophores with procarps were observed in September and October, cystocarps in winter (November to March); as late as May cystocarps may be met with but more or less empty. D.K.D. Vidensk. Selsk. Skr., 7. Række, naturvidensk., og mathem. Afd., VII, 4. 69 538 The nemathecia are borne on the short stipe of peltate leaflets dispersed on the surface of the frond of separate asexual plants. They are flat broad bodies that cover a great part of the stipe, in a number of two or more. When several nemathecia are present, they may meet and jointly cover a great part of the surface of the stipe. The structure of the nemathecia has been well described and pictured by DARBISHIRE (1895, p. 28) who ascertained that the nemathecium is only connected with the supporting organ in the middle where it has arisen from the cortical tissue, while the basal layer of the nemathecium is for the rest appressed to the frond. The nemathecia increase at the margin by the formation of tangential walls. Two years before, SCHMITZ treated the nemathecia of this Alga in his paper on Actinococcus (1893, p. 399 et sequ.). DARBISHIRE’s statements are in many respects in good accordance with those of SCHMITZ but as to the basal layer the two authors disagree. While DarBIsHIRE describes this layer as consisting of one or two layers of cells and as distinct from the surface of the frond with which it is in contact, SCHMITZ found that the growing border of the nemathecium is separated from the surface of the supporting frond by a slit. At a certain distance from the margin, the basal layer appears in contact with the surface of the frond with which it becomes closely united, the cells of the basal layer giving off prolongations toward the superficial cells of the frond with which they are said to fuse, with the result that the slit entirely disappears, and finally almost all the superfieial frond-cells are united with one or more cells of the basal layer, and the arrangement of the cells of the latter becomes very irregular. This fusing process takes place, according to SCHMITZ, even at the insertion of very young nemathecia and the author concludes from this that the nemathecia of this and some related species are particular parasitical alge growing on the surface of the fronds of Phyllophora and fusing with the presumed host-plant through cell-fusions. SCHMITZ gave to the parasite the name of Calacolepis incrustans. If this interpretation were true, the parasite would only attack the asexual plants and these would then be devoid of tetra- sporangia. As this is very improbable, particularly convincing facts must be demanded for supporting such an interpretation. It must be regretted that SCHMITZ has given no drawings illustrating the fusing process. DARBISHIRE has not succeeded in observing it (1894, p. 369); he declares (1895, p. 28) that the nemathecium only is in connection with the stipe in the place where it has arisen from the cortical cells. In this place the cortical cells first divide and grow out, and the young nemathecium thus formed breaks forth from the cortex; he can not, therefore, accept the view of SCHMITZ. I, too, have not succeeded in observing the fusions recorded by Scuitz. In specimens collected in September the formation of the nemathecia is easily observed. In the youngest stages a small group of cells situated just within the surface are seen dividing and extending outwards, causing a vaulting and distending of the cuticle. This distending early involves a bursting of the cuticle, and the active cells protrude, surrounded by their thin special membranes (fig. 523 B, C). The bursting 539 of the cuticle usually takes place in the middle, and the borders of the old cuticle are then later found surrounding the base of the young nemathecium (fig. 523 D). In other cases the bursting seems to take place at the periphery, and the nema- thecium is then covered by a calotte of cuticle originating probably from the sur- face of the stipe (fig. 523 E). In the young stages the ar- rangement of the cells may be rather irregular; some- times a single cell is seen to be more active and rich in cell-contents than the others, and producing a great part of the cells of the excrescence (fig. 523 A). The diameter of the quite young nemathecia is small, corresponding only to the diameter of a very small number of cortical cell-rows, but the diameter early begins to increase, the marginal growth taking place by vertical division of the marginal cells. The insertion of the nemathe- cium is, however, not en- larged by this process, the growing borders of the nema- thecium not being connected with the surface of the frond but separated from it by a slit (fig. 523 E, F) or in contact with it. The nema- thecium at the same time increases in height and is Fig. 523. then composed of parallel Phyllophora epiphylla. Young stages of nemathecia in September. 625 :1. or radiating filaments which later, in winter, produce tetrasporangia. As mentioned above, I have never seen a fusing process like that described by Scumirz; at all events it did not take place in the younger stages such as those represented in fig. 523. From the above it must be concluded that the nemathecia are the true organs of Phyllophora epiphylla and do not belong to a parasite. The name of Colacolepis incrustans must therefore be abandoned. 69* 540 The sporangia form long chains in the nemathecial filaments; only the ultimate cell is sterile, as shown by DARBISHIRE (1895, p. 28, fig. 36). As late as April I found sporangia partly divided into four cells, partly only divided by a transverse wall; they measured 9—14 x 6-7 u (9 X 7 to 14 X 6 w). The frond reaches a length of up to 20 cm. The breadth is variable; outside Skagen the maximum breadth varies from 5 to 10 mm, in the northern and eastern Kattegat from 4 to 7 (rarely 9) mm, in Km, Ks, Sa and Su from 2 to 4 (rarely 5) mm. As mentioned above, the ramification by dichotomy is less pronounced in the inner waters than outside Skagen (Ns and Sk). Phyllophora epiphylla is confined to the waters with a comparatively high salinity: the North Sea, Skagerak, Northern, Eastern and Southern Kattegat. Outside these territories it has only been collected by dredging in one place (one specimen) in the central part of the Kattegat (Km). Further it has been found loose on the beach sparingly at Hofmansgave (Sa) and frequently in the Øresund north of Helsingør; to the latter places it is probably carried from the Swedish coast. It grows in rather deep water, on stony or gravelly bottom, in Ns, Sk and Kn in 5.5—41 m depth, in Ke at 15—25 metres’ depth. Localities. Ns: Jydske Rev, eD, 41 m; eC, 26 m; eO and eP off Agger; eR; eT; XR off Klit- møller. — Sk: Off Hanstholm 13 m; at Bragerne, 10.5 m; ZK*, 7.5—9.5 m and ZK® 11.3—13 m off Len- strup; Hirtshals, washed ashore; Skagen, washed ashore. — Kn: Herthas Flak, 19—22 m; Læsø Trindel, several places, 15—13 m: GM, Engelskmands Banke; UB, east of Nordre Ronner, 9—11.5 m; north of N. Ronner 7 m; east side of Hirsholmene; XG, east of Deget 4—5.5 m; Frederikshavn (Schmidt 1863). — Ke: Groves Flak, 19 m (!, Borgesen); HZ, Store Middelgrund 25.5 m; Gilleleje and Nakkehoved, washed ashore (Schouw, Lyngbye). — Km: HT, Fornæs lighthouse i SW ‘/s W 7 miles, 16 m. — Ks: At Hesselo (Lyngbye); D, at gronne Revle; off Tisvilde Leje, 3 miles, 15 m (A. Otterstrom); ad littus Vejbye prope fontem Helenæ et Raageleje (Lyngbye). — Sa: Hofmansgave, washed ashore (Hofm. Bang, Caroline Rosen- berg), was not recorded from this locality by LyNGByE, seems therefore to be rare. — Su: Washed ashore at Hellebæk and at Helsingor (Orsted, C. Rosenberg, Joh. Lange, Borgesen,!). Loose form: f. Bangü (Horn.) Fries. Fucus Bangii Hornemann, Flora Danica, tab. 1477 (1813). Spherococeus Bangii Agardh Synops. (1813) p. 24; Kützing, Phyc. gen. (1843) p. 410, Taf. 59 II, Tab. phye. Bd. 18 (1868) Taf. 84. Chondrus Bangii Lyngbye Hydr. (1819) p. 17, tab. 3. Phyllophora Bangii E. Fries Summa veg. Scand. (1845—49) p. 126; Darbishire (1895). Rhizophyllis ? Bangii J. Agardh. Sp. g. o. Il.ı p. 223. (1851). This pretty little alga, characterised by its much incised frond, was discovered by Horman Bane at Hofmansgave at the North coast of Fyn, where it is frequently found washed ashore and from which locality innumerable specimens have been distributed, in particular by Horman Bane and by his foster-daughter Miss CAROLINE ROSENBERG. LYNGBYE referred it to the genus Chondrus and described a fructifica- tion consisting in “‘tubercula subglobosa 4-granulata in substantia frondis remote et inordinate sparsa”. This supposed fructification, however, does not belong to this Alga but is due to some alien organism, probably germinating spores of Furcellaria 541 fastigiata, which frequently occur on this substratum (comp. Kürzıng, Phye. gen. Taf. 59 II). The only later author who has considered them as tetrasporangia is J. AGARDH who on this basis, though with doubt, referred the Alga to the genus Rhizophyllis. E. Fries transferred it to the genus Phyllophora', where it has since had its place, and with which genus it agrees well in the anatomical structure. r— Fig. 524. A, Phyllophora epiphylla, typical narrow frond from Helsingør. B—E, Ph. epiph. f. Bangü. B, off Gerrild Klint, 7.5 m. C, Silderøn south of Læsø, 2—4 m, together with Ahnfeltia plicata f. D, KF south of Læsø, 6.5 m. E, Hofmansgave (Caroline Rosenberg), large specimen. °/, nat. size. The plant has always been found loose, and reproductive organs have never been found. During my dredgings in the Danish waters I have met with this Alga in numerous localities in the inner waters where the water is comparatively little agitated, on sandy bottom, very often in company with Zostera marina, entangled between its 7 Hauck, Meeresalg. p. 144 cites JENSEN as author of the combination Phyllophora Bangii, owing to the fact that he has only known it from Rabenhorst’s Alg. Europ. exsicc. No1299 where TH. JENSEN has communicated it with Fries’ name. N DN \ CLP \ U by ER N A NN N > HATE 2 NN ZS N | 88 LR SK ALES K N m SD À - TES WW / EN SS SAN) ot of EST) SN eee = N | VE mr D 2 RU = I CR D (a N IN a EEE 4 > FAN TG DST AN ya SET D We Fig. 525. Phyllophora epiphylla f. Bangii, specimen from Baaring Vig, North side of Fyn, producing a branched shoot without crenulated border. :/, nat size. 542 rhizomes and together with various other loose Alge. As it has been found only in the inner Danish waters and the adja- cent part of the western Baltic Sea and, according to J. AGARDH, at the coast of Bohuslän, it must be extremely probable that it might be a loose sterile form of any of the species of Phyllophora occurring in these or the adjacent waters, and I many years ago had arrived at the conviction that this species was Ph. rubens'. An examination of a large amount of material from various localities has fully confirmed this opinion. Firstly it must be pointed out that the colour and the consistency are identical in Ph. epiphylla and Ph. Bangii; and none of them adhere to the paper when drying. The area of the latter does not coincide with that of the genuine species but is situated outside it (9: more to the south and west). Near the boundary between the two areas loose forms occur that are only little incised and then much resemble genuine specimens of Ph. epiphylla (comp. Fig. 524 B—D). The fronds of these specimens are partly linear with the border entire in part of its length. Similar specimens may also be met with in the waters north of Fyn. The specimen shown in fig. 525 has a great com- plex of shoots with entire borders springing from a shoot with the usual incisions; the first agrees exactly with a narrow specimen of Ph. epiphylla, 1 mm broad. The specimen represented in fig. 526 is also very instructive; it shows the proliferation characteristic of the species and a feeble mid-rib, and further the linear segments of the frond with border partly entire partly more or less incised. In the specimens agreeing with the typical Chondrus Bangü Lynes. the broader parts of the frond are always present but are usually shorter and provided with feebler or deeper incisions, and a midrib is never present. Fig. 524 E shows a well developed specimen of this form; some of the lateral shoots are narrow without broader parts. * Comp. WARMING, Oecology of plants. Oxford 1909, p. 178. Fig. 526. Phyllophora epiphylla f. Bangii. Hofmans- gave, Caroline Rosenberg. 2: 1. ED RE In other specimens the frond is much narrower than in the just named ones; the breadth of the frond is, indeed, variable, but 1—2 mm broad parts of the frond with feeble incisions as in the typical Ph. Bangü do not occur. LYNGBYE named this form f.tenuior and numer- ous specimens from Hofmans- gave are to be found in the herbarium. I have also found it in numerous localities and it is easy to distinguish from the broader form, and it is remarkable that f. fenuior is the only form occurring in the southern part of Lille Belt, in Store Belt and the western Baltic Sea. On the other hand it occurs together Fig. 527. Phyllophora epiphylla f. Bangii, tenuior. Dredged south of Ærø, 7 m. 2:1. with the broad form in several localities in the waters north of Fyn. In the Western Baltic Sea it occurred in considerable quantities, in some localities together with other loose Algæ. Some of the specimens growing here produced shoots of a differ- ent character, being destitute of the numerous warts or lacinule but having long diverging branches with even borders. (Fig. 528 C). As these shoots are continuous with the usual crenulated form, their connexion with f. fenuior is evident notwith- Fig. 528. Phyllophora epiphylla f. Bangii, thinner form (f. tenuior Lyngb.). A with an expansion, C producing shoots without lacinulæ. A and B Hofmansgave; C, south of Æro. A and C 3:1, B 2:1. standing the different shape. Like- wise, the f. tenuis must be supposed to arise from the thinner shoots of the typical Ph. Bangü. F. tenuior does not branch by proliferations and is thus very different from the typical Ph. epiphylla. This species has thus the power of keeping alive in a loose condition, the shape of the frond being gradually much altered. In localities situated near the boundary of the genuine species specimens occur that are only different by the frond being partly more or less incised. In the typical Ph. Bangü he border is incised in its whole length, some parts of the frond being, however, broader, 1—2 mm broad, and only minutely crenulated; branching by proliferations 544 may be met with. In the inner localities only a finer form, usually only 0.2—0.5 mm broad or less, is met with, f. fenuior LyNGB., without proliferations. The branches are alternate, divaricate, curved, with a varying number of branchlets. The loose forms nearly always occur in water of lower salinity than that in which the typical species occurs; they often vegetate in water with a salinity of 20 °/oo or less. Localities. «: Ph. epiph. f. Bangii typica. 8: Ph. epiph. Bangii f. tenuior. — Kn: Frydenstrand by Frederikshavn, «. = Ke: FD, east of Læsø 9.5—11 m. — Km: ZC, 4—5 m, XE 2—4m and KF, 6.5 m south of Læsø, alla; XF at Læsø Rende, 8.5m, & and a little 8; entrance to Mariager Fjord, Th. Mortensen, 8; BH, off Gerrild Klint, 7.5 m, «. — Sa: PN, Kalo Vig, 5.5—11 m, 8; PL, Wulffs Flak, 9.5—13 m, «; PK, Norsminde Flak, 5.5 m, 8; MQ, south of Paludans Flak, 11.3 m, $; aV, east of Ende- lave, 10 m, «; aX south of Endelave 4.5 m, «; aH Lillegrund at Fyns Hoved, 7,5 m, «; aY, aZ and NZ, north coast of Fyn, & and 3; Hofmansgave, washed ashore, « and $. (Hofman Bang, Lyngbye, Car. Rosenberg a. 0.); NY, entrance to Odense Fjord, 6.5 m, «; Einsidelsborg (Car. Rosenberg); GC, east of Æbelø, 13 m, «; DJ, east of belo, «; Æbelø (Lyngbye). — Lb: Off Bjornsknude, 9.5 m, «; AL, Baaring Vig, 7.5 m, «; Flækojet « (Biol. Station); DE, Thoro Rev. 5.5 m. 8; DB, Lille Grund, 7.5 m; dH, east of Hesteskoen, 15 m, 8 — Sb: Off Refsnæs, 19 m (C. H. Ostenfeld) 8; Lerchenborg Strand, washed ashore, 3 (O. Smith); GS, Lysegrunde, 3; LN, Stavreshoved, 8; GQ, Slettings Grund, 7,5 m, 8; NU, off Strandskov at Bovense, 13 m, 8; AB, off Teglværkskov by Nyborg, 7.5 m, 8; cL, NE of Sprogø, 25—27 m, 8; BS, Palegrund, 7.5 m, 8; VB Omø Tofte, 5.5 m, 8; fP, east of Hov lighthouse, 5.5 m, ß; DP and UJ at Onse Vig, 7 m, 8; DQ, west of Nakskov Fjord, 5.5 m, 8. — Bw: cF, south of Kegnæs, 8.5 m, 8; dO, north side of Bredgrund, 5 m, 2; dP, east side of the same, 7.5 m, 8; fT, south side ot Ærø, 7 m; off Drejet, 7 m, B; UQ, off Tillitse, 12 m, 3. 4. Phyllophora Traillii Holmes et Batters. Traill, Monograph of the Alge of Firth of Forth. Proceedings of the Roy. Phys. Soc. of Edinburgh 1882, p. 13, sine descr., Holmes et Batters, A revised list of the Brit. Mar. Algae, Ann. of Botany Vol. V, 1890, p. 89, sine descr.; Batters, Mar. Algæ of Berwick 1899, p. 114, plate XI, figs, 6—11; id., A Catalogue of the Brit. Mar. Alg. 1902, p. 66. At Fladen in the Eastern Kattegat I found in October 1922 at 17 metres’ depth a small number of specimens of a little Alga which I think must be referred to the imperfectly known species Phyllophora Trailli. They were found growing on stones together with young plants of Chetomorpha Melagonium and Chondrus crispus and were only 3—6 mm high (fig. 529). They agree with Batters’ description and drawings, and some of them bear small marginal leaflets which appear dark under the microscope. The fronds are feebly branched, laterally at the base or by dicho- tomy or they are still entire. They are contracted at the base in a short cylindrical stipe and issue from a well developed attachment disc. Owing to the very small number of specimens I cannot ascertain whether the leaflets contain procarps. According to BATTERS the cystocarps, which are entirely immersed in the leaflets, ripen in January and February at the British coasts. I have had for comparison original specimens from E. M. HoruEs collected at Cumbrae, Scotland in March and April; they were small and sterile, without marginal leaflets. In the harbour of Østerby on the north coast of Læsø in the Northern Kattegat 545 three specimens were met with (July 1924) which must probably be referred to the same species. They are up to 1.5 cm high with a linear frond, partly bearing numer- ous marginal leaflets which are often longer and nar- rower than in the above mentioned specimens; the leaflets are all flat and sterile. These specimens are all with- out base; they were perhaps loose. A specimen dredged in the North Sea NW of Thybo- ron in 31 metres’ depth was finally referred to this species, though with some doubt. It is 1.8 cm high, branched, with marginal leaf- Fig. 529. lets, and sterile in August. Phyllophora Trailli. Fladen, 17 metres’ depth. 10 : 1. The species has been met with at several places on the coasts of the British Isles (comp. Barrers 1902), and it has also been recorded from the East coast of the United States by Corrıns. Tetraspores are unknown, and the structure and development of the cystocarps have not been examined. Localities. Ns: aT Thyborøn beacon SE ‘/2 E 14 miles, 31 m. — Kn: Ostero harbour, Læsü. — Ke: fH, Fladen, 17 m, October. Ceratocolax K. Rosenv. 1. Ceratocolax Hartzii K. Roseny. Kolderup Rosenvinge, Deux. Mém. 1898, pp. 34—39. When in 1898 I described a new Alga under the above name, growing parasitic- ally on Phyllophora Brodiæi at the coasts of Greenland, I was not aware of the fact that the same or a nearly related species had long before been observed by LyneByE (Tent. 1819, p. 11). In describing Spherococcus Brodiwi 8, concatenatus, this careful investigator characterized it as being set with “verrucis aggregatis, uvæformibus, pedicellatis, frondis e margine ortis”’. He did not take these bodies for fructifications, as they contained no “semina”. REINKE directed the attention of SCHMITZ to these bodies and repeatedly sent him specimens of them from the Baltic Sea. SCHMITZ took much pains in examining them and finally arrived at the conclu- sion that they must be interpreted as “Produkte parasitischer Florideen’’. “Unter der Einwirkung eines ziemlich kleinen intramatrikalen Parasiten-Geflechts entwickeln sich traubenförmige Wucherungen des Phyllophora-Thallus; in diesen Wucherungen D.K.D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4 70 546 verbreiten sich intramatrical und langsam fortsprossend die intercellular kriechenden verzweigten Zellfäden des Parasiten; dann aber wachsen zu gegebener Zeit reichlich Zweigbüschel des Parasiten von den central gelagerten Parasiten-Geflechte auswärts hervor und bilden in analoger Weise wie bei Act. roseus an der Oberfläche je eines Höckers der Phyllophora-Wucherung ein fertiles flaches Polster, dessen antiklin- fädige Zellreihen Ketten von Sporangien ausformen. Ich bin geneigt anzunehmen, dass diese traubenförmigen Wucherungen von Ph. Brodiwi durch eine eigenartige zweite Species von Acfinococcus verursacht seien. Doch unterlasse ich es, schon jetzt diese Species durch Aufstellung eines selbständigen Namens zu unterscheiden” (Scamirz, Actinoc. 1893, p. 380). These bodies have also been examined by DARBISHIRE who found them at Helgo- land as well as in the Baltic (Bo- tan. Centralblatt, 1894, p. 369). He met with tetra- sporangia which were usually quite colourless (white) and pro- carps with long, protruding 1ri- chogynes. On the other hand he : = Eis 7530. 2 did not observe Ceratocolax Hartzii. A, from Hesteskoen east of Als, June. 11 : 1. B, from Højen near Faa- = x borg. September. 11:1. C, from fN off Ballen, east of Samsø. August. 6:1. the “intramatri- cal” filaments described by Scamirz. He concludes as follows: “Ich halte die ganze Erscheinung für eine pathologische Wucherung von Ph. Brodiei. Hierfür spricht u. A. die weisse Farbe der Tetrasporen und ferner der Umstand, dass von den sehr zahlreichen Prokarpen aus nie ein Cystocarp gebildet wurde, obgleich ich öfters an den Trichogynen wohl erhaltene Spermatien haften sah”. The Greenland plant which I described in 18987 grows on the arctic form interrupta of Phyll. Brodiæi, on the flat side or on the border of the frond. It formed much branched bushes, 4—5 mm in diameter. At the base it penetrates a little way into the host plant, growing intercellularly. The cylindric branches bear globular nemathecia, while sex organs were not observed. The nemathecia remind one of those in Phyll. Brodiei. The plants were not holoparasitic as they were red when living. The same species has later been met with at the coasts of Iceland (J6Nsson) and in the Arctic American archipelago”, on the same host-plant. ? On page 35 in my paper (Deux. Mém. 1898) 1.5 fig. should be corrected into fig. 7 A. ? K. RosENVINGE, Mar. Alg. coll. by Simmons dur. the and Norw. Arct. Exped. Oslo 1926. 547 The specimens from the Danish waters to be described below agree so well with the Greenland specimens that I think they must be referred to the same species. In describing them the differing views of SCHMITZ and DARBISHIRE will be taken into consideration. The organism in question, according to LynG- BYE, always grows on the loose, sterile f. con- catenata of Ph. Brodiei, and the specimens examined by Scumitz were probably also growing on this host-plant. It is, in reality, very common on this form in the Danish waters, but it also attacks the typical, fructiferous Phyll. Brodiæi and has the same appearance in both cases. It is much branched, meee ‘ x 2 Fig. 531. the branches pointing in all directions. When Ceratocolax Hartzii, Vertical section of tetra- the branches issue near the base, the outer out- SPore-bearing plant. From Lille Belt, April. 30 : 1. line of the plant becomes nearly globular, the ends of the branches reaching about the same distance from the centre (fig. 531). In other cases there is a cylindrie stipe under the branched frond (fig. 530 A, B). The branches are repeatedly branched and often so crowded that the whole com- plex of branches is head-like. The branches are cylindric or a little complanated but never flat, often irregularly curved; in spring they usually end in a globular Fig. 532. Ceratocolax Harlzü. A, sec- tion of cortex ofthe lower portion of the frond. B, medullar cells showing nuclei and chromato- phores. 625 : 1. swelling, while later in the year the tips of the branches are not swollen but often much branched (fig. 530 B, C). The colour of the plant is pink, in particular in spring, or somewhat varying from yellowish to greenish according to the season and other external conditions, like that of the host-plant, but usually brighter, and brighter toward the tips of the branches. The structure of the frond is somewhat similar to that of Phyllophora Brodiei, but the consistency is softer. The cortex consists of outward directed cell-rows the innermost cells of which gradually pass into the medullary tissue. In the lower, sterile parts of the branches, the cortex is comparatively thick, consisting of regular parallel cell-rows, up to 6—8 cells long (fig. 532). In the upper, fertile regions, the cell-rows are shorter and not so densely crowded; the intercellular substance is here especially soft, and the arrangement of the cells is therefore often disturbed by microtomizing owing to the swel- ling of this substance (comp. figs. 537—539). The cortical cells are connected by primary pits in the transverse walls, but secondary pits may also occur in the longitudinal walls (fig. 532 A). The cells seemed often to contain a single calotte-shaped chromatophore, but in well-fixed 70* 548 material the cortical cells showed in some cases a system of narrow, thread-like bodies of which it was not easy to decide whether they were distinet chromato- phores or branches of a much divided single chro- matophore. In several cases a single nucleus was met with. The inner tissue consists principally of iso- diametric cells, increasing in diameter inwardly. The outer medullary cells have a structure similar to that of the inner cortical cells but they usually show two or three nuclei, and the inner cells a greater number. The medullary cells, in particular the larger inner ones, usually contain numerous small starch- grains and can be said to constitute a storage tissue (fig. 533). These cells are connected by numerous pits, Fis. 533. primary and secondary ones, and it may happen that Ceratocolux Hartzï. Section of medullar a wall separating two cells is traversed by two pits. ER Wau ee tesa: an A system of smaller cells situated between the a large storage cells and produced by budding from them is present in the interior of the frond: they are usually long and narrow and must if anything be regarded as representing a conducting tissue. Its cells are con- nected with the surrounding cells by secondary pits (fig. 533). It seems probable that these cell-rows have been interpreted by Scumirz as belonging to a parasite while the surrounding larger cells were supposed to belong to a hypertrophy of the host plant: nothing has, however, been found by me to support this inter- pretation. In the paper (1898) where I have first described the species, I have stated that Ceraiocolax penetrates into the medullar tissue of Phyllophora and sometimes even reaches the opposite face of the frond. In the Danish specimens I have never found the parasite penetrating so far into the host; usually the bound- ary line between the two organisms is situated nearly at the level of the surface of the host or is a little elevated towards the middle (Plate VIII, fig. 5). The limit is usually fairly distinct, though it is not always possible to say with certainty whether a cell belongs to the one or the other Fig. 534. Ceratocolax Hartzü. Vertical section of the of the two organisms. This is in particular so in marginal zone growing in the outer wall of sed 2 Phyllophora. The walls of the parasite are the central part of the limiting zone. The parasite 4 ine. The undermost cells of the parasite has a softer consistence than the host, and its penetrateintothecell-wallsofthe host. 670:1. walls swell much more when treated with distilled water and various reagents; I also in some cases succeeded in obtaining a sharp boundary line when staining with hematoxylin after HEIDENHAIN and then with 549 orange or safranine, the walls of Phyllophora staining intensely while those of Ceralocolax remain unstained or much feebler stained (fig. 534). In thin vertical sections it is then in some cases possible to observe, at the periphery of the insertion of the parasite, that the latter penetrates into the ouler cell-wall under the cuticle, lifting the latter and sending thin haustoria from the lowermost cells into the cell-walls of the host (fig. 534). The cells are usually very small at the periphery of the insertion while they are much larger at the centre where it may sometimes be rather difficult to distinguish the cells of the two organisms from each other (Plate VIII, fig. 5, 6). But it is often evident that medullar cells of the host are separated from their neigh- bouring cells and incorporated in the tissue of the host as described already in 1898 (fig. 8 A). In the plant represented in fig. 531 the lowermost part has the character of an attachment disc growing under the euticle of the host plant (comp. Plate VIII, fig. 5), and such a disc may sometimes have a considerable extension. An unusu- ally strong development of the attach- ment dise is shown in Plate VIII, fig. 8, where it is very thick and encompasses the marginal part of a frond of Phyllo- ee phora. More frequently, however, the limit Ceralocolax Hartzii. dpe ee the limiting zone between the parasite and the host is in between the parasite and the host. 550 : 1. the angle where the short cylindric stem meets with the surface of the host (fig. 530 À, Plate VIII, 4). It seems further to happen sometimes that the lowermost portion of the parasite is encompassed by a funnel-shaped outgrowth from the host consisting of a continuation of the cortical tissue of the latter, as shown in Plate VIII, fig. 7, where the medullar tissue of the host, too, extends considerably upwards in the centre of the stem. It is owing to the firm consistency and the high staining power of the cell-walls of the funnel- shaped cortex that it is assumed to belong to the host-plant. On the other hand the parasite may penetrate into the host-plant (Plate VIII, 4). When the small cells of the parasite meet with the large medullar cells of the host, they penetrate partly between, partly into the cells. The formation of secondary pits is very lively on both sides of the boundary line, and pits between the host and the parasite may be observed (fig. 535); but in other cases the medullar cells are invaded and often filled with the small cells of the parasite and then evidently killed (comp. fig. 535 to the right and Plate VIII, 4), and a number of the cortical cells must also have perished as a consequence of the attack of the parasite. As mentioned above, nemathecia were observed by Scumirz (1893), DARBISHIRE 550 (1894) and myself (1898). They are very common in the Danish waters in spring. The branches of the nemathecia-bearing plants usually terminate in a globular swelling, and the nemathecia arise on the surface of these swellings. Nothing has been found to support the supposition of a genetical relation between the inter- cellular conducting tissue and the nemathecia, for the said tissue is only to be found at a certain distance below the young nemathecia. These arise by simultane- ous division of the peripheral cells on a long stretch by periclinal walls, with the result that the surface on the stretch in question is covered with close anticlinal cell-rows (fig. 531, Plate VIII, fig. 9). The cells of these rows are rounded oblong or ellips- oidie and have an abundant plas- matic content; the thin plasmatic threads connecting the cells of the filaments are often easily visible in the young stages (fig. 536 D), later they could not be observed, and the regular arrangement of the cells is usually disturbed in the microtomized sections owing to the swelling of the intercellular substance. The nemathecia have often a limited extent, but two or more young nemathecia may fuse to- SS Ceratocolax Hartzii. ee cats filaments. 4,nuclei gether; the best developed ones in the resting stage, ROSE ET, April and May. C—D, nuclei form globular bodies at the end in the first division. E, sporangia two- or four-parted. F, sporangia four-parted. 625 : 1. of the branches about */2 mm in diameter (fig. 530 A, 531). In such cases the nemathecium occupies only the outer portion of the globular body while the central part is a parenchymatous tissue identical with the medullary tissue of the branches. The last one or two cells of the nemathecial cell-rows are sterile, the others develop into sporangia. The number of the fertile cells in the cell-rows is usually only 6 or 7. Fig. 536 A shows young sporangia with nuclei in the resting stage, but, without distinct chromatophores. Nor could the latter organs be distinguished in the later stages, perhaps with the exception of fig. 536 B where some of the seriate small bodies may possibly be reduced chromatophores. The dividing nucleus is lengthened with pointed ends, often curved and eccentric, sometimes of the same length as the cell. I regret that I was not able to observe the chromosomes in material treated with Flemming’s weaker solution or with formalin-sublimate. The spindle-shaped bodies were often found divided in the middle, but the following divi- sions were not observed, so that it was not decided whether the next nuclear divisions take place before the first cell-division. At any rate, the sporangial cell is first divided ee 551 by a transverse wall and afterwards by two longitudinal walls (fig. 536 E, F). The ripe sporangia are colourless; they contain a dense mass of protoplasm and numer- ous very small starch-grains. Chromatophores could not be detected, but colourless plastids are probably present. Young nemathecia with cells in the resting stage were met with in February, but as early as March four-parted sporangia were found, though most of them were still undivided, and in April and in particular in May numerous ripe sporangia were observed. Sporangia were rarely met with in June and never after that month. The ripe sporangia are 9—19 w long, 8—11 w broad, most frequently 14—15 w long, 8,5—10 w broad. — Single long sterile cells may occur between the sporangia; they are most easily observed in partly emptied nemathecia. The sexual plants differ from the sporangia-bearing ones by having no swollen globular ends. They are often much branched at the tips, but these branches have only the character of small warts (fig. 530 C). In sections of such irregular tips of the frond procarps may be found, often several —— HW ae A SR en of procarps were m Wy sn) observed in several plants, but only incom- So Ba pletely developed. The fertile character of these 0 lø 4° groups of cells is disclosed by their size and RER ©; their abundance in plasmatic contents. When treated with hæmatoxylin after HEIDENHAIN they remained nearly black even after diffe- Fig. 537. tiati FOR 1 2 that tl tr Ceratocolax Hartzii. Procarps, two with protruding rentiation tor a long time, so a ne struc- trichogynes. August. 625 : 1. ture of the cells, in particular the presence of nuclei, could not be distinguished. Only in a specimen gathered in November and treated with formalin-alcohol it was observed that most of the cells of the procarps contained several small nuclei (fig. 539). The best developed procarps were found in specimens gathered near Samso in August. Fig. 537 C shows such a pro- carp with long, protruding trichogyne; the carpogonial branch is here three-celled and borne on a large cell which is probably an auxiliary cell, much as in Phyllo- phora Brodiei. Spermatia adhering to the trichogyne like those observed by Darsi- SHIRE, I have never observed. The other procarps from the same plant (fig. 537 A-B) can probably be interpreted in a similar manner, a trichogyne, however, being only developed in fig. A. In both procarps a lateral cell is borne on the first cell of the carpogonial branch. Feebly developed trichogynes are shown in fig. 538 but at any rate in some of the procarps here represented a three-celled carpogonial branch cannot be pointed out, and the procarps shown in fig. 538 C, too, can scarcely be reconciled with the type of a three-celled carpogonial branch. If the three-celled row of dark cells in fig. A is a carpogonial branch, a lateral cell is borne on its second cell. Fig. B apparently shows a supporting cell with two an > POS OO Fig. 538. Ceratocolax Hartzii. Incompletely developed procarps. June. 625:1. two-celled carpogonial branches. The interpretation of fig. C is difficult; to the left is shown what seems to be a three-celled carpogonial branch, but to the right of it two trichogynes are seen, the connection of which with carpogonial branches is doubt- ful. Nearly all the procarps observed had no well deyeloped carpogonium and no trace of a trichogyne. Procarps were observed in nearly all the months of March to No- vember, in particular from May to November. They thus occur partly at the same time as the nemathecia, partly (after May) alone. Any indication of a further development of the procarps, in particular from the auxiliary cells, was not observed, and cysto- carps are unknown (comp. aboye). As mentioned above, DARBISHIRE observed spermatia adhering to the trichogynes (1894, p- 369), but he did not describe the antheridia and spermatia. I have often seen what I supposed to be antheridia, most frequently in procarp-bearing specimens but I am not fully convinced of their sexual character. In sexual individuals the outer cortical cells are often disunited to a greater or less extent, in particular in specimens treated with FLEMMINGS solution, and the outer cortex then consists of oblong or short cells imbedded in a hyaline gelatinous substance. The cells are not very different from the ordinary cortical cells but often contain a very distinct nucleus, situated near the lower end of the cell and stained intensely by treatment after HEIDENHAIN; the subjacent cells may then be the antheridia-producing cells (spermat- angial mother-cells, SVEDELIUs). Comp. fig. 540 (Plate VIII, fig. 10). If the here described cells are really antheridia, the species is usually monoecious. Fig. 539. Ceratocolax Harizii. Procarps with short trichogynes or without trichogynes. Nuclei visible in most of the cells. November. Sublimate-alcohol. 625 : 1. Evacuated tetraspores have not been observed, nor their germination, but young plants raised in a culture were met with. On the 25th of May 1929 specimens 553 of Phyllophora Brodiwi partly beset with Ceralocolax Hartzii bearing ripe tetra- sporangia were placed in a glass vessel with sea-water and kept there for a long time. Three months later a number of young plants of Cerato- colax had arisen on other fronds or other shoots of Phyllophora, undoubtedly from tetraspores set free from the nemathecia, eo comp. fig. 541. In the middle of September these specimens 0 O00 Q 0) contained no organs of reproduction. In April 1930 the tips of the branches of one of them were globular and turned out to be 9@ @ ge nemathecia, being composed of radiating cell-rows. Some of the v® = cells of the latter were 4-parted, but the sporangia were not = quite normal, probably owing to the unfavourable conditions of the Fig. 540. 3 “9 atts Ceratocolax Hartzii. Sup- culture. It must then be concluded that plants arisen by germina- sea antheridia. Au- tion of tetraspores are able to produce tetrasporangia directly. gust. Formalin. 625 : 1. The tetraspores seem to be the only reproductive cells which reach normal development, at any rate in the Danish waters. They are pro- duced in spring, particularly in March to May. The sex organs are abortive and cystocarps are never produced. The specimens gathered after June never contain nemathecia but only sex organs, at least procarps, and might therefore be designated as gametophytes, but sex organs may also appear in the spring months, particularly in May, simultaneously with the nemathecia. It is pos- sible that there exist distinct sexual and asexual indi- viduals, resp. gametophytes and sporophytes, bul at any rate in some cases procarps and nemathecia were found with certainty in the same individual, and this is perhaps a normal occurrence. It seems that sex organs normally arise in specimens first producing tetrasporangia, but this point deserves further investigation. The Danish specimens have here been referred to the same species as the Greenland ones though there are or seem to be some differences. In specimens from East Greenland the parasite was found penetrating deeply into the frond of Phyllophora, deeper than in the Danish specimens, but I have later found Greenland Fig. 541. specimens where the connection between the two orga- Ceratocolax Hartzii. Nearly 4months nisms was much as in the Danish specimens. Another eae denied heen difference is that sex organs have not been observed in deposited in May specimens of the Greenland specimens, but that may perhaps be due to Phyllophora Brodiei, one of which insufficient investigation. Finally the sporangia seem to bore a nemathecium-bearing Cera- 5 . . tocolax. Drawn in September. 2:1. be larger in the Greenland specimens than in the Danish ones; in the former I found them 22—26 w long, 12-16 u broad, while in the latter they were only 9—19 w long, 8-11 # broad; but the dimensions of the sporangia seem to be variable. D.K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. ogmathem. Afd. VIT. 4. 71 In the Arctic Sea Ceratocolax Hartzii has been found with ripe tetrasporangia in spring (March, May), just as in the Danish waters. But it is remarkable that unripe nemathecia have been met with repeatedly in summer, June (West Green- land), August (East Greenland), July and September (Arctic America, K. ROSENVINGE, 1926). It seems probable that nemathecia occur all the year round in the Arctic Sea. The systematic position of the genus Ceratocolax remains uncertain so long as cystocarps are unknown, and the sex organs are only known as imperfectly devel- oped and abortive. An affinity to the genus Phyllophora on which it is parasitic is highly probable. The species is spread in nearly all the Danish waters, in particular the inner, more protected waters where it occurs at depths from 2 to 18 metres, perhaps most frequently on Ph. Brodiei f. concatenala. It is met with in all seasons and reaches a diameter of from 2.5 to 5 mm. The greatest diameter, 5 mm, was met with in specimens gathered in May and September. Localities. Ns: On Ph. Brod. f. concatenata at Blaavandshuk (C. M. Poulsen). — Lf: LY, on Ph. Br. concat., between Gellerodde and Inderrön at Lemvig. — Kn: At Friis’ Sten between Vesterø and N. Renner, on Ph. Br. typ. 3m. — Ke: HY, Store Middelgrund, 15 m, on Ph. Br. typ.; ad Nakkehoved (Lyngbye), on Ph. Br. typ., washed ashore. — Sa: fN*, off Ballen, Samsø, 11.3 m, on Ph. Br. typ.; Hof- mansgave, on Ph. Br. concat., numerous specimens gathered by Hofman Bang, Lyngbye, Car. Rosen- berg. — Lb: Off Snoghøj; Fænø Sund; dE, Holst’s Banke 8—13 m, on Ph. Br. typ.; dH and dH’, east of Hesteskoen, 15—19 m, on Ph. Br. typ. — Sf: CA, Højen near Faaborg, on Ph. Br. concat. and filiformis (fig.517 C).— Sb: Off Stavreshoved at Kerteminde; Bay of Kerteminde, on Ph. Br. concat.; NS, between Knuds- hoved and Slipshavn, on Ph. Br. concat.; XS, Kloverhage south of Nyborg, 5—6 m, on Ph. Br. concat.; fP, ‘/2 mile east of Hov lighthouse, 10 m, on the same; UJ, near the broom at Onsevig, 7.5 m, on the same. — Su: OH, north of Lous’ Flak, 10 m; at Dragør, on Ph. Br. concat. — Bw: bV, N.E. of Kobbel Skov, 7—13 m, on Ph. Br. conc.; bY, off Sønderskov, Sønderborg 11 m, on the same; cD, Middelgrund south of Als., 8—12 m, on Ph. Br. typ. Ahnfeltia E. Fries. 1. Ahnfeltia plicata (Huds.) Fries. El. Fries, Corpus florar. provincial. Sueciæ. I. Flora Scanica 1835, p. 310; J. Agardh, Sp. g. o. Alg. II pars I, 1851, p. 311; N. Wille, Bidr. (1885) pp. 13, 15, 50, plate II, figs. 11—12, plate V, fig. 52; B. Jönsson, Dickenwachst. 1891; Buffham, Anther. (1893), p. 302, fig. 43, 44; Schmitz, Actinoc. 1893, p. 397; Printz, Trondhjemsfj., (1926), p. 63; Gregory, New light on the so-called parasitism of Actinococcus aggregatus K. and Sterrocolax decipiens Schm., Annals of Bot. Vol. 44, 1930; Chemin, Ahnfeltia plicata Fries et son mode de reproduction. Bull. soc. bot. de France, t. 77, 1930, p. 342; Kolderup Rosenvinge, The reproduction of Ahnfeltia plicata. K. D. Vid. Selsk. Biol. Med- delelser, X, 2, 1930. Fucus plicatus Hudson Fl. anglica, ed. alt. 1778, p. 589. English Botany, Vol. 16, 1803, plate 1089. Fucus albus ? Oeder, Flora Danica, tab. 408, 1768. Gigartina plicata Lamouroux, Thalass. 1813, p. 48; Lyngbye, Hydr. 1819, p. 42. Gigartina Griffithsie Lyngbye Hydr. 1819, p. 43, tab. 11 C, (non Turner)’. * An examination of the specimens from Funen referred by LyxsByE to Gigartina Griffithsiæ has shown me that the “tubercula” interpreted by LyneByE as “fructus” are not nemathecia but attachment discs of Cystoclonium purpurascens growing on Ahnfeltia plicata. Gymnogongrus plicatus Kützing, Spec. Algar. 1849, p. 789; Tab. phyc. 19, 1869, pl. 66; Harvey, Phyc. Brit. Vol. III, 1851, plate 288. Sterrocolax decipiens Schmitz, Actinoc. 1893, p. 397. The upright fronds spring from an expanded, thin firm disc intimately attached to the substratum, always stones, of a characteristic violet blue colour. By the colour it is usually easily distinguishable from other incrusting Floridez, as for instance Hildenbrandia prototypus, which has a similar consistence but is either blood-red or yellow. The crust may reach a considerable extension before the first upright frond arises. Young fronds 1—5 mm high are often met with singly on the sides of stones picked up in summer at 1 to 2 metres’ depth (fig. 542). But young fronds in greater number placed close together may also occur; then it is not always easy to decide whether they spring from one particular dise or from several fused together. Old specimens form light bushes composed of numerous fronds Fig. 542. Ahnfeltia plicata. Young frond springing from an expanded disc. 10 : 1 (2). springing from an area of small extent. Such a case is shown in fig. 543 where Fig. 543. Ahnfeltia plicata. Cluster of fronds springing from a thin disc appearing light in the photograph, extending as far as to the dark area to the right. Slettings Grund, Store Belt. November. 3 : 1. The fronds are cylindrical, rigid, horny, branched by dichotomy and by lateral ramification. They are usually forked at the top about 100 fronds spring from an area with a maxi- mal diameter of 1 cm whereas the basal crust from which they have arisen has a maximal dia- meter of more than 2 In this case the crust has the appearance of being of single origin. The crust is built up of small almost squarish- cells, about 3 « in diameter, arranged in vertical rows, with firm, gelatinous cell-walls. The superficial cells are rounded outwards, but the outer cell-wall is scarcely thicker than the others (fig. 544). In older crusts this structure is some- times interrupted by tissue with larger, more ir- regular cells. The upright frond arises as a wart from the disc, a great number of the vertical filaments participating in it and showing divergence of the filaments, of which it is composed, and thus early showing conformity with the upper end of the cylindrical fronds. cm. not Fig. 544. Ahnfeltia plicata. Ver- tical section of crust 625 : 1. and later produce lateral branches, which have usually the character of adventitious shoots, but the lateral branches may also arise near the top. They appear in great number on the older fronds when the apical growth has TA 556 been arrested by decay. A lateral branch often arises early near the dichotomy, and may then later suggest a trichotomy (fig. 545 A, C). Harvey's figure (1851, pl. 288) shows a specimen branched throughout by dichotomy, whereas KÜTzINGS picture 1869, pl. 66 represents a specimen almost exclusively branched by lateral rami- fication. The thickness of the frond is nearly the same in its whole length, varying from 500 to 900 w. It increases a little from the growing apex downwards, but the increase does not continue gradually from the growing apex io the base of the frond. From a short distance downwards the diameter varies irregularly between 400—500 u and 900 x. The branches are often thinner at the base than at a higher level. The cross section of the frond is circular or a little oblong. The frond may often reach a height of 16 em but searcely exceeds this size. It is unknown how long it takes before this size is reached. The growth of the perennial frond ceases in winter and begins again in early spring. In a specimen collected in the middle of May, the new portions of the frond were 1 to 1.5 cm, long, but I have not ascertained the annual increase in length of the frond. In a vigorous specimen from Frederikshayn (Deget) gathered in the middle of July I judged the increase of the year to be up to 3 cm, and I think that the annual increase in length will not generally exceed this figure. If this is correct. | the tallest specimens should be at least 5 years 4 i old. But the specimens may certainly become much nen older, for many shoots die entirely or in part and are Ahnjelia plicafa. A, frond branched £ by dichotomy. B, frond with dicho. replaced by new lateral shoots. In autumn specimens tomous and lateral ramification. C. may be met with in which a great number of the frond mainly with lateral ramifica- > > = i Hm OLES shoots have white tips, a sure sign of death and decay. The species often forms large carpets covering the upper or lateral faces of larger stones. Such carpets may certainly attain a great age, owing to the power of the expanded basal layer to produce new fronds. The colour of the frond depends on the amount of light to which it is exposed. When growing in shady places it is lurid, showing a characteristic violet tint when observed against the light, and the same is the case with the lower parts of older fronds in the shadow of the younger ones, but the upper part of ihe fronds which are exposed to the full day-light in summer are prettily green, in autumn yellowish green. In winter the young portions of the fronds are much darker, not very different in colour from the older ones. JONsson thinks that the darker colour of the older 557 fronds is caused by the new cortical layers becoming darker than the foregoing ones, and that the lowermost parts of the fronds are the darkest because they contain the greatest number of cortical layers. In my opinion the dark colour of these portions of the frond is due to the fact that they are best protected against the destructive action of the light upon the phycoérythrine. I have once, at Frederikshavn (Borre- bjergs Reef), met with a frond having the ordinary lurid-violaceous colour, but bearing a branched shoot, 6.5 cm long, having a pronounced blue-green colour contrasting with the colour of the rest of the frond. This shoot was at least 2 or 3 years old. It evidently contained much phycocyanin but not phycoërythrine. ft NAT M) M The apical meristeme of the frond is built up of numerous thin, closely united filaments directed vertically U y AHUU towards the periphery and thus diverging. The outer cell- IN DONNA? rows are gradually, by the growth of the frond, directed OS) u A vertically to the longitudinal axis of the frond. The diameter \() () Ve of the outer cells is about 3.5 w, and the superficial cells are (de (V © scarcely thicker in the older parts of the frond. These rows NY 1 of cells branch frequently in the meristematic portion of the frond, the apical cell dividing by an oblique cell-wall by which (N a new apical cell is cut off, while a branch is produced from / Al the segment cell, the upper portion of which is cut off by a B cross wall (fig. 546 B). À The central part of the frond is built up of long . PE De Ahnfeltia plicata. A, vertical cylindrical cells with very rigid refractive cell-walls, giving the section of apical meristeme. central cylinder the character of a mechanical tissue (comp. 2; from a similar section = showing ramification of the WILLE, 1885, p. 13, 50, Plate II, fig. 12, V, fig. 52). The cells cortical cell-rows. 625 : 1. are terminated by transverse walls which are about as thick as the longitudinal ones; they do not, therefore, seem much adapted to the function of conducting substances, so much the more as the central pits are very thin and not easy to observe (fig. 547). The length of the cells is, however, great, though very variable; some cells were very long, up to 780 w long, others much shorter, and it seems that a distinction can be made between very long-celled filaments and others consisting of short cells; the latter are perhaps of secondary origin. At the peri- phery the cells are shorter and gradually approach the inner cortical cells in size. WILLE (1885, p. 50) attributed Ahnfeltia plicata to the Florideæ with incompletely developed conducting tissue; he considered the last-named tissue, situated between the mechanical and the assimilatory systems, as such a conducting tissue. It, however, seems more adapted to a conduction between the assimilatory tissue and the central cylinder than for conduction in a longitudinal direction. The central cylinder has not only a mechanical function but also serves as storage tissue; I found the cells filled with starch-grains in summer and autumn (July to October) whereas in fructiferous plants they were without starch in spring (March to May). The intermediary 558 tissue thus serves to convey the products of the assi- milation to the central cylinder, and later to transport the dissolved nutrient media from the central tissue to the periphery. The cortex has about the same structure as the basal disc; it is composed of small, nearly squarish cells with slightly rounded angles, arranged in radial rows having the same diameter in their whole length (comp. KüTziNG, 1869, pl. 66, fig. e, WILLE, 1885, fig. 11). The cell-walls are moderately thick, the outer wall thicker, firm, not gelatinous. The whole cortex has a firm structure owing to the small diameter of the cells, and certainly contributes to the rigidity of the frond. The cortical cells contain one small nucleus. The chromatophores are not easy to distinguish owing to the small dimensions of the cortical cells. There often seemed to be one parietal plate at the upper end of the cells; but in a specimen treated with FLEN- MING’s weaker solution and stained after HEIDENHAIN with erythrosin and examined under high power several disc-shaped chromatophores Fig. 547. were observed in each cell, eg mes SIMONI hn 1S, BAS) 18), GEIR also the primary pits are to be seen. Secondary fusions between cells of different cel — rows now and then appear (fig. 548 A). The cortex of the older fronds shows a stratification which is the LUE effect of a periodical increase in thickness, which has Bron been the subject of a thorough investigation of B. JOns- 0 SON (1891). The growth in thickness takes place in toit the outermost layer of cells which keep their dividing * \ power. This, however, is not always in activity but is DOGS interrupted by resting periods leaving their trace in Øg C boundary lines characterized by thicker and more re- Fig. 548. fractive membranes. Jonsson thinks these boundary lines {nnfeltia plicata. Transverse sec- arise because the walls of the outermost celis become thicker nn ena and more refractive than the inner walls during the resting showing pit-connections and chro- period, whereas the new cells formed at the beginning Re are EN Sam of the growing period have comparatively thin walls. This layers (*) 1200 : 1. explanation is certainly true but the figure (l.c. plate I, fig. 4) illustrating it does not give a true idea of the real structure. The boundary line is shown by Jønsson as a continuous thick wall corresponding to the outer wall of the frond, 559 whereas the radial walls show no thickenings. This is undoubtedly due to the fact that the drawing has been made from a section which was not sufficiently thin. In examining a section only one cell thick it is evident that the thickenings in particular con- cern the radial walls. In the cells situated at the limit between two cortical layers the radial walls are much thickened at the base but the thickening diminishes upwards, with the consequence that the lumen of the cell is conical downwards and the area of the basal wall is very small. Thus no continuous thick transverse wall arises by Fig. 549. theminekeningmotethestransversesswall, but ithe, Afufelltaiplicatas Crossisection of older trond 2 x showing several irregular layers in the cortex. thickened lower parts of the radial walls of 83:1. the limiting layer of cells appear in thick sec- tions as a thick refractive wall traversing the cortical tissue. The presence of a continuous thick transverse wall would not be easy to reconcile with the explana- tion given by Jönsson, and it would be very unfavourable for the conduction of matter in a radial direction. In older fronds, Jönsson usually found from 4 to 6 cortical layers, once up to 12. The layers may be regular, but irregularities occur, the layers being incom- plete, encompassing only a part of the stem, or secondary layers appear within the ‘primary ones, dividing them, over part of their extent, into two or three subdivisions. Printz (1926, p. 63), who often found 6—8 layers, thinks that they indicate the number of years, while Jonsson speaks with reservation of this question. I found the stratification so irregular in some cases that it was impossible to state the number of the layers. On one side of the frond the number of layers was high, e.g. 9, while on the other side it was much smaller owing to the fact that some boundary lines were vanishing, others confluent (fig. 549). Moreover, it was not always possible to distinguish the secondary layers from the primary ones. If the layers were regular annual pro- ductions like those of the ligneous Dicotyledons, one might expect to find the number of layers increasing from the top downwards; but that is, at any rate, not always the case. For in a large specimen I found about 3 layers near the base, at a higher level about 7. The diameter of the stem and the thickness of the cortex was also smaller than at a level one cm higher up, namely 530 w and 130 « against Fig. 550. Ahnfeltia plicata. 2 : End of frond 670 w and 248 w. In the same frond the thickness of the cortex with nemathecia. i arly ‘ as 057125; December. 2/,:1 increased from the top to nearly one cm above the base (100; 125 158; 178; 200; 248 u). In this case the cortex has thus continued growing except in the lowermost part of the stem. A regular increase of the number of cortical layers could not however be ascertained in this case. 560 The older fronds are often beset with warts which have nothing to do with the fructification, nor do they seem to be undeveloped young branches, for they do not show the anatomical differentiation of the latter and must be considered as luxuriations of the cortex and may show stratification like this. Sometimes a cavity produced apparently by some parasite was found at the bottom of it, having its base at the inner limit of the cortex, and partly filled with what seemed to be decayed remains of the cells of the host which took a deep blue stain by methylen blue. They had an opening at the top of the wart and had been left by the parasite. It seems doubtful, however, whether the warts had really been caused by the supposed parasite, for in other warts no cavity seemed to be present, and similar cavities were found without causing such warts. In other warts the cavity was found filled with a granular matter which seemed to be small bacteria. The first described cavities have perhaps also been in- habited by bacteria which have left them later. The bacteria observed were very small; there seemed to be cocci and short rods. SCHMITZ has described tubercles containing bacteria in several other Florideæ (Botan. Zeit. 1892). Tee Fig. 5519 s Reproduction. The reproduction of Ahn- Ahnfeltia plicata. First origin of nemathecia. September. 670 : 1. feltia has been imperfectly known and disputed until quite lateiy. From the beginning of the ninetienth century, at least, cushions on the frond have been described and usually considered as the fructification of the species. LyNGByEe (Tent. 1819, p. 42) observed them in spring but did not meet with any spores. C. AGARDH (Spec. alg. 1822, p. 313) stated that they were composed of articulate filaments and named them nemathecia. Kitzinc (Tab. phyc. 19, tab. 66, 1869) thought that the nemathecial filaments were transformed into seriate spores, but that has not been confirmed. The spores were first described by BurrHam (1893, p. 302) and Schmitz (1894, p. 397) who found that the spores are only produced in the end-cells of the nema- thecial cell-rows, these cells each giving rise to one monospore. SCHMITZ submitted the nemathecia to an anatomical investigation and arrived at the conclusion that these bodies were not organs of the Ahnfeltia but that they were parasites, which he called Sterrocolax decipiens, growing on the surface of Ahnfeltia and penetrating into the cortex of the latter by numerous “Senker”. But this inference was only founded on the presence of the said processes and not on the study of the develop- ment of the nemathecia or of the “Senker”. Hence ScHmiTzs inference is not conclusive, and it would lead to the absurd conclusion that no kind of reproduc- tive organs had ever been observed in Ahnfeltia plicata. To elucidate the question of the nature of the nemathecia I have examined their development and the ger- mination of the spores. The results of my investigations have been published in a particular paper (1931) where 1 have also mentioned two smaller papers of GREGORY and CHEMIN treating the same question and published shortly before the publication 561 of mine. Referring the reader for details to the latter, I shall here shortly give its substance, using again most of its illustrations. The nemathecia form small cushions on the surface of the frond, orbicular or usually elliptical or oblong in outline (fig. 550). They arise in September from a group of superficial cells growing out simultaneously and dividing by cross walls (fig. 551). In September the cushions were only 1—2 cells high; in the middle of October the nemathecial cell-rows had grown longer, and the nemathecia had attained a larger extension by continued produc- tion of new nemathecial filaments at the margin (fig. 552). The continuity of the nemathecial fila- ments with the cortical cell-rows was stated in Wee nel a Øg HR Sean FEU Fig. 552. | SSIES 775) 2 CSI a) ®) SAGE Fig. 553. Ahnfeltia plicata. From a nemathecium, October. A, nemathecial filaments show- ing flask-shaped cells below and genera- tive cells above. B, upper end of primary nemathecial filament. C, flask-shaped end-cell. 1080 : 1. 1930 by GREGORY Ahnfeltia plicata. Nemathecium, October. A, vertical section, 244:1. B—D, upper ends of and CHEMIN. The nemathecial filaments with generative cells. first-named author 670 : 1. maintained that the development of the cushion begins with a localized hypertrophy of the cortical tissue of Ahnfeltia. The nemathecial filaments are very thin, often only 2—3 u broad. At this period (October) two kinds of cells different. from the others appear. 1) flask-shaped cells, attenuated upwards, often appear in great number at the bottom of the nemathecium, arresting the growth of the filaments on which they are terminal (fig. 553). They have some resemblance to carpogonia but are not borne on particular cells comparable to carpogonial filaments and have only a small and feebly developed nucleus, and they cannot, therefore, be considered as true carpogonia but might probably better be interpreted as reduced hair- cells (comp. K. RosENVINGE 1931, p. 8). 2) genera- tive cells, thicker and richer in contents than the other cells, terminal or lateral, arise at the upper end of the nemathecial cell-rows, singly or in small groups which seem to arise by division of a single cell. The generative cells or some of them grow out, at first in particular in a horizontal direction, forming more or less irregular cell-rows, the cells of which are larger than the sterile cells. Some of them may be rather hyaline D.K. D. Vidensk. Selsk. Skr.,7, Række, naturvidensk. og mathem. Afd., VII, 4. 72 = Sa (=) OS Fig. 554. Ahnfeltia plicata. Vertical sections of nemathecia, October, showing groups of generative cells and horizontal or obliquely upward growing cell-rows springing from them. 625 : 1. and poor in contents, while others have a rich plasmatic content (figs. 554, 555). Fig. 555 A shows the border of a nemathecium the outer portion of which is built up entirely of generative cells and their deri- vates. In fig. 554 B is shown a group of generative cells, situated at a low level in a nemathecium, from the upper cells of which new branched cell-rows growing obliquely upwards are produced. The lower part of this group is reminiscent of the “Senker” described by Scumirz. In specimens collected in the middle of November the nemathecia had grown thicker and had also increased in circum- ference (fig. 556, Plate VIII, fig. 11). The generative cells which have arisen in October are found again in the lower portion of the cushion, partly immediately over the limit towards the cortex, partly ata somewhat higher level. They are easily recognisable by their greater size, their irregular shape, their dense cell-contents and their high staining power. A great number of upward growing cell-rows issue from them (figs. 557, 558). These cell-rows resemble the primary nemathecial filaments, but are, at any rate at first, somewhat thicker than the primary ones; they form new, secondary nemathecial filaments constituting the upper layer of the nemathecium. The irre- gular shape of the genera- tive cells depends partly on the fact that fusions often take place between cells from different cell- rows (fig.557). It is prob- ably these fusions to which GREGORY refers (1930, p. 768), when he thinks it possible that they may represent a very much reduced sexuality. The nuclei of these cells were usually not very Fig. 555. Ahnfellia plicata. From a nemathecium, October. A, vertical section of the border. B, generative cells giving rise to horizontal cell-rows. C, generative cells and flask-shaped cells. A 960 : 1. B and C 1080: 1. 563 TPS UTP 1/7 We distinct; at all events nothing has been found to support such an assumption, and it must be remembered that fusions occur between ordinary cortical cells too (comp. p. 558). The development of the primary nema- thecial filaments is to a great extent stopped by the formation of the flask-shaped cells and the generative cells; these filaments are replaced by new, secondary nemathecial filaments, and it Fig. 556. seems: probable that the development of the Alfa plicata. Vertical section of nemathe- cium, November. 160 : 1. other primary nemathecial filaments, which have not produced any of the aforementioned particular cells, is also arrested after the formation of the generative cells and their derivates, so that the upper layer of the nema- thecium is exclusively or for the most part built up of secondary nemathecial cell-rows. The marginal portion of the nemathecium is composed in the winter months of horizontal cell-rows which have probably taken their origin from generative cell-rows or their derivates like those shown in fig, 555 A, and must therefore be considered as secondary nemathecial filaments. The under side of the peripheral part of the nemathecium is appressed to the surface of the frond, but the under- most nemathecial cell-rows are not connected with the cells of the cortex (fig. 556). The narrow cells of the secondary nemathecial filaments contain a small nucleus and one or morechromatophores. The apical cell has more plasmatic con- tents and a larger nucleus. It is at first scarcely thicker than the other cells but, when the cell-divi- sions are finished, it takes an oblong or obovate shape and develops into a mono- sporangium. This or- gan contains 2 to 4 TUE \ Fig. 557. or more very distinct Ahnfeltia plicata. Vertical section of lowermost part of nemathecium, November chromatophores, most The irregular cells rich in plasmatic contents are situated at the level of the sur- 2 face of the frond*. 1080 : 1. frequently rod-shaped or ribbon-shaped, and it is remarkable that these bodies not seldom were found lying in pairs close together (figs. 560, 561). My assumption is that they were on the point of fusing together DE 72 564 along their longitudinal axis. It is in accordance with this interpretation that the ripe monospores seem to contain one single chromatophore (fig. 562 G). The nucleus of the monosporangium is most frequently found in the resting stage, showing a large nucleolus or central body surrounded by a well marked hyaline halo but no chromosomes. x In other cases the central body was differentiated into small grains staining intensely with hæma- & <= toxylin. When they were most distinct, the number # DB Pre ET ES EIN Sg, % DAS ~ < = VE UZ; of the latter was seen to be four (fig. 561). In a Hate ME å a dividing nucleus (fig. 561 42) two groups of such IF "00 | 4 grains were to be seen. There can be no doubt = that these grains were chromosomes. When GRE- UP SER Gory (l. c. p. 768) states that “There is some re de an evidence that there are eight chromosomes in the apical cells and in the monospores of Sterrocolax decipiens”, it seems probable that this remark alludes to such dividing stages. The nuclear divisions observed were evidently all mitotic, and no indication of a synapsis stage or a heterotypic division was ever met with. It must be concluded from my investigations that the chromosome number of the (secondary) nemathecial filaments and the monospores is 4, and the nuclei of the frond seem to have the same number (comp. K. RosENVINGE 1931, p. 19). The monospores ripen in winter and are still to be found in May. The ripe sporangia are ellipsoid or obovate. The number of chromatophores in the ripe sporangia is not easy to observe in fixed and stained material; there is a great amount of matter staining with hematoxylin surrounding the nucleus. A further fusion of chromatophores perhaps takes place here. After the evacuation of a Fig. 559. Fig. 560. Ahnfeltia plicata, November (Flemming, Heidenhain). End-cells Same material as fig. 559. Four end- of (secondary) nemathecial filaments showing nucleus and chro- cells from the same section showing matophores. In F the limitation of the nucleus is indistinct, a nucleus and chromatophores, the latter group of ‘4 chromosomes is situated to the right of the central apparently partly fusing together. body. 1800: 1. 1800 : 1. 465 monosporangium, a new sporangium can be developed from the cell beneath it (fig. 562 D, E). The ripe nemathecia are yellowish. Germination of the monospores. CHEMIN (1930, p.350) has observed the first stages of the germination of the spores and stated the interesting fact that the attachment disc does not arise directly by cell-divisions of the spore, but that the germinating spore first gives off a short germ tube which by segmentation forms a small orbicular disc. This (may be contiguous to the spore cell or connected ©. Fig. 561. Ge Ahnfeltia plicata. From a nemathecium from Frederikshayn, Fig. 562. Henn. Petersen, May (Alcohol, Heidenhain). End-cells of nema- Ahnfeltia plicata. A—F from the same material as in thecial filaments showing very distinct chromatophores partly fig. 561. Ripe monospores are present in C. The nar- paired, and nucleus. In A‘ the nucleus is apparently in the row, clavate intensely stained cells in E are perhaps first dividing stage, in A*, the nucleus has lately divided and end-cells of obliterate primary nemathecial fila- the two daughter nuclei show each four chromosomes but ments. G, living spore set free in May. A—D 670 : 1. are still without nuclear membrane. 1800 : 1. E—F 1080:1. G 670:1. with it by one or two cylindrical cells. This mode of germination agrees with that found in Gloiosiphonia capillaris (comp. the present work, part II, p. 277; comp. also Dudresnaya (Kıruıan, Entw. Florid. 1914, p. 238). According to CHEMIN the proto- plasm of the ripe spore is colourless and does not contain any trace of chromato- phores or phycoérythrine. It was only in the two weeks old discs that “des chro- matophores pariétaux s’organisent dans les cellules les plus âgées et chaque germination apparaît sous forme d’une petite tache rose”. I did not find the spores just set free from the nemathecium colourless, but containing a yellow-brown chro- matophore and numerous refractive bodies (starch). It is probable that the single chromatophore has arisen by repeated fusions of the originally multiple chromato- phores, as described above. In the cultures established in May 1927 the first stages of the germination were unfortunately not observed. Only about three months after the sowing the young germlings were detected as small violet (not rosy) orbicular discs recalling those described and figured by CHEMIN. They were merely somewhat larger, the smallest ones consisting of about 30 cells, and no germ- tube was to be seen. In several cases the discs bore single hyaline hairs. Nor was I able to observe any germ tube on recently re-examining a slide containing numerous germlings from my culture in 1927, conseryed in glycerin. As the germ- lings were nearly three months old, it is, however. quite possible that a germ-tube may have been present but decayed later without leaving any trace. It would be of interest to see whether the germina- tion always takes place in the manner described by CHEMIN, or whether the germ disc may also arise by direct segmenta- tion of the spore cell. In CHEMIN's cul- tures the discs multiplied after two months, new filaments growing out from some of the marginal cells and producing a new disc at their extremity. Such a multiplica- tion was not observed in my cultures. Upright shoots were not given off in CHEMINS cultures nor in mine. In my older cultures. the discs increased in diameter and became thicker, the cells æn dividing by horizontal walls, in particular Ahnfeltia plicata. Se obtained by sowing mono- in the middlemost part. An old dise spores in May 1927. 4—C about three months old, in B measured 90 x in diameter. These discs åre, D a two years old germling. 4C 85:1. Dci agreed exactly in colour and structure É S i with the more expanded discs found in Nature from which the upright fronds of Ahnfeltia spring (comp. figs. 542 to 544). The discs met with in Nature often reach a considerable size before the formation of the first upright frond takes place. The principal conclusion from what has been set forth above is that SCHMITZS view that the nemathecia are of a parasitic nature cannot be upheld. The nema- thecia are outgrowths from the frond of Ahnfeltia, as maintained also by GREGORY and CHEMIN. They are the only organs of reproduction and finally produce mono- spores. Sex organs and tetrasporangia do not exist. As to the interpretation of the very peculiar mode of reproduction of Ahnfeltia reference may be made to the discussion in my previous paper (1931, conclusions, p. 21—25). Here I shall merely emphasize that the generative cells appearing in the young nemathecia are considered as reduced procarps, and that the cell-filaments growing out from them are considered as corresponding to the sporophytic phase of the typical 567 diplobiontic Florideæ. The frond and the primary nemathecial filaments make the first generation, corresponding to the gametophytic generation of the diplobiontie Florideæ, though sex organs are not produced, whereas the cell-filaments springing from the generative cells, the secondary nemathecial filaments and the mono- sporangia, belong to the second, sporophytic generation arising from the first without any process of fertilization. As no fertilization takes place and no other nuclear fusion has been observed, it must be supposed that no diploid nuclei occur, and it is in good accordance herewith that the number of chromosomes seems to be the same (4) in the two generations, and that the formation of the monospores takes place without chromosome reduction. The monosporangia must most probably be considered as reduced tetrasporangia which have failed to be divided owing to the wanting Sr 7 reduction division of the nuclei, and the nema- EIER thecia of Ahnfeltia would then be comparable to RS the nemathecia of Phyllophora Brodiei. In the x discussion in my previous paper (1931, p. 24), yet another interpretation has been taken into consideration, namely that the secondary nema- thecial filaments might be considered as gonimo- blast cell-rows. The whole complex of secondary A B nemathecial filaments would then be a compound Fig 563 bis cystocarpium and the monospores must be Ahn/éltia plicata, f. tenuior, A, from NU, off Bovense, Store Belt. B, from aV, east of Samsø. regarded as carpospores. This interpretation LAB seems, however, to be less probable than the first. Comp. SvepELius, Nuclear Phases and Alternation in the Rhodyphyceae. Beih. z. Botan. Centralbl. Bd. 48 (1931) Abt. I, p. 57. The systematic position of the genus Ahnfeltia remains doubtful, as sex organs and cystocarps are wanting. The presence of nemathecia perhaps warrants its classification among the Gigartinacecæ. la ) Ahnfeltia plicata occurs in all the Danish waters except the Baltic Sea around Bornholm (Bb), from a little below low-water mark to 10 metres’ depth, always growing on stones. Localities. Ns: Thyboren, on a groin. — Sk: Hanstholm, washed ashore; 13 miles SW by W !/2W of Rubjerg Knude light-house, 14 m, sand, a small specimen (C.A.J.); Hirtshals, the mole, stones west of the mole, Emstenen. — Lf: Common on stony ground from Kobberod, 2—4 m, to Hals mole (F. Børgesen). — Kn: Krageskovs Rev; Hirsholmene; Strandby; stony reefs around Frederikshavn; several localities north of Læsø; Nordre Ronner; TL. — Ke: Søborg Hoved Grund and Vesterlands Grund at Gilleleje; Gilleleje harbour. — Km: Vesterø harbour Læsø; XF South of Læsø; BO off Stens- nes; Gerrild Bay (Lyngbye); KG off Nordstrands Klint, Anholt. — Ks: Grenaa harbour; NB, Havknude Flak; Jessens Grund; EJ and HQ, Lysegrund; Hesselo (Lyngbye); Lynæs harbour; GG, Sjællands Rey Sa: Common on stony ground. — Lb: Common from Bogense harbour to Brandso, Linderum, at Sonder- balle Hoved and dG, Hesteskoen. — Sf: CC, Hornenæs: CA near Faaborg; Ærø (Kjærbølling); Skaaruper (E. Rostrup). — Sb: Numerous localities along the coasts from 1 to 7 metres’ depth, abundantly e.g 568 off Stavreshoved near Kerteminde at 2—4 metres’ depth. — Sm: Orehoved. — Su: Off Ellekilde and Hellebæk; Sletten harbour; Middelgrunds Fort. — Bw: Off Kobbel Skov, 1—2 m; dO, Bredegrund; fT south of Marstal, c. 10 m. — Bm: Præstebjergs Rev, 7 m. Loose form: f. fenuior Lyngbye Tent. Hydr. 1819, p. 42. In the inner Danish waters, in sheltered localities a loose form frequently occurs, in particular in the Zostera-formation, entangled among the rhizomes together with other loose Alga. It is well described by LyNGByE under the above name, and authentic specimens collected at Hofmansgave by LYNGBYE are to be found in the herbarium of the Botanical Museum at Copenhagen. It is characterized by small dimensions (about 1—2 cm in diameter) and by the thin dichotomous frond with divaricate branches. It often forms irregular clumps with the branches pointing in all directions. It propagates by vegetative division, the frond by degrees dying away at the base during continued dichotomizing at the top (fig. 563 bis). Localities. Kn: 6 miles SSW’/2W of Læsø Trindel’s light-ship, 8 m (C. A. Jorgensen); fE, east side of Krageskovs Rev, 7 m; Frydenstrand near Frederikshavn. — Km: XC, XE (Silderen), KT and XF south of Læsø; 5'/2 miles N by E%/4 E of Østre Flaks light-ship (CG. A. J.); entrance to Mariager Fjord (Th. Mortensen). — Sa: PL, Wulffs Flak; AS, Mejlgrund; aV between Samsø and Endelave, 10 m, abundantly; aY at Fyns Hoved; MQ south of Paludans Flak, 11 m; Endelave bay (Thomsen); Hof- mansgave (Lyngbye); cU and NZ north of Fyn; at the beacon east of Æbelø. — Lb: FY and AX, Bjornsknude; FZ, Kasserodde; dA, at the beacon Fyrrenden N. VI. Rhodymeniales. Fam. 16. Rhodymeniacez. 1. Rhodymenia palmata (L.) Grey. Greville, Algæ Brit. 1830, p. 93; Harvey, Phye. Brit. II, pl. 217 (1849); J. Agardh, Sp. g. 0. Vol. Il pars II (1852) p. 376; Thuret, Rech. s. la fécond. des Fucacées etc. Seconde partie. Ann. sc. nat. 4° sér. tome 3, 1855, p. 43, pl. 3, figs. 8, 9. Wille, Morph. og phys. Stud. over Alger. Nyt Mag. f. Naturvid., Bd. 33, II, 1891, p. 99. Buffham 1893, p. 294, Pl. 13, figs. 13, 14; V. M. Grubb, Prelim. Note on the reprod. of Rhodym. palm. Annals of Botany, Vol. 37, No 145, 1923; E. M. Delf and V. M. Grubb, The spermatia of Rhodymenia palmata, Ag. Ann. of Botany, Vol. 38, No. 150, 1924; Ch. Killian, Le développement morphol. et anatom. du “Rhodym. palm”. Annales d. sc. nat. 10° ser. t. 8, 1926; Printz, Algenveg. d. Trondhjemsfjordes 1926, p. 72; M. A. Westbrook, Contrib. to the cytology of tetrasp. plants of Rhod. palm. Ann. of Bot., Vol. 42, No. 165. 1928. Fucus palmatus L. Spec. plant. II, p. 1162 (1753). Fucus bullatus O. Fr. Miller, Flora Danica, tab. 770, 1778. Fucus caprinus M. Vahl, Flora Danica, tab. 1128, 1794. Fucus delicatulus M. Vahl, Flora Danica, tab. 1190, 1797. Spherococcus palmatus Kützing, Phyc. gener. 1843, p. 409. Taf. 63 I, Tab. phyc. 18, Tab. 89, 90. The frond springs from an orbicular attachment disc, but a smaller or greater number of fronds, besides the primary one, may issue from the same disc, though usually of a smaller size. An attachment disc more than 1 cm in diameter showed in the centre the remains of the decayed primary shoot, near it three fronds produced later, and at the border a | | Gy a) great number of small, feebly developed fronds. The frond | EN Ns BZ of the first year has a short cylindrical stipe which is N) | ZEN flattened upwards into the wedge-shaped base of the flat \ | || frond. This may be undivided or more or less cleft at the 1 | LATE top, the first is very often the case in the Danish waters. A B C DEZE Young plants are found in summer, e.g. on the stipes or Fig. 564. > 5 2 50 Rhodymenia palmata Young the laminæ of Laminaria digitala and L. hyperborea, and „jants growing on the frond of are easily recognisable by their structure. They must have Laminaria digitata, August. Nat arisen by germination of tetraspores produced in winter. Fa The development of the young plants has been described by Kırrıan (1926) on the basis of material from the above-named substratum. The growth of the frond stops at the end of summer. In specimens from greater depths and from the inner waters D.K.D. Vidensk. selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII.4. id 570 the frond of the first year is usually undivided or only feebly divided at the top, but adventitious shoots may be produced at the margins. Broad fronds more or Fig. 565. Rhodymenia palmata, Lille Belt. A, Fredericia harbour, June. B, Middelfart, July. C, Kongebro, August :/, nat. size. less divided were principally found in harbours where they were protected against the waves and not strongly illuminated. The ramification of the primary frond, and of the secondary segments, takes place by dichotomy or polytomy or, more rarely, in a more irregular manner, the growing power of the upper marginal zone ceasing at one or more points. KırLLıan has shown (l.c. p. 204) that a cleaving of the frond may also take place by longitudinal slits arising under the mechanical influence of the waves either accidentally or in certain predestined places, much as in the Laminarie. It seems, however, that this mode of division is rarely realized in the Danish waters where the species never occurs in places so much exposed to the influence of the waves as on the rocky shores of the Atlantic. è Adventitious shoots arise at the margin of the frond in autumn and winter and grow out in the spring months to new assimilating frond segments. Their number is vari- able and their arrangement indeterminate. The segments are contracted at the base into a stipe, and this is usually so for the apical segments as well as for the lateral ones, and they have then all the character of adventitious shoots. Sometimes, however, though more rarely, there is only a slight or no constriction at the base of the apical segment or of the upper portion of the frond that has grown out after the last resting period, and the new portion then appears as a = direct continuation of the old frond, produced by continued activity of the same marginal meristematic zone. Comp. fig. 566. Such cases were in particular observed among the \ broad fronds growing in harbours and further in repeatedly NÅ \ dichotomously divided narrow specimens from the Øresund. The difference between the new and the old frond is usually É very distinct owing to the brighter colour of the first, and N often too owing to the presence of organs of reproduction on i the latter. IE may happen that the upper portion of the frond / dies or is eaten by animals in the course of the first year; adventitious shoots are then produced from the cicatrized = ; : x i ig. 566. border of the resting frond. The marginal fronds may poaymenta palmata. Helle- produce new marginal adventitious fronds in the following bk, February (Børgesen). int dth > b ated Ed Four generations of shoots are winter, an e same process may be repeated once more. FEEDS SE DER Three or four generations of shoots frequently occur, from which it can be concluded that the frond may reach an age of three or four years (fig. 566). The frond often attains a length of 20 cm, more rarely 24—27 cm (Lille Belt, Øresund). The frond segments of each year usually measure 10—13.5 cm. As to the structure of the adult frond reference may be made to WILLE (1891). The marginal meristematic zone at the upper end of the frond does not =X 132 972 show particular apical cells nor a marginal series of apical cells but consists of a great number of close cells without distinct arrangement. The frond is built up Fig. 567. Rhodymenia palmata. From Eastern Kattegat, near Læsø Trindel, 19 m. May. Photo, ?/, nat. size. of an inner tissue of one or two layers of large thick-walled cells, a medullary layer or mechanical tissue (WILLE 1891, p. 104), and an outer assimilating tissue Fig. 568. Rhodymenia palmata. Superficial cells from young plant. 622 : 1. consisting of 1 to 2 layers of smaller cells containing numerous chromatophores (fig. 568). An intermediate layer, (secondary mechanical tissue WILLE), is situated between the assimilating and the medullary layers. The young fronds and frond-segments bear numerous hyaline hairs, developed from ordinary peripherical cortical cells from which they are separated by a basal wall situated at the level of the surface of the frond (fig. 569). The hairs appear on the young plants, but only when they have reached a length of about 8 mm. In the older fronds the hairs only occur in the young segments while they are still growing. The hairs are very numerous but are confined to distinct 573 spots, where each superficial cell may bear a hair, while no hairs are found out- side these spots (fig. 569, comp. L. K. R. 1911, p. 212). They are easily visible in the living plants, and the spots can be distinguished in dried specimens (fig. 567). The hairs were met with in the | months of March to July; they are Li then shed, and the plants are hairless \ ze from August to the end of the winter. “ y \ AP The hairs were first described by WILLE VA "Ari, EN (1891, p. 103). V. M. Gruss took them S Fig. 569. for trichogynes (1922, P- 151), a view Rhodymenia palmata. A, transverse section through a part which cannot be maintained, as true of a spot of hairs (400 : 1), B, base of a hair (630 : 1). (From procarps have never been ascertained, and as the hairs occur on tetraspore-bearing and on male individuals, while female specimens are unknown; the hairs are purely vegetative organs agreeing with the hyaline hairs of such common occurrence among the Florideæ. The large medullary cells do not contain starch as storage matter. On the other hand the frond contains a soluble carbohydrate which, according to Kyrın Fig. 570. Rhodymenia palmata. Stipe of young plant. The large cells of the medullar tissue are to be seen in the upper part of the stipe. About 50 : 1. K. Rosenvinge 1911, p. 212). (Zeitschr. physiol. Chemie 101 1918, p. 245), is trehalose and may amount to 14.8 p.c. of the dry weight.! Kırrıan has followed the development of the germinating spores, without doubt tetraspores, which he found on stipes of Laminarie. The spore is divided by vertical and horizontal divi- sions, forming an hemispherical attachment organ, at the top of which a cell becomes larger than the others and takes the function of the initial cell of the young frond, which is at first fusiform, later flattened. The apical initial cell only functions in the quite young frond; it is early replaced by a multicellular meristeme, but its existence is of great interest, suggesting, as emphasized by Kırrıan, that Rhodymenia palmata may be derived from the type with a central axis (“Centralfadentypus”). The upper portion of the stipe contains a medullar tissue gradually tapering downwards. In a cross section it appears as an oblong or elliptical group of large cells sharply bounded towards the thick cortical tissue composed of radiating cell-rows. This cortex shows stratification in older fronds (comp. Jonsson 1891, p. 23, KırLıan 1926, p. 207). In a specimen from Skagen, which was judged to be two or three years old, the presence of two or three layers in the cortex was ascertained. 7 According to a recent note by H. Corın and É. GUÉGUEN the sweet principle of this Alga is a monogalactose of glycerol. (Acad. d. sciences, Paris, July 21, 1930; cited from Nature, No. 3176, Vol. 126). 574 The attachment disc increases in diameter by marginal growth (comp. KILLIAN 1926, p. 206), but the thickness increases too by continued apical growth of the vertical cell-rows of which it is composed. The large disc mentioned above showed a horizontal zonation, evidencing the periodicity of the growth. The number of the layers was not always easy to ascertain, because the limits between the layers were often indistinct and sometimes confluent, much as in the cortex of Ahnfeltia (comp. p. 559); at least 4 or 5 layers could be distinguished. The reproduction of Rhodymenia palmata is remarkable by the fact that tetrasporangia and antheridia have long been known while female sex organs and cystocarps have hitherto been searched for in vain. The tetrasporangia are produced in irregular patches on both sides of the frond; they arise from superficial cells, being early cut off from a stalk-cell, which remains short, while the surrounding sterile cells divide by transverse walls, forming short cell-rows which make up the greater part of the sori (comp. Kürtzıng, 1843, Taf. 46 1). The sporangia are cruciately divided. The development and the cytology have been carefully examined by Miss M. A. WESTBROOK (1928). Reference is made to this publication for details, the principal facts only will be related here. In the prophase of the first division of the tetrasporangium a double spireme stage and a synizesis were ascerlained, and although this occurrence “is not absolute proof of meiosis, the constant association of the three in the sporangia of other Florideae ‘suggests that in Rhodymenia too chromosome reduction is effected” (p. 164). The number of chromosomes could not, however, be determined with certainty, and the reduction division is therefore not quite settled. In the cortical cells, the number of chromosomes was judged to be greater than twenty. The ripe tetraspores, according to WESTBROOK, contain numerous starch grains, small discoid plastids and an inconspicuous central nucleus. The sori arise in the fronds or frond-segments which have been produced the winter before. The development of the sori probably begins in autumn, for ripe tetrasporangia occur in winter (January to April). But the first stages of the sori were not observed by me. In the fertile specimens gathered in March and April, the sporangia were to a great extent exhausted. It seems that the tetraspore-bearing parts of the fronds normally die after the dissemination of the spores. Sori are therefore not to be found in summer and early autumn; in two cases only emptied sori were still met with in July (Bw) and September (Ks). At more northern coasts the occurrence of the tetrasporangia is not limited to the winter, for at Iceland (Jönsson) and in Trondhjem Fjord (Printz) they may be met with the whole year, and at the isles of Færûe they were met with in April, May, June and November (BoRGESEN), while at the coasts of England and France (Cherbourg) they only occur in winter. The antheridia form patches on both sides of the frond similar to the tetra- sporic sori but of a paler colour. They were first mentioned and figured by THYRET on SI =D | (1855, p. 43, figs. 8—9), later by BurFHAM (1893, p. 294, pl. XIII, figs. 13—14), and more recently E. M. DErr and V. M. Gruss have given an account of their development (1924). According to the latter authors, the development of the male sori begins with a transverse division of the superficial cells. The lower cell thus formed is the basal cell, the upper one the antheridial mother-cell, which can produce in alternate succession at least four antheridia. Male specimens were met with in March and April. Female sex organs and cystocarps are quite unknown; and as they have certainly been searched for repeatedly by many algolo- gists in this wide-spread alga, it seems prob- able that they are really wanting. As mentioned above (p. 573), the interpretation of the hyaline hairs as trichogynes cannot be maintained. When the carpogonia are wanting, the question of the occurrence of a reduction division in the developing tetrasporangium will be of great interest. In case the reduction division can be definitely ascertained, a mixie might be supposed to take place at one or other moment of the life-history of the species. If a regular meiosis does not take place, there will be good accord- ance with the fact that a normal fertilization does not occur. In any case the spermatia are functionless though their structure is apparently quite normal. According to the facts known it must most likely be assumed that the reduc- tion division in the tetrasporangia is initiated but not fulfilled owing to the wanting process of fertilization. Rhodymenia palmata grows on stones and on various Algæ, most frequently on the stipes of Laminaria digitata and hyperborea, further on Fucus serratus, Furcellaria fastigata, Chondrus Fig. 571. Rhodymenia palmata. From the Baltic, QZ off Moens Fyr, 7.5 m, July 1894, ?/, nat. size. crispus, Phyllophora membranifolia and on roots of Zostera. It occurs most frequently at depths of (5), 7—20 m, more rarely down to 24 m. At slighter depths, 1 m, it has only been met with in harbours (Frederikshavn, Lille Belt). It grows 576 in company with various other Algæ and usually constitutes only a slight part of the vegetation. It was found most abundantly in the Øresund, not only in deep water of high salinity south of Hveen but also at smaller depths in localities with a much lower mean salinity (around Taarbæk Rey). In the Baltic Sea-its occurrence seems rather dubious. It is true that it has been recorded at Darsserort by REINKE and in two localities in Bm in the neighbourhood of Mgen; but in the two latter places it only occurred in a loose condition. In the one (SD) the small specimens were found in deep water on sandy bottom in company with several other loose Algæ; the specimens had an attach- ment disc, but most of them were attached to loose specimens of Furcellaria. In the other place (QZ), numerous long specimens were found at 7 or 8 metres’ depth on stony bottom in company with Fucus vesiculosus, Fuc. serratus and other attached Algee, but all the specimens of Rhodymenia palmata were certainly loose (fig. 571). Most of them had no basal portion; in some of them, to be sure, an attachment disc was present, but this seemed not to have been in function at the moment of collecting, or it was attached to a fragment of Furcellaria or a little stone only 5 mm in diameter. The specimens were long (up to 28 cm), mostly repeatedly dichotomous, linear, about 5 mm broad; although collected at the end of July they were beset in the greater part of their length with more or less confluent dark spots which turned out to be sporangial sori with checked sporangial mother-cells. These sori occupied a much longer portion of the frond than in the normal fronds and often occurred on two or three consecutive frond segments. Altogether the spec- imens remind of the specimens growing in the Øresund, and it seems highly probable that they have been introduced into the Baltic Sea by storms from the West, when the salt bottom water overflows the threshold at Saltholm and carries with it the Algæ torn off by the movements of the water. They have then been able to vegetate for some time in the loose condition in a locality where the salinity is only 8—10 p. m. Several other Algæ occurring here in loose forms have undoubtedly the same origin. Localities. Not met with in Ns, Sk and Lf. — Kn: Harbour of Skagen; NV Rev, 7—9 m, Tyskerens Rev, Hvidstens Rev, NØ Rev at Hirsholmene; east of Græsholm, south of Hirsholm, 11 m; between Hirsholm and Kölpen, 7.5 m; at Deget; harbour of Frederikshavn; Tonneberg Banke 16—18 m; Læso Trindel 11—15 m. — Ke: ZE!, ZF, fH, Fladen, 17—22.5 m; Groves Flak 19 m (Borgesen); on the shore at Nakke (Lyngbye, April 1834). — Km: Gjerrild Bugt (Lyngbye, on the shore). — Ks: RL, near Ostindiefarer Grund, 15 m; on the shore at Tisvilde (Lyngbye) and Rorvig (E. Rostrup). — Sa: Vejro Sund; PG west of Hatter Rev, 8 m; GD, north point of Sejerø, 11—14 m; PE off Revsnæs, 23.5 m. DK Bolsaxen 13—15 m; AH’, Lille Grund at Fyns Hoved, 9.5 m. — Lb: Fredericia, harbour; Strib, harbour; Middelfart, harbour and 15—20 m (Rasch,!); Kongebro; off Snoghøj, 15—19 m; Feno Sund; off Stenderup, 13—15 m. — Sb: GU, off Asnæs, 19 m; GP, at Halskov Rev, 10—11 m; UE, at Vresens Puller, 7 m. — Su: Hellebæk on the shore (Borgesen); Kronborg, on the shore (Nolte, C. Rosen- berg, Steenberg, Ørsted); PZ, east of Hveen; TF’, Staffans Flak, 12—13 m; bM, south of Hveen, 22.5 m; OH and bN, off Vedbæk, 10 m; east of Taarbæk Flak, 12.5 m, (S. Lund); Taarbæk Rev, 12—15 m, abundantly; OG", between Trekroner and Middelgrund. — Bw: Not observed by me; according to Reinke not met with in the western Baltic except at Darsserort at 20 metres’ depth. — Bm: On the ETES shore at Stevns (C. H. Ostenfeld); SD, N.E. of Moens Klint, 23.5 m, sand, loose, though several spec with attachment disc; QZ off Moens Klint, 7.5 m, abundantly, loose, some with attachment disc. Similar specimens collected by Liebman at Moen, undoubtedly on the shore, are to be found in the herbarium of the Botan. Museum of Copenhagen. Fam. 17. Champiacez. Chylocladia Grev. 1. Chyloeladia kaliformis (Good. et Woodw.) Hook. Hooker, British Flora Vol. I, 1833, p. 297; Harvey, Phyc. Brit. II, 1849, pl. 145; Berthold, Pringsh. Jahrb. XIII, 1882; Debray, Bull. sc. du dép. du Nord 2° Ser., 9° an., 1886, p. 258; Debray, Bull. sc. de la France et Belg., t. 22, 1890, p. 405; Hauptfleisch, Fruchtentwickelung, Flora 1892, p. 360; Hassencamp. Bot. Zeit. 1902; Kylin, Studien 1923, p. 37—44. Fucus kaliformis Good. et Woodw., Trans. Lin. Soc. Vol. III, 1797, p. 206, tab. 18. Gastridium kaliforme Lyngb. 1819, p. 70. Lomentaria kaliformis Gaillon, Resume méth. des classifications des Thalassiophytes. Dict. des scienc. nat. Strasbourg 1828, p. 19; Kützing, Phyc. gen. 1843, p. 440, pl.55; Nägeli, Neu. Alg. 1847, p. 246, tab. X, figs. 13—21. Flora Danica (Liebman) tab. 2578, 1852; J. Agardh, Sp. g. o. II, 3, 1863, p. 731; Kützing, Tab. phye. 15 tab. 86, 1865; Wille 1887, p. 76—79, figs. 55 —64. As to the nomenclature of the species, reference may be made to the explana- nation by HAUPTFLEISCH (1912, p. 308). The structure of the frond has been treated by several authors (NAGELI, BERTHOLD, WILLE, DEBRAY, HAUPTFLEISCH, HASSENKAMP, Kyrın). The reader is referred principally to the papers of HASSENKAMP and Kyrın quoted above; here only the most important facts will be adduced. The frond is tubular, articul- ated with diaphragms at the constrictions. The wall of the frond is composed of one layer of large cortical cells, from the outer edges of which smaller cells are cut off by oblique walls. These small cells do not form a continuous layer but form a reticulate system of outer cortical cells. The large, primary cortical cells are at first angular, nearly isodiametrical, when seen from the face; later they increase considerably in the direction of the longitudinal axis of the frond. — There is not one apical cell at the tip of the frond, as indicated by NÄGeErı and WILLE, but a number of cell-rows meet at the apex, each with an apical cell dividing by transverse walls. Within the cortex run a number of about 16 to 20 longitudinal, narrow cell-rows, and at regular intervals the cavity of the frond is traversed by Fig. 572. Chylocladia kaliformis. Surface view of frond septa composed of a single layer of cells. The h, hair-cells. 200 : 1 D. K. D. Vidensk. Selsk. Skr.,7. Række, naturvidensk. og mathem. Afd., VII, 4. 74 large cortical cells originally contain one nucleus, later a greater number (comp. KyLiN 1923, p. 39), and numerous very small chromatophores, situated at the outer | Fig. 573. Chylocladia kaliformis. Tip of frond with hairs. 195 : 1. wall or at the anticlinal walls, or even at the inner wall of the cells; they are orbicular or shortly rod- shaped, often arranged in curved rows. The refractive bodies observed by BERTHOLD (1882, p. 690) in the large cortical cells in specimens growing in sunny localities at Naples, were not met with in the Danish waters, but that is undoubtedly due to the fact that the species here is exposed to a much smaller intensity of light; it always occurs in rather deep water (7—18 m), the sea-water is much more troubled here than usually in the Mediterranean, and the sunlight does not penetrate so deeply, owing to the smaller height of the sun. The blue iridescent gloss of the plant described by BERTHOLD I have never seen; nor does it seem to have been observed at the coasts of the British Islands. The colour of the living plants col- lected in July and Au- gustis bright pink, often yellowish or greenish. A greenish plant took a bright pink colour in drying. The younger por- tions of the frond usu- ally bear numerous vigorous hyaline hairs produced by some of the small cortical cells. They arise as outgrowths from these, cut off by a transverse wall (comp. Kyrın 1923, p. 38, fig. 27 d); in a young stage they contain abundant protoplasm and a single nucleus. A number of these young hair-cells may remain in the juvenile stage, while others grow out early as long hairs of the usual structure (figs. 572, 573). The hairs are very thick, about 9—11 x, and may reach a length of 1 mm or more. It probably depends on outer conditions whether the hair-cells grow out or remain rudimentary. Comp. BERTHOLD (1882, p.692), who found that their occurrence is largely A Fig. 574. Chylocladia kaliformis. A, portion of frond with adventitious shoots at the constrictions. above two shoots above the constriction, below a shoot below the constriction and to the left a quite young shoot exactly in the constriction. 63:1. B, the last-named shoot 200: 1. C. young shoot over the constriction 200 : 1. 219 determined by the intensity of the light. In the Danish waters the hairs were con- stantly met with in July and August and were also observed in September. Ramification. The most common mode of ramification of the frond is lateral, the branches arising at er some distance from the tip, in | | the young furrows, exactly at the level of the diaphragms or | a little higher. One, two or three, or rarely more branches may arise in the same furrow, and the branches are there- fore often verticillate, but the branches of the same furrow do not arise simultaneously. The development of these branches is altogether acrope- talous, but some furrows re- main branchless, especially in the branches. According to DeEBRAY (1886, p. 15), the branches “proviennent des cel- lules du diaphragme adhérentes à la couche corticale. Si la paroi présente plusieurs assises de cellules, les petites cellules extérieures sont soulevées et séparées les unes des autres par le bourgeon se formant au-dessous d'elles”. It is, how- ever, not obvious from the des- cription of DEBRAY, which is not illustrated by drawings, whether it refers to Ch. Kaliformis or 107,04 4 to a related species. At any CH. dthea fel || rate, my obervations, which are, Fig. 575. however, not very thorough, do Chylocladia kaliformis. Dried specimen with cyslocarps dredged by the i . à late Professor C. H. Ostenfeld, North of Hirsholmene. August. Photo, not agree with that of DEBRAY. Reste True, the branches often arise exactly in the middle of the furrow. at the level of the diaphragm, but other branches are evidently placed at a little distance above this level, and an origin like that postulated by DEBray is consequently precluded. My observations seem to accord better with the assumption that the branches take rise from divisions of superficial cells (fig. 574). 74* 580 In older portions of the frond adventitious branches arise in indeterminate places. They seem to arise, like the primary ones, by divisions of one or a number of superficial cells. The adventitious shoots may be rather numerous in older fronds; they are thinner than the primary ones. Fig. 576. Chylocladia kaliformis. Young plants growing on a cystocarp-bearing spec- imen of Chylocladia kaliformis. August. A, with two fronds springing from the same attachment disc. 105 : 1. B, showing a dichotomy of the frond. 70:1. There exists yet a third mode of ramification, namely by dichotomy. DEBRAY described such a ramification which he had particularly observed in Chylocladia mediterranea (1886, p. 13). I seems to be rare in Ch. kaliformis, for I have only observed a few instances of dichotomy, most obvious in a young plant (fig. 576), the growing-point of which had been bifurcated before the appearance of the first diapraghm; both branches show two diaphragms’. : Reproduction. The antheridia were shortly described Fig: 577 by Burrnam (1891, p. 249, pl. 15, figs. 3—4) who found them ee UR ER forming pale patches as irregular rings around the frond, but with annular patches of an- 2 2 . theridia-producing cell-rows. otherwise they have not been mentioned; Kyrın dit not observe area Fie il them. I have examined a male specimen collected in August at Hirsholmene and preserved in alcohol by Mr. BoyE PETERSEN. The ring-shaped patches detected by BUFFHAM arise near the apex of the frond, in the transverse furrows at the level of the diaphragms. They are originally narrow, occupying only the furrow itself but increase early at their upper and lower margins and then form rather broad belts with irregular borders. In the young rings and at the borders of the older ones a great number of very small cells bud off from the edges of the cortical cells. These ! I have observed the same ramification in Ch. kaliformis var. squarrosa at Biarritz; some joints were found to be bifurcate. 581 cells divide actively and form close cell-rows growing inward from the edges of the cortical cells which are thus covered by a reticular layer the meshes of which diminish gradually in diameter by the growth of the creeping cell-rows, and the older parts of the fertile layer may finally be continuous, covering also the central parts of the cortical cells. From the upper side of the creeping cell-rows new small cells are early bud off, forming very short upright cell-rows the end-cells of which produce each a spermatium. The spermatia are shortly obovate, about 4 x in diameter and contain a large nucleus (figs. 578 C, D). The spermatial layer is covered by a thick gelatinous layer (comp. Batters 1. €.) which renders it very difficult to obtain good thin sections show- ing the development of the antheridia. The development of the carpogonial branch and of the cystocarp have been examined by several authors (JANCZEWSKI, SCHMITZ, HAUPTFLEISCH, Has- SENKAMP and, latest and most exhaustively, by KyLiN (1923)). As I have nothing to add, I shall content myself by refer- ” ring to the excellent paper of Kyrın, adducing only the prin- Fig. 578. cipal facts. The curved 4-celled Chylocladia kaliformis. Antheridia-producing cell-rows. A, seen from carpogonial branch is borne on the en a eee oe aug D: transverse ection of the antheridia-producing layer. 625 : 1. one of the large cortical cells. This supporling cell has early cut off two lateral cells which become auxiliary mother-cells. These cells (or one of them) bud off an auxiliary cell, before the fertilization. The fertilized nucleus of the carpogonium divides in the carpo- gonium, which forms two protuberances fusing with the two auxiliary cells. The auxiliary cell buds off outwards a cell, the first gonimoblast cell which is divided by radial walls into a number of pyramid-shaped cells which divide by a cross wall into an inner, smaller, and a larger outer cell; the latter is the young carpospore, the inner cells fuse together with the auxiliary cells. By further fusions of the basal cells with the auxiliary cells and with cells of the inner fruit- wall a large fusion cell arises which bears the carpospores on the outer side. The large globular cystocarp is surrounded by a wall without apical pore, built up of 3 or 4 layers of cells. The tetrasporangia are irregularly spread in the cortex. As shown by Kyrın (1923, p. 43), they arise from large cortical cells of the 8rd or 4th order which are not 2 De Coe - > terminal cells but segment cells, and are therefore connected with at least two neighbouring cells by primary pits. The ripe tetrasporangia project into the central cavity (comp. Kürzıng, Phyc. gen., tab. 55 IV). The germination of the tetraspores begins, according to Kyrın (1917, p. 5), by formation of vertical walls by which the spore is divided into four quadrant cells which are then further divided by horizontal walls. After 6 days the germlings had the appearance of multicellular globular bodies giving off at the base some 4 rhizoids, and showing at the top a group of smaller, meristematic cells, the initial cell-group of the upright frond. I have examined the germination of tetraspores and carpospores in cultures, but the cell-divisions were usually irregular, without doubt owing to the unfavourable conditions in the cultures, and only a small number of germlings resulted. The best developed of them showed after 17 days a thick, more or less orbicular attachment dise and an erect shoot issuing from it. Older germlings were found in Nature, the youngest growing on fructiferous specimens of Chylocladia kaliformis, both in tetrasporiferous and in cystocarp-bearing individuals. These germlings had usually a thick, hemispherical or nearly oo ES = 2: Be. >08 So, Fig. 579. Chylocladia kaliformis. Young plant growing ona cystocarp- globular attachment body, and springing from it an upright bearing specimen of the same meer Anant, Beil frond. When this was about half a mm high, it was cylin- drical without constrictions, and with an outer layer consisting of small, rather uniform cells. Not unfrequently two fronds were issuing from the same attachment disc (fig. 576). In the germ- ling represented in fig.579, which was about 1 mm high, the frond is inflated, hollow with at least one septum and with longitudinal cell-rows in the cavity. The identity with Chyl. kali- formis was thus indubitable. These germlings were met with in August and probably originated from spores of the fronds on which they were i 2 Hi83580: , x Chylocladia kaliformis. Young plants, growing on Rhodomela found growing. More developed young and Brongniartella, September. A, 3.5:1. B, 2:1. plants, met with in September and October, were only from a few mm to 2 cm high; they were provided with hairs, but only feebly developed or rudimentary. The species has only been met with in the Northern and Eastern Kattegat. Its absence in the North Sea and Skagerak is certainly dué to the want of protected 583 localities. It has been met with at 8—19 metres’ depth in water of comparatively high salinity (about 30 p.m.) on gravelly or stony bottom, but is very often attached to other Algæ (Phyllophora membranifolia, Furcellaria fastigiata, Brongniartella byssoides, Corallina officinalis) or to dead leaves of Zostera. It has only been observed in the months of July to October. Well developed fructiferous specimens, up to 26 cm high, were met with in July and August, but they seem to die away at the end of summer, for in September small specimens only were observed. Germlings were found in Nature already in August, and the small specimens found in September must be supposed to originate from spores produced in the foregoing summer. They were all sterile. It must further be supposed that the growth of the new plants is arrested during winter and spring and is only resumed in the following summer. Localities: Kn: Tonneberg Banke, TP and PO, 16—18 m, stony ground, young specimens, September; TQ, near the light-ship at Læsø Trindel; FF, near Læsø Trindel, 15 m; Nord Øst Rev at Hirsholmene; east of Hirsholmene (Ostenfeld); Nordvestrev at Hirsholmene; TY south of Hirsholm, east of Kolpen (A. Otterstrom); Trestensrev (Henn. Petersen); various places near Nordre Ronner; 7—11,5 m. — Ke: ZG, ZE!, VY, Fladen, 17-—19 m. Lomentaria Lyngb. 1. Lomentaria elavellosa (Turn.) Gaillon. Gaillon, Dietionnaire des sciences natur. Vol. 53. Extrait, Strasbourg 1828, p. 19; Le Jolis, Liste des Alg. mar. 1864, p. 132; F. Debray, Structure et développement des Chylocladia, Champia et Lomentaria. Bull. scient. de la France et de la Belgique, tome 22. Paris 1890, p. 399; Haupt- fleisch, Flora 1892, pp. 325—350, figs. 58—77; Killian, Entw. Florid., Zeitschr. f. Bot. 6, 1914, pp. 246— 248; Kylin, Studien, 1923, pp. 44—49. Fucus clavellosus Turner, Trans. Lin. Soc. VI, 1801, p. 133, pl. 9, Hist. Fucorum I, 1808. tab. 30. Gastridium clavellosum Lyngbye 1819, p. 70, tab. 17. Chondria clavellosa C. Agardh, Spec. alg. Vol. I, 2, 1832, p. 353; Hornemann, Flora Danica tab. 2200, 1834. Chylocladia clavellosa Grey. in Harvey’s Manual 1841, p- 71; J. Agardh, Sp. g. o. II, 2, 1852, p. 366. Chrysymenia clavellosa J. Agardh, Alg. m. medit. 1842, p- 107; Harvey Phye. Brit. I, 1846, pl. 114. Chondrothamnion clavellosum Kützing, Tab. phye. XV, tab. 81, 1865. As emphasized by earlier author’s e. g. Ky in (1923, p. 44) there is much accordance between Lomentaria clavellosa and Chylocladia kaliformis as to the structure of the frond. The cortex forming the wall of the hollow frond consists, at least in older portions, of two layers of cells, the outer layer of smaller cortical cells being here continuous. The medullary longitudinal filaments (fig. 581) are more irregular and often connected with each other by lateral pits. Diaphragms are wanting. Fig. 581. Lomentaria clavellosa. Cross section of frond, 420 : 1 ca The fronds spring singly or several from a flat or cushion-shaped attachment disc (fig. 582). The branches arise at some distance below the apex; they are some- Fig. 582. Lomentaria clavellosa. A, small plant with cystocarps from Skagerak off Lonstrup, August. 33:1. B, lower portion of plant growing on Desmarestia aculeata, Hirsholm, October. 4.7: 1. times opposite, more frequently alternate, biseriate and the fronds are therefore often flat, but the branches may also issue from all sides of the branches. When the branches are regularly oppo- site or alternating, distichous at regular inter- vals, it seems probable that the branches corre- spond to the verticils in Chylocladia, and the regions where they are inserted to the diaphragms. Adventi- tious branches with indefinite position may occur later; they are much smaller than the primary ones. Some shoots grow out and obtain a similar length and character to those of the main shoot, others remain short, but there are all transitions between the long and the short shoots. I have once met with a branchlet ending in an attach- ment disc (fig. 583); it occurred as a branch of the second order at some distance from the base in a specimen growing on the Bryozoan Valkeria uva. The principal branches come near to the main frond in length and thickness; the latter attains a diameter of 1 to 1.5 mm. The branches of higher orders are much narrower, often very thin. Specimens referable or approaching to f. sedifolia have not been met with at the Danish coasts; the specimens growing here are always very slender. The young portions of the frond still in develop- ment are usually beset with numerous hyaline hairs, like those in Chylocladia kaliformis, but much thinner and shorter; they are about 2.5 w thick. They were ob- served at all the seasons, where the species was generally met with (May, July to October), though they were not met with in all the specimens observed. The antheridial sori appear, as shown by Ky in (1923, p. 47), as patches on the branches of the last or penultimate order, probably always in particular male plants. The cells producing the antheridia (spermatangia) bud off from the small outer cortical cells as small Fig. 583. Lomentaria clavellosa. A branch ends in an attachment disc. 12:1. colourless cells rich in protoplasm and containing one nucleus (mother cells of the spermatangia Kyrın l.c., fig. 33). Specimens with antheridia were observed once in Skagerak, on the Ist of August, and once in Northern Kattegat, on the 13th of July. SL oc on The development and structure of the carpogonial branch and of the cystocarp have been treated by Hauprrieiscu (1892) and Kyrın (1923). Reference may be made to the description of Kyrın. The tri-cellular carpogonial branch arises as an outgrowth from a primary cortical cell (supporting cell) which becomes multinuclear. Two auxiliary cells are usually present the mother-cells of which bud off from the supporting cell, but one only is developed after fertiliza- tion. After the entering of a sporogenous nucleus in the auxiliary cell, a cell buds off from its upper side, and from this cell several gonimolobes are produced. The wall of the cystocarp has a well developed pore at the top. For more details see the papers quoted. The tetrasporangia are embedded in the cortex, and form groups at the bottom of depressions in the cortex of the younger parts of the frond; the sporangia do not project inwards into the cavity of the frond (fig. 584). They are tetrahedrally divided. The germination of the spores has been studied by KILLIAN (1914, p. 246), but owing to difficulties with the cultures he f . s 2 ) É | x \ I 7 or VA A ; | 2 WR 5 ip: | | Be 12 | Fig. 584. Lomentaria clavellosa. Au- gust. Tip of tetraspore-bear- ing frond, 30:1. was not able to follow the first stages of the development of the germlings. The youngest stage figured by Kırrıan is an orbicular disc showing in the middle Fig. 585. Lomentaria clavellosa. Germlings obtained in cultures. A—C and E—F 8 days old. D 15 days old, 560 : 1. D. K. D. Vidensk. Selsk, Skr., 7. Række, naturvidensk, og mathem, Afd., VII, 4. 75 586 a group of four initial cells. The middlemost part of the disc projects and forms an upright frond which is first cylindrical, later vesicular, and the four apical cells become the first initial cells of the frond. In my cultures in the laboratory of marine biology at Frederikshavn in 1928 and 1929 the conditions were evidently also unfavourable to the germination, for most of the spores did not germinate, the divisions of the germinating spores were not regular, and the four initial cells could not be observed. After 7 or 8 days the germlings had the shape of discs or cushions with rhizoids issuing from the margin. The cell-divisions were more or less irregular, and sometimes portions of the original spore- cell did not take part in the divisions producing the germ- ling. A group of initial cells could not be detected, but the cells often showed a very appa- rent arrangement in rows, an evident proof of the presence of a meristeme (fig. 585). After 17 days the germ- lings had grown much larger, having usually an orbicular disc composed of radiating cell-filaments about 100 w in diameter and an upright frond of about the same length as the diameter of the disc. The Fig. 586. upright fronds were nearly Lomentaria clavellosa. Germlings found in Nature, growing on Polysi- eylindrical unbranched The phonia urceolata, Tonneberg Banke, northern Kattegat, July. A, B ER $ 560:1, C, 200 : 1. characteristic structure of the apex could not be observed. Hairs were wanting (August 4th) (fig. 585 D). Germlings from the same culture a month and a half older had only reached a length of 150 to 224 w and did not show the normal structure, but their colour was normal. The fronds were often somewhat curved, sometimes showing incipient branching. Growing under better conditions, the germlings would probably have reached a larger size. Germlings were repeatedly met with in Nature in the months of July to Oc- tober, growing on various Algæ, as e.g. Polysiphonia, Desmarestia aculeata, leaves of Zostera or tests of Hydroids. They must have arisen from spores set free at the same season, and generally they agreed with the germlings obtained in the cultures. Those found in the middle of July reached a length of 0.2—0.3 mm (fig. 586), whereas germlings met with in August reached a length of 2 mm. The largest specimens of the young plants gathered in October reached in the various localities lengths 587 of 2.5 mm, 7 mm and 2 cm, but smaller specimens, partly disc-shaped without any upright shoot, occurred with them. It must be concluded that the spores germi- nate in the middle and at the end of summer, and that the germlings or the majority of them remain small and feebly developed in autumn and grow out only in the following summer; but it seems quite probable that, under favourable external conditions, the earliest developed germlings may reach the stage of fructification in the same season in which they have arisen. Lomentaria clavellosa only occurs in the northern Danish waters with high salinity (North Sea, Skagerak, northern and eastern Kattegat) and has only once been met with, many years ago, in the Great Belt at a great depth. On the other hand it has not been met with in the Limfjord, undoubtedly owing to the varying temperature in this area. It grows at depths of 9 to 31 metres, deepest in the North Sea (24.5—31 m) and the Eastern Kattegat (14—26.5 m), on gravelly or sandy bottom with small stones or on stony bottom, very often atlached to various Algæ, e.g. Halidrys, Corallina offic., Polysiphonia spp. etc., further on dead leaves of Zostera, on various Hydroids, Flustra foliacea and shells of molluses. It has not been observed in winter and early spring and has probably a small size in this period. The specimens collected in May were only 2—3 cm high and sterile. The maximum of development is reached in July and August when the specimens may reach a length of up to 18 cm (Groves Flak) and are fructiferous, with ripe tetrasporangia and cystocarps at least after the middle of July. Localities. Ns: ZQ, jydske Rev, 24.5 m; aF N.W. of Thyboron, 31 m. — Sk: SY, north of Løkken, 13 m; ZK (0, 3, 7, 11) 8—19 m; various places N.W. of Hirtshals (YK, YL, XO ete.), 13—15 m, off Hirtshals (Borgesen). — Kn: Herthas Flak, 19—22.5 m; Tonneberg Banke, 16—19 m (Boye Peter- sen!); fG and dS near Læso Trindel, 15—16 m; Nordostrev and Norvestrev at Hirsholmene; south of Hirsholm, 11 m; Trestensrev (Henn. Petersen), N.E. of Deget 11.5—13 m (Stamm) and Borrebjergs and Laursrev, 7.5—11 m at Frederikshavn; VU, north of Læsø, 15 m; at Nordre Ronner, near the double broom, 11—14 m; TM, N.W. by N of Nordre Ronner, 15 m. — Ke: Fladens lightship in S by E, 1 mile, 23 metres; EX and EV, Groves Flak. 26.5 and 22.5 m; Groves Flak 19 m (Borgesen); EU, Lille Middel- grund, 14 m. — Sb: According to Magnus (Botan. Unters. der Pommerania Exped. Kiel 1873, p. 66 and 74) this species (Chrysymenia clavellosa J. Ag.) has been dredged in Store Belt W.S.W. of Romsø at 51 metres’ (27 Faden) depth; it has not otherwise been met with in this water. 2. Lomentaria rosea (Harv.) Thur. Thuret in Le Jolis, Liste des Alg. mar. de Cherbourg 1864, p. 131; Farlow, Mar. Alg. New England, 1881, p. 155. Chrysymenia Orcadensis Harv., Manual Brit. Mar. Algæ. Sec. edition, London 1849, p. 100. Chrysymenia rosea Harv. var Orcadensis Harv. Phye. Brit. Vol. III, 1851, pl. 301. Chrysymenia rosea Harv. Phyc. Brit. III, pl. 358 A. Chylocladia rosea (Harv.) J. Agardh, Sp. g. o. Alg. III 1876, p. 298. This rare and imperfectly described species has only been met with once, in July 1892 in the eastern Kattegat, at 22.5 metres’ depth. The two dried specimens 75* represented in fig. 587 are the only ones collected in the Danish waters. As the structure and fructification of the species have been very little mentioned in the literature, only little can be adduced here on these matters. The specimens have a pink colour. The main shoots are lanceolate, the ee branches mostly opposite, com- Fig. 587. paratively narrow; the lower- Lomentaria rosea. Photo, °/, nat. size. most lanceolate, but most of them linear, 0.5—0.8 mm broad, sometimes a little broadened upwards. All the shoots are narrowed at the base. The anatomical structure of the frond seems to be similar to that of L. clavel- losa. The outer, small-celled cortical layer is subcontinuous, as in the above-named species, or interrupted, the small cells being only developed over the edges of the larger inner cells (fig. 588). The long medullary cell-rows running longi- tudinally within the cortical tissue were also distinguishable in the dried material. Hyaline hairs the tips of which were filled with proto- plasm were met with abundantly in the young pinne. Both specimens are fructiferous, containing ; NS DES. 5 Ä © ë Lomentaria rosea. Surface view of a broad numerous sori of tetrasporangia in the pinnæ. frond. 350 : 1. The areas of the frond-wall containing the sori are concave, in accordance with the generic character. The tetrahedrically divided tetrasporangia were ripe in July. Sex organs and cystocarps seem to be entirely unknown in this species. It has been met with at the coasts of the Northern Atlantic (United States, Iceland, Færûôes, British Isles, Helgoland, Norway, Sweden), but from all localities only mentioned with tetrasporangia. Locality. Ke: South end of Groves Flak, 22.5 m, July 12th 1892. VII. Nemastomatales. Fam. Rhodophyllidaceæ. Cystoclonium Kützing. 1. Cystoclonium purpureum (Huds.) Batters. Batters, Catalogue Brit. Mar. Alg., Journ. of Bot. 1902, p. 68. Fucus purpureus Hudson Fl. Angl. 1762, p. 471 (not seen, teste Batters). Fucus tuberculatus Lightfoot Fl. Scot. II, 1777, p. 926. Fucus corallinus ©. Fr. Müller Fl. Dan. tab. 709 (1777). Fucus scorpioides O. Fr. Müller Fl. Dan. tab. 887! (1782). Gigartina confervoides Lyngbye Hydr. 1819, p. 43 (quoad specim. Dan.).” Gigartina purpurascens Lyngbye Hydr. 1819, p. 46 (exclus. var. y rostrala). Sphærococcus purpurascens Hornemann, Fl. Dan. tab. 1835 (1825). (Primary branches too numerous). Cystoclonium purpurascens Kützing Phye.gen. 1843, p.404, Taf. 58 I; id. Tab. phyc. 18 p1.15 (1868); J. Agardh, Sp. g. o. ILı, 1851, p. 307; Wille Bidrag, 1885, pp. 17, 30, 33, 76, pl. II figs. 20—22, IV figs.46, 47, VI figs. 74—76; Schmitz u. Hauptfleisch 1896, p. 370, fig. 222 C; A. Henckel, Sur l’anat. ete. des Algues mar. Cystoclonium purpur. et Chordaria flagelliformis; Seripta bot. Petropol. fasc. 19, 1902; Kolderup Rosenvinge, Hyal. hairs, 1911, pp. 206— 209, fig. 4; Kylin 1907, p. 131; id. 1917 p. 22; id. Entwick. Florid., 1923, pp. 22— 30. Hypnea purpurascens Harvey, Phyc. Brit. pl. 116, 1846. Gracilaria purpurascens Nägeli, Die neu. Algensyst. 1847, p. 241. The structure and development of the frond of this common species has repeatedly been studied by NÄGELı, KÜTZING, WILLE, HENCKEL and Kyrın. The apical cell of the frond is divided by oblique walls that are inclined alternately to the right and to the Fig. 589. 1 : 3 A is Cystoclonium purpureum. This figure is interpreted in J. AGarpu’s Sp. g. 0. Il.ı p. 307 as re- pin of fro showing D D Tip of frond showing presenting Cystoclonium purpurascens; in the same work Il.ıı p. 587, however, the apical cell and ils it is determined as Gracilaria confervoides “(fide spec. a Hoffm. datis)”. The divisions. 560 : 1. latter determination cannot be upheld; the figure represents a Furcellaria beset with two specimens of an Alga which is probably Cystoclonium purpureum. It should be noted, however, that the picture does not correctly represent the base of a Cystoclonium fixed to the Furcellaria, and the specimen to the left is not fixed to it at all. Cystoclonium purpureum is very often fixed to this substratum in Nature, whereas Gracilaria confervoides is always fixed to stones. * In LYNGBYE's herbarium one specimen only of Gigartina confervoides is to be found. It bears the following inscription: “Ex Hindsholm Fioniæ, Jan. 1816, ded. Hofman”. It is an old denudated specimen of Cystoclonium purpureum easily recognizable by the base which is still preserved. On the wrapper LYNGBYE has first written: Fucus confervoides; Fucus has then been changed into Gigartina and (probably later) purpurascens has been added to the name Gigartina. It is without doubt this specimen which is mentioned by LYNGBYE l. c. left, as shown by Kyrın (1923, p. 23), thus producing two rows of alternating segments (fig. 589). The central cell-row is only discernible in the upper end of the frond, later on it cannot be distinguished from the other longitudinal filaments filling up the central part of the frond. The outermost cell-layer has the function of assimilating tissue; it produces numerous long hyaline hairs (comp. K. ROSENVINGE 1911, KyziN 1923), which arise in spring and early attain a considerable length, about 1 mm or more, with a diameter of about 10 w (fig. 590). They form a hyaline clothing on the fronds still growing. N N When the growih ceases, the hairs are shed and are therefore not met with in autumn and winter. The distinction between the assi- milating and the storage tissues is not very sharp. WILLE and HENCKEL (1902, p. 6) count up to 5 layers of the assimilating tissue while Kyrın (1923, p. 23) has only one. Within this follows a storage tissue which has also a mechanical function, and the central part of the frond is filled up by the conducting tissue built up by longitudinal filaments, primary and secondary, composed of long cells the transverse walls of which, as shown by WILLE (1885, p. 76, pl. VI, figs. 74—76), are perforated by numerous fine threads of protoplasm. B The main stem is very distinct, Fig. 590. in particular in the lower part of Cystoclonium purpureum. A, upper end of frond showing the frond where it is less branched hyaline hairs. 200: 1. B, two superficial cells, the one bearing a young hair. 325:1. After living plants. than above. Near the base, however, a number of horizontal or downward bent branches arise which may reach a considerable thickness but only a length of a few, up to 5cm (fig. 591). In contact with the substratum they form low hapters which afford a better fastening for the plant (fig. 592). When with increasing age the surface of the plant is very much increased, the primary attach- ment disc would not suffice to resist the pull caused by the movements of the water. The basal shoots taper gradually towards the top but are not much branched. Upright shoots are sometimes given off from them, and they may thus have the character of stolons but new fronds are usually only produced near the primary ones, and the horizontal shoots have therefore no significance for the propaga- tion of the species. ER The tendrils frequently occurring at the ends of the branches have been known for a long time. LyNGByE described them (1819) as peculiar to a particular variety 8, cirrhosa. They were later mentioned by J. Acarpx (Flor. Morph. 1879, p. 10) and in particular by WILLE (1885, p. 33) and HENCKEL (1902, p. 12) who studied their development and structure. They arise at the ends of branches which become long and thin whithout branchlets and are twisted, 5 or 6 worms of a screw often lying close together. The twisted part of the shoot bears a number of short, thick branchlets forming a small bush. The tendrils may remain free or catch fronds of other Algz or of its own. When growing on Halidrys siliquosa the tendrils winding round branches of the host plant are particularly numerous, giving the Cystoclo- nium a very solid attachment. Specimens with tendrils are met with in all the Danish : Fig. 591. waters; their occurrence seems to depend Cystoclonium purpureum. A, young plant growing on on external conditions. WILLE found them Furcellaria. February. 5:1. B. lower portion of frond. : . ag É 2 July. Nat. size. in specimens from a locality with fairly agitated water, and HEnckEL thought that they might be caused by the contact with an algal frond. This can only be decided by experiments. The tendrils have been met with, from 1 to 20 metres’ depth. In the North Sea and Skagerak, which are much agitated, specimens with tendrils frequently oceur; but, on the other hand, specimens growing on the moles at Hirtshals and at Hanstholm where the sea is usually much agitated had no tendrils. At the greater depths the influence of the waves can only be feeble, but the water is here agitated by the currents. WILLE raises the question whether the cluster of small shoots issuing from the Fig. 592. Cystoclonium purpureum. Creeping shoots with haies 2 8 tle but he leaves that undecided (1885, p. 34). HENCKEL has never found tendrils having the character of stolons, nor have I myself ever found tendrils surviving during the winter and giving rise to new individuals next year. tendrils might give rise to a new individual, 592 As ripe spores are produced in summer (July to August) and are able to germinate immediately, young plants must occur already in summer. As shown in fig. 593, the germinating spores divide by orthogonal or more irregularly orientated walls forming a hemispherical body, scarcely larger than the spore. This is the attachment disc. After two weeks, in a culture at Frederikshavn in July, many of the cushions had produced a shoot, one of the superficial cells, not always at the sum- mit of the cushion, taking the character of an apical cell Fig. 593. (fig. 593 F). Sometimes two Cystoclonium purpureum. Germinating tetraspores, Frederikshavn, July. h e 3 I F 13 days old. A—E 350:1. F 560 :1. shoots arise simultaneously from the same cushion. From the under face, appressed to the substratum, short unicellular hapters spring (fig. 594). (Compare Kyrın 1917, p. 7). A germling in a more advanced stage, agreeing well with those observed in cultures, was met with at the end of September at 16 metres’ depth in the Northern Kattegat (fig. 595). The plants which arise from the spores germinating in summer probably reach a considerable degree of development before winter. In the Little Belt I found in February 2—4 cm long plants growing on Furcellaria. In some cases one frond only was given off from the basal cushion, in other cases two or a greater Fig. 594. number, but some of them were then (ysloclonium purpureum. Germling 12 days old, seen usually broken off (fig. 591 A). In March from above. 560 : 1. corresponding specimens were about 7 cm long. In the Northern Kattegat specimens which had apparently arisen from spores in summer, reaching only a few centimetres in length but having a great number of densely crowded shoots springing from the attachment disc, were frequently met with in autumn (September to November) (fig. 596); their growth is Ciisioeta Reda pure! arrested during the winter and only begins again in early spring. Germling found growing The development of the sex organs has been studied by on Antithamnion Plu Kyrım (1923). The species is dioecious. The antheridia arise on mula, September. 75:1. the surface of younger shoots which may finally be entirely covered by them. They are, according to Kyun (1. c. p. 30), borne on „Spermatangien- Mutterzellen” which are cut off from the cells of the outermost, assimilating layer Fig. 595. of cells. Some of the latter, however, remain unchanged (cf. BurrHam 1893, p. 293). The spermatia, according to Kyrın, contain about 20 chromosomes. The antheridia were met with in the Danish waters in June and July. 7 The carpogonial branch was first described and figured | by Schmitz and HAUPTFLEISCH, (1896, p. 369, fig. 222 C). The 4) development of the procarp and of the cystocarp has been carefully treated by Kyrın (1. c. pp. 25—29) and will therefore only be very briefly mentioned here. The mother-cell of the } carpogonial branch is early cut off on the inner side of a Neil superficial cell, but when fully developed the carpogonial FR) Br) branch appears inserted on the inner side of the inner cortex > (storage tissue). It is three-celled, and the lowermost cell Cut > Ly produces a small lateral cell. The auxiliary cell, which is ff 1 early developed, is situated near the carpogonium and issues 3% BR ge I. from the same cell which bears the carpogonial branch. After Cnam tourner the entrance of a diploid nucleus from the fertilized carpogo- Lowermost part of young nium into the auxiliary cell the first gonimoblast cell is a CES RASE formed from the inner side of the latter. The lowermost cell basal shoots bud off from of the gonimoblast fuses with the auxiliary cell, and later ""* achment aise: Sep" similar fusing processes take place between the latter and other cells of the gonimoblast. For further details on the development compare KYLIN (l. c.). The structure of the ripe cystocarp has been pictured by Kirzine (1843, Taf. 58). Ripe cystocarps were met with in the Limfjord in June, otherwise everywhere in July and August. In September and October they were more or less empty. The tetrasporangia arise in the cortex and are transversely divided. In a ripe state they were met with in June (Limfjord) and in July to September. The tetra- spores germinate immediately after exhaustion, but it may happen that they are not set free and then germinate within the mother plant still surrounded by the sporangial membrane (fig. 597). After frutification the fronds die entirely or with the exception of the lowermost portion. The cluster of horizontal shoots issuing from the base of the plant is able to survive through the winter, and new upright fronds then arise from them, or Fig. 597. Cystoclonium purpureum. Tetraspores smaller shoots from the foregoing year not having Segmented within the sporangial wall reached the stage of fructification survive through September. 200: 1. the winter and develop next summer into large fructi- fying fronds. The species is then perennial, or may at least keep alive and fructify during two years; but many individuals never become perennial because D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. 76 594 the Algæ or the parts of the fronds to which they are attached die after having fructified. Cystoclonium purpureum is common in all the Danish waters from the North Sea to the Western Baltic Sea, whereas it has not been recorded in the Baltic Sea proper. It grows in depths from a little under low-water mark to 20 metres’ depth, rarely deeper (21.5 m in the eastern Kattegat, 24.5 and 35 m in the Little Belt), on stones and on various Algæ (Furcellaria, Halidrys, Fucus serratus, Phyllo- phora Brodiei, Ahnfeltia and several others), further on oysters and other shells of bivalves. The largest specimens have been met with in the North Sea, Skagerak and the Northern Kattegat, where a length of 50 cm can be reached. In the inner waters the length does not usually exceed 20 cm, and the largest specimen col- lected in the Western Baltic was only 13 cm long. The species is only little variable and no varieties or named forms can be distinguished. We shall merely mention that in exposed localities in the North Sea and Skagerak large specimens may be met with which are remarkable in having a number of long principal branches beset with numerous short branches of the second order in their whole length. Localities. Ns: Not met with at Esbjerg-Fane and on the groins at the entrance to the Lim- fjord. Vorupør, 3 m (S. Lund); XR, off Orhage, 11—13 m; in the bay at Ørhage (Klitmøller), 2 m. — Sk: YT off Helshage, Hanstholm, 5.5—13 m, at Roshage, 2m, mole immediately beneath low-water mark; YM, YN*, Bragerne 2.5—10.5 m; SY off Løkken; ZK off Lønstrup; several places, XO, VJ ete. off Hirtshals, 5—15 m and abundantly on the mole. — Lf: Common from one to 7 metres’ depth and from XV and LZ in Nissum Bredning to Hals mole; e.g. Oddesund, Thisted Bredning, Sallingsund, Live Bredning and Legster Bredning. — Kn: Common everywhere on stony bottom from Skagen harbour, Herthas Flak, 20 m and Læsø Trindel, 16 m, southwards. — Ke: Several places in Fladen, Groves Flak, Lille Middelgrund from 10—22 m, further GJ, OO and Gilleleje harbour. — Km: Several places from Læsø Rende to NC off Fornes, 4—11 m. — Ks: Several places from Grenaa harbour to Hastens Grund and D, grønne Revle. — Sa: Numerous localities from 0 to 15 metres’ depth. — Lb: Several places, from 1 to 35 metres’ depth, from Bogense harbour to dH east of Hesteskoen, 15 m. — Sf: Several places. — Sb: Several places, 1 to 19 m. — Sm: S.E. of Masnedo, c. 3 m. — Su: Helle- bæk; Kronborg; PZ, east of Hveen, 13.5 m; Taarbæk Rev, 12 m; off Skovshoved, 11 m. — Bw: bY south of Als; cG off Kegnæs; cE, Middelgrund south of Als, 13 m; DX Vodrups Flak, 13 m; DV south of Marstal; LA, south of Lolland, 7.5 m; UL, Øjet 20 m; KY, Femerbelt 12 m. Some specimens of Cystoclonium purpureum gathered in the neighbourhood of Frederikshavn and in the Limfjord were set with numerous tumours reaching a diameter of 2.5 mm or more. The smaller tumours are globular with even surface, the larger more irregular, somewhat resembling cauliflower. They are seated on both the thin and the bigger branches; in the first case they often cause a back- ward bending of the frond (fig. 598). Small shoots of Cystoclonium may issue from the surface of the tumours (fig. 598 B). The colour is bright, nearly white, yellow or rose to red-brown. Such tumours have been shortly mentioned as early as 1808 by TURNER (Fuci, p.18, plate 9, figs. f,g,h) who described them as swellings ‘unconnected 595 with the fruit” and depicted them as irregularly spherical bodies from which small adventitious shoots are given off. SCHMITZ gave a more detailed description of the tumours, especially their anatomical structure; he showed that the interior of the tumours is built up of a medullar tissue of interwoven cells whereas the cortex is some- what similar to that of the normal plant. In the cortex rhizoids may appear, sometimes in great numbers. Scumirz further stated that almost the whole tissue of the tumours, in particular the cortex, is filled with small, nearly oval bacteria. The bacteria live intercellularly in the middlemost layer of the cell-walls. When they are very numerous, they penetrate towards the surface of the tumour, numerous rhizoids are then produced, the cells are partly disun- ited and the bacteria can escape into the sur- rounding water. SCHMITZ supposes that the tumours are galls occasioned by the bacteria. The tumours have recently been examined by CHEMIN who confirmed the observations of Fig. 598. Cystoclonium purpureum. Parts of frond with tumours. A, 3:1. Fig. 599. Cystoclonium purpureum. Upper end of shoot with hapters and a tumour. 23:01. Schmitz. He states that the bacteria are “légèrement ovoides et leur grand axe atteint à peine 1 w’. He mentions an attempt at inoculating bacteria from a gall to another indi- vidual of Cystoclonium, without result however, but nevertheless he agrees with Schmitz in considering the tumours occa- sioned by the bacteria; in all the tumours examined he found bacteria. The tumours from the Danish waters examined by me agree with those described by the authors quoted, as to the outer appearance and anatomical structure; but there is the discrepancy that I have not been able to observe the inter- cellular masses of bacteria. In the swollen membranes of the tumours, only the homogeneous substance of the middle- most layer was to be seen, no bacteria, even after staining with gentiana-violet, and this was the case, too, in the large tumours with disunited cells. Only scattered rod-shaped bacteria much larger than those described by CHEMIN were sometimes observed. It seems doubtful, therefore, whether the tumours are really caused by bacteria; their etiology must be left for further research. * Fr.Scamirz, Knöllchenartige Auswüchse an den Sprossen einiger Florideen. Botanishe Zeitung 1892. ) = E. CHEMIN, Action des Bactéries sur quelques Algues rouges. Bull. de la Soc. bot. de France 1927, p. 441- 76* 596 In 1907 (Studien, p. 127) Kyrın described a new parasitic Alga, Choreocolax Cystocloni, growing on Cystoclonium purpureum. It forms irregular globular bodies, 1—4 mm in diameter, yellow-white, often with a tinge of pink; they have a cortex built up of radial cell-rows and an inner tissue of isodiametrical or irregular larger cells, and between them and springing from them long branched cell-rows which penetrate from the base of the parasite between the cells of the host. The parasite usually occurred abundantly on one.and the same individual of Cystoclonium; it was always sterile. The supposed parasite bears so much resemblance to the tumours here treated, that the question arises if they might possibly be identical with them. Judging from Kyrın’s description, the outer appearance is the same, and there seems too to be much accordance as to the anatomical structure, though the hypha-like cell-rows show some disagreement; but the occurrence of these ele- ments seems to be rather variable. I have not observed stages like that shown in Ky in’s fig. 29 a, which is said to represent filaments of the parasite penetrating between the cells of the host. Altogether it must be said that the parasitic char- acter of the bodies described by KyLiN cannot be said to be proved. Considering further the fact that the supposed parasite was always sterile, it seems highly probable to me that they are identical with the tumours here described, and that like these, they are merely luxuriancies caused by some unknown agency. It should be stated that Kyrın did not mention bacteria in the tissue of the tumours. The tumours have been met with repeatedly in the environs of Frederikshavn, particularly east of Deget (Boye Petersen), off Feggeklit in the Limfjord, in Lille Middelgrund in the eastern Kattegat and near Ostindiefarergrund in the southern Kattegat. Euthora J. Agardh. 1. Euthora eristata (L.) J. Agardh. J. Agardh, Nya alger fran Mexico. Ofvers. af K. (svenska) Vetensk. Ak. Förhandl. 1847; id., Sp. g. o. Vol. II, pars II, p. 385, 1851; N. Wille, Morph. og physiol. Studier over Alger. Nyt Mag. f. Natur- vidensk. Bd. 32. II. 1891, p. 107 ff, Tavle II; Kylin, Entw. Flor. 1923, pp. 36—37. Fucus gigartinus L.? Oeder, Flora Danica, Tab. 394. 1768. Fucus cristatus L., Turner Fuci I. 1818, Tab. 23, p. 48. Spherococcus cristatus Agardh Synops. 1817, p. 29; Lyngbye, Tent., 1819, p.13, Tab. 4 D. Rhodomenia cristata Greville Alg. Brit. 1830, p. 89. Rhodymenia cristata Harvey, Phyc. Brit. III, tab. 307, 1851. Callophyllis cristata Kützing, Tab. phyc. 17, tab. 93, 1867. This pretty little subarctic Alga has only been met with in a few places in the eastern Kattegat at 22—25 metres’ depth. It will only be briefly mentioned here, as I have no new observations on the morphology and the development. The fronds are rather narrow, mostly alternately pinnate, more rarely secund or subdi- chotomous and flabelliform. The structure of the frond has been described by WILLE and Kyrın. As shown by these authors, the segments of the frond terminate in an apical cell dividing by oblique walls. The frond has an assimilating tissue consisting of about two layers of small cells while the inner tissue is composed of large thick-walled cells, by Witte denoted as a mechanical tissue. There is also a feebly developed conducting tissue between the large inner cells. The antheridia seem to be unknown; in the Danish waters they were not met with. The procarps arise near the border of the young frond and consist, according to Kyuin (1.c.), of a three-celled carpogonial branch and an auxiliary cell borne on the same cell which bears the carpogonial branch. The development of the cystocarp has not been followed, but Kyrın has given a drawing of a nearly ripe cystocarp and shown that Fig. 600. Euthora cristata. From Groves Flak, Eastern cell-rows grow out from the cystocarpial wall and Kattegat, 24.5 m. With cystocarps. Photo, 0-9 . D ° nat. size. divide the gonimoblast into smaller portions. The tetrasporangia arise in groups in the last segments of the fronds and are cruciately divided; they have not been met with in the Danish waters. The species has been dredged in the months of May and July, always on stony bottom at considerable depths, consequently in water of high salinity, growing on the hapters of Laminaria hyperborea and L. saccharina and on Hydroids, such as Tubulina and Sertularia. The fronds reach a length of 1—3.5 cm. Most of the specimens gathered in May had procarps or more or less developed cystocarps. Ripe cystocarps were met with in July. Localities. Ke: ZF, 26.5 m, and JQ 21.5—30 m, Fladen; EV, 22.5 m and JT, 24.5 m, Groves Flak. Rhodophyllis Kützing. 1. Rhodophyllis bifida (Good. et Woodw.) Kützing. Kützing, Botan. Zeit. 1847, p. 23, Tab. phyc. 19, pl. 50, 1869. J. Agardh, Sp. g. o. II, pars II, 1851, p. 388; Nageli, Neu. Algensyst. 1847, p. 234; Reinke, Lehrbuch d. allg. Bot. 1880, p. 119; Wille, Entwickl. 1887, p. 71, figs. 38—39; Schmitz u. Hauptfleisch (Engl. u. Prantl) 1896, p.376; Nien- burg, Florideenkeiml., Hedwigia 51, 1912, p. 303; Killian, Entw. Florid., Zeitschr. f. Bot. 6, 1914, p. 248; Kylin, Entw., 1923, p. 31. Fucus bifidus Good. et Woodw. Trans. Lin. Soc. Vol. III, 1795, p.159, pl. 17 fig. 1. Rhodymenia bifida Greville, Harvey, Phye. Brit. I, pl. 32, 1846. The structure and development of the frond have been described by NAGELI, WILLE, KırLıan and Kyrın. The tips of the dichotomous frond have a marginal row of apical cells, some of which, the prineipal ones, divide by alternate, oblique walls. The frond consists of three layers of cells, the middlemost of which is composed of hypha-like filaments forming a net-work with large meshes. Hyaline hairs were not observed. 598 According to KırLıan the first stages of the germination of the carpospores and the tetraspores much resemble those of Lomentaria clavellosa. An attachment disc is produced_ by vertical divisions of the spore-cell. One of the cells of this disc, one of the original octant-cells, early becomes larger than the others and gives rise to the leafy frond. According to KYLIN, the species is monoecious. The antheridia arise scattered on the surface .of the frond, 3 to 5 small cells are cut off from a cortical cell, and each of these small cells produces 2 or 3 spermatangia. The development of the procarp and of the cystocarp has been carefully examined by Kyrın. The following facts only shall be mentioned here. The procarps arise near the border of the frond. The three-celled carpogonial branch is borne on a supporting cell which also supports Fig. 601. Rhodophyllis bifida. From Groves Flak, 19 m, collected by dr. F. Borgesen. 4, with cystocarps, B, with tetraspores. Photo, nat. size. an auxiliary cell. From the outer side of the supporting cell and the auxiliary cell branched cell-rows are produced which form a cortical layer over the procarp. The auxiliary cell having received a dipoid nucleus from the fertilized carpogonium produces on its inner face the first gonimoblast cell from which a number of carpospore-producing bushes are given off. Fusions take place between the auxiliary cell and the inner gonimoblast cells. The ripe cystocarp has no particular ostiole. The tetrasporangia are scattered over the surface of the outer segments of the frond. They arise by transformation of primary cortical cells and divide by trans- verse walls. Rhodophyllis bifida has only been met with in Skagerak and the northern and eastern Kattegat at considerable depths, 14—27 m, where the salinity is high and the temperature slightly varying. It grows on stony or gravelly bottom, often attached to Hydroids or Algæ (Halidrys). The largest specimens, up to 3 cm long, were found in August and September whereas the specimens gathered in May were only 3 mm high. Cystocarps and ripe tetrasporangia were met with in August and September. Localities. Sk: XO and YK N.W. of Hirtshals, 11—15 m. — Kn: Herthas Flak, 20—22.5 m (!, F. Borgs.); TO, Tonneberg Banke, 18 m. — Ke: Groves Flak, IT, EX, EV, 22.5—26.5 m, Groves Flak (F. Borgs.), 19 m. Fam. 19. Plocamiaceæ. Plocamium Harv. 1. Plocamium coccineum (Huds.) Lyngb. Lyngbye, Tent. 1819, p. 39, tab. 9 B; Kützing, Phycol. gen. 1843, p. 449, Taf. 64; Harvey, Phyc. Brit. I, pl. 44, 1846; Nägeli, Neu. Algensysteme 1847, p. 228, Taf. X, figs. 22—37; J. Agardh, Sp. g.o. Alg, Vol. II.2, p. 395, 1852; Kützing, Tab. phycol. Bd. 16, Taf. 41; Schmitz, Untersuch. 1883, p. 26, Taf. V, figs. 37—38; Buffham 1884, p. 338, 1891 p. 249, Plate 16, figs. 8—9; Phillips, Developm. of the cystocarp in Rhodymeniales, Ann. of Bot. 11, 1897, p. 352; Oltmanns, Morph. u. Biol. 1904, pp. 597, 646, 661; Kylin 1923, pp. 49—53. Fucus coccineus Hudson, Flora Anglica. Tom. II, 1778, p. 586, Goodenough and Woodward, Transact, Lin. Soc. 1797, III, p. 187. The structure of this common Atlantic species has been described by KüTzING (1843), NÄGELT 1847, OLTMANNS (1904) and Kyrın (1923). The ramification and the cell-divisions at the tips of the frond were carefully explained by NAGEL1 who stated that “> in the vegetative pinnæ the apical cell is first + divided by transverse walls, whereas they XV “beendigen ihr Wachsthum meist durch shiefe A Wände’...“DieSporenäste und Keimäste dagegen | wachsen durch schiefe Wände in der Scheitel- Fig. 602. zelle” (1. Cc. p. 228). KYLIN says (1923, p- 51) N re re that he has not observed the oblique divisions of the apical cells, and it must be admitted that the apical cell of most of the vegetative pinnulæ are divided only by transverse walls. NAGELI’s statement is, however, correct, at least for the feebler vegetative and for the male pinnule. In the lowermost, feeblest pinnula in a row, the last dividing walls of the apical cell are oblique, alternating (fig. 602), whereas the upper pinnulæ are divided by trans- verse walls to the very end of their growing activity, and in the tetrasporiferous pinnule the apical cells early begin to divide by oblique walls; the lateral ones are even divided only in this manner (fig. 603). In a female plant with young procarps, I found only transverse divisions in the apical cell of the pinnule. As to the anatomical structure and its development reference may be made to the quoted paper of Kyrın. We shall merely emphasize that the frond contains a central row of long cells rich in protoplasm, and is built up of an inner tissue of large parenchymatous cells which can be designated as a storage tissue, as it is rich in starch grains, and an outermost layer of small cells, which is essentially an assimilatory tissue; its cells contain numerous small chromatophores. Hyaline hairs are not produced. Antheridia were not observed in the Danish specimens. According to BUFFHAM (1891) and Kyrın (1923, p. 53) they form a layer on the surface of the pinnule of the last and penultimate order. The procarps arise in great numbers at the edges of the young branches of the flattened frond, at the inner as well as the outer edges. Their development has been described by Scumitz, PHırLLıps and Kyrın. Referring the reader to Kyrın’s paper, I shall only mention that the carpogonial branch is 3-celled and that the supporting cell (Tragzelle) according to Schmitz and Kyrın develops directly into an auxiliary cell, while Paiccips thought that the auxiliary cell was cut off from the supporting cell after fertilization. The first gonimoblast cell is cut off from the outer side of the auxiliary cell; it gives rise to several lateral cells which produce each a gonimolobe. The wall of the globular cystocarp consists of 3—4 cell-layers. The tetrasporangia are produced in particular pinnæ (stichidia) which are very different from the vegetative ones. They are flattened, simple and lanceolate or branched with nearly opposite or alternate, divaricate branches. The tetra- sporangia are included, biseriate. OLT- MANNS (1904, p. 661) compares them to INNE the stichidia in Tenioma and says that Fee) > | they are situated beside the central axis. ERO er The latter assertion, however, is not cor- Core c rect, for there is no axial cell-row in the fertile part of the stichidia, owing to the ; ; Fig 605 AR fact that the apical cell of this organ is Plocamium coccineum. Young stichidia. A, 560 : 1. B—C = 350 : 1. divided by oblique segment walls, as pointed out by NAGEL1. The first segments of the fertile pinnæ are cut off by transverse walls, but after the formation of e.g. 4 segments by this mode of division, the apical cell divides for the rest of its active period by alternating oblique segment walls. The segments cut off from the wedge-shaped apical cell are first divided by a periclinal wall. The outer daughter cell divides by anticlinal cell-walls and gives rise to the marginal portion of the cortex or wall of the stichidium. The inner daughter cell divides by two periclinal cell-walls by which are cut off two peripheral cells which by anticlinal cell-divi- sions give rise to the cortex on the two faces of the stichidium,. while the middle- most cell is a young tetrasporangium. The sporangia are therefore contiguous and form a continuous zigzag line along the longitudinal axis of the stichidium. The wall of the stichidium consists of only one layer of cells. When the stichidia are branched, the insertion of the branches is high, the breadth of the branches is greatest at the base and diminishes upwards. The branches are fructiferous from the very base. The uppermost cells continuing the zigzag row of sporangial mother- cells remain sterile. As is well-known, the sporangia divide by three parallel walls. The primary nucleus is first divided into two, a transverse wall is produced in the middle of the cell, and the two daughter nuclei enter into the resting stage before the next divisions take place (fig. 604 C). 601 BuFFHAM reports (1884, p. 338) that he has met with “a fine plant, divided near the base, bearing tetraspores on one half and coccidia on the other”. If a similar case should be met with again, it would be of interest to ascertain whether the plant is really a single individual or if its origin might possibly be due to the fusing of two distinet individuals. The germination I have not observed; but according to Kyrın the germination of the carpospores begins with the formation of a disc-shaped body (“Keimscheibe’’) (1923, p. 53, fig. 34 e). Fig. 604. Plocamium coccineum. From Hirtshals, September (A) and from the Færûe Islands, May, collected by F. BORGESEN. Stichidia. A and B, optical longitudinal sections. C and D cross sections. E, undivided sporangium. F, ripe sporangium. 350 :1. Plocamium coccineum has only been met with in the North Sea and Skagerak. It has only been collected in the months of June to October, but this is due to the fact that dredgings in these waters have not been made in winter and spring. It has been found at depths from 2 to 18 metres in Skagerak, and a small spec- imen was found in the North Sea at 27 metres’ depth. It grows on stones and on various Alg® (Laminaria hyperborea, Rhodomela, Phyllophora membranifolia, Furcellaria). The Danish specimens agree with the typical North European form. Though the species has not been collected in winter and spring, it is evident that it is perennial. In specimens gathered in June the new shoots had a brighter colour than the older ones, and the old portions of larger plants are often largely covered with Membranipora pilosa. The fronds reach a length of up to 10 cm. Tetrasporangia and cystocarps D.K.D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. 77 602 frequently occur in August; they were also met with in September, but the stichidia were then partly emptied and thrown off. Young stichidia were observed in June. Localities. Ns: Washed ashore at Römö (C. M. Poulsen); eR, 9 miles NW ‘/2 N of Lodbjerg lighthouse, 27 m, a small incomplete specimen 7 mm long, October. — Sk: Bragerne, 2.5 m, on Rhodo- mela, 4 cm, sterile, July; Dana St. 2900, east of Bragerne, 9 m, 1.5 cm high, sterile, October; washed ashore at Lokken (Mrs. Witthoft), 4 cm in diameter with ripe cystocarps; ZK" abreast of Rubjerg Knude, 18 m, 4—6.5 cm high and two other places off Lønstrup, about 8.5 m, on Phyllophora membranifolia; repeatedly washed ashore at Lonstrup; off Hirtshals, 12 m, F. Borgesen, on Laminaria hyperborea, 7—8 cm in diam.; Bredegrund and Mollegrund off Hirtshals, 9—15 m, several specimens, up to 7.5 cm high, and washed ashore at Hirtshals. The Botanical Museum of Copenhagen possesses two well developed specimens of Plocamium coccineum which according to the label were collected in Øresund by ØRSTED but are named Delesseria alata. These specimens originate from the herbarium of C. M. PouLsen; they were not labelled by ØRSTED and it cannot be imagined that this botanist should have confounded the two species in question. It must therefore be supposed that a confusion of the labels has taken place. Pl. coccineum has not otherwise been met with in the Danish waters within Skagen. At the western coast of Sweden it occurs at Bohuslän (Skagerak), but KJELLMAN records it with doubt from Skelderviken. Fam. Gracilariaceæ. Kyrın, 1930, p. 54. Gracilaria Grev. 1. Gracilaria confervoides (L.) Greville. Greville, Alg. Brit. 1830, p. 123; Harvey, Phyc. Brit. I, 1846, pl. 65; J. Agardh, Sp. g. o. II pars II, 1852, p. 587; Thuret in Le Jolis, Liste d. Alg. de Cherb. 1863, p. 134; Thuret, Et. phyc. 1878, p. 81, pl.40; T. Johnson, The procarp and fruit in Gracilaria confervoides Grev., Ann. of Bot. I, 1888, p. 213, pl. 11; T. H. Buffham, Anther., 1893, p. 4, pl. 13, figs. 11, 12; Killian, Entwick. 1914, p. 254; Phillips, Origin of the cystocarp in the genus Gracilaria. Ann. of Bot. 39, 1925, p. 787; Sjöstedt, Florid. Studies, Lunds Univ. Arsskr. 22 no. 4, 1926, pp. 51—64; Kylin, Entwick. 1930, p. 55. Fucus confervoides L. Sp. plant. ed. 2, II, 1763, p. 1629. Gigartina confervoides Lam. Thal. 1813, p. 48; Lyngbye Tent. 1819, p. 43. The closely placed cylindrical fronds spring in a fairly great number from a fleshy flat disc. Harvey says that there is “a small disc accompanied by fibres” (Phyc. Brit. pl. 65, Manual, sec. edit. 1849, pl. 16), and his figure shows a “radix fibrosa”. Other authors mention only a dise, and I have myself not seen any fibres in the Danish specimens. The disc has a parenchymatous structure, being composed of vertical or ascending cell-rows. The cells were in summer filled with numerous starch-grains. The disc increases in circumference by marginal growth and may reach a diameter of at least 0.5 cm; it becomes slowly thicker by continued growth of the vertical cell-rows of which it is composed. The periodicity in the growth may cause a stratification; the presence of one secondary layer could be ascertained in an older disc examined. The upright cylindrical fronds reach a length of up to 32 cm, though most of the specimens collected scarcely exceeded 20 cm in length. The ramification is 603 pronouncedly lateral, the branches arising at a long distance below the apex. All the shoots taper upwards. As to the structure of the tip of the frond, the authors do not agree. Kırrıan (1914) described the germination of the carpospores and found that the spore divides by vertical walls, forming an orbicular disc increasing by continued anticlinal and periclinal cell-divisions. The central part of the disc becomes vaulted, and one of the central cells develops more vigorously than the others; it becomes the initial cell of the primary upright frond issuing from the disc. The young frond has then a single triangular initial cell at the top (l. c. figs. 5—10); but KırLıan thought that this cell was later divided into a greater number of initial cells, and Ssö- STEDT (1926) is of the same opinion. KyLIN has, however, recently shown (1930, p. 55) that the tips of the older fronds have the same structure as that described by KırLLıan in the germling, and the species can thus be referred to the type with a central axis (“Centralfaden-Typus”), although an axial cell-row is not present. The structure of the frond has been finely illustrated by THurET (1878) and described by Ss6stEpT and Kyrın (1930). The frond is early differentiated into a thin cortex composed of two or three layers of Fig. 605. cells and a large medullary tissue built up Gracitaria confervoides. M Transverse serhomoffrenn of large, round, isodiametrical cells not With a hair. B and C, basal portions of hairs. D, cortical cells. E, medullar cells showing secondary lengthened in a longitudinal direction. These pits seen from the face. A—D 560 : 1. E 420: 1. cells are connected by numerous pits, partly secondary, and are without any rhizoids (fig. 605 E). The young cortical cells con- tain one nucleus while the older and inner cells may contain a greater number. Each cortical cell contains several chromatophores which are long, linear, ribbon- shaped, bent and sometimes branched; they are most easily seen in the inner cortical and the outer medullar cells (fig. 605 D). The young parts of the shoots bear numerous hairs (fig. 605). They were first briefly mentioned by me (1911, pp. 206, 208). Later PrirLırs observed the hair- producing cells but misinterpreted them as carpogonia (1925), whereafter SJÖSTEDT (1926) gave a description of the development and structure of the hairs (in Gr. compressa). They arise early (in Gr. confervoides) from primary cortical cells which remain undivided and therefore by continued growth become larger than the surrounding dividing cortical cells (fig. 605 A). The hair-bearing cell is con- nected with the hair by a narrow pit the transverse wall of which is situated "== 11 a little lower than the surface of the frond. Kyrın thought that the hairs are rarely developed, albeit the hair-bearing cells frequently occur. I found numer- ous and very well developed hairs in July and August (fig. 606). The antheridia occur in particular individuals; they arise, as shown by THURET (1863, p. 134 and 1878, pl. 40, figs. 1—3) in globular erypts sunk whithin the surface of the frond, the antheridia-producing cells clothing the cavities, whereas in other species of the genus these cells form patches on the surface of the frond. The observations of THURET were confirmed by BurrHam (1893), and I have found the same in Danish specimens. The development of the carpogonial branch, the goni- moblast and the cystocarp has been exhaustively treated by SsöstEpr (1926, pp. 54—63), and his observations have been confirmed by Kyrın (1930, pp. 55—59) who has given Fig. 606. further drawings. According to these authors, the carpogonial Gracilaria confervoides. From branch is two-celled and developed from a primary cortical Hirtshals, August. Tip of frond à 0 with numerous hairs. Photo. Cell. The supporting cell of the carpogonial branch becomes Wat. very rich in protoplasm and multinucleate, and the same is the case with the basal cells of the vegetative branches issuing from the supporting cell. A connection takes place between the carpogonium and a vegetative cell in its environs, but not with one predesigned in structure and nuclear conditions, and the diploid nucleus remains in the carpogonium. According to SJÖSTEDT, a true auxiliary cell cannot therefore be pointed out in the genus Gracilaria. Further cell-connections take place with the result that a large ramified fusion-cell is produced, of which the carpogonium constitutes an essential part (fig. 607). Shortly after the formation of the fusion-cell, gonimoblast-cells are cut off from several points of its surface. The gonimoblast consists in an advanced stage of an inner parenchymatous layer, forming a placenta surrounding the fusion cell and an outer layer consisting of radiating cell-rows the outer cells of which are transformed into carpospores (fig. 608). At the periphery of the cystocarp particular long, : = from Tonneberg Ban- N at Biarritz. 5 O 5 ®) BORNET collected atB ABU ke, Northern Kattegat, a 0 ©) The lower part of the frond 19 m, July. The fila- / isting 9 ingle row ment is by exception ° Q Con ay consisting CARS ngl not attenuated at the OVA DE B SES Cc of cells showed a thickness top: g IG ON of 17—35 u, and the middle- most part a thickness of 32—63 4, most often FÉES about 46 w. The plants may reach a length of Erythrotrichia reflexa. B, young plant. A et C, basal parts of plants. 350 :1. 5 mm but are usually shorter, about 2 mm gta or smaller. The thickness gradually increases towards over the middle, longitudinal divi- sions beginning at various distances from the base. The number of vertical septa in Fig. 613. Erythrotrichia reflexa. After living plants. In Bmonosporangia are to be seen. In C, the basis of the plant was hidden. D, monospores. After living plants. 340 : 1. each joint of the middlemost part of the frond may be about 4. Near the top the filament is again tapering; longitudinal divisions are wanting. As nearly all the observed spec- imens were unbranched, it appeared doubtful whether the Danish spec- imens ought to be referred to CROUAN’s species. One specimen only was found which showed a little branch issuing near the base (fig. 613 C). According to CrouaAN the fronds are branched or simple, with branches arising near the base, alternate or opposite. The young plants are cylindrical, monosiphonous, fixed to the substratum (various Algæ) by rhizoids produced by the lowermost cells of the filaments (fig. 612 B) and forming a conical attachment organ composed of several closely united branched cell-filaments (fig. 612, A, C). Crouan described the “root” as colourless; I found it of the same dark purple colour as the upright filament. Each cell of the filaments con- tains a stellate chromatophore with a central pyrenoid and long, simple or dichotomously branched arms bentalong the vaulted outside of the cell. In the polysiphonous portion of the frond the central part of the chromatophore is more or less approached to the outside of the cell. The sporangia (gonidangia) are cut off by longitudinal or somewhat oblique walls from cells in the poly- siphonous part of the frond (fig. 613). They are a little smaller than the vegeta- tive cells, about 14—16 w in greatest diameter, often broadly obovate, and are easily recognizable by their dense contents. The stellate chromatophore is not so distinct _615 as in the vegetative cells, but the pyrenoids are easily observed. In the exhausted spores the chromatophore is very distinct (fig. 613 D); its arms are shorter than in the vegetative cells. In the living spores the chromatophore was red, while the pyrenoid appeared with a yellowish colour. In a certain position the chromatophore showed an incision on one side where the nucleus probably was situated. The living spores showed no amoeboid changes of shape, but were able to execute gliding movements on the slide.! The Danish plants are here referred to Erythrotrichia reflexa although they are almost all unbranched and their dimensions larger than those of the French specimens, and though there seem also to be differences as to the attachment organ. Crovan attributed to his species a “Racine discoide incolore”. I have not observed the attachment organ of the original specimens in Crouan’s Exsiccate No. 394, but I have seen the attachment organs in specimens of the same species from Biarritz communicated by Borner (herb. THURET), and these agreed with those of the Danish specimens; I think, therefore, that Crovan’s short description of the attachment disc is founded on some incomplete observation. Colourless attachment organs are otherwise not known in the genus Erythrotrichia. As to the nearly complete want of ramification in the Danish specimens, it is noteworthy that only one little branch has been met with, although the species has been observed repeatedly during recent years. On the other hand the greater part of the specimens examined from the collection of Crovan were unbranched, and all the filaments examined of the specimen from Biarritz were unbranched. The greater thickness of the filaments in the Danish specimens is perhaps due to the different external conditions. As long as Er. reflexa and its variation is not better examined in differ- ent localities, it is impossible to decide with certainty whether the Danish species is the same as that from the coast of France. The species was found growing on various Algæ (Polysi- phonia urceolata, Cystoclonium purpureum, Sphacelaria saxatilis and Callithamnion Hookeri) at 1 to 19 metres’ depth; it was only observed in July and August. Localities. Kn: N.W. end of Tonneberg Banke; Hirsholm harbour (Henn. Petersen); Frederikshavn harbour; Borrebjergs Rev, Marens Rev. Fam. Naccariaceæ Kylin 1928. Atractophora sp. In July 1929 I found on a stone picked up from a depth of about 2 metres in the neighbourhood of Frederikshavn a small red Alga, only 2 mm high, issuing from a circular disc. As the Fig. 614. {iractophora Sp.? 33:1 ! Comp. L. KorneruP ROSENVINGE, On Mobility in the reproductive Cells of the Rhodophycee. Botan. Tids. 40 p. 72. species was unknown to me I tried to get other individuals in the same locality and in other similar places but without success. The only existing little specimen Fig. 615. Atractophora sp.? A, tip of frond. 625 : 1. B, portion of branch. 440 : 1. showing a very characteristic structure, I think it useful to give a short description of it and some figures in order to render an identification of the species possible. The frond has a distinct axial cell-row which bears at each joint a whorl of branches, from the base of which downward growing cell-rows issue, which form a thick cortex surrounding the axial cell-row. The branches are mostly pinnate, with opposite branchlets and with limited growth; branch- lets of the second order may occur. Many of the end- cells of the pinnæ and pinnulæ bear a hyaline hair. The lowermost branches are simple or feebly branched. Branches of the same kind as the primary axis, with enduring growth, occur. The colour of the plant is brownish-purple, somewhat resembling that of Plumaria elegans. The plant recalls Atractophora hypnoides in the general structure’; but it differs so much that it cannot be identified with it. As I had no material for comparison, I applied to Mr. E. CHEMIN at Paris who has most kindly sent me some dried specimens of Atr. hypnoides from the north coast of France. An examina- tion of these specimens, some of which were young, con- firmed that the plant from Deget was decidedly differ- ent from Atr. hypnoides. The branches of the latter are similar to the primary axis, bearing shoots on all sides, and the cortex built up of ! Comp. CROUAN, Ann. d. scienc. nat. III ser. t. 11, 1848, p. 371, pl. 11 A; NäÄcELIı, Morph. u. Syst. d. Ceram. 1861, p. 388; ZERLANG, Flora 1889; Kyrin, Ent- wick. Florid. Studien. 1928, p. 12; o C © PRA GD {ONS VG Ga 057 JO GROSS OO JO o DOM TOG B GS SE ROSH Cha) do PVO QS IS © ROC o op OS 60 20 en 8 PO Go OS CV Ro E90 SP En B01 OÙ (Ome) Rey | Fig. 616. Atractophora sp.? Portion of the ‘main axis. The cell-rows of the cortex are a little separated by pressure. The long cells of the axial cell-rows are to be seen in the middle. 625 : 1. E. CHEMIN, Sur le développement des spores de Naccaria Wiggii Endl. et Atractophora hypnoides Crouan, Bull. soc. bot. France, t. 74, 1927, p. 274. 617 the downwards growing cell-rows budding off from the base of the branches has a quite different structure from that of the Danish specimen. In the French plant it remains filamentous, consisting of parallel cell-rows and it has a comparatively small thickness, while the cortical cell-rows in the Danish plant are early divided by numerous transverse and longitudinal walls, the latter being both radial and tangential, with the result that the cortex becomes thick and is built up of numerous short cells, whereas the axial cell-row is narrow (fig. 616), in contradistinction to Atr. hypnoides where it is very broad. Finally the cortical cell-rows of the latter bear numerous short simple or feebly branched filaments which do not occur in the Danish plant (comp. Crovan lI. c. fig. 3—5). In spite of the differences quoted it seems probable that the Danish plant belongs to a species related to Atractophora hypnoides. Locality. Kn: South coast of the isle of Deget near Frederikshavn. Fam. Rhizophyllidaceæ. Chondrococcus Hornemanni (Mertens) Schmitz. This species was first described by MERTENS in 1815 (Göttinger gel. Anzeiger 1815 No. 64) under the name of Fucus Hornemanni. It was mentioned and described 1819 by LYNGBYE who writes (1819, p. 35) that it was found in Øresund “ubi ad oram Helsingoræ hance speciem elegantem et quidem rarissimam cel. Forskaal olim legisse fertur”. LYNGBYE named it Desmia Hornemanni and gave a very good picture of it (l.c. Tab. 7 C). The original of this figure is to be found in The Botanical Museum at Copenhagen, labelled by MERTENS: F, Hornemanni; on the back of the sheet HORNEMANN has wrilten: “legit Forsk: ad oras Helsingorze’. The species was referred to Spherococcus coronopifolius by C. AGARDH in Synops. Alg. Scand. 1817, p. 30, and later united with Spherococcus Lambertü (Suhr) by J. AGARDH (Sp. g. 0. Il.ır. 1852, p. 641) under the name of Desmia Hornemanni (Mert.) Lyngb., which name is still kept in his Epicrisis, 1876, p. 357, while Kürzıng referred the species to the genus Chondrococcus. There can be no doubt that this Alga has not been found growing in the Öresund. LYNGBYE had evidently his doubts as to the correctness of the locality cited, and J. AGARDH wrote (1852, p. 642): “cum nave forsan trans- vecta?”. Scumitz (Marine Florideen von Deutsch-Ostafrika, Engler’s Bot. Jahrb. Bd. 21, 1895, p. 171) pointed out that Chondrococcus Lambertii, which is common at the Cape, is specifically quite different from the true Ch. Hornemanni which occurs in the Northern Indian Ocean. I can fully confirm this distinction. In Ch. Hornemanni the pinne are generally opposite while in Ch. Lambertii the branches are alternate and more distant, and the frond broader. It can be imagined that the specimen described and figured by LyNGByE has been collected by Forsskär in the Red Sea, but that a confusion of labels has occurred after Forsskau’s death, during the last part of the journey or later. D. K, D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. 19 618 Genera incertæ sedis. Conchocelis Batters 1892. 1. Conchocelis rosea Batters. E. A. Batters, On Conchocelis, a new genus of perforating Algæ, in G. Murray, Phycological Memoirs, Part I, London 1892, pp. 25—28, Pl. VIII. G. Nadson, Die perforierenden (kalkborenden) Algen. (Russian with abstract in German), Scripta Botanica Horti Univ. Petropolit. fasc. 18, 1900, pp. 14—19, 36—37. L. Kolderup Rosenvinge, On the Marine Algæ from N. E. Greenland. Meddelelser om Grønland, 43, 1910, p. 111. H. Printz, Algenveg. d. Trondhjemsfjordes. Skrifter utg. af D. Norske Vid.-Akad. Oslo. 1926, pp. 54, 257. Batters described in 1892 a perforating red Alga living in the calcareous shells of Molluses gathered near the coast of Scotland. The frond consists of a horizontal layer of thin, branched interlaced filaments giving off irregular inflations, which are simple or branched, and consist of from two to ten cells, each containing a star- shaped chromatophore. According to BATTERS the plant appears to be reproduced by means of spores formed in the cells of the inflations, one spore in each cell. He had “seen globular bodies which appear to be spores escape from the cells”. In accordance with Bornet he referred the plant to the Porphyraceæ (Bangiacee). The plant seems to be widespread for it has been met with repeatedly at the shores of northern Europe and in the Arctic Sea, but it is as yet imperfectly known. Napson advanced (1900) the opinion that it was not a Rhodohycea but only a red variety of the green Alga Osireobium Quekeiti Born. et Flah.: this opinion, however, has not been accepted by later authors (KoLDERUP ROSENVINGE 1910, Printz (1926), and it can be taken for granted that Conchocelis rosea has been confounded by Napson with a red variety of Ostreobium Queketti. Printz found such a red form of the last named Alga in the neighbourhood of Trondhjem, and I found a similar form in the Northern Kattegat, but they were both quite distinct from Conchocelis rosea. After having examined specimens of the latter gathered in East Greenland I maintained, though with doubt, that it could be referred to the Bangiacew, which classification was principally founded on the lack of pits in the transverse walls and the supposed presence of spores comparable to the monospores of the Bangiacee. On examining the Danish specimens of the species, I have, in order to gain a better determination of its systematic position, directed my attention in particular to the structure of the chromatophores, the presence or want of a pit in the transverse walls, and the reproduction. The species is fairly widespread in the Danish waters where it grows in the shells of various molluscs; but it is most easily accessible when it occurs in the calcareous tubes of Spirorbis and Pomatocerus triquetrus, two Serpulids often attached to Furcellaria a. o. Algæ, and the shells of which are frequently pink owing to the abundant occurrence of Conchocelis rosea. For a study of the finer structure of this plant the shells of these Serpulids were treated with acetic acid, Carnoy’s fluid, 619 Nawashin’s mixture or picric acetic acid. The latter treatment was particularly good for demonstrating the nuclei and the pit-connections between the cells. The peripheral part of the frond is formed of long thin filaments, usually 3—4 w thick, sometimes only 2 « or still thinner. Where there is ample room the filaments may be long and straight and consist of very long cells; they may be simple or bear opposite or alternate branches rising rectangularly near the upper end of the cells. The branches are partly different from the long straight filaments by being composed of shorter more or less swollen, spindle-shaped or more irregular cells. (Comp. figs. 617—619). Later the filaments become very much branched and densely felted together, forming a more or less continuous layer within the surface of the shell. The cylindrical cells contain a small number of long ribbon-shaped or perhaps branched chromatophores and, in the middle of the cell, a nucleus which is often rather inconspicuous and feebly stained with hematoxylin. The transverse walls are very distinct but it is usually impossible to distinguish a central pit by application of dry lenses; but with high magnifying power a callus button deeply stained with hematoxylin on each side of the transverse wall could some- times be observed (fig. 617 A, E), a sure sign of the presence of a pit. The structure of the inflated cells is similar to that of the cylindrical cells; the nucleus was in some cases very distinct (fig. 618 B-F), the chromatophores shorter. The transverse walls of the inflated cells have the same small diameter as those of the long cells. The contents of the inflated cells is at first not very rich, but later it often becomes dense and rich in granular matter, probably floridean starch, as it takes a red-brown colour with iodine, and the inflations may then resemble the chlamydospores of Fungi (fig. 618 J). A new kind of cell-rows, different from those hitherto mentioned, spring, usually from the inflated cells, but sometimes perhaps directly from the long thin cells. The cells of these rows are different from the others by greater breadth and denser con- tents. Besides the cell organs they contain much floridean starch which gives the cell a granular, untransparent character. The cells are broader, not only in the middle but also at the transverse walls, which have a much larger diameter than the other cells. The cells of these filaments are cylindrical or a little inflated, almost of the same length as breadth, and they are uniform. These cell-rows are always branched but have a limited growth. The branches are usually more or less curved. As it must be supposed that they normally produce monospores, they will be called fertile cell-rows. In material from different shells they showed, how- ever, certain differences; as I feel doubtful whether these variations are due to differences in the external conditions offered by the various tests in which the plants grow or if they may possibly be expressions of genotypical differences, specimens from various shells will be mentioned separately, and the drawings illustrating them are arranged so that each of the three groups of drawings (figs. 617—619) originates from plants growing in the same shell or, as to those growing in Spirorbis, at least from specimens of this Serpulid seated on the same 79* 620 host plant. They are all here provisionally regarded as belonging to the same species, Conchocelis rosea. The specimens shown in fig. 617 grew in Spirorbis sp. attached to Furcellaria fastigiata gathered near Frederikshavn in July. The fertile filaments are here thick, about 14— 16 w in diameter, and the cells are usually more or less inflated or rounded, with convex outer-walls, of the same length as the breadth or shorter, rarely a little longer. Longitudinal or intercalary transverse or inclined divisions occur here ogg à =n SE SIR 5 TR SE a ur Fig. 617. Conchocelis rosea, in lest of Spirorbis sp. from Hjellen near Frederikshavn, treated with picric acetic acid. A, cell of long, thin filament, showing nucleus, chromatophores and pit-connections in the transverse walls. B, long fila- ment with opposite branches, one with inflated cells. C, branched filament with partly inflated cells. D, row of broad cells with distinct flat chromatophores lining the wall. E, fertile cell-row springing from a thin filament, showing pit-connection in the transverse walls. F, branched fertile cell-row. G, fertile cell-row, with branch and an oblique intercalary wall. H, fertile cell-row the cells of which produce each a monospore. 630 : 1. and there (fig. 617 G). The pit connections in the cross walls appeared distinctly in these specimens which had been treated with picric acetic acid, the callus button in the middle of the wall being intensely stained with hemalum (figs. E—H). A young stage is shown in fig. E, where a 4-celled complex of fertile cells is seen in continuity with the thin filament from which it has originated. The larger bushes of fertile cell-rows may somewhat resemble a frond of Stigonema, but the outer wall is firm, not gelatinous. The cell-structure is often difficult to observe owing to its dense character. A central nucleus intensely stained with hematoxylin was always to be seen but its finer structure could not be observed. Many cells with dense contents suggested the presence of a stellate chroma- tophore as supposed by Batters and formerly by myself, and the nucleus then 621 seemed situated in the middle of the chromatophore, suggesting a pyrenoid; but on observing well fixed cells with less dense contents, I succeeded in ascertaining that the intensely stained body was not a pyrenoid in a stellate chromatophore but a real nucleus situated in the cytoplasm and surrounded by chromatophores (fig. E, F). According to BATTERS (l.c. p. 26) the “inflations”, by which term he denotes the fertile cell complexes, usually consist of from two to ten cells. The branched com- Fig. 618. Conchocelis rosea. In shells of Pomatacerus triqueter. A—H, collected at Københavner Rev near Frederikshavn, treated with picric acetic acid, stained with hemalum. J—L from Marens Rey at Frederikshavn. A, long cell showing chromato- phores and nucleus. B and C, long filament with branches consisting of inflated cells. D, E, F, inflated cells. G, branched complex of broad filaments. H, end of fertile cell-row. J, a couple of inflated cells with dense contents springing from a thin filament. K, a fertile cell-row in connection with thin filaments. L, four cells of a fertile cell- row from a section through a decalcified shell, showing the central nucleus and radiating plasma-strings, while the chromatophores are feebly stained. A—F, H—K 630:1. L 730: 1. plexes of fertile cells here described contain a much larger number of cells, about 50 or more. It is probably such complexes of which Barrers treats when he writes (1. c. p. 27) that “the inflations often become detached from the horizontal filaments and are capable of an independent existence”, and that he has found them of all sizes and shapes. The continuity of the larger complexes of fertile cells with the thin filaments was not indeed observed by me, and it is probable that their growth can be continued, if their connection with the thin filaments should 622 be interrupted. I have also met with smaller groups of inflated cells consisting of 4 or 5 cells, resembling those figured by Batrers but containing flat chromatophores lining the outer walls and one to three dense bodies, perhaps nuclei (fig. D). These cell-groups seemed not fully normal. — Fig. H shows a row of inflated cells the content of which is contracted and more or less globular, undoubtedly monospores; the callus buttons of the separating walls are very distinct. Fig. 618, A—H show details from Conchocelis growing in a tube of Pomatocerus triqueter gathered in the same locality near Frederikshavn in July, while figs. J—L are from similar specimens gathered in a neighbouring locality three days later. The tube of Pomatocerus was coloured finely rose for a long way by the perforating Alga. The youngest part of the red shell contained principally very long straight filaments. A group of fertile cells in connection with thin filaments is shown in fig. K. Numerous large complexes of fertile cells were met with in the older part of the shell (fig. G). The cells of these cell-rows were cylindrical, scarcely swollen, usually a little longer than broad, and the diameter smaller than in the specimens from Spirorbis, viz. 9—11 u. The structure of the fertile cells was not obvious, although the specimens had been treated with picric acetic acid or with Nawashin’s mixture. An intensely stained nucleus could, however, be observed, but the shape and the number of the chromato- phores were indistinct and a pit in the transverse walls was not usually discernible. In some cases dense bodies, intensely stained with hematoxylin, were observed in the chromatophores (fig. H); as these bodies were in some cases angular, they were perhaps crystalloids. In a transverse section of a shell treated with Nawashin’s mixture and stained with hzematoxylin after Heidenhain the fertile cell-rows were seen growing inwards in the shell from the vegetative layer. With high power of enlargement a central callus button proving the presence of a pit-connection was ascertained (fig. L). A number of strings recalling the arms of a stellate chromato- phore were seen radiating from the central intensely stained nucleus; they seemed to be strings of protoplasm, whereas the presumed chromatophores were comparatively small and feebly stained. The specimens drawn in fig. 619 grew in Spirorbis but agreed as to the fertile cell-rows with those just described from Pomatocerus. Fig. C shows a two-celled group of fertile cells given off from a spindle-shaped cell. The nuclei were intensely stained, whereas the chromatophores were very indistinct. The fertile cells were cylindric, which is also apparent in fig. E, where four globular monospores are to be seen. The investigations here communicated have shown that there is a distinct difference between 1) a vegetative stage consisting of branched filaments composed of long, thin, cylindric cells and inflated, more or less spindle-shaped cells, both with narrow transverse walls, and 2) fertile branched cell-rows consisting of uni- form, broad cells separated by broad cross-walls. The presence of a central pit in the cross-walls has been ascertained, and it has been shown that the cells contain a nucleus and probably always more than one chromatophore. The formation of a 623 monospore in the fertile cells, as presumed by Batters, has been confirmed, and it seems that all the cells of the fertile cell-rows are capable of producing a monospore. The formation of monospores is in good accordance with the reproduction of the Bangiales, but the presence of pit-connections between the cells shows that Conchocelis cannot be referred to this group, as such connections have never been observed within the Bangiales. The plant must therefore be referred to the Floridee, but its relationship within this group is very doubtful. several Nemalionales, but they are there always produced in particular monosporangia different from the other cells. Monospores have other- wise been found in female plants of Nitophyllum punctatum' where they arise in cells scarcely different from the vegetative cells, situated in groups near the procarps. This occurrence seems, however, to have no bearing on the consideration ofthe relationship of Conchocelis. Further researches are needed for the elucidation of this question. Conchocelis rosea has been met with in nearly all the Danish waters except the Baltic, growing in the calcareous shells of the Serpulids Spirorbis and Pomatocerus triquetrus and of various mol- luses (Buccinum undatum, Lütorina littorea, Mytilus, Cyprina islandica, Astarte? a. o.). According to Dr. JonHs. SCHMIDT it has also been met with in a Monospores are known in Fig. 619. calcareous stone. It has been gathered at depths from 1 to 32 metres. Fertile cell-rows have been met with in the months April to October (it has not been gathered in the winter months). Localities. Ns: eP, off Lodbjerg light-house, 24 m, in Buceinum undatum. — Lf: Nykøbing, in Bucc. und. (Teil- mann Friis). — Kn: fG, Tonneberg Banke, 15 m; off Aalbæk, 22 m, in Bucc. und.; at Hirsholmene and in numerous places near Frederikshavn, most frequently in Spirorbis and Pomato- cerus. — Ke: Groves Flak. 23m and 32 m, in Cyprina isl. Conchocelis rosea. From shell of Spirorbis from Deget near Frederikshavn, treated with Carnoy’s fluid, and stained with hematoxylin. A, long cell showing chromatophores. B, in- flated cells. C, spindle-shaped cells; a fertile cell-row is given off from one of them. The nuclei are distinct, the chromatophores only feebly stained. D, end-cell of a broad cell- row, a pit-connection is seen in the trans- verse wall. E, Four globular monospores are formed in a fertile cell-row. A, B, D 630 :1. C 510:1. (F. Borgesen,!); Søborg Hoved Grund, in Littorina lit. Gilleleje, in Spirorbis. — Km: East of Læsø Rende, in Spir.; — Sa: 1'/2 miles N.E. by N. of Sejerø, in Mytilus; Lille Grund, in Spir. — Sb: Hov Sand, in Spir.; Lohals, in Spir. Spodsbjerg Mole, in Spir.; off Holmegaard, in Spir. — Su: Skodsborg, in a calcareous stone (determ. Johs. Schmidt). Halosaccion ramentaceum (L.) J. Agardh. About 50 years ago Mr. O. SmitH sent me some Algæ cast ashore at Lerchen- borg, Store Belt. Among these Algæ a specimen of Halosaccion ramentaceum is found, 1 N. SvEDELIUs, Über Sporen an Geschlechtspflanzen von Nitophyllum punctatum. Ber deut. bot. Ges. 32, 1914, p. 106. 624 a very strange finding, as this species has never otherwise been met with in the Danish waters. Since the nearest known localities of this subarctic species are the Trondhjems- Fjord and the Færåe Islands, and as the specimen is quite normal and bears no sign of haying been drifting for a long time in the Sea, I consider it most probable that the specimen in question, which has not been labelled by Mr. Smith, has been intermixed by an error among the Alge found at the coast of Store Belt. I am much indebted to Dr. HENNING E. PETERSEN who has helped me in making microphotographs, to Lector J. BoyE PETERSEN for having kindly photo- graphed a number of dried specimens reproduced in the text, and to Mr. SØREN Luxp who has assisted me on several excursions. By the kindness of the authorities of the Fishery Department I have had the opportunity of making researches onboard in various boats belonging to the Fishery Control and Fishery Researches, for which permission I tender my best thanks. And finally I owe a debt of gratitude to the trustees of the Carlsberg Fund for a grant which has enabled me to defray various expenses in connection with the present part of my work. INDEX Synonyms are printed in italics. Page Acrochetium (see Chantransia) ............ 80 Actinococcus roseus (Kütz.) ................ 525 — subcutaneus (Lyngb.) K. Rosenv.......... 525 Ahnfeltia plicata (Huds.) Fries............. 554 LEN ORTEN DEREN 568 Antithamnion boreale (Gobi) Kjellman ..... 368 — cruciatum (Agardh) Nägeli ............. 359 Ph ROUE 00 0.000.080 04 an are RR 359 (th TAINS Wo ATARANRPEEPERPE ee 359 — Plumulag(Ellis)ihuretesee sen 362 Apoglossum ruscifolium (Turner) J. Agardh.. 474 Asterocytis ramosa (Thwaites) Gobi......... 77 Atractophonagspspeme EE TE CE EC 615 Bangia fusco-purpurea (Dillw.) Lyngb....... 56 = foi ARE CHE 60 Bonnemaisonia asparagoides (Woodw.) Agardh 401 Brongniartella byssoides (Good. et Woodw.) SCT EAN Re ee nee eee 445 Callithamnion Brodiæi Harv. .............. 313 = BOL ARSososcsccdseoctbecodode 336 — corymbosum (Engl. Bot.) Lyngbye........ 325 — fruticulosum J. Agardh................. 320 —EurxcellarierJ. Agardhy 25.5. 25.0200 6 00 336 — Hookeri (Dillw.) Agardh f. Areschougii K. ROSEN cern Ne fees lous Miers eters 309 — LOSCUMAEALV EVE RE sovs 0D 331 — tetragonum (With.) Ag. ................ 317 — van OVERNET cobcocccooeoedet orne 319 — var. fruticulosa J. Agardh............... 320 ES D ce 345 Ceramium abyssale Henn. Petersen ......... 384 — arborescens J. Agardh ................. 382 ——äreschousiekyline en. .... 384 — atlanticum! Henn. Petersen." 383 — Boergesenii Henn. Petersen ............. 383 — cimbricum Henn. Petersen............ . 318 — danicum Henn. Petersen ............... 381 — Deslongehampsii Chauvin .............. 380 Page Ceramium diaphanum Harv. et J. Agardh ... 376 = == TE Gin WL IRD adc gow saccodeece 377 = = JR GUACONC ES Jel AS pos agnbmoortoacc 377 — — een Jets IPMS EEE CE roe 377 == = eco HOLE SIT 377 = TE LOS LET LC OT EE TS cocoa socodnace 377 = 1H VHA IIIB sms ob Cent 06000 377 — fruticulosum (Kützing) J.Agardh......... 385 = — 6 CHENOA FOIE soe Fåre aske den 385 — — f, penicillata (Aresch.) H.Ptrsn. ..... 385 — Rosenvingii Henn. Petersen emend. auct... 382 —= one BSY IT eos dede danes seer 382 — rubrum (Huds.) Agardh. ............... 386 tT aASCiCU Latah PÉTSNE ER anne ters 387 — — f.modificata H. Ptrsn................ 387 — — fssubtypical HePtrsnt.. on 387 = == ieee We IPS Scdocscssteseuuun 387 — — firresulanis) EH MP ETSD nen 387 — — f.irregularis subcorticata H. Ptrsn..... 387 = = LCR Isl, WES, soos EEE ER CCE EE 387 — —= Prolene A ETS ane sone 387 — — fadivaricatal Hr Pörsn.. ee ert: 387 — scandinavicum Henn. Petersen........... 383 — septentrionale Henn. Petersen ........... 386 ——strictum) Grevillevet Harveys)... 2-1-1 377 = = THO Jal, AI Ge Ge ono eDobdoecce 378 — — f. stricto-tenuissima H. Ptrsn. ...... 378 — tenuissimum (Lyngb.) J. Agardh ........ 376 — vertebrale Henn. Petersen .............. 380 Ceratocolax, Hartzii K. Roseny........ 545 Chantransia (Euchantransia) attenuata K. ROSeDVA EEE er ee Men eee aaa eeu 106 — baltica K. Rosenv. . . . AE SOS 97 —eytophaga RK. Rosenv. Sn 121 — Daviesii (Dillw.) Thur. 104 — Dumontiæ K. Rosenv. ... 124 — emergens K. Rosenv. ...... 128 — endozoica Darbish. .... 128 80 D.K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. Page Chantransia gynandra K. Rosenv............ 88 ——hallandicaw MN érsonccaccnsoosessece 93 REY PIO SEE dogonos 97 FE JDBAOP oooncscosocasegoonbosuseotos 97 a HINA (BY oaoocoscenaseesanouce 97 — lites NOUS. scecseconssesenc505s 117 — ImnOrRE UG IROSSINA RE EEE SR 130 PR ho dome æ -Loboccpoccosesescoesboss 130 FIBOIySIP HOMER SET ee 131 — TESTA UG Rosen VAE EEE ET 118 —— Weer NG IRGOSOING EE PE EEE CRE does 114 = MOD II forms UC MGIIN, EEE EE 99 — Nemalionis (De Not.) Ard. et Straf....... 126 IGN Rocca core oo 94 POLY las fan hes OSCAR EEE EL 115 —= bolyidisoKRosenyrar EE ee ee 132 — ZreductawKe Rosen van re 120 — Zrhipidandr a0 KR Osen var 91 == SHG NC RONG AT ee 108 — Winn (tie) KV ee 100 FE > aimphicarpal Ke ROSEN VE donor 100 — == fh BME HO IROSSING EC 2102 — virgatula (Harv.) Thur. emend.......... 109 i sens Gb ANS) SIE SE REED descace 110 PRÉCCEICANRAROSENVAE PE EE CEE EC EEE 111 yasecundata (Lyn gb) er EEE ECC Eee 112 — (Grania) efflorescens (J. Ag.) Kjellm...... 134 no DECLIN ALAN Gy IT Nie ety 138 PARC bread KØR os Vara ee 139 Chondria dasyphylla (Woodw.) Agardh ..... 406 Chondrococcus Hornemanni (Mert.) Schmitz.. 617 Chondrus£crispus (2) Stackh eee 499 — a feabbreviacamhy ellin semper 505 — SS TEETER MIE Liéooohocsecoesotospocs 507 = = iE SUES VND EE EP snd ssonsccues 506 a CONS AS ee pir ne nn 505 — — Enno MAO, Cacotectacenceons 506 ent D OLY. COOLO Mam hy ell meme ee 506 — BAN aes areola Dado Ho acetate clos ors 505 ON CIN A A Is Soe een 507 Choreocolax Cystoclonii Kylin ............. 596 Choreonema Thuretii (Bornet) Schmitz ..... 258 Chylocladia kaliformis (Good. et Woodw.) |p Kile eaten Ure ea oe cei Ne en CE 577 Colacolepis incrustans Schmitz............. 538 GonchocelisgroseauBatterstr rn rene 618 Gorallınagotficinalis@lr pe PEER PRE 269 MUD EUS ESS EEE 274 Cruoria pellita (Lyngb.) Fries, Areschoug ... 180 Page Cruoriella codana K. Roseny. .............. 188 —2Dubyil(Grouan)ESchmitzee er PE EEE 193 Cruoriopsis danica K. Rosenv............... 184 — gracilis) (Kuckuck) Batters 202002 187 Cystoclonium purpurascens (Harv.) Kütz. ... 589 — purpureum (Huds.) Batters............. 589 Dasya coccinea (Huds.) Ag............. ::- 402 Delesseria alata (Huds.) Lamour. .......... 481 — sanguinea (L.) Lamouroux............-. 475 — Tuscijolia (Turn) Lamour 222% 474 — sinuosa (G. & W.) Lamour. 467 Desmia Hornemanni Mert.................. 617 Dilseayeduliss Stackhouse ee ee eee eee 160 Dumontia filiformis (O. Fr. Mill.) Grey. ..... 155 — incrassata (O. F. Müll.) Lamour.......... 155 Epilithon membranaceum (Esper) Heydrich. 234 Erythrocladia irregularis K. Roseny......... 72 rt SUDINteS TASK ROSENVE EE EEE EEE 73 Erythrotrichia carnea (Dillw.) J. Ag. ....... 67 — ceramicola (Lyngb.) Aresch. ............ 67 — reflexa (Crouan) Thuret ................ 613 Euthoraseristata (FI) J Agardh 200200022 596 Furcellaria fastigiata (Hudson) Lamouroux .. 164 Gigartinamamillosa(Good.et Woodw.)J.Agardh 509 Gloiosiphonia capillaris (Huds.) Carm....... 276 Goniotrichum elegans (Chauv.) Le Jolis..... 75 Gracilaria confervoides (L.) Greville ........ 602 — — SE HOMIES) 2 occa cscesecsen5eo0es 606 Halarachnion ligulatum (Woodw.) Kützing .. 163 Halosaccion ramentaceum (L.) J. Agardh ... 623 Harveyella mirabilis (Reinsch) Schm. & Rke.. 494 Helminthocladia purpurea (Harv.) J. Ag..... 147 Helminthora divaricata (Ag.) J. Agardh..... 149 Heterosiphonia plumosa (Ellis) Batters...... 402 Hildenbrandia Crouani J. Agardh .......... 207 EP EO EO LY PI SENAT OO eres eee eee 202 Hutchinsia implicata Lyngb................ 423 ——ilepaddicola END EE EEE ECC CCC CCE 411 Kylinia rosulata K. Rosenv................. 141 Laurencia pinnatifida (Gmel.) Lamouroux..- 403 Lithophyllum (Dermatolithon) Corallinæ (Grouan) Heydr re ee 265 — — macrocarpum (Rosan.) Foslie ........ 263 FatypicalEoslier yon aera rer 263 föıntermediaWKoslies pres ee 263 — — pustulatum (Lamour.) Foslie. ........ 268 — (Eulithophyllum)orbiculatum(Foslie)Foslie 258 Lithothamnion (Eulithothamnion) calcareum (Pallas) Aresch) so TE 226 Page Lithothamnion (Eulith.) glaciale Kjellm. .... 221 var collencsa (PROS) ES 06 EE MS 222 ven Granit (POS)scccocoscovuncouonsoan 222 — — leve (Strömf.) Fosl.................. 215 — — Lenormandi (Aresch.) Foslie. ........ 216 — — norvegicum (Aresch.) Kjellman ....... 224 — = MER HAGA ocbeosnoancsoodogduds 219 — (Phymatolithon) lævigatum Foslie....... 232 — — polymorphum (L.) Aresch. .......... 228 Lomentaria clavellosa (Turn.) Gaill. ........ 583 = POSER (Han) WOR 6 so os00ouoococvgode 587 Melobesia Fosliei K. Rosenv. ............... 249 — Laos ROMO ooh usssssasccodcnooeon 238 — limitata (Foslie) K. Rosenv.............. 245 — membranacea (Esper) Rosanoff.......... 234 = HOO OA KC TOM coneccacacnecuccs 256 = me PORNO ron 252 = SUDA Ih. IRON asoosseooscscn00066 243 — INRA BONE ee 258 = WOO NVOSUOIMNEY IEG IRONS ee dede daD on O0d 253 Membranoptera alata (L.) Stackhouse....... 481 FED alticateeys mrp ae ee een ser 486 Nemalion multifidum (Web. et Mohr) J. Ag... 144 Odonthalia dentata (L.) Lyngbye........... 459 Petrocelis Hennedyi (Harvey) Batters....... 174 Phycodrys rubens (Huds.) Batters.......... 467 GETEILT DTA ee leads eke 473 6 TEA A osoaseease bepcaceocavat 473 MISUDIINEATIS EE ER PEER EE SE 473 Phyllophora Bangti (Horn.) Fries .......... 540 Sa brodicein (urns) EA rad ee ee 521 == = To CONCATENATANEMNED ES EE 533 = = HIM ee do moe ee 533 — SION eo dias Ge 533 — epiphylla (Fl. Dan.) Batters............. 535 — — f. Bangii (Hornemann) Fries ......... 540 = = — BOND IAN, o sod acaccoed0one 543 — membranifolia (G. et W.) J. Agardh ..... 512 = jaeirouill DAWA, EEE EEE CEE 533 — rubens (Good. et Woodw.) Grev.......... 512 a vaıllııaklolmeswetsBatterser CFE tse 544 Plagiospora gracilis Kuck. ................ 187 Platoma Bairdii (Farlow) Kuckuck ......... 162 Plocamium coccineum (Huds.) Lyngb....... 599 Plumaria elegans (Bonnem.) Schmitz ....... 352 Polyides rotundus (Gmel.) Grev. ........... 172 Polysiphonia atrorubescens (Dillw.) Grev.... 435 — Brodiæi (Dillw.) Grev. ................. 430 — elongata (Huds.) Harvey 415 Page REN DIC AR re sc 115 PB, Schuebelerii (Foslie) K. Rosenv 115 My WUE UO MORON EEE EEE Per 415 = nigrescens) (Engl Bot)NGrev. 7.00 439 Fpectinatay JA PARA EEE REC PET EE 139 Vo MUO NC ES. dis ANEAGIN oh be osocsouoncoccer 439 fulaccidam Ares ch re iar tenes 439 CO SHAE. 4 ong occpaanosocoun ne 439 Ss 0rthocanp au ROSE Eee ee Ce 412 ——Zutceolatau (DIN) GTV EEE rer re 406 — violacea (Roth) Greville, emend......... 422 MMVIOlaC ea ATESCh EE Sr Oct CRETE 422 Banbuillosan(Dillw.)PArescher re 422 VITENUISEC EEE UC N eters 1422 dssaculeatam (Ags) EE RE LE 423 Porphyra atropurpurea Olivi .............. 65 — Coin JAN . oc coacconcnoadcocges 69 = IEA WATTS mood oo odor ond, 65 = ro (EL) SA ssvneonaacceue 60 flinearise (Greve) Ha rese 60 RES GN) IWMI essensen sene 60 BET (LIN) amer, 55 5600500600. 61 Porphyropsis coccinea (J. Ag.) K. Rosenv. ... 69 Büilotagelegans@Bonn ES EEE MO02 — uno (Li) AS cosoccooooccouosceucre 356 Rhizophyllis? Bangii (Horn.) J. Agardh..... 540 Rhodochorton chantransioides Reinke....... 134 — membranaceum Magnus................ 393 — penicilliforme (Kjellm.) K. Roseny........ 388 = Ron (Ata) NEN Soc ca oencecce 390 Rhododermis elegans Crouan .............. 197 — Georgii (Batters) Collins................ 199 Rhodomela subfusca (Woodw.) Agardh...... 451 CATE ora soner og RER Eee 451 8, lycopodioides (L.) Gobi.............. 451 y, virgata (Kjellm.) K. Roseny........ . 451 d, tenuior (C. Agardh) Svedelius ........ 451 By AlN SOO IK ROSIN oo cade ooooneccus 451 Rhodophyllis bifida (Good. et Woodw.) Kützing 597 Rhodophysema Georgü Batters............. 199 Rhodymenia palmata (L.) Grev........... 569 Sarcophyllis edulis (Stackh.) J. Agardh .. 160 Scinaia furcellata (Turn.) Biv... 149 Seirospora Griffithsiana Harv.. 347 Spermothamnion repens (Dillw.) K. Rosenv.. 298 «, Turneri (Mertens) ........ 298 8, roseolum (Agardh) ................ 298 Sterrocolax decipiens Schmitz 560 Trailliella intricata Batters.. Io ol roro) ro ro to CORRIGENDA . 30, 1.9 from top, to be added: 9.5 m. . 45, 1.12 from bottom, for E. by N.'/; N. read W. by S.'/s S. 68, 1.5 from bottom, for Hveen read Hveen, 10,5—19 m. 112, 1.14 from bottom, for Sa read Lb. 277, 1.14 from bottom, for The fronds read The apical cells of the fronds. 284, 1.6 from bottom, for f. robusta Kjellm. read f. typica. 375, 1.19 from top, for 10 high read so high. 402, 1.18 from bottom, for Dasay read Dasya. . 467, 1.7 from top, for sinuosis read sinuosus. See further p. 150. EXPLANATION OF PLATE VIII. Microphotographs. Figs. 1—3. Phyllophora Brodiei. Sections of nemathecia (from K. Rosenvinge 1929). 1. Auxiliary cell with protuberances. 375: 1. 2. Vertical section of nemathecium showing the central cell and a smaller nemathecium on the under face of the frond, evidently arisen by fusion of several small cushions. 64:1. 3. Transverse section of nemathecium showing the central cell. 77:1. Figs. 4—10. Ceratocolax Harlzü. Fig. 4. From Lille Belt, April. Vertical section of basal part of frond. Cells of the parasite penetrate into some of the cells of the host. 75:1. Fig. 5. From Store Belt, May. Vertical section of basal part of frond. 124:1. Fig. 6. Vertical section of base of young frond arisen by germination in aquarium, September 1929. The lowermost cells penetrate as haustoria into the host plant. 76:1. Fig. 7. From Lille Belt, April. Vertical section of base of plant and the host plant. 76:1. Fig. 8. From Middelgrund, south of Als, June. Base of plant encompassing the marginal part of the frond of Phyllophora. 80:1. Fig. 9. At Friis’ Sten NW of Læso, May. Vertical section of nemathecium not yet ripe. 150:1 Fig. 10. From Store Belt, May. Section of branch with supposed antheridia. 166:1. Fig. 11. Ahnfeltia plicata. Vertical section of nemathecium. 120:1. D. K. D. Vipensk. SELSK. SKR., 7. R., NATURV. OG MATH. AFD., VII. 4 [L. KoLpERUP ROSENVINGE] PI. VII. { u AU NUL ANA BANGS Mémoires de l'Académie Royale des Sciences et des Lettres de Danemark, Copenhague, 7me série, Section des Sciences, t. VII, net THE MARINE ALGÆ OF DENMARK CONTRIBUTIONS TO THEIR NATURAL HISTORY PART I INTRODUCTION. RHODOPHYCEZÆ I. (BANGIALES AND NEMALIONALES) BY L. KOLDERUP ROSENVINGE WITH TWO CHARTS AND TWO PLATES D. KGL. DANSKE VIDENSK. SELSK. SKRIFTER, 7. RÆKKE, NATURVIDENSK. OG MATHEM. AFD. VII. 1 LES KOBENHAVN HOVEDKOMMISSIONÆR: ANDR. FRED. HOST & SON, KGL. HOF-BOGHANDEL BIANCO LUNOS BOGTRYKKERI 1909 Pris: 6 Kr. 15 Dre. == ar Plz eo to » liars a AN Bi: er MAR AU a hy ST ng ae - Det Kel. Danske Videnskabernes Selskabs Skrifter, 6te Række. Naturvidenskabelig og mathematisk Afdeling. ee med ARR 1330-8 ee EN IEEE EE me soe ce ate 1° Prytz, K. ‘Undersegelser over Lysels Brydning i Dampe og tilsvarende Vædsker. 1880......... 2. 3. Steenstrup, Jap. Scpiadarium og Idiosepius, to nye Slægter af Sepiernes Familie. Med Bemærkninger om Boas, d.E. V. Studier over Decapodernes Slegtskabsforhold. Med 7 Tavler. Résumé en français. 1880 to beslegtede Former Sepioloidea D'Orb. og Spirula Emk. Med 1 Tavle. Résumé en francais. 1881 Colding, A. Nogle Undersøgelser over Stormen over Nord- og Mellem-Europa af 12te—14de Novb. 1872 og over den derved fremkaldte Vandflod i Østersøen. Med 23 Planer og Kort. Résumé en français. 1881 Boas, J.E. V. Om en fossil Zebra-Form fra Brasiliens Campos. Med et Tillæg om to Arter af Slægten Hippidion Med? Mav ler: RS gress mee patente che TE OR ete COR CCE TENUE Steen, A. Integration af en lineær Differentialligning af anden Orden. 1882 . . . . . . .. belay Ata ee - Krabbe, I. Nye Bidrag til Kundskab om Fuglenes Bændelorme. Med 2 Tavler. 1882 - . . . . . . . . .. Hannover, 4. Den menneskelige Hjerneskals Bygning ved Anencephalia og Misdannelsens Forhold til Hjerneskallens Primordialbrusk. Med 2 Tavler. Extrait et explication des planches en francais. 1882 — Den menneskelige Hjerneskals Bygning ved Cyclopia og Misdannelsens Forhold til Hjerneskallens Primordialbrusk. Med 3 Tavler. Extrait et explic. des planches en francais. 1884 ......... — Den menneskelige Hjerneskals Bygning ved Synotia og Misdannelsens Forhold til Hjerneskällens Pri- mordialbrusk. Med 1 Tavle. Extrait et explic. des planches en français. 1884 . . . . . . . . . . . . . Lehmann, A. Forseg paa en Forklaring af Synsvinklens Indflydelse paa Opfattelsen af Lys og Farve ved direkte Syn MelSi-Tayle- “Resume enSITANCAIS ASSET LE TE RENE ERemedt 08Tanter 1881-80 ECS EN SE ESSEN REESE SER Sarees bs Do os 4 Warming, Eug. Familien Podostemaceae. iste Afhandling. Med 6 Tavler. Resume et explic. des planches eee AS LT en PE tes to br ne ot pete a lo it ee dé O'S à 0 erg Lorenz, L. Om Metallernes Ledningsevne for Varme og Elektricilet. 1881 .............. esas Warming, Eug. Familien Podostemaceae. 2den Afhandling. Med 9 Tavler. Resume et explic. des planches “GIDE CAS LS S 2 Reet ee ele os ee a OR me Ae Seo es eae EE LEE Christensen, Odin. Bidrag til Kundskab om Manganets Ilter. 1883....................-..4. 2 Lorenz, u AKazvespredningens“Mheoni: 171888 aa Se ee ER ER EEE Gram, J.P. Undersøgelser ang. Mængden af Primtal under en given Grænse. Résumé en français.. 1884 Lorenz, L. Bestemmelse af Kvikselvsejlers elektriske Ledningsmodstande i absolut elektromagnetisk NE N a RP ES Wty ET aero wee oi Sho NE ae a a ee Traustedt, M. P. A. Spolia Atlantica. Bidrag til Kundskab om Salperne.. Med 2 Tavler. Explic. des plinchesseneican cal See glo SE emer ies alo ees erste oe tee ere) ae eee ee Bobr, Chr. Om lltens Afvigelser fra den Boyle-Mariotteske Loy ved lave Tryk. Med 1 Tavle. 1885... — Undersøgelser over den af Blodfarvestollet optagne Ilimangde udførte ved Hjælp af et nyt Absorptio- meter. Med POSTERS PI ASS GE Me ee Me DS Re MG iota Canal eas 5 . Thiele, T.N. Om Definilionerne for Tallet, Talarterne og de tallignende Bestemmelser. 1886 ....... DEI Aredab-Tayler, 1889-86. Ges iene, morue ee Be nS ecient RMS DR Se Zeuthen, 1.6. Keglesnitsleren i Oldtiden: 1885 . . .. . . . . . . . . . . . . . . . .. PAST EN RM EEE Levinsen, G M.R. Spolia Atlantica. Om nogle pelagiske Annulata. Med 1 Tayle. 1885 . . . . . . . . .. Rung, G Selvregistrerende meteorologiske Instrumenter. Med I Tavle. 1885 . . . . . . . . . . . . . . . . Melnert, Fr. De eucephale Myggelarver. Med 4 dobb. Tavler. Résumé ct explic. des planches en {PAN CALS 188 OT ee cars ee de CN ae er DV CS AU ae arene aera min pana er EST ER ME med 25 eshawlens pl SSO=28S Arne AS ER EE M RE me EEE NE Boas, J.E. Y. Spolia Atlantica. Bidrag til Pleropodernes Morfologi og Systemalik samt til Kundskaben om deres geografiske Udbredelse. Med S-Tavler. Resume en français. 1886 . . . . - . . . . . . . . . . Lehmann, 4. Om Anvendelsen af Middelgradationernes Metode paa Lyssansen. Med 1 Tavle. 1886. Haunover, A. Primordialbrusken og dens Forbeniag i Truncus og Extremiteter hos Mennesket fer Fod- selen. Extrait en francais. 1887 len ne ee Tat ae ER ee ee ee Tee MEER DU DA Lütken, Chr. Tillæg til «Bidrag til Kundskab om Arterne af Slægten Cyamus Latr. eller Hvallusene». Med f-FTayles ResumerenTrancaisı>. LEST ER EEE -—— Fortsatte Bidrag til Kundskab om de arktiske Dybhays-Tudsefiske, særligt Slægten Hinantolophus. Med 1 Tavle. Résumé en francaise LIST MN ES NET ES CR CE CRE CRE EE IEEE — Kriliske Studier over nogle Tandhvaler af Slegterne Tursiops, Orca og Lagenorhynchus. Med 2 Tavler: Resume en francais 1887 2 25102 0 Bese eee eee ee eee Koefoed; RE. SLadier i-Platosoforhindelser:: 218884 „IS fs cic ok ei eee ee owe ere Warming, Eug. Familien Podostemaceae. 3die Afhandling. Med {2 Tavler. Resume et explic. des planches Ony{rancaiss SSS ieee esa che UP eal eRe Renee al ican ue She eee SEN BEE ER el" à IV), med {1b Tavlersogt, Korte 1889 I EEE ES RE Lütken, Chr, Spolia Atlantica. Bidrag til Kundskab om de tre pelagiske Tandhyal-Slægter Steno, Del- phinus og Prodelphinus. Med I Tavle og 1 Kort. Resume en français. 1889. .....:..... Valentiner, I. De endelige Transformalions- Gruppers Theori. Résumé en francais. 1889 ....----- Hansen, D.d. Cirolanidæ et familie nonnulle propinquæ Musei Hauniensis. Et Bidrag til Kundskaben om nogle Familier af isopode Krebsdyr. Med 10 Kobbertavler. Resume en français. 1890..... Lorenz, L. Analytiske Undersøgelser over Primtalmængderne. 1891 . . +... . . . . . . . . . . . ene (Fortsættes paa Omslagets S.3.) - 50. 50. (Forts, tra Omslagets 5,2.) WI, med 4 Tavler. 1890—92 1. Lorenz, L Lysbevægelsen i og uden for en af plane Lysbelger belyst Kugle. 1890.......-....+. 2. Sorensen, Willlam. Om Forbeninger i Svommeblæren, Pleura og Aortas Væg og Sammensmeltningen deraf med Hvirvelsejlen særlig hos Siluroiderne, samt de saakaldte Weberske Knoglers Morfologi. Med 3 Tavler. Resume en français. RESORT le tas BU M EL NO NE EEE 3. Warming, Bug. Lagoa Santa. Et Bidrag til den biologiske Plantegeografl. Med en Fortegnelse over Lagoa Santas Hvirveldyr. Med 43 Illustrationer i Texten og 1 Tavle. Résumé en français. 1892..... VAR EMEA VIRUS ODA Ver ea en le nee ee NO, a awe 1. Gram, J.P. Studier over nogle numeriske Funktioner. Résumé en francais. 1890 . . ........... 2. Prytz, K. Methoder til korte Tiders, særlig Rotationstiders, Udmaaling. En experimental Undersogelse. KGS STEELE NERE MS ION Lee LE, JR QE elk AA SN SENTE PC AR 3. Petersen, Emil. Om nogle Grundstoffers allotrope Tilstandsformer. 1891 ....... EPS ten cc 4. Warming, Eug. Familien Podostemaceae. Ade Afhandling. Med ce. 185 mest af Forfatteren tegnede Figurer i 34 Gpupper. Resume et explication des fisures.en francais. 1891 ../............-+.- 5. Christensen, Odin T. Rhodanchromammoniakforbindelser. (Bidrag til Ghromammoniakforbindelsernes Kemi. HG) AGO ea Rennes MORTE SoTL ae Coe ARR OR SE 6. Lütken, Chr. Spolia Atlantica. Scopelini Musei Zoologici Universitatis Hauniensis. Bidrag til Kundskab om det aabne Hays Laxesild eller Scopeliner. Med 3 Tavler. Résumé en français. 1892 . . . .. Te Petersen, Emil. Om den elektrolytiske Dissociationsvarme af nogle Syrer. 1892 ............... §. Petersen, 0.6. Bidrag til Scitamineernes Anatomi. Résumé en francais. 1893 .............-.-. 9. Lütken, Chr. Andet Tillæg til «Bidrag til Kundskab om Arterne af Slægten Cyamus Latr. eller Hval- lusene». Med 1 Tavle. Résumé (ON FIAT N CA IS TB ution cues leo len TE RE TE RE Te cao 10. Petersen, Emil. Reaktionshastigheden ved Methylætherdannelsen. 1894..............-. Rene tole VAT Em OURS Lave ES 05 IS Ba Sela, Silas aah SMA se ica) cease LR ames te 1. Melnert, F. Sideorganerne hos Scarabæ-Larverne. Les organes latéraux des larves des Scarabés. Med suraylei Ahtsumeretexplicationrdes-planches en francais. W895) 5. ee 2. Petersen, Emil. Damptryksformindskelsen af Methylalkohol. 1896 . . .. .................... 3. Buchwaldt, F. En mathematisk Undersøgelse af, hvorvidt Vædsker og deres Dampe kunne have en fælles Tilstandsligning, baseret paa en kortfattet Fremstilling af Varmetheoriens Hovedsætninger. Résumé : ER AMEN TRS ge bis en DAME CR MO TE IP RS SE RO RCE SE Lane rotor es Er LE RSS RS ES RER NE TT ee 5. Johannsen, W. Studier over Planternes periodiske Livsyltringer. J. Om antagonistiske Virksomheder i StORSRULe Sean dereM Do dm eo shale TOA a AM on 6 ab ceo a Blows Gibco Siodho She co oc 6. Nielsen, N. Undersogelser over reciproke Potenssummer 0g does rene paa Rækker og Integraler. 1898. ERNEST an CIS 9 8225100 DS NER RER CE ER SEEN RE PP EE 5 1. Steenstrup, Japetus, og Liitken, Chr. Spolia Atlantica. Bidrag til Kundskab om Klump- eller Maanefiskene (Molidæ). Med 4 Tavler og en Del Xylografier og Fologravurer. SOSE SEN, A lage 2. Warming, Bug. Familien Podostemaceae. 5te Afhandling. Med A2 Figurgrupper. Résumé en français. 1899 3. Meyer, Kirstine Om overensstemmende Tilstande hos Stoiferne. En med Videnskabernes Selskabs Guld- medaille belønnet Prisafhandling. Med en Tavyle. 1899 . . . . . . . . . . .. RME EC ee 4. Jorgensen, S. M. Om Zeise's Platosemiæthylen- og Cossa’s Platosemiamminsalte. Med 1 Tayle. 1900 .. 5. Christensen, A. Om Overbromider af Chinaalkaloider. 1900 . . . . . . . . ... . . . ... .... . . . . .. 6. Steenstrup, Japelus. Heleroteuthis Gray, med Bemærkninger om Rossia-Sepiola-Familien i Almindelighed. Wied! en: Tess. TSO se as re ee Re ee le ee le N ee 7. Gram, Bille Om Proteinkornene hos oliegivende Fre. Med 4 Tayler. Résumé en français. 1901 8. Meinert, Fr. Vandkalvelarverne (Larve Dytiscidarum). Med 6 Tavler. Résumé en français. 1901 ERS ENTE dewalt SO == M9 ODER RE RR ee leer CO el chen au RE 1. Juel, €. Indledning i Laven om de grafiske Kurver. Resume en français. 1899 . . . . . . . . . . . . .. 2. Billmann, Eluur, Bidrag til de organiske Kvægsolvforbindelsers Kemi. 1901. . . . . . . . . . . . . . .. + 3. Samsoe Lund og Rostrup, E. Marktidselen (Cérsiwm arvense). En Monografi. Med 4 Tavler. Résumé en PALI AT SEI) DM Rn Bra ie el re ee een een el RE See 4. Christensen, A. Om Bromderivater af CNE oiderne og om de gennem disse dannede brintfalligere For- bind els er O ESTER ENTER Re ER ehe a) M UT Tente een eh ae Tm XL, med 10 Tavler og'1 Kort. 1901—03: : - RR . : . . . . . . . | ON Oe neue 1. Warming, Bug. Familien Podostemaceæ. 6te Afhandling. Med 47 Figurgrupper. Résumé en français. 1901. 2. Ravn, J. P.J. Molluskerne i Danmarks Kridtaflejringer. I. Lamellibranchiater, Med 1 Kort og 4 Tayler. 1902. 3. Winther, Chr. Rotationsdispersionen hos de spontant aktive Stoffer. 1902 . . . . . . . . . . . DORE 4. Ravn, J.P. J. Molluskerne i Danmarks Kridtaflejringer. II. Seaphopoder, Gastropoder og Cephalopoder. NCIS ARV ORION A RER = lee) ete en on lee enellae 5. Winther, Chr. Polarimetriske Undersøgelser If: Rotationsdispersionen i Oplosninger . . . . : . - + + see 6. Ravn, d. P.J. Molluskerne i Danmarks Kridtaflejringer. I. Stratigrafiske Undersøgelser. Med 1 Tavle. RESUMERENAILANCHISEHNLIOSN TE I CE den een MONS neun ee NS XII, med 3 Tavler og 1 Kort. an: EEE ANA D OO elle eet eae Ê 1. Forch, Carl, Knudsen, Martin, und Sorensen, S. P. L, Berichte über die Konstantenbestimmungen zur Auf "stellung der hydrographischen Tabellen. Gesammelt von Martin Knudsen. 1902...:....- 2. Bergh, R. Gasteropoda opisthobranchiala. With three plates and a map. (The Danish expedition to Siam NSO GEO OS Meret Oey arb M EE PM ES EN en: ehe 0 3. Petersen, ©. 6. Job., Jensen, Soren, Johansen, 4.0, og Levinsen, J. Chr. L. De danske Farvandes Planktgn i AOC NCIS 0 S119 Oem 0 RAA EL TR NET. of sis see alm «0 Rene 4. Christensen, 4. Om Chinaalkaloidernes Dibromadditionsprodukter og om Forbindelser af Alkalotdernes Chiorhydrater med hojere Metalchlorider. 1904... 6.6 eee eee ee ne ee ee ee ee 10. Nom CO + a = 1 = wo MWe weten m Botaniske Skrifter udgivne af det Kgl. danske Videnskabernes Selskab (udenfor Skrifternes 6te Række, se Omslagets S. 2—3): ot Børgesen, P. An ecological and systematic account of the Gaulerpas of the Danish West Indies. 1907... . Christensen, Carl. Revision of the American species of Dryopteris of the group of D.opposita. 1907. ..... . 8 Drejer, S. Symbole carieologiez, med 17 Tavler: 2:44 fol)? 2.02 2% "a2 = 2 L ER ee PRE * Gotische, C. M. De mexikanske Levermosser, efter Prof. Liebmanns Samling, m.20 Tavler. 67 . - . . - .. .. Liebmann, F. Mexicos Bregner. 49 ....... RTE Choe ee dd ee EME Sr OA EEE —— Mexicos Halvgres og Philetæria, m.1 Tavle. 50 ......: us » | —— Mexicos og Central-Americas neldeagtige Planter. 51 ...-.----.-----,-+-+-+-:- Be ; Petersen; 10. 6: Undersøgelser over’ Tr&ernes. Aarrinze:* 1904. 2 >... ee es ee ee 1. Schouw, d.Fr. De italienske Naaletræers geographiske og historiske Forhold, m. 1 Kort Ar er Ege- og Birkefamiliens geographiske og historiske Forhold i Italien, m. 1 Kort: =: 470.1. ss - Om en Samling Blomstertegninger i den kgl. Kobberstiksamling. 49 . . . . . . . . . . . . . . . . . . . z Warming, Eug. Forgreningsforhold hos Fanerogamerne, betragtede med særlig Hensyn til Klevning af Viext- punktet, m. 11 Tayler og mange Træsnit. Resume en français. 72 -.......... EEE SER —— Bidrag til Vadernes, Sandenes og Marskens Naturhistorie. 1904................... TRS Ørsted, A. S. Centralamericas Gesneraceer, m. 12 Tavler. 58... ......... ....... ......... z — Om en szregen Udvikling hos visse Snyltesvampe, naynlig om den genetiske Forbindelse mellem Sevenbommens Bævrerust og Pæretræets Gitterrust, m. 3 Tavler. 68 - …. ........ ......... —— Bidrag til Kundskab om Egefamilien i Fortid og Nutid, m. 8 Tavler og 1 Kort. Resume en français. 71. ee) serie, Section des Sciences, t. VII, no 2 | CONTRIBUTIONS TO: THEIR NATURAL HISTORY Ben PART II =). RHODOPHYCEE IL Se (CRYPTONEMIALES) a i: We? | > BY. : L. KOLDERUP ROSENVINGE WITH TWO PLATES i ; ; x a \ : D. Ke. Danske VIDENSK. SELSK. SKRIFTER, 7. RÆKKE, NATURVIDENSK. OG MATHEM. AFD., VII. 2 — ixo-+——_ x 5 KOBENHAVN HOVEDKOMMISSIONÆR: ANDR. FRED, HOST & SON, KGL. HOF-BOGHANDEL : . BIANCO LUNOS BOGTRYKKERI 1917 THE MARINE ALGE OP DENMARK Pris: 6 Kr. 85 Ore. de | Academ Royale AAA et des Lettres de Danemark, Copenhague, | | | I Primordialbrusk._ Med 3 Tavler. Extrait et explic. des planches’ en français. 1884 . . . . 2.” . —— Den menneskelige Hjerneskals Bygning. ved Synotia og Misdannelsens Forhold til Hjerneskallens Pris mordialbrusk. Med 1 Tavle. Extrait et explic. des planches en français. 1884 ..........-.. . Lehmann, A. Forseg paa en Forklaring af Synsvinklens Indflydelse paa Opfattelsen af Lys og Farve ved direkte Syn. Med 1 Tavle. Résumé en ARRET NER Ie ae REDE SEERE eh IE, med 20 -Tayler, ASSIS GENE sien ee RS EC Warming, Eug. Familien Podostemaceae. 1ste Afhandling. Med 6 Tavler. Resume et explic. 8 planches ENHÉTANCAIS. LOS ES AN REE RE RO LA Fe SEE Cr RS D OC TS RS TS aR Lorenz, lL. Om Metallernes Ledningsevne for Varme og Elektricitet. 1881 .................. Warming, Eug. Familien Podostemaceae, 2den ATARI, Med 9 Tavler. Résumé et explic. des planches LES PE DE EMA EP LE DES AE EL, A Re En PE Yee Oo Eu Share Christensen, Odin. Bidrag til Kundskab om Manganets Ilter. ASS oie N he eaten co RSS na ire Nice Lorenz, L. Farvespredningens Theori. 1883... ..... . . . . ... .................... Gram, J.P. Undersøgelser ang. Mængden af Primtal under en given Grænse." Pésumé en français. 1884. Lorenz, L. Bestemmelse af “Kviksolvsojlers elektriske Ledningsmodstande i absolut elektromagnetisk IER Rae (Gis RUA ES enon aa er M RE ee renner crs Cale ms DREAM EHE Traustedt, M. P. A. ‘Spolia Atlantica. Bidrag til Kundskab om Salperne. Med 2 Tavler. Explic. des planches Cis eV TE LS SD YANN cuca La ET Pr ler a EE ES ENS N A A ia” a Bohr, Chr. Om Iltens Afvigelser fra den Boyle-Mariotteske Lov ved lave Tryk. "Med 1 ravie 1885 . meter. Med Maylene 886 ERNST REN SARA ey . Thiele, T.N. Om Definitionerne for Tallet, Talarterne og de tallignende Bestemmelser. 1886 wane LAS TEL .m6d.'6. Tayler, 188586 ae 0.02 aoe a ee se PRE Re Re PNR Qu Zeuthen, H. 6 Keglesnitsleren i Oldtidens 1885... 2. . 2.4.4. ete ea plies een Levinsen, 6. M.R. Spolia Atlantica. Om nogle pelagiske Annulata. Med ITA IE i885 ees RER Rung, 6. Selvregistrerende meteorologiske Instrumenter. Med 1 Tayle. 1885................. Meinert, Fr. De eucephale Myggelarver. Med 4 dobb. Tavler. Resume et explic. des s planches en francais. 1886.01. . nun ee ER NEE Ny CSE) OT ea Healy as NO ata LP NS EN MON med 25 Tavern 188688 22 8 2a ne en ANS SN Pr sO EO colin at EEE SR aq : Boas, J.E.V. Spolia Atlantica. Bidrag til Pter opodernes Morfologi og Systematik samt til nl om deres geografiske Udbredelse. Med 8 Tavler. Resume en français. 1886 ......... ©. Det Kgl. Danske Vilanskabörnes en Skrifter, . 6te "Række. g Naturvidenskabelig og Mat honatisk Afdeling. Sorel I, med 42 Tavler, 1880—85 : . : Se 02.4.5... aa N lage Pet es Prytz, Ke ‘Undersogelser over Lysets Brydning i Den: og tilsvarende Vædsker. 1880....... DSA Boas, J. E.V. ” Studier over Decapodernes Slægtsk#bsforhold. Med 7 Tayler. Resume en francais. 1880 Steenstrup, Jap. Sepiadarium og Idiosepius, to nye Slægter af Sepiernes- «Familie. Med: Bemærkninger. om to beslægtede Former Sepioloidea D'Orb. og Spirula Lmk. Med 1 Tavle. Résumé en français. 1881 Colding, A. Nogle Undersøgelser over Stormen over Nord- og Mellem-Europa af 12te—144e Novb. 1872 og over den derved fremkaldte Vandflod i Østersøen." Med 23 Planer ogKort. Resume en francais. 1881 Boas, J. E.V. Om en fossil Zebra-Form fra Brasiliens Campos. Med et Tilleg om to Arter af Slegten Hippidion- Med, 2 Tavler ASS DR a Mewar). ee ESS Steen, A. Integration af en lineær Differentialligning af anden Orden ASSR ES ESKE ee Krabbe, H. Nye Bidrag til Kundskab om Fuglenes Bændelorme. Med 2 Tavler. 1882 ........... Hannover, A. Den menneskelige Hjerneskals Bygning ved Anencephalia. og Misdannelsens Forhold. til Hjerneskallens Primordialbrusk. Med 2 Tavler. Extrait et explication des planches en français. 1882 —— Den menneskelige na, Bygning ved Cyclopia og Misdannelsens Forhold til Eisen ons Undersøgelser over den af Blodfarvestoffet optagne Iltmængde udførte ved Hjælp af et nyt Absorptio- Lehmann, A. Om Anvendelsen af Middelgradationernes Metode paa Lyssansen. Med 1 Tavle. 1886. Hannover, Å. Primordialbrusken og dens Forbening i Truncus 08 Extremiteter OS Mennesket. far Fad-- selen:‚Extraitsenfrangaist 1837. REE SSR ee ee RN N Re RR Lütken, Chr. Tillæg til «Bidrag til Kundskab om Arterne af Slægten Cyamus Lath! eller Hvailusenes. Med'1Tayle” Resume" en! francais: 18872 „ra. m Re ER ae see tere -— Fortsatte Bidrag. til Kundskab om de arktiske Dybhavs- “Tudsefske, særligt Slegten Hinan dos Medel) Tavler Resume, envairancals van lO STONES EE SES EN OR RS —— Kritiske Studier over. nogle Tandhvaler af Slægterne Tursiops, “Orca og Lagenorhynchus. Med 2 Tavler)” Resumé den francais 1887 sr Mea a cen ee Ws ES EET eae sera OG eae NESA aan Koefoed, E. Studier i Platosoforbindelser. 1888 ES ER NE D ERE A PART ACCES Warming, Eug. Familien Podostemaceae. 3die Afhandling. Med- 12 Tavler. Resume et explic. des planches ON PLAN CRISS OU SSS NEA TR al peo once D ARRETE PACS RENE Ie tw hala sala TA RAR gs eRe cee Re wee Wmed 11 Tavler og ie Kort: S89 IT ATEN caer hiya Co RS RE A A Rte Lütken, Chr. Spolia Atlantica. Bidrag til Kundskab om de tre pelagiske Tandhval-Slegter Steno, Del- ; phinus og Prodelphinus. Med 1 Tavle og 1 Kort. Résumé en francais. 1889.......... 5 Valentiner, H. De endelige Transformations- -Gruppers Theori. Résumé en français. 1889 ......... Hansen, H. J. Cirolanidæ et familie nonnullæ propinque Musei Hauniensis. Et Bidrag til Kundskaben om nogle Familier af isopode Krebsdyr. Med 10 Kobbertavler. Resume en français. 1890. Lorenz, L. Analytiske Undersøgelser over Primtalmængderne. 1891 . . .................... # (Fortsættes paa Omslagets S. 3.) BS u gee SEE A Atay rs ÿ un f (Fortsat fra Omslagets S, 2.) VII Oy lei ain By aC iy NN lee ie ee iis Oe Bene OLA Een EN à ue a orent, L. Lysbevægelsen i og uden for en af plane Be belyst Kugle. 1890 . hrs ee VIL a med 4 Tavler. BIO SAS SES ENN SEE eue Le & oie Tele te Gram, J.P. Studier over nogle numeriske Funktioner. Résumé en français. 1890............. 2. Pryta, K. Methoder til korte Tiders, særlig Rotationstiders, Udmaaling. En experimental Undersøgelse. METRE CUT EURTIEX OR ES DONE Re ON rasa ENES Na TE a Petersen, Emil. Om nogle Grundstollers ale wone Tilatandsformerns 18947200 MN re a ercuetenen ees 5 Warming, Eug. Familien Podostemaceae, 44 Afhandling. Med c. 185 mest af Forfatteren tegnede Figurer i i 34 Grupper. Résumé et explication des figures en, francais. Pr, 18912 MSN RES RE EU a. See Odin T, 'Rhodanchromammoniakforbindelser., (Bidrag til Chromammoniakforbindelsernes Kemi. DIRT DE cen ae EN ee REN N Ns a EEE £ Lütken, Chr. Spolia Atlantica. Seopelini Musei Zoologici Universitatis Hauniensis. Bidrag til Kundskab 7 om det aabne Havs Laxesild eller Scopeliner. Med 3 Tavler. Résumé en français, 1892 ... 8 Petersen, Emil. Om den elektrolytiska Dissociationsvarme af nogle Syrer. 1892 . .. ............ Petersen, 0.6. Bidrag til Scitamineerhes Anatomi. Résumé en français. 1893 ............... 9. Lütken, Chr. Andet Tillæg til «Bidrag til Kundskab om Arterne af Slægten Cyamus Latr. eller Hval- ER lusene». Med 1 Tavie. Résumé en ALAM CAISSE re I= tha Eee ete Te dar : ‘Petersen, Emil. Reaktionshastigheden ved Methylætherdannelsen. 1894........... an eee > yee med sg avlere 1 895-— 98> Freenet drake al ee TL SE 1. Meinert, F. Sideorganerne hos Scarabe-Larverne. Les organes latéraux des larves des Scarabés. Med D 3 Tavler. Résumé et explication des planches en francais. 1895 .................... 22. stars, Emil. DamptryKsformindskelsen af Methylalkohol. 1896 ....:................... “3. Buchwaldt, F. En mathematisk Undersøgelse af, hvorvidt Vædsker og deres Dampe KUNNE have en fælles SØ "Tilstandsligning, baseret paa en kortfattet Fremstilling af Varmetheoriens Hovedsætninger. Résumé kr FONE EAN CRIS ES ION EN SS REE ee selene ec SES SEE D Te Era ne 4. Warming, Bug. Halofyt-Studier. 1897 ..... re ee a ee ER er ve 5. Johannsen, W. Studier over Planternes periodiske ne I. Om antagonistiske Virksomheder i ER: Stofskiftet,, sorlienunder- Modnins+ogcHvle." 1897 22.50 2 me ee eee te 6. Nielsen, N, Undersøgelser over reciproke Potenssummer og deres Anvendelse paa Rækker og Integraler. 1898. \ MONS nodal ravers GIS GOL sista ee N ee ee ee eher . Steenstrup, Japetus, og Lütken, Chr. Spolia Atlantica. Bidrag til Kundskab om Klump- eller Maanefiskene 3 (Molide). Med 4 Tavler og en Del Xylografier og Fotogravurer. 1898 . ..........., ... 2. Warming, Bug. Familien Podostemaceae. 5te Afhandling. Med 42 Figurgrupper. Resume en frangais. 1899 3. Meyer, Kirstine. Om overensstemmende Tilstande hos Stofferne. En med Videnskabernes Selskabs Guld- medaille belønnet Prisafhandling. Med en Tavle. 1899 ..................,.,...... 4. Jorgensen, S.M. Om Zeise's Platosemiæthylen- og Cossa’s Platosemiamminsalte. Med 1 Tavle. 1900 . . 5. Christensen, A. Om Overbromider af Chinaalkaloider. FOOD N IR LE ROSES PA ee PINS 6. Steenstrup, Japetus. Heteroteuthis Gray, med Bemærkninger om Rossia- -Sepiola-Famillen i Almindelighed. Wa _ Med en Tavle. 1900 - ee ee TR Gram, Bille. Om Proteinkornene hos oliegivende Fre. Med 4 Tavler Résumé en frangais. 1901 8. Melnert, Fr. Vandkalvelarverne (Larve Dytiscidar um). Med 6 Tavler. Résumé en français. 1901 ERSTER Taylor? 18091000 ESS ae SR AT. Ra a. seid wre a5 Juel, C. Indledning i Læren om de grafiske Kurver, Resume en français. 1899 ...-,,..,....,. »2 Biilmann, Einar. Bidrag til de organiske Kvægsølvforbindelsers Kemi. 1901.......-..... : 3. Samsee Lund og Rostrup, E. Marktidselen (Cirsium arvense). En Monografl. "Med 4 Tavler. Résumé en AR RTC AIS SLO 0 N ee al Ghote etats le sighs 1g ates Date 14. Christensen, A. Om Bromderivater af Chinaalkaloiderne og om de gennem disse dannede brintfattigere For- 3 Ind EISEN OR ES AES A vel ones cere og RE the pe. "pral" Lee dire eue Sehe 2 el medAlONTaLIerA0g 1 Korte 100103 VIE ES en pen era ER: 1. Warming, Eug. Familien Podostemaceæ.. 6te Afhandling. Med 47 Figurgrupper. Resume en français. 1901. 2 Ravn, J. P. J. Molluskerne i Danmarks Kridtaflejringer. I. Lamellibranchiater. Med 1 Kort og 4 Tayler. 1902. 3. © Winther, Chr. Rotationsdispersionen hos de spontant aktive Stolfer. 1902 . . . . . . . . . . . . . . . . . . . 4. Ravn, J. P.J. Molluskerne i Danmarks Kridtaflejringer. II. Scaphopoder, Gastropoder og Cephalopoder. Mode Senna Vier RO D cme ER NN SEE late ave Sie ee Banane i ten) Chr. Polarimetriske Undersøgelser Il: Rotationsdispersionen IL Oplaaningertt re 02. a ee eee 6. Ravn, J. P.J. Molluskerne i Danmarks Kridtaflejringer.. Ill. Stratigrafiske Undersøgelser. Med 1 Tavle. ET Résumé en français. 1903 ........... | ES PC DT PE CEN SEE IP Net 2a es NC Med Tavler opt KO 100204 EEE chee + 2 2 aie OT ces seis» oe wale Bun Carl, Knudsen, Martin, und Sereusen, S. P. L, Berichte über die Konstantenbestimmungen zur Auf- - stellung der hydrographischen Tabellen. Gesammelt von Martin Knudsen. 1902 ..... ‘Bergh, R. Gasteropoda opisthobranchiata. With three plates and a map. (The Danish expedition to Siam ! BAS GE SKI ms) ER DES tre RE PR à dns à een ee 69 4 + + eles agate «lemme ES Petersen, €. @. Joh. Jensen, Seren, Johansen, A. C., og Levinsen, J. Chr, L. De danske Farvandes Plankton i Karens SIS — 100 lemme OD SES ER EN en elle « ler ehe se ons es © 0 aera + 5 ar ske neh “4. Christensen, A. Om Chinaalkaloidernes Dibromadditionsprodukter og om Forbindelser af Alkaloldernes = Chlorhydrater med højere Metalchlorider. 1904................... ............ 10. 13. A Botaniske Skrifter + udgivne af det Kgl. danske Videnskabernes Selskab” "(udenfor Skrifternes, 6te Række, se Omslagets S. 23): : ts Borgesen, F. An ecological and systematic account of the Caulerpas of the Danish West Indies. 1907. Christensen, Carl. Revision of the American species of Dryopteris of the group of D. opposita. 1907 Drejer, S. Symbolæ caricologice, med 17 Tavler. 44. fol. ................. Sy OR gti ota QUE Gottsche, (. M. De mexikanske Levermosser, efter Prof. Liebmanns "Samling, m. 20 Tavler. 67 ; ‘Hansen-Ostenfeld, Carl. De danske Farvandes Plankton i Aarene 1898—1901 Phytoplankton og Protozoer 1 Résumé en français. 1913 ..... ER Re NE en NE DS RE DE TRS ARR ~—— —— J. Résumé en DEIN Ree NOY Sia SES SEKS Se se ES SÆDE SEES PR EVER SEES 2 Hempel, Jenny. Researches into the Effect of Etherization on Plant-Metabolism. 1911 ........ Ris Re =; Liebmann, F. Mexicos Bregner. 49........................ eee ee! NEE LEE AR = Mexicos Halvgræs og Philetæria, m. 1 Tavle. BO a EEE ER RE N WR SRG en s ae —— Mexicos og Central-Americas neldeagtige Planter. 51 .............:......................... eee ioe D Petersen, Henning Eiler. Danske Arter af Slægten Ceramium (Roth) Lyngbye, m. 7 Tavler. Resume en francais. 1908.......... Petersen, Johannes Boye. Studier over danske aérofile Alger, m. 4 Tayler. Résumé en francais. 1915 Petersen, 0.G. Undersogelser over Træernes Aarringe. 1904 Raunkiær, €. Livsformen hos Planter paa ny Jord. 1909 Rosenvinge, L. Kolderup. The marine alge of Denmark, I. With 2 charts and 2 plates. 1909 ......... = Rordam, K. Undersagelse af nogle Græssers og Kloverarters kemiske Sammensætning paa forskellige Noa : stadier. NATS ERIE PRES RES PRET SORA A LEA Sar bo he SNL RE SOEBEN BER 0 Schouw, J. Fr. De italienske Nee „geographiske og historiske Forhold, m. 1 Kort AP Re ee —— Ege- og Birkefamiliens geographiske og historiske Forhold i Italien, m.1 Kort. 47 — Om en Samling Blomstertegninger i den kgl. Kobberstiksamling. 49 ................ rev venn sne Warming, Eug. Forgreningsforhold hos Fanerogamerne, betragtede med særligt Hensyn til Klevning af Væxt- punktet, m. 11 Tavler og mange Træsnit: Résumé en français. 72 —— Bidrag til Vadernes, Sandenes og Marskens Naturhistorie. 1904 ne Ørsted, A. S. Centralamerieas Gesneraceer, m. 12 Tavler. 58......7....... De ER de A — Om en særegen Udvikling hos visse Snyltesvampe, navnlig om den genetiske Forbindelse mellem | Sevenbommens Bævrerust og Pæretræets Gitterrust, m. 3 Tavler. 68 DENTS PE DD ADM ES ont Ne OC 2 —— Bidrag til Kundskab om 2 DORE IE i Fortid og Nutid, m. 8 Tavler og 1 Kort. Résumé en ee 71: dal t ih? Mémoires de l’Académie Royale des Sciences et des Lettres de Danemark. € ‘openhague, Section des Sciences, 7€ série, t. VII, n° 3. THE MARINE ALG OF DENMARK PART III RHODOPHYCEAE III. (CERAMIALES) ‘ BY L. KOLDERUP ROSENVINGE WITH THREE PLATES D. KGL. DANSKE VIDENSK. SELSK. SKRIFTER, 7. RÆKKE, NATURVIDENSK. OG MATHEM. AFD., VII. 3. OLED KOBENHAVN | BIANCO LUNOS BOGTRYKKERI 1923—24 | Pris: 14 Kr. 25 Øre. Det Kgl. Danske Videnskabernes Selskabs Skrifter. Naturvidenskabelig og mathematisk Afdeling, öde Række. I, DNS RAR ee ce a | Prytz, K. og J. N. Nielsen: Undersogelser til Fremstilling af Normaler i Metersystemet, grundet paa Sammenligning med de danske Rigsprototyper for Kilogrammet og Meteren. 1915.......... Rasmussen, Hans Baggesgaard: Om Bestemmelse af Nikotin i Tobak og Tobaksextrakter. En RHUSRSUNAERSO SELS E TOI GRR ES Re Ne Christiansen, M.: Bakterier af Tyfus-Coligruppen, forekommende i Tarmen hos sunde Spæd- kalve og ved disses Tarminfektioner. Sammenlignende Undersøgelser. 1916 ................... . Juel, C.: Die elementare Ringfläche vierter Ordnung. 1916 ................................. Zeuthen, H. G.: Hvorledes Mathematiken i Tiden fra Platon til Euklid blev en rationel Viden- Ska PA VECMUN Be STNG BEM PALATLCAIS game LO le TEN deca rors foie inner ee ee ee Sn ed 4g Lavierse1 Ol Gol OLS eee seep cts hale dees chi aah see roa ie arses ee tee . Jørgensen, S.M.: Det kemiske Syrebegrebs Udviklingshistorie indtil 1830. Efterladt Manuskript, MUGciVetRAMmOUCLIOLOERSEI OL Sa Lema Sarensen: 1.91 Gis CNE REC CE cree Hansen-Ostenfeld, Carl: De danske Farvandes Plankton i Aarene 1898—1901. Phytoplankton og Protozoer. 2. Protozoer; Organismer med usikker Stilling; Parasiter i Phytoplanktonter. Med 4 Figurgrupper og 7 Tabeller i Teksten. Avec un résumé en français. 1916 .................. . Jensen, J. L. W. V.: Undersogelser over en Klasse fundamentale Uligheder i de analytiske Funk- once Wheat’ Tb. TONG. REA OCR AE RESTE aon top ou db poco occ Hoehne . Pedersen, P. O.: Om Poulsen-Buen og dens Teori. En Experimentalundersogelse. Med 4 Tav- ler NOS ES 80» ne SO TS Reise Sele RE EET OP SS pee seme ere 5. Juel, C.: Die gewundenen Kurven vom Maximalindex auf einer Regelfläche zweiter Ordnung. 1917 Warming, Eug.: Om Jordudlobere. With a Résumé in English. 1918 ...................... III, med 14 Kort og 12 Tavler, 1917—1919 ................ Oats a ce Wesenberg-Lund, C.: Furesostudier. En bathymetrisk Undersogelse af Molleaaens Soer. Under Medvirkning af Oberst M. J. Sand, Mag. J. Boye Petersen, Fru A. Seidelin Raunkiær og Mag. sc. C. M. Steenberg. Med 7 bathymetriske Kort, 7 Vegetationskort, 8 Tavler og ca. 50 i Texten trykte SER AGS TD NGS Gn Theme, NOW) Shee ee cer Lehmann, Alfr.: Stofskifte ved sjælelig Virksomhed. With a Résumé in English. 1918 ...... Kramers, H. A.: Intensities of Spectral Lines. On the application of the Quantum Theory to the problem of the relative intensities of the components of the fine structure and of the Stark effect of the lines of the hydrogen spectrum. With 4 plates. 1919.............. LE Se 110 ted 1G Ae TO RER ONE Sr ee a CAD = coco nee ng Bohr, N.: On the Quantum Theory of Line-Spectra. Part 1. 1918 .................... = Same RATE TETE Eee estate sec semelle sie see comen mere — = => 106 1 ee PSE Sp ooo SO ET PDA SO AI OS Re CCE . Warming, Eug.: Okologiens Grundformer. Udkast til en systematisk Ordning. 1923 .. d Wesenberg-Lund, C.: Contributions to the Biology of the Danish Rotifera. With 15 Plates and LS BERKER, GREE. Gyn sd cie mie ete nie sien ce nen DSE sr øret . Hertzsprung, Ejnar: Effective Wavelengths of Stars in “the Pleiades on Aalen taken at Mount Wilson. With 4 Figures and 1 Map. 1923........ 1 11. von Wy med 57% Tavler > Mc N EEE En PR Bjerrum, Niels und Kirschner, Aage: Die Rhodanide des Goldes und das freie Rhodan. Mit einem: Anhang-über, das Goldchlorid 2491872". - 212 Zee ee Cou ce ee Orla-Jensen, S.: The Jactic acid Bacteria: With 51 Plates. 1919, SEES SER ‘Brünnich Nielsen, K.: Zoantharia from Senone and Paleocene Deposits in Denmark and Skaane. With te Rlates: LE FEE en cale esters sue ce ete nee ee CONTRE Petersen, Axel: Bidrag til de danske Simuliers Naturhistorie. Med 2 Tavler, 53 Figurer og 1 Kort 1 Texten: 19245 ANR es ee eee eee ne Seis ce ee er ce ee RE RER NE med 12 Tavier Ar Me OR RTE INR RN ON RE A EEE Christensen, Carl: A Monograph of the genus Dryopteris. Part II. 1920.................... Lundblad, O.: Süsswasseracarinen aus Dänemark. Mit 12 Tafeln und 34 Figuren im Text. 1920. Børgesen, F.: Contributions to the knowledge of the Vegetation of the Canary Islands (Teneriffe and Gran Canaria). With an appendix: Lichenes Teneriffenses, scripsit Edv. A. Wainio. 1924..... WII (under Pressen). Wesenberg-Lund, C.: Contributions to the Biology of the Danish Culicidæ. With 21 Plates and HS SBigures si the tere JLI20 21ER IE Er More Se ee oe pe oe ete eee eee VIII. Jessen, Knud og Jens Lind: Det danske Markukrudts Historie. Med 1 Oversigtsskema. 1922— 23. Témoires de l’Académie Royale des Sciences et des Lettres de Danemark, Copenhague, Section des Sciences, 7€ série t. VII, n° 4. THE MARINE ALGÆ OF DENMARK CONTRIBUTIONS TO THEIR NATURAL HISTORY PART IV RHODOPHYCEE IV. (GIGARTINALES. RHODYMENIALES. NEMASTOMATALES) | BY L. KOLDERUP ROSENVINGE WITH ONE PLATE D. KGL. DANSKE VIDENSK. SELSK. SKRIFTER, 7. RÆKKE, NATURVIDENSK. OG MATHEM. ÅFD., VII. 4. I en KOBENHAVN HOVEDKOMMISSIONÆR: ANDR. FRED. HOST & SON, KGL. HOF-BOGHANDEL BIANCO LUNOS BOGTRYKKERI A/S 1931 = LE Pris: Kr. 9,75. 12 nw Det Kgl. Danske Videnskabernes Selskabs Skrifter. Naturvidenskabelig og mathematisk Afdeling, öde Række. By 19152 1917 oS oF EDEN foes Sn a ee ee PS en oe ENST ee Prytz, K. og J. N. Nielsen: Undersøgelser til Fremstilling af Normaler i Metersystemet, grundet paa Sammenligning med de danske Rigsprototyper for Kilogrammet og Meteren. 1915.......... Rasmussen, Hans Baggesgaard: Om Bestemmelse af Nikotin i Tobak og Tobaksextrakter. En kritisk Undersøgelse, 19162 ose nee = hetero ee arin CaO eee oes Ce eoee Christiansen, M.: Bakterier af Tyfus-Coligruppen, forekommende i Tarmen hos sunde Spæd- kalve og ved disses Tarminfektioner. Sammenlignende Undersogelser. 1916 Juel, C.: Die elementare Ringflache vierter Ordnung. 1916 ............................... . Zeuthen, H. G.: Hvorledes Mathematiken i Tiden fra Platon til Euklid blev en rationel Viden- skab. Avec un résumé en francais. 1917 II, med 4 Tavler, 1916—1918 . Jergensen, S.M.: Det kemiske Syrebegrebs Udviklingshistorie indtil 1830. Efterladt Manuskript, udgivet afOne Jorgensen Og US. PL. Sorensen. AIG ea. - ace es eee eee Hansen-Ostenfeld, Carl: De danske Farvandes Plankton i Aarene 1898—1901. Phytoplankton og Protozoer. 2. Protozoer; Organismer med usikker Stilling; Parasiter i Phytoplanktonter. Med 4 Figurgrupper og 7 Tabeller i Teksten. Avec un résumé en francais. 1916 .................. Jensen, J. L. W. V.: Undersogelser over en Klasse fundamentale Uligheder i de analytiske Funk- tioners Dheor= FO Go. eee PE ER EC reece eee eee ee eee Pedersen, P. O.: Om Poulsen-Buen og dens Teori. En Experimentalundersogelse. Med 4 Tay- i TS nee VOTE BR ae en teas Se ie nS ee ete ae ne Toro ReneS SRS bas So 55 5 Juel, C.: Die gewundenen Kurven vom Maximalindex auf einer Regelflache zweiter Ordnung. 1917 Warming, Eug.: Om Jordudlobere. With a Résumé in English. 1918 III, med 14 Kort: og: 12) Tavler, 1917 1919 en ee ee oe eee eee Wesenberg-Lund, C.: Furesostudier. En bathymetrisk Undersogelse af Molleaaens Soer. Under Medvirkning af Oberst M. J. Sand, Mag. J. Boye Petersen, Fru A. Seidelin Raunkiær og Mag. sc. C. M. Steenberg. Med 7 bathymetriske Kort, 7 Vegetationskort, 8 Tavler og ca. 50 i Texten trykte Figurer- | Ayecun-resume, en français 2190 7i 122 2 ee nee ait EEE Lehmann, Alfr.: Stofskifte ved sjælelig Virksomhed. With a Résumé in English. 1918 ...... Kramers, H. A.: Intensities of Spectral Lines. On the application of the Quantum Theory to the problem of the relative intensities of the components of the fine structure and of the stark effect of the lines of the hydrogen spectrum. With 4 plates. 1919........................... IV, med 15. Tavler og 1 Kort ar... 22 oe ee ee ee eee Bohr, N.: On the Quantum Theory of Line-Spectra. Part I. 1918............................ = Sammer Part II. 1918 32.5 Se sere cette ee eee RC EE EN RE RE eee — aS a EEE ea oe toro ans SRA on SOS UE On Ace soo cos swoon quon Warming, Eug.: Okologiens Grundformer. Udkast til en systematisk Ordning. 1923 ......... 3. Wesenberg-Lund, C.: Contributions to the Biology of the Danish Rotifera. With 15 Plates and 18 Textfigures: 1923 22. SS ns RS RE oe ses Ss Ce FS RS Sisson Ror Ie ert oh eer eae EE Hertzsprung, Ejnar: Effective Wavelengths of Stars in the Pleiades from plates taken at Mount Wilson. With 4 Figures and 1 Map. 1923 ro EME OD MEAVIeD tats ay meni Eee Ss DRE VEUT » Bjerrum, Niels und Kirschner, Aage: Die Rhonadide des Goldes und das freie Rhodan. Mit EinemwaAnuhangnubersdas@Goldehlorid. MOT PE M Ra se sue Orla-Jensen, S.: The lactic acid Bacteria. With 51 Plates. 1919 ............................. Brünnich Nielsen, K.: Zoantharia from Senone and Paleocene Deposits in Denmark and Skaane. NV CR A TIERE TED a ae eee Dee EEE Er Petersen, Axel: Bidrag til de danske Simuliers Naturhistorie. Med 2 Tavler, 53 Figurer og 1 Kort 1 Toto Nos dodo mar drondioens done. 6 cen LM ON CROCE ETI Onin tease DE DEAR D DIS EE AE TAVERNE adel LEE Christensen, Carl: A Monograph of the genus Dryopteris. Part II. 1920..................... Lundblad, O.: Süsswasseracarinen aus Danemark. Mit 15 Tafeln und 34 Figuren im Text. 1920. Børgesen, F.: Contributions to the knowledge of the Vegetation of the Canary Islands (Teneriffe and Gran Canaria). With an appendix: Lichenes Teneriffenses, scripsit Edv. A. Wainio. 1924 AR me di AVIET he ee ec Sm ANE RRQ GES SES Meh ts sd Wesenberg-Lund, C.: Contributions to the Biology of the Danish Culicidæ. With 21 Plates and HoRkiguresginkthern text 1920 2 Mr PE ARE ET ee a ce eme nee Norlund, N.E.: Stirlings Interpolationsrække. 1924 ........................................ Levinsen, G. M. R.: Undersogelser over Bryozoerne i den danske Kridtformation. Efter For- fatterens Dod udgivet af Dr. K. Brünnich Nielsen og Dr. Th. Mortensen. Med 8 Tavler. 1925.... VIII. Jessen, Knud og Jens Lind: Det danske Markukrudts Historie. Med 1 Oversigtsskema. 1922 — 23, IX, med 5 Tavler. Thoroddsen, Th.: Die Geschichte der isländischen Vulkane (nach einem hinterlassenen Manu- Skript) MIE TS EL Ratelne 9 2 5 een RE ARR release ais at ele ele ee elle ara X, med 30 Tavler og 2 Kort ...... Reach CMP N MO ET Re Wesenberg-Lund, C.: Contributions to the Biology of HEART Geniculatum Ayrton. With Ib RS 00e L'an tarp la bio Dane ec Ele ee RE PEAR BO à Po On 2 DEP ao Micoletzky, H.: Die freilebenden Süsswasser- und Moornematoden Dänemarks nebst Anhang über Amôbosporidien und andere Parasiten bei freilebenden Nematoden. Mit 13 Tafeln und einer Textfigur sowie mehreren Tabellen. 1925 .................................. RS ET Bete N Gram, J. P.: Tafeln für die Riemannsche Zetafunktion. Herausgegeben von N. E. Nôrlund. 1925 . Johs. Schmidt: On the distribution of the Fresh-Water Eels (anguilla) throughout the world. II. Indo-pacific region. A bio-geographical investigation. With two charts and ten text-figures. 1925. . Jul. Hartmann: A Comparison between the Flow of Water and Mercury in Pipes with a view to testing the Osborne Reynolds’ Law of Similarity. With 3 Plates and 18 Figures in the text. 1926 ERSTEN EI ARTAVTETE ER A RE NR ne ae sie VA ser ik er 1. Luplau Janssen, C.: La Surface de la Planète Jupiter 1919—1924. Avec 7 planches. 1926..... 2. Wesenberg-Lund, C.: Contributions to the Biology and Morphology of the Genus Daphnia with some Remarks on Heredity. With 2 Plates and 21 Textfigures. 1926........................... “3. Braae, Johannes: Eine Reihe differentieller Beobachtungen am Meridiankreis der Kopenhagener Universitatssternwante ga Sem ee nee te nen eters) ee 4. Ravn, J. P. J.: De irregulære Echinider i Danmarks Kridtaflejringer. Med 5 Tavler. 1927..... 5. Mortensen, Th.: On the Postlarval Development of some Cidarids. 1927............. >. GD Reed Wa Ay A Gi oh ica aoe A ee eng CAT ae ey. Noy, SA 1. Kramp. P. L.: The Hydromedusz of the Danish Waters. 1927........... ee 2. van den Bos, W.H.: The Multiple System & Ursae Majoris. 1928..... i Le 3. Bohr, Harald og Jessen, Berge: Om Sandsynlighedsfordelinger ved Addition af konvekse Kurver. Med 34 Figurer. 1929 .......... ‘Gets atime Sibi aaah OD re HU Goa TE I, mal BETEN A A ET OBERE Ravn, J. P. J.: De regulære Echinider i Danmarks Kridtaflejringer. Med 6 Tavler. 1928 Clausen, Hans: On the Crystal Structure of Cryolithionite. With 4 Figures in the text. 1928 ao 16. 24. 50. 60. 00. ww Boas, J. E. V.: Biologisch-anatomische Studien über den Hals der Vogel. Mit 23 Tafeln und 20 Figuren him Text: 19290 22.22.22 So Meee RS N ee a TER Berg, Kaj and Gunnar Nygaard: Studies on the Plankton in the Lake of Frederiksborg Castle. With; 62Plates and’ 27*Fisures in thertexle 1929" SE RME RE ER eee CE ae II. med 30 Tavler og 8 Shemaer rs ss SAREEN ee RE A SE ROSES . Wesenberg-Lund, C.: Contributions to the Biology of the Rotifera. Part II. The Periodicity and Sexual ‘Periods: With 15-Plates and!:8Schemata- 41930) 2. -._... 12. 2 er oe ee ee eee Bøggild, O. B.: The Shell Structure of the Mollusks. With 15 Plates and 10 Figures in the text. 1930 III, (under Pressen): Ostenfeld, C. H.: The Distribution within Denmark of the higher Plants. Results of the topo- graphic-botanical Investigation. I. A brief Historical Survey of the Investigation. With one Plate. 1931 Jessen, Knud: Samme. II. The Distribution of the Papilionaceæ within Denmark. With nine LIES UE ER abe Moree ER En ee en Eee Bama nie US D Go te bes iv. (ander Pressen): Mortensen, Th.: Contributions to the Study of the Development and Larval Forms of Echino- derms: HE With oPlates VIT 9315 ee se tee ees eee eee ee eee ae eee Brøndsted, H. V.: Bygningen af Snuden og Ansigtsmuskulaturen hos nogle Pinnipedier med særligt Hensyn til Oppusiningssekken hos Klapmydsen. Med 12 Tavler. Mit einem deutschen Resume. 1931 Wesenberg-Lund, C.: Contributions to the Development of the Trematoda Digenea. Part L The Biology of Leucochloridium Paradoxum. With 6 Plates and 7 Textfigures. 1931................. Mortensen, Th.: New Contributions to the Knowledge of Cidarids. I—II. With 13 Plates. (Under Pressen). n Ni DS LEE sr 0e nn: re A N | AMNH LIBRARY I || 100170269