LfflRARY OF THE NEW YORK bOTANlCAL GAilDEN University of California Publications in BOTANY VOLUME VIII Parts I and II 1919-1920 WILLIAM ALBERT SETCHELL R. M. HOLMAN EDITORS UNIVERSITY OF CALIFORNIA PRESS BERKELEY, CALIFORNIA v. 0 /9/?A' THE MARINE ALGAE OF THE PACIFIC COAST OF NORTH AMERICA Parti. MYXOPHYCEAE Part II. CHLOROPHYCEAE BY WILLIAM ALBERT SETCHELL NATHANIEL LYON GARDNER UNIVERSITY OF CALIFORNIA PRESS BERKELEY, CALIFORNIA The University of California Press Berkeley, California The Cambridge University Press London, England Printed in the United States of America CONTENTS PAGES No. 1. The Marine Algae of the Pacific Coast of North America. I. Myxophyceae, by William Albert Setchell and Nathaniel Lyon Gardner 1-138 No. 2. The Marine Algae of the Pacific Coast of North America. II. Chlorophyceae, by William Albert Setchell and Nathaniel Lyon Gardner 139-374 Index 370-382 The first part of the Marine Algae of the Pacific Coast of North America, comprising an account of the Myxophyceae, or Blue-Green Algae, is presented without introduction or explanation, pending the publication of the other three parts which are in advanced preparation. It is intended to issue with the completed volumes a statement as to the principles followed, methods used, territory covered, sources of information, material, etc., as well as to make acknowledgment to the various authorities, students, and collaborators, who have been of the greatest assistance in carrying out the long and laborious task. W. A. Setchell and N. L. Gardner. I TP- UNIVERSITY OF CALIFORNIA PUBLICATIONS BOTANY Vol. 8, No. 1, pp. 1-138, plates 1-8 November 29, 1919 THE MARINE ALGAE OF THE PACIFIC COAST OF NORTH AMERICA PART I MYXOPHYCEAE BV WILLIAM ALBERT SETCHELL AND NATHANIEL LYON GARDNER CONTENTS PAGE Subclass I. Myxophyceae 2 Order 1. — Coccogonales 4 Family 1. — Chroococcaceae , 5 1. Synechocystis 6 2. Synechococcus 7 3. Mcrismopedia 8 4. Chroococcus 9 5. Placoma 11 6. Anacystis 12 7. Chlorogloca 15 Family 2. — Chamaesiphonacea'e 20 8. Dermocarpa 21 9. Xenococcus 30 10. Pleurocapsa 36 11. Hyella 40 12. Radaisia 45 13. Gomphosphacria 49 Order 2. — Hormogonales 51 Suborder 1. — Homocystineae 52 Family 3. — Oscillatoriaceae 52 Subfamily 1. — Spirulineae 53 14. Arthrospira 53 15. Spirulina 55 Subfamily 2. — Oscillarieae 57 16. Oscillatoria 58 2 . Uuivcrsity of California Publications i)i Botanij [Vol.8 PAGE Subfamily 3. — Lj-ngbyeae 67 17. Phormidium 68 IS. LyiiKbya 72 19. Plcctonema 78 20. Symploca 80 Subfamily 4. — Schizotricheac 83 21 . Hydrocoleum 84 22. Microcoleus : 85 Suborder 2. — Heterocj'stineae , > 89 Family 4. — Xostocaceae 89 23. Anabaena 90 24. Nostoc 92 Family 5. — Rivulariaceae .■ 93 25. Calothrix ■. 94 26. Dichothrix 103 27. Isactis 104 28. Rivularia 105 Family 6. — Stigonemataceae 109 29. Mastigocoleus 110 30. Brachytrichia Ill Literature cited 113 Subclass I. MYXOPHYCEAE stiz. Thallophytes of simple construction possessing a blue coloring matter, known usually as phycocj^anin, in addition to the chlorophyll ; plants unicellular, or in colonies of regular or irregular form, or in longer or shorter, simple or branched filaments ; cells discoid to globular, cuneiform or variously shaped, possessed of a distinct but very thin cell wall, a protoplast differentiated into a central chromatin containing body (nucleus, but without membrane) and outer color containing layer (cytoplasm and chromatophore?) ; granules (reserve materials?) of various kinds generally found in the cells, often arranged very definitely as regards certain cell walls ; cells whether single, in colonies of regular or irregular form, or in filaments com- monly surrounded by a more or less ample tegument of gelatinous to cartilaginous consistency, colorless or of various shades of yellow, brown, red or purple, structureless or stratified in various ways, com- monly in the form of a "sheath" in the filamentous forms, the sheath enclosing one to several or many rows of cells (or trichomes). Multi- plication: (1) by cell division, separating single cells (coccogonia) or short filaments (hormogonia) ; (2) by spores, either formed within a cell (gonidangium) in larger or smaller numbers (gonidia) or by diffc'rentiation as to size, shape and contents, and the formation of a thick outer coat (resting spores) ; sexual reproduction unknown. 1919] Setchell-Gardner : Myxophi/ceae 3 Myxophyceae Stizenbergor, Dr. Ludwio; Rabonhorst's Algen Sach- sens, 1860, p. 18. Myxophykca AVallroth, Fl. Crypt. Germ., vol. 2, 1833, p. 4. Gloesipheae Kiietz., Phycologia geiieralis, 1843, p. 179. Phycochromophyccae Rabenh., Fl. Eur. Alg., vol. 1, 1864, p. 1. Cryptophyccoe Thiirct, in Le Jolis, Liste des Alg. dii Cherbo\irg, 1863, p .13. Cyanophyceae Sachs, Lehrb. d. Bot., ed. 4, 1874, p. 248. • Schizophyceae Cohn, Ueber Thallophytsystem, 1879, p. 279. The Myxophyceae, or Cyanophyceae, as they are perhaps better known, constitute a fairly compact and easily to be distinguished group of more simple and smaller plants. The cell structure is simple in tiiat the protoplast lacks the distinct differentiation into cytoplasm, nucleus, and chromatophore found in other groups of the Thallophyta and in the Embryophyta, and there is certainly no distinct mitosis. The stature is slight as compared with that of plants of most other groups, the largest plants being only a few centimeters high. The morphological differentiation of the various genera and species is also simple. The reproductive methods are very simple indeed, being either pureh^ vegetative or by non-sexual spores. Neither sexual reproduction nor zoospores are known in the Myxophyceae. Some filamentous species are motile, at least under certain conditions, and tiie hormogonia are said also, in the case of certain if not all species, to be motile, although largely of microscopic or very slight dimensions. The cells, colonies or filaments of most of the Myxophyceae occur in such numbers and so densely aggregated, or even agglutinated together as to form laj'ers or masses of various shapes which are sufficiently conspicuous to be readily visible or even very noticeable. The Myxophyceae inhabit damp places or shallow waters even at fairly high temperature, and some non-marine members of the group even ascend, in thermal waters, to about 77° C or possibly higher. The Myxophyceae are often found in waters containing decomposing organic material. Some of those inhabiting calcareous waters are concerned in causing deposits of tufa or travertine, while some species bore their way into shells. Some species in silicious thermal waters, in turn, are closely associated with the deposit of sinter, IMany species are epiphytic, some even are more or less deeply endophytic while some are associated with fungi in lichen formation. The Jlyxophyceae do not seem to be closely related to the other groups of Phycophj'ta although there are certainl}^ close resemblances 4 University of California Puhlications in Botany [Vol.8 to be seen between the vegetative conditions of certain unicellular forms of Myxophyceae and those of Chlorophyceae. A much closer resemblance is seen to be with various forms of the Schizomycetes or Bacteria, so close, in fact, that it is often difficult to decide whether a given cell or filament ought to be assigned rather to the one or to the other group. Yet there are differences, as West has clearly pointed out (1916, pp. 38, 39). It has been the custom, however, to group the Myxophyceae and Schizomycetes together in a group by themselves which Cohn has designated as the Schizophyta. Key to the Orders 1. Vegetative multiplication by single cells (coccogonia) : unicellular forms either single or in larger or smaller globular or irregular colonies, seldom filamentous.... Order 1. Coccogonales (p. 4) 1. Vegetative multiplication by groups of two to many cells (hormogonia); multi- cellular forms, distinctly filamentous Order 2. Hormogonales (p. 51) Order 1. COCCOGONALES atkinson Thallus unicellular, associated into loose, more or less gelatinous families, or occasionally' pluricellular, free floating or attached ; multi- plication by direct cell divisions or by division of specialized cells (gonidangia) into few to many small, non-motile cells (gonidia), or by both. Atkinson, A college text book of Botany, 2d ed., 1905. p. 163. Coccogoneae Thuret, Essai Class. Nost., 1875, p. 377. Thuret {loc. cit.) was the first to emphasize the distinction between the two groups of Myxophyceae, or Nostoehinees, as he designated them. The Coccogoneae were distinguished from the Hormogoneae (Thuret, loc. dt.) merely by name without further definite statement. In 1886 Bornet and Flahault (p. 323) stated that the separation between the two groups w^as made on account of their method of mul- tiplication but without stating the exact nature of the method. The group was first definitely characterized by Kirchner (1898, p. 50) and it was defined again by West somewhat later (1916, p. 40) . The proper distinction is that vegetative reproduction may take place by single cells (coccogonia) instead of by short rows of cells (hormogonia) and in general the members of this group may be distinguished as being unicellular (or in non-filamentous colonies) instead of being properly filamentous. 1919] Setchell-Gardner : Myxophijceae 5 The majority of the species whether in filamentous form (as a few of them are) or unicells, or even the non-filamentous colonies, do definitel}" reproduce by vegetative cell division, separating cells which individually are capable of further growth. A few species, particu- larly those of the genus Dennocarpa, have no strictly vegetative method of multiplication, reproducing only by gonidia, j'et in every other way are closely allied to the rest of the genera included under Coccogonales and must, therefore, be placed in this order. The order is usually divided into two families, viz., Chrooeoccaceae and Chamaesiphonaceae. Key to the Families. 1. Multiplication by vegetative cell division (coccogonia) or by encysted cells (resting spores) ; strictly non-filamentous Family 1. Chrooeoccaceae (p 5) 1. Multiplication by vogotativo coll division (coccogonia) and by endogenous gonidia; unicellular, in globular or irregular colonies and, at times, distinctly filamen- tous Family 2. Chamaesiphonaceae (p 20) FAMILY 1. CHROOCOCCACEAE naeg. Cell solitary or associated into families of indefinite shapes and sizes, free floating or attached ; cell wall usually thin, surrounded by a more or less copious gelatinous or mucilaginous, at times highly colored, tegument; protoplast homogeneous or granular; multiplica- tion wholly by vegetative cell divisions in one, two, or three planes, the cells separating immediately, or remaining in contact for a longer or shorter period of time after which the teguments dissolve and liberate them. Naegeli, Gatt. einz. Algen, 1849, p. 44. Naegeli, in founding the family Chrooeoccaceae, included some eight genera, all of which, by common agreement, remain within the limits of the family. Later writers added genera some of which have been separated to form the family Chamaesiphonaceae of Borzi. Vari- ous distinctions have been attempted between these two families but it seems to us that the only satisfactory basis, at present at least, is that of the lack of gonidia-formation in the Chrooeoccaceae and its presence in the Chamaesiphonaceae. This was, at least, one of the important distinctions in the mind of Borzi (1882, p. 312). Later writers have found difficulties in this (cf. "West, 1916, p. 41) because of possibly greater prevalence of gonidia-formation among members of the Myxophyceae than had been previously described. Some of the described cases, however, must, as it seems to us, be more definitely 6 Vnivcrsity of California Puhlicatians in Botany [Vol.8 substantiati'cl aiul more carefully studied, to constitute a reall}' decisive objection. In this account the presence or absence of gonidia, together with the presence or absence of certain other characteristics to be em- phasized under Cluunacsiplionaceae, will be used in determining the nicnibei-sliiji of each of the families of the Coccogonales. Key to the Gener.\. 1. Cell division in 1 plane; plants 1-2 celled 2 1. Ceil division in 2 planes forming a plate-like colony 3. Merismopedia (p 8) 1. Cell divi-ion in 3 jilanos forming solid c )lonies 3 2. Cells globular without distinct tegum3nt 1. Synechocystis (p 6) 2. Cells longer than broad or thick, tegument present neither thick w^r strati- fied '. 2: Synechococcus (p 7) 3. Cells within the colony with distinct, often stratified teguments 4 3. Cells within the colonj- without distinct or stratified teguments 5 4. Colonies irregular in shape not forming a distinct thallus 4. Chroococcus (p 9) 4. Colonies forming a distinct, lobulated, hollow thallus 5. Placoma (p 11) 5. Colonics free, or only slightl}' attached, cells without definite arrangement 6. Anacystis (p 12) 5. Colonies epiphytic or partially endophytic, cells arranged in more or less distinct vertical rows 7. Chlorogloea (p 1.5) 1. Sjmechocystis Sauvageau Cells spherical, free, separating soon after division, with very thin walls, and blue-green protoplasts ; cell division in but one plane ; tegu- ments wanting. Sauvageau, Sur les algues d'eau douce, 1892, p. cxv, pi. 6, fig. 2. The genus Synechocystis is to be distinguished hy its spherical cells, elongating slightly just before division, dividing in only one plane, and absolutely devoid of tegument. Its nearest relatives are the species of Synechococctts. Synechocystis aquatilis Sauvageau Plate 1, fig. 7 Cells globose, 5-6/a diam., single or geminate, cell wall hyaline and very thin ; protoplast verdigris green. Forming an irregular layer in pools of salt marsh. Alameda, Cali- fornia. Sauvageau, loc. cit.; Gardner, Cyt. studies in Cyan., 1906, pp. 239, 268, 280, pi. 26, figs. 40-44; Collins, Holden and Setchell, Phyc. Bor.- Amer. (Exsicc), no. 1206. 1919] Setchell-Gardner : Myxophyceae 7 The description given above is translated from Forti (1907, p. 26) and is Sanvageaii's description of the, plant found at Ilammam- Salaliin, Algeria. It ma}' be seriously questioned whether the plant distributed by Gardner from the dripping sides of a water tank at Berkeley, California, which was submitted (in duplicate) to Sau- vageau by F. S. Collins and received his sanction, is the same as no. 1552 Gardner which was found forming an irregular layer in pools of a salt marsh at Alameda, California. The cells of the latter speci- men are slightly smaller than those of the Berkeley specimen or as given for the type. The cells of the Alameda plant are 4— 4.5/^ in diameter in the strictly spherical stage and show no tegument even on being treated with methylene blue. 2. Synechococcus Naeg. Cells elliptical or cylindrical, single or adhering in pairs for some time after cell division, free from enveloping jelly; color blue-green or yellowish; cell wall tliiii ; division in but one plane; tegument lack- ing, or at least extremely thin. Naegeli, Gatt. einz. Alg., 1849, p. 56, The genus 8 xjnedio coccus is closely related to the genus SynccJio- cystis and the two seem to intergrade. Thej^ are both imicellular, in the strict sense, with divisions in a single plane. They are both lacking in tegument, but some species of Synechococcus seem to have a light enveloping jelly and approach the genus Gloeothece. As in other cases among the Chroococcaceae, it seems best to retain the distinction as generic even though it be slight. The type species of Synechococcus is S. elongatus Naeg. from the Katzensee near Zuricli in Switzerland. Synechococcus curtus Setchell Plate 1, fig. 6 Cells single or united by strands of transparent jelly, slightly elongated, with obscure cell wall, and pale bluish-green protoplast; cells S/x diam., 6/m long just before dividing, the pair of daughter cells up to 8/A long before separating. Growing in warm salt water. Oakland, California. Setchell, in Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1351, March, 1907 ; Gardner, Cyt. studies Cyan., Novem- ber 10, 1906, p. 239 (MS. name; no descr.). 8 University of California Puhlications in Botany [Vol.8 The species of Syncchococcus are to be distinguished from one another by their diameters and bj^ the relation of proportion between these and their U'ligths. The present species is of intermediate diam- eter as these range among the species of the genus, and very short in proportion. Some of the cells approach spherical and consequently resemble Synechocystis, but the majority are at least somewhat longer than broad even in stages just succeeding division. 3. Merismopedia ]\Ieyen Cells spherical, or narrow ellipsoidal, with thin cell walls, and firm, hyaline, structureless teguments becoming dififluent and binding the cells together; division regularl}^ in two planes, building up colonies, at first square, or regularly rectangular, later often irregular in outline through injury or failure of certain cells to continue division. Meyen, Wiegman's Arch. f. Naturgesch., Jahrg. 5, vol. 2, 1839, p. 67 {nomen nudum); Kuetzing, Phyc. Gen., 1843, p. 163 (descr.). Gonidium Ehrenb., Infusionsth., 1838, p. 59 {nomen nudum) ; Mene- ghini, Syn. Desm. hue Cog., 1840, p. 213 (descr.). Agmenellum de Brebisson, De quelq. nouv. genres d'Alg., 1839 (May), p. 2, Diet, univ. d'hist. nat., vol. 1, 1841, p. 187; Trevisan, Prospetto della Flor. Eug., 1842. The plants which have passed undisputedly under the name of Merismopedia for so many decades form a well defined and recog- nizable generic unit. When the historj^ of the name is investigated, it is found, unfortunateh', to possess no valid status. Merismopedia was used by Meyen simply as part of a binomial and with no definite diagnosis in 1839, and was probably published comparatively late in the year. It seems, therefore, to be a nomen nudum. It was first accompanied by a proper diagnosis in Kuetzing 's Phycologia gcneralis in 1843. In the meantime two other names were suggested, Gonidium by Ehrenberg and Agmenellum- bj'- de Brebisson. The name Gonidium is also to be held as a nomen nudum since it was used by Ehrenberg as a subgeneric designation under Gonium. He remarks (1838, p. 59), however, that he would, if he understood the plants better, place both Gonium tranquillum and G. glaucum in a new genus Gonidium, but he prefers to leave them under Gonium. In 1840 Meneghini took up and described Gonidium as a genus, on the ground, as he distinctly states, that it antedated the genus Agmenellum of de Brebisson. 1919] Setchell-Gardner : Myxophyceae 9 Agmenelhnn was published as a genus by de Brebissou in May, 1839, with complete diagnosis and naming of the type species, A. quadruplicatum Breb. It seems, therefore, that AgmeneUum is the first valid publication and ought to be adopted, but following the principle enunciated by the various International Congresses that names of undisputed use for a long series of years may be conserved, we have retained Mfrismopedia until proper action may be taken. Merismopedia Gardner! (Collins) Setchell Plate 8, fig. 7 Plants up to 3 cm. or more long, delicate, membranaceous, very irregular in foinn, more or less lacerated and folded, 7-8/a thick; cells closely placed, cylindrical, 6-6.5ju, long, 3.5-4/x in diam. ; protoplast bluish green, homogeneous. Floating in pools of salt water, salt marshes of Alameda, Cali- fornia. Setchell, in Gardner, Cyt. studies Cyan., 1906, p. 239 {nomen nudum). Prasiola Gardncri Collins, in Colli^is, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1185 (1904), Green Alg. N.A., 1909, p. 221 (in note). Merismopedia Gardneri has been collected only once in i)ools of salt water on a marsh in Alameda, California, but it was plentiful at that time. Since then the type locality has been filled in wdth earth. It showed a remarkable resemblance to species of Prasiola, but was decidedly of a more bluish tint, which is even more pronounced in dried specimens. The cytological structure agrees well with that of other Myxophj^ceae and lacks the characteristics of the cells of Prasiola. It is gigantic for a Merismopedia, surpassing even the Merismopedia convoluta Breb., hitherto known as the largest member of the genus. 4. Chroococcus Naeg. Cells single or united into small colonies of 2, 4, or 8 cells, spherical, or more or less flattened when in colonies ; contents blue-green, violet or yellowish ; tegument comparatively thin although distinct, firm, uniform or nearly so, not gelatinous, that of the original cell enclosing the entire small colony; division in three planes. Naegeli, Gatt. einz. Alg., 1849, p. 45. 10 University of Calif ornia Piihlic^tions in Bot(uiij f'^^oi- ^ The gt-'ims Chruococcua, as establislied by Naegeli in 1849, was dis- tinctly set off and used in practically the exact sense of the present time. The type of the genus, as designated by Naegeli, is the Pleuro- coccus rufcscois Breb. published as a manuscript name by Kuetzing (1846, p. 9) under his Protococcus riifescens. Some difference of oi)inion seems to exist as to the present status of this type. Raben- horst (1868, p. 28) uses the name of de Brebisson in his account of the "Chlorophyllophyceae" and West (1916, p. 93) restores the genus Protococcus and reckons P. rufescens (Breb.) Kuetz. among the Chlorophyceae. An examination of the type specimen in Herb. Kuetzing, for which privilege we are indebted to Dr. Weber-van Bosse, demonstrates clearly that the plant of de Brebisson is a Chroococcus in the sense of Naegeli. Naegeli, hoAvever, evidently derived his concep- tion of the genus from Chroococcus rufescens var. turicensis Naeg., as described and figured bj'- him (1849, p. 46, pi. 1, fig. 1). All of the stages figured bj' Naegeli are to be found in the type material, so that it seems likely that no considerable differences are to be found between the species and its variety. From Naegeli 's figures and from the species other than the type referred to Chroococcus by Naegeli, there can be no doubt as to his conception of the genus. The genus Chroococcus is compared by Naegeli (1849, p. 53) with Gloeocapsa Kuetz. and Aphanocapsa Naeg., who states that while they are closeh^ related to one another, they are distinctly set off from the other genera whose descriptions follow in Naegeli 's monograph. The whole difference, as Naegeli says, lies in the fact that in Chroococcus the teguments are thin, in Gloeocapsa thick and firm, while in Aphano- capsa they are thick but so soft that they coalesce into a structureless jelly. All other characteristics are secondary, and there occur forms which might with equal reason be referred to one or another of the three genera. It may seem best, at some time, to unite Chroococcus with Gloeocapsa, but, for the present, we shall follow the custom and retain both as distinct genera. Chroococcus turgidus (Kuetz.) Naeg. Cells spherical or ellipsoidal when single, or angular from mutual compression when in colonies, 1-4, rarely 8, in colonies, 13-25/x, rarely 40/x diam., tegument comparatively thick, often somewhat lamellate, hyaline, cell wall thin, not distinct; protoplast vivid blue-green, homogeneous, or becoming faded more or less, and granular. 1919] Setchell-Gardncr : MyxopJiyceae ' 11 Growing in fn sh and in brackish water along high-tide line, Alaska to central California. Naegeli, Gatt. eiuz. Alg., 1849, p. 46; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 179. Protococcxs turgidufi Knetzing. Tab. Phyc, vol. 1, 1846, p. 5, pi. 6, fig. 1. The type of the species is to be found in Herb. Kuetzing and shows the plant to bo mingled with fragments of a moss and consequently as occurring in fresh water. Tiie type locality is not given with definiteness but is stated in the Species algarum (1849a, p. 198) to be Germany. Single cells of the type are about 8/a in diameter, but with the teguments are 12-16/a in diameter. The teguments show distinct stratification and colonies of eight cells, of total diameter of 40/^, are frequent. Altogether the type specimens correspond exactly to Kuetzing 's figures and description. Chroococcus turgidus is not properly a marine species but an inhabitant of fresh water. The forms occurring in the brackish water of pools of the salt marshes and just above high water mark are larger, with variable color of the protoplast. Most, if not all of them, are more properly to be referred to the following variety. Chroococcus turgidus f. submarinus Ilansg. Plate 1, fig. 14 Single cell spherical, protoplast 22-26/x diam., tegument 5-6/a thick; two-celled colony 40^5/* diam., 50-60/x long, cells angular; extremely variable in color in the same collection. Growing on CJiaetomorpha calif ornica Collins, in rock pools along high-tide line, at present credited to a single locality, Laguna Beach, Orange County, California, but probably extending along the entire coast in suitable habitat. Hansgirg, Beitriige Kennt. Meeresalgen, 1889, p. 6 ; Collins, llolden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1551. Although a single locality is quoted, it seeras probable that the forma submarinus really includes all the specimens found in strictly brackish water. 5. Placoma Schousb. Colonies spherical or lobed, solid or hollow, with cells arranged more or less radially, at least toward the surface, and quaternate ; tegument of colony structureless, special teguments of cells more or less stratified as in Gloeocapsa; division in three planes. 12 Vnivcrsiti/ of Californm Publications in Botany [Vol.8 Schousboe, in Boriiet aud Thuret, Notes Algol., fasc. 1, 1876, p. 4. Pl^conm is a geuus of three known species founded on P. vesiculosa Schousb. from "Tingin" on the coast of Morocco. There are now three kno\\Ti species, one of whieli (P. africana Wille) is an inhab- itant of fresh water while P. vcsi-culosa Schousb. and P. violacea S. and G. are marine. M. A. Howe (1914, p. 11) has indicated the presence of a species on the coast of Peru, but has not assigned to it any definite specific name. Placoma is closely related to EntopJiysalis, Oncohijrsa and Chon- drocystis. From Eniophysalis, it differs in its more hemispherical type of thallus, from Oncohyrsa in its less strictly and regularlj^ radi- ating rows of cells, while from Chrondrocystis, it differs in the pos- session of Gloeocapsoid teguments enveloping the cells. Placoma violacea S. and G. Plate 4, fig-. 1 Thallus microscopic, 175-250/a diam., irregular to somewhat spherical, verrucose, tegument pale violet ; cells 3.5-4/a diam., in groups of 2-8, usually of 4, mostly without order in the interior, but arranged radialh' toward the periphery, angular when young, becoming spher- ical later, special teguments very distinct and violet toward the sur- face, hyaline below; protoplast homogeneous, pale blue-green. Forming a sort of pulverulent or verrucose black layer, intermixed with other Myxophj'ceae, on logs along high water mark. Cape Flattery, Washington. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918a, p. 456. Placoma violacea resembles P. africana Wille (1903, p. 90), a fresh water species from South Africa. Besides the difference in habitat, P. violacea has larger cells, aggregated into larger colonies, and pos- sesses a violet colored tegument. 6. Anacystis ]\Ienegh. Cells spherical to oval, with very thin cell walls and blue-green or violet protoplast, associated into small spherical or' more or less lobed and irregular colonies, and embedded within a copious gelatinous tegument, within which they are either uniformly distributed or seg- regated in small groups ; cell divisions in all planes. 1919] Setchcll-Gardner : Myxopliyceae 13 Meneghini, Conspeet. Alg. Eugan., 1837, p. 6 (in part), cenni siilla organogr. e fisiol. delle Alg., 1838, p. 25 (sp. excL), Monogr. Nost. Ital., 1842, p. 92 (emend.) ; Reichenbaeh, Nom, gen. pi. syst., 1841, p. 18; de Brebisson, Diet. univ. d'hist. nat., vol, 1, 1841, p. 417; Endlicher, Gen. PI., suppl. Ill, 1843, p. 11; Kuetzing, Tab. Phyc, vol. 1, 1846, p. 7 (as subgenus of Microcystis) , Sp. Alg., 1849a, p. 209. Microcystis Kuetzing, Tab. Phyc, vol. 1, 1846, p. 7 (in part). Poly- cystis Kuetzing, Tab. Phyc, vol. 1, 1846, p. 7 (as subgenus of Micro- cystis), Sp. Alg., 1849flf, p. 210 (in part). In selecting the proper generic name for the group of species which lias been for some years included under the name of Polycystis Kuetzing and more recently still under the name of Microcystis Kuetz- ing, it has seemed desirable to scrutinize closely the literature bearing on the subject. Microcystis was proposed by Kuetzing in 1833 to include ten species (1833a), now variously referred, but no one of which remains in the more recent revisions of the genus. Further- more the variety of algae, fungi, and gemmae included under the orig- inal Microcystis precludes any preponderance of species of one genus or general idea. The first species in the list, Microcystis Noltii Kuetz., would now be referred to Euglena as the type specimen clearly proves. In 1843 (p. 170), and again in 1845 (p. 148), Kuetzing enumerated four species under his Microcystis, M. Noltii still being included and placed first. No one of the four is unmistakably a Microcystis in the sense of later authors, M. Noltii and M. olivacen being species of Euglena, M. parasitica being doubtful but probably a Microcystis of the later usage, while M. icthyohlahe, as used here, is largely, at least, what is now called Clathrocystis aeruginosa (cf. also Nordstedt, 1911, p. 264). In 1846 in the first volume of the Tahulae Phycologicae (p. 7) Kuetzing separated his genus Microcystis into three, retaining in Microcystis only M. olivacea, M. austriaca and M. Noltii. These are all, seemingly at least, species of Euglena. In 1849, in liis Species Algarum (pp. 208, 209) Kuetzing retained the same species, adding to them M. minor, a very similar species. It seems, therefore, that the final conception of Kuetzing points toward Euglena rather than toward the species included by later writers. Most writers, however, have employed Kuetzing 's genus Polycystis founded in 1846. This is the second of the two segregates from Microcystis and is fairly definite in its content. Kuetzing assigns it three species, viz., P. elaheus, P. . violacea, a species growing on fragments of crockery at Brest. Nothing further seems to have been done in the study of the genus 22 University of California PuWications in Botany [Vol.8 until Reinseh (1874, p. 15) founded liis genus Sphaenosiphon as a member of tlie "^Mflanophyceae" and described a number of species, some showing gonidial stages {loc. cit. pi. 25, fig. 2c, 2d, 3c). The genus was properly placed and illustrated by Bornet and Thuret in the Notes algoloejiqins (1880, pp. 73-77, pi. 26, figs. 3-9). Since then the number of species has been increased to over twenty and there are doubtless many more awaiting discovery by careful search and study. The cells of Derniocarpa vary from spherical, or almost hemi- spherical, to obovate and pyriform, or even elongated linear, but the genus possesses one seemingly certain distinction in that its cells undergo no vegetative division, reproducing only by gonidia. This it shares only with Cyanocystis Borzi. The difference between the two genera is in the manner of the dehiscence of the gonidangia. In Cyanocystis the gonidangia are circumscissile, the top separating as a lid by a smooth transverse rupture. In some species of Dermocarpa, the entire wall or, at least, the greater portion of it, dissolves, releas- ing the gonidia, but in other species, the wall ruptures by a slit at the apex. Whether these distinctions are sufficient for separating the two genera will be left for future study and decision. Key to the Species. 1. Cells solitary (or at most slightly gregarious) 2 1. Cells aggregated into dense layers 4 2. Adult cells (especially gonidangia) hemispherical....!. D. hemisphaerica (p 22) 2. Adult cells (especially gonidangia) nearly spherical 3 2. Adult cells (especially gonidangia) ovoid to pyriform ...4. D. suffulta (p 26) 3. Adult cells about 2.5/a in diam 3. D. sphaeroidea (p 26) 3. Adult cells 8-16/". in diam 2. D. sphaerica (p 24) 4. Adult cells (especially gonidangia) narrowly to broadly pyriform 5. D. fucicola (p 27) 4. Adult cells (especially gonidangia) spherical to narrowly cuneate 6. D. pacifica (p 27) 4. Adult cells (especially gonidangia) very variable in shape in same layer 7. D. protea (p 28) 1. Dermocarpa hemisphaerica S. and G. Plate 3, fig. 21 Cells epiphytic, solitary, hemispherical, attached by the flat plane surface, 18-21/i, diam. at the base, 10-13/x high ; contents of cell bright blue-green, homogeneous; cell wall hyaline, moderately thick, homo- geneous, reproduction by successive divisions of the whole protoplast, forming spherical gonidia 0.8-1. 2/x, diam. 1919] Setchell-Gardncr : Myxophyceae 23 Growing on Rhodochorton Rothii in moist, shaded places along high-tide level, or even above. Moss Beach, San Mateo County, Cali- fornia. The above locality is the. one from which the type material has been obtained, but the plant has been observed growing on the same host at a number of different localities along the California coast. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 438, pi. 37, fig. 21 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 2253. Dermocarpa hemisphaeriea is a somewhat aberrant plant. The individuals are small, mostly solitary, and multiplication is wholly by means of gonidia. In size and distribution on the host it resembles Xenococcus in the early stages of development of that genus, but differs from it in not having increase by means of vegetative cell divisions. In its solitary habit and method of reproduction it resem- bled Cyanocystis, but differs from that genus in its method of escape of gonidia. Those of D. hemisphaerica escape through a small open- ing at the apex of the gonidangia, and those of Cyanocystis escape by means of a circumscissile splitting of the gonidangia. It seems more nearly to fulfil the requirements of the genus Dermocarpa, as now generally understood than of any other genus of Chamaesiphonaceae. It differs, however, from previous conceptions of species of that genus ill tlic iiictliod of the formation of gonidia. They are formed in this species by successive divisions of the contents of the gonidangia, those in earlier described species being formed bj- simultaneous division. In this respect it is like some species of Pleurocapsa as well as more recently described species of Dermocarpa. Dermocarpa hemisphaerica is commonly associated with Chloro- gloea conferta (Kuetz.) S. and G. and Dermocarpa suffulta S. and G. The early stages of the development of D. hemisphaerica and D. suffulta are very similar to each other, but they soon differentiate into their characteristic shapes, and at maturity are very readily distinguishable. Chlorogloea conferta is very frequentlj^ also present and in such abundance as to completelj^ cover up the other two species, hence this condition along with the presence of diatoms and other foreign material, has made the separation of these forms somewhat difficult. The type material is comparatively free from foreign substances and the plants of D. hemisphaerica and D. suffulta are both fruiting, are abundant, and comparatively free from Chloroyloea. This condition has made it possible to trace the life history of each of these three species, establishing beyond a doubt that they are not to be considered stages in the life history of a single form. 24 rninrsity of California Puhlications in Botany [Vol.8 Dirmocarpa himisiyhacrica seems closely related to Pleurocapsa amithystca Rosenvinge (1893, p. 967). This is especially true of the early vegetative stage aud of the beginning of spore formation {loc. cif., p. 968, figs. C, D). Later developments of P. amethystea depart from that of D. hemisphaerica (cf. Rosenvinge, loc. cit., figs. E, F, G). 2. Dermocarpa sphaerica S. and G. Plate 5, fig. 14 Cells solitary or contiguous, spherical, 8-16/j, diam., pale blue- green ; cell wall thin, hyaline ; protoplast finely granular ; gonidangia spherical, 8-16/li diam. ; gonidia angular at first, becoming spherical at maturity', 2.5-3/a diam., formed by simultaneous division of the proto- plast, escaping by dissolution of the entire gonidangial wall. Growing on various species of algae in the littoral belt, frequently in salt marshes. Ranging from Whidbey Island, Washington, to cen- tral California. The type material was found growing on a species of Lynghya, Lands End, San Francisco, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918«, p. 457, pi. 39, fig. 14. Xenococcus Schoushoei Setchell and Gardner, Alg. N.W. Amer., 1903, p. 180; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 554 (not Thuret, in Bornet and Thuret, 1880, pp. 73-77, pi. 26, figs. 1, 2). Dermocarpa sphaerica is the plant which has commonly passed for Xenococcus Schoushoei on the Pacific Coast of North America. Examination of a bit of the type material of Schousboe's Coleonema arcnifera, upon which Thuret founded the genus, shows that the Pacific Coast plant belongs to a different genus. Xenococcus Schous- hoei, as described and figured by Thuret, has increase in the number of individuals by means of vegetative cell divisions. This is the con- dition in which Schousboe found the type material, the plants being young and the gonidial stage having not yet appeared. Our plant which has passed under the name of Xenococcus Schoushoei, does not divide vegetatively, and hence belongs to the group of which Dermo- carpa may be taken as a type, in which there is increase only by the formation of gonidia, instead of the group of which Pleurocapsa may be taken as a type, in which there is increase by both vegetative cell divisions and by gonidia. Kirchner (1898, p. 58) and Forti (1907, pp. 119, 120) recognize five genera of Chamaesiphonaceae which have no vegetative cell divi- 1919] SetcheU-Gardner : Myxophyceae 25 sions and which reproduce exclusively by gonidial formation. These are Cyanocijstis Borzi (1882, p. 314), Dermocarpa Crouan (1858, p. 70), Clastidium. Kirchner (1880, p. 195), Chamaesiphon A. Br. and Grun. (ef. Rabenhorst, 1865, p. 148), and Godlcwskia Jancz. (1883, p. 227). Kirchner separates the first three genera from the last two because of tlie simultaneous division of the whole protoplast of the gonidangium into gonidia, whereas in the last two genera the gonidia are abstricted successively from the apex of the gonidangium, the basal portion always remaining sterile. Forti adopts this arrangement except the statement as to the simultaneous division of the protoplast. It is necessary to modify Kirchner 's statement in regard to the simultaneous division of the protoplast in Dermocarpa since we have found ill several species that the gonidia result from successive divi- sions in different planes. This condition is notably true of D. protea S. and G. A further exception to the statement of Kirchner must be made in D. Leihlemme (Reinseh) B. and Th. and in D. stiff lUta S. and G., in that only a portion of the protoplast of the gonidangium is con- verted into gonidia, the basal portion in each species uniformly remain- ing sterile. There is but little likelihood of confusing Dermooarpa with either Chamaesiphon or Godleivskia, on account of their cylin- drical shape, and method of formation and liberation of gonidia, or even with Clastidiioii, which is narrow and c^dindrical and possesses a seta at the outer end, but in attempting to place a species like D. sphaerica, or D. sphaer&idea S. and G., the question arises as to which genus, Dermocarpa or Cyanocystis, if both of these are to be consid- ered valid genera, should receive them. Tlie method of escape of gonidia in D. sphaeraid^ea has not been determined, but in D. sphaerica the whole wall of the gonidangium dissolves and the group of gonidia is left free in position. The only distinction between Cyanocystis and Dermocarpa, as brought out l)y both Kirchner and Forti, is that of the method of escape of gonidia. In the former they escape by a circumscissile rupture and in tlie latter by a dissolution of the apex of the gonidangium. If the method of escape of the gonidia is to be taken as sufficient for generic distinction, it will be necessary to create another genus for D. sphaerica which does not conform to either of the above methods. It seems preferable in this case to refrain from extending the number of genera, but to reduce it rather, and since Dermocarpa is the older genus to adopt that to receive our species, and reduce Cyanocystis in ease furtlier study makes it necessary or desirable. 26 University of California Publications in Botany [Vol.8 3. Dermocarpa sphaeroidea 8. and G. Plate 2, fig. 7 Cells spheroidal or sliglitly obovate, somewhat angular when com- pressed, solitary, or mostly grouped together in small clusters, up to 25/A diam. ; cell wall liyaline, homogeneous, thin, 1.5/x thick; cell con- tents pale blue-green at maturity, finelj' granular; gonidangia 18-25|u, diam., the whole cell contents dividing into small spherical gonidia. Growing on Porphyra perforata forma lanceolata along high-tide level. Lands End, San Francisco, California. April, 1917. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 440, pi. 36, fig. 7. This species of Dermocarpa probably grows on other hosts than that mentioned above in the same locality. Groups of cells resembling those of this species have been observed intermixed with Radaisia and Pleurocapsa growing on small species of EnterotnorpKa and Viva, but it is difficult to determine the separate members in such a mixture. The material found on Porphyra was free from other forms. It seems to occupy an intermediate position, as regards its gregarious habit, between D. fucicola Saunders and D. suffulta S. and G., the former growing in compact colonies and the latter almost singl}^ 4. Dermocarpa suflfulta S. and G. Plate 2, fig. 9 Cells solitarj' or loosely associated into small groups, ovoid, pear- shaped or sometimes stipitate, 17-20/i, long, 10-14ju, diam. at the larger end ; contents bright blue-green ; cell wall hyaline, homogeneous ; goni- dangia formed from the upper part of the cell, leaving a cone-shaped, sterile, basal portion ; gonidia 8-12 in a gonidangium, 4-6jU. diam. Growing on Rhodochortoti Rothii near high-tide limit in shaded places on rock. Moss Beach, San Mateo County, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 440, pi. 36, fig. 9. These plants were found growing in moderate abundance in com- pany with Dermocarpa hemisphaerica S. and G. and with Chlorogloea conferta (Kuetz.) S. and G. Of all the known species it seems most closely related to Dermocarpa Leihleiniae (Reinsch) B. and Th. It differs from that species in being narrower in general, in having fewer and larger gonidia, and in having a larger part of the cell changed into a gonidangium. Nearly half of D. Leihleiniae remains sterile. 1919] Setchell-Gardner : Myxophyceae 27 It is also closely relatod to D. solitaria very recently described by Collins and Hervey (1917, no. 2155 MS and 1917a, p. 17) from Ber- muda. Both species have the same habit of growth on the host, being mostly solitary instead of being aggregated into dense clusters as are most species of Dermocarpa. D. solitaria, however, is much longer than D. siiffuHa, being np to 75/i, long. 5. Dermocarpa fucicola Saunders Plate 8, fi^s. '), 6 Cells densely crowded into groups of irregular shape and indefinite size, up to 12 mm. across, of very dark olive green to purplisli violet color, 22-3{V diam., 40-60//. high at maturity, broadly pj^riform to balloon-shaped, narrowing into a stipe-like portion below ; gonidia formed by the simultaneous division of tlie whole protoplast, 4-5ju. diam. Growing on many different species of algae. Common along the whole coast from Puget Sound, Washington, to southern California. Saunders MS., in Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 801, Alg. Harriman Exped., 1901, p. 397, pi. 46, figs. 4-5; Setchell and Gardner, Alg. N.W. Araer., 1903, p. 181; Collins, Holden and Setchell, Phye. Bor.-Amer. (Exsicc), no. 1251. The above description is based upon authentic material taken from our fascicles of Fhycotheca B or eali- Americana, specimens dis- tributed by Saunders under no. 801. It is presumabh' from material of this distribution that Saunders drew his original description of the species. These specimens are just coming into maturity, as shown from the scarcity of the gonidangia. The measurements are based upon the mature cells, that is the gonidangia, very few of which mea.sure 40/x long, the majority being between 50/^ and 60[x long. We express some doubt as to whether the gonidia are formed by simul- taneous or by successive divisions of the protoplast. No indications of successive divisions were seen, all of the gonidia noticed being completely formed. ('}. Dermocarpa pacifica S. jukI G. Plate 3, figs. 22-24 Cells aggregated into colonies up to 200/Lt diam., varying in shape from nearlj' spherical, broadly ovate or pear-shaped, to narrowlj'' wedge-shaped, 30-45/i, long, 20-35/a diam.; cell walls thick, hyaline, 28 Univcrsiti/ uf Calif ornki ruhlications in Botany YWm^.^ lioinogeneoiis ; coll contents bright bliie-green or olive green when young, changing to brownish when old; gonidia numerous, 2/i, diam. Growing on Chaetomorpha acrta in a tide pool near high -tide limit. Cypress Point, Monterey County, California. January, 1917. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 4:39. pi. 37, figs. 22-24. The plants of this species were found associated with Xenococcus Chaetomorphae and the two species were so abundant as to give the host plant a very dark color. The shapes of the cells of D. pacifica are determined, to a certain extent, by their position on the host and by their age. The younger cells of C. aerea are cylindrical, but they become quite torulose at maturity. This change in the shape of the host cells modifies the form of certain cells of the epiphyte. If the gonidia of the Dermocarpa happen to locate at the cross walls when the host cells are young, increase in the size of the cells of both the host and the epiphj'^te causes the cells of the epiphyte to become much crowded and thus assume a narrow wedge shape. As the cells of the host plant mature and begin to disintegrate the younger Dermocarpa cells that have had more room in which to expand are liberated and become broadly oval or even spherical. The cell contents become much darker and brownish at maturity, and when mounted in glycer- ine and acetic acid change to purple. The contents of the whole cell change into gonidia by simultaneous division. 7. Dermocarpa protea S. and G. Plate 4, figs. 4, 5 Cells extremely variable in shape and size, broadly pyriform to narrowly cuneate, 40-120/* long, 6^0/x diam. at the apex, 3-7 /x at the base ; cell wall hyaline, 2-3/a thick ; protoplast homogeneous, light blue-green ; gonidia 3-3. 5/a diam. formed by successive divisions of the protoplast. Growing on Spangomorpha sp. West coast of Whidbey Island, Washington. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918fl, p. 456, pi. 38, figs. 4, 5. A single specimen of this species of Spongomorpha with the above epiphyte growing upon it has thus far been collected. The terminal portions of tlic liost were so thickly clothed with the epiphyte as to give them a very decidedly dark appearance. Microscopic examin- 1£>19] Setchell-Gardncr: Myxophyceac 29 ation showed that the colonies were unusually variable in shape and in size, some capping tlic filaments, others completely surrounding and obscuring them for some distance, and still others small and widely separated. Material scraped from the filaments and magnified revealed a surprising variation in the shape and size of the vegetative cells, as well as of the gonidangia. Among the collection one could select cells in both vegetative and reproductive conditions which would conform to the description, in shape and in size, of each of several well known species ; but since there is such perfect gradation in lengths and in widths, both in purely vegetative cells and in tlie gonidangia, ranging in size of mature cells from 6/x to 4()/x wide in the upper parts, and from 40/a to 120/a long, it is impossible to segre- gate them into species. Considered as a species D. protca represents the largest known species of Dermocarpa, and has the greatest range of variation in size and in shape of the cells. Plate 4, figs. 4, 5 represents some of these found among the gonidangia. Dermocarpa protea is an excellent example of the formation of gonidia by successive and progressive divisions of the gonidangia to form gonidia. This method is represented in the gonidangia irre- spective of shapes and sizes, and is another evidence in support of their all belonging to a single species. Kirchner (1898, p. 58) in his key to the genera places Dermocarpa in the group which produces the gonidia by simultaneous division of tlic protoplast. In Cytological Studies in Cyanophyceae (1906, p. 281) Gardner expressed the opinion that Dermocarpa fucicola Saunders produces gonidia in this manner. We have since examined authentic material of that species and, although the gonidangia are very sparse, it appears to form tluiii by simultaneous division; l)ut liaving exam- ined other collections from our coast which seem to be of the same species, judging from the shape and size of the cells, which clearly show that the formation of gonidia is by successive divisions of the proto- plast, some doubt may still be entertained as to which method D. fuci- cola follows. This subject must have more careful stud.v and may prove to be a more stable character than shapes and sizes of cells upon which to establish species. Dermocarpa prasina (Reinsch) B. and Th. has been credited to our coast by Saunders (1898, p. 397) as occurring on " Sphacelaria race- mosa arctica" and " Sphacelaria cirrhosa" and extending from Puget Sound to the Shumagin Islands in Alaska. It seems to us unlikely that this species should l)e represenlcd in these waters, but we have 30 University of California Publications in Botany [Vol.8 no specimens of Sphacelaria from them, nor have we seen any speci- mens of Saunders. The Dermooarpa prasina of Setchell (1899, p. 54) is indefinite and undoubtedly most!}' what was later named I), fucicola bv Saunders. 9. Xenococcus Thur. Cells spherical or more or less angular due to mutual pressure when closely aggregated, scattered or collected into a continuous stratum, usually epiphytic ; cell contents pale blue-green or dark violet, homogeneous; reproduction by cell division in two planes, and by formation of gonidia. Thuret, Essai Class. Nost., 1875, p. 373 (nomen nudum), in Born, and Thur., Notes Algol., vol. 2, 1880, pp. 73-75 (description of type) ; Hansgirg, Phj'siol. u. Algol. Studien, 1887, p. Ill (lim. mut.), Prodr. Algenfl. Bohm. II, 1892a., p. 128. The genus Xenococcus was founded by Thuret in 1880 (Notes Algol., vol. 2, pp. 74, 75) upon X. Schousboei Thuret as the type species, but no distinct and definite generic diagnosis was given. Thuret had already mentioned the genus in 1875 (Essai Class. Nost., p. 373), but neither described it nor mentioned a type species. Hans- girg (1887, p. Ill) discussed Xenococcus and its limits, but set the limits beyond those instituted by Thuret and repeated these later in what is probably the first formal diagnosis of the genus (1892a, p. 128). Bornet (in 1889 and 1892) reduced Xenococcus under Dermocarpa Crouan, but Kirchner (1898, p. 58) restored it to generic rank. The species of Xenococcus, as was understood by Thuret, differed from those of Dermocarpa particularly in their lack of gonidangia. When Batters discovered gonidangia and gonidia in Xenococcus Schousboei, it seemed necessary to reduce the species under Dermocarpa, and this was suggested by Bornet. Kirchner, however, brings forward the fact that Xenococcus Schousboei differs from the species of Dermocarpa in that the cells divide vegetatively, and consequently restores Xeno- coccus to independent rank. Achille Forti (1907, p. 133) "^.tates that the vegetative division is in three directions, but Thuret {in Bornet and Thuret, 1880, p. 75) emphatically says that they divide perpen- dicularly to the surface of the substratum and in this direction only. An examination of a portion of the type material indicates cell divi- sion in two directions, perpendicular to one another and to the surface of the substratum. 1919] Setchell-Gardner : Myxophyceae 31 Key to thk Species. 1. Cell wall thin, iiiconsipicuous 2 1. Cell wall thicker, cmispicuous 3 2. In extended colonies of 1-several layers 1. X. acervatus (p 31) 2. Solitary or in small colonies of 1 layer 2. X. Gilkeyae fp 32) 3. Cells more or less elongated in horizontal diameter, polymorphic 5. X. Chaetomorphae (p 35) 3. Cells not elongated in horizontal diameter 4 4. Cells forming continuous layers, cell walls often diffluent, fjonidia 1 5-2/* in diam 3. X. Cladophorae (p 33) 4. Cells in small colonies, cell walls dense, not diffluent, gonidia 2.8-3.5/x in diam 4. X. pyriformis {p 34) 1. Xenococcus acervatus S. and G. Plate 5, fig. 13 Cells wholly epiphytic, dividing in t^v() planes perpendicular to the host, building colonies at first one cell deep, later confusedly heaped uj), of indefinite extent; cells angular at first, soon becoming spherical or pear-shaped, 3-6/x diam., cell wall thin, hyaline; proto- plast homogeneous, pale blue-green; gonidangia unknown. Growing in great profusion on Enteromorpha sp. in salt marsh pools. San Francisco Bay, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918a, p. 459, pi. 39, fig. 13. Pleurocapsa amethyst&a var. Schmidtii Collins, in Collins, Holdcn and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1704. The first publication of the name P. amsthystea var. was by Bor- gesen (Mar. Alg. Fiier., 1902, p. 524), Johannus Schmidt having identified one of Borgesen's species from the Fiieroes as belonging there. Borgesen stated that Schmidt would comment on the species later in Helgi Jonsson's paper. Jonsson's paper appeared in 1903 btit Schmidt mentions only a plant from Iceland under the above name {"P. (unethystm var."). Collins {loc. cit.) considers our plant to be of the same variety as the Iceland plant and gives it a varietal name without furtlx-r comment. In llie absence of gonidangia it is not at present possible to give a complete comparison of our plant with the description of the Green- land plant, P. amethystea, of Rosenvinge (1893, p. 968), nor with the variety of that species growing in Iceland, determined by Schmidt {in Jonsson, 1903, p. 378). There are no specimens of either of these available at present for comparison. Rosenvinge 's figures and descrip- tion of P. (unethysfea show plainly that the cells divide in three planes, which places it witli tln' genus Pleurocapsa. Schmidt states that the 32 I'nivdsity of Californkt Public-atiotis in Botany [Vol.8 Iceland plant differs from the Greenland plant onlj' in color, but for- bears naming it on that character alone. The Iceland plant seems, therefore, certainly to be a Pleurocapsa. Our plant divides vegeta- tively in but two planes, and, accepting Thuret's understanding of his genus Xenococcus, it belongs to that genus rather than to Pleurocapsa. A brief discussion of the structure and relation of these two genera is given in Gardner's New Pacific Coast Marine Algae II, 1918, p. 436. Xenococci(s acervatiis differs from P. amethystea in the number of planes of vegetative cell divisions, in the shape and size of the cells and in their color, the color of the latter being "sordide violacea, " and the former pale blue-green. None of the seven illustrations of Rosenvinge (loc. cit.) resembles very clearly any phases of the develop- ment of our plant except A, the surface view of a group of vegetative cells. At times the cells as viewed in the median plane of the host plant are piled up several cells deep, as though they had arisen by horizontal divisions. If this were the case, our plant would properly belong to the genus Pleurocapsa. This docs not seem to be the case, however, as the cells above the surface layer are very generally spherical, appar- ently independent, and very variable in size. They appear rather to be gonidia in various stages of development, that have come to rest on the surface layer, or in some cases, seem to have grown in position where they were formed. The cell walls are decidedly gelatinous, which is conducive to holding the colonies together. 2. Xenococcus Gilkeyae S. and G. Plate 5, fig. 11 Cells solitary or aggregated into small colonies, spherical when solitary, angular and more or less elongated in colonies, 4—7 /x, rarely 9/A diam. ; cell wall inconspicuous, hyaline ; protoplast light blue-green ; gonidangia of the same shape and size as the cells; gonidia 0.8-1/x diam., formed by successive divisions of the protoplast. Growing on the filaments of Elachistea sp. which is epiphj^tic on Fucus sp. Lower littoral belt. Sitka, Alaska. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918a, p. 462, pi. 39, fig. 11. Having vegetative cell divisions in but two planes perpendicular to the substratum, Xenococcus Gilkeyae is a typical member of the genus. It is an exceedingly delicate species but the type material 1919] Seichell-Gardner : Myxophyceae 33 being in excellent vegetative and reproductive conditions is clearly definable. The gonidia appear to be the results of two lines of devel- opment of the vegetative cells. Some gonidia seem not to divide vegetatively after coming to rest, but continue to increase in size until maturitj'- is reached, then by a few successive internal divisions the whole protoplast is progressively converted into gonidia. In some cases the first division takes place horizontally cutting off a small por- tion of the base of the protoplast, which in some instances seems to remain sterile, at least the whole upper part is converted into gonidia before the basal portion is (pi. 5, fig. 11a). In other cases the first division is through the center of the cell. Other gonidia develop for a time after coming to rest, then divide vegetatively several times, generating small colonies before advancing to the gonidial stage (pi. 5, fig. 116). 3. Xenococcus Cladophorae (Tildcn) S. and G. Plate 4, fig. 8 Plants forming a more or less continuous layer one cell deep, or occasional!}^ associated in small groups ; cells variously shaped, angu- lar, prismatic, spheroidal or pyriform, 8-15/x, occasionally 22ju, diam. ; cell walls prominent, hyaline, homogeneous, often diffluent ; protoplast pale blue-green, homogeneous ; gonidangia the same shape and size as the vegetative cells; gonidia formed by successive divisions of the protoplast, 1.5-2/A diam. Growing on Cladophora sp. in a tide pool, Baird Point, Strait of Juan de Fuca, British Columbia. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918a, p. 461, pi. 38, fig. 8. Pringsheimia scutata f. Cl-adophorae Tilden, Amer. Alg. (Exsicc), no. 382, type. Chlorogloea tuberculosa Setchell and Gardner, Alg. N.W. Amer., 1903, p. 182 (in part) ; Tilden, Minn. Alg., vol. 1, 1910, p. 46 (in part). So far as we are able to discover on the available specimens of Cladophora distributed by Miss Josephine Tilden under no. 382 of her American Algae, there are no epiphj^tes present belonging to the Chlorophyceae. On the contrary, there is a mixture of species belong- ing to the Myxophyceae. One of these, a very small-celled form, very sparse in the dis- tribution at our disposal, as suggested by us (1903, p. 182), seems to be closely related to Chlorogloea tuberculosa (Hansg.) Wille. The 34 University of California Piillic-ations in Botany [Vol. 8 material is too sparse and scattered to admit of a very positive deter- mination as to what species it really may be. There are also groups of well defined vegetative cells of a species of Fleitrocapsa. Judging from its present vegetative stage it seems to be undescribed. There are, however, no gonidangia that we have been able to discover, and as the material is very scanty we forbear naming it at present. Howe (191-i, p. 12) states that he is unable to find in Miss Tilden's distri- bution, mentioned above, any member of the Chlorophyceae that he could interpret as being her Pringsheimia scutata forma Cladopiiorae, under which name no. 382 was distributed, but suggested that possibly the species referred to was that of a Derniocarpa, thus indicating tliat genus as being present in the material he examined. By far tlie most abundant species present in our material is no one of these bvit is the plant described above. Some specimens of the host are much contorted by its presence. This species seems most likely to be the one upon which was based Pringsheimia scutata forma Cladophorae, and is the plant, in part at least, later described and figured as Chlorogloea tuberculosa by Miss Tilden (Minn. Alg., 1910, p. 46, pi. 2, fig. 42). 4. Xenococcus pyriformis S. and G. Plate 5, fig. 121 Colonies small, single or occasionally confluent, young cells some- what angular, pyriform to subspherical at maturity, 10-15|U, diam., 12-20/t long; protoplast bright blue-green; cell wall conspicuous, dense, hyaline ; gonidangia the same shape and size as the cells ; gonidia 2.8-3. 5/x diam., formed by successive divisions of the protoplast. Growing on Rhodochorton Rothii on rock ledge along high-tide level and above. Cape Arago, at the entrance to Coos Bay, Oregon. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918a, p. 463, pi. 39, fig. 12. This species having cell divisions in only two planes perpendicular to the substratum, thus forming colonies only one cell deep, is to be placed under Xenococcus rather than under Pleurocapsa, and, while its pyriform cells suggest species of Derniocarpa, it differs from mem- bers of that genus in having vegetative cell division. In size and shape of cells it differs from any other species of Xenococcus, as yet described. 1919] Setchell-Gardncr : Myxophyceae 35 5. Xenococcus Chaetomorphae S. and G. Plate 2, ligs. 2-i Vegetative cells extremely variable in shape and size, some spherical, some very angular and of nearly equal dimensions, and some long and narrow, tapering to sharp points at both ends as seen from above, up to 25/A in vertical diameter, tlic narrower cells up to 45/a long; gonidangia the same shape as the vegetative cells ; gonidia formed by successive divisions of the whole protoplast; color bright blue-green. Growing on Chaetomorplia acrea in a pool near high-tide limit. Cypress Point, IMonterey County, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 436, pi. 36, figs. 2^. This species was found associated with Dermocarpa pacifica, and it is somewhat difficult to distinguish the two species. Both species produce gonidia in great abundance, and plants of both species may be found in all stages of growth at the same time. They are very abundant, intermingled, and as seen from above are very angular on account of lateral pressure resulting from growth. There appears certainly to be vegetative growth in the Xenococcus, as the continuous areas covered by it, comprising many hundreds of cells, seem far too great to have arisen from a single group of gonidia; also should tjie gonidia escape singly they could never by chance become so uniformly and closely associated as they often are to be found. The cells of Xenococcus in all stages of growth are extremely angular and very variable in shape and size ; sometimes being much crowded at the cross walls of the host plant, the tendency is to elongate vertically. Frequently groups of cells seem to have started to grow on the cell walls of young cells of the host between the cross-walls, and as the host coll elongates the cells of the epiphyte seem to elongate abnor- mally ill the direction of the long diameter of the host (pi. 2, fig. 2). There are no particular shapes and sizes of gonidangia, since any of the long narrow cells, small angular cells, or large spherical cells may be transformed into gonidangia. The gonidia are formed by suc- cessive divisions of the whole of the protopla.st (pi. 2, fig. 4). On the whole, it seems almost certain that we have here two plants of different genera closely and intimately associated, and it certainly is not possible to distinguish the individuals of the two in all stages of their development. 36 University of California Piihlicatians in Botany [you 8 10. Pleurocapsa Thur. Cells splierical or angular, and many sided by pressure, united into more or less gelatinous colonies of various shapes and sizes arising by cell divisions in three planes; protoplast blue-green, olive green, yellowish or violet ; reproduction by vegetative cell divisions and by gouidia formation. Thuret, in Hauck, ]\Ieeresalg. Deutschl., 1885, p. 515. The genus Pleurocapsa while named by Thuret was published by Hauck {loc. cit.). The type specimen of the species Pleurocapsa fuliginosa Hauck, the type of the genus, was collected at Trieste as is evidenced by the label of the specimen in Herb. Hauck at present in the possession of Dr. Anna Weber-van Bosse, through whose kind- ness it has been possible to examine a fragment. The species properly to be referred to Pleurocapsa are to be distinguished from those of XenoGOCCUs by forming a less definite layer and by division in three directions, while from those of Gloeocapsa, they differ chiefly by form- ing gonidia. The genus Pleurocapsa, as given by Forti (1907, pp. 120-123), is credited with ten species, of which one occurs on limestone walls, four are marine, while five are of fresh water. The fresh water species referred to Pleurocapsa, especially those described by Hans- girg in his Physiologische und algoloische Mittheilungen (1890), are not readily to be reconciled with the description and distinctions as indicated above. They need further study. From the figures it seems that their affinities tuqj possibly be rather with Radaisia, or possibly even with Chaniaesiphon. Certainly no such filamentous arrangement of the cells is to be found in Pleurocapsa fuliginosa Hauck or the other marine species now referred to the genus. Key to the Species. 1. Teguments (enclosing jelly) hyaline 2 1. Teguments (enclosing jelly) yellowish brown 3. P. entophysaloides (p 38) 2. Cell wall hyaline 1. P. fuli^nosa (p 36) 2. Cell wall brownish 2. P. gloeocapsoides (p 37) 1. Pleurocapsa fuliginosa Hauck Colonies forming a thin, dark crust on wood and rocks, each colony being 50-100/a diam., cells 5-20/a diam., with colorless mem- brane and homogeneous, golden, reddish brown or sordid violet con- tents. Growing on piles. Seattle, Washington. 1919] Setchell-Gardner : Myxophyceae 87 Hauek, Meeresalg. Deutschl., 1885, p. 515, fig. 231 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 181. The type of Pleurocapsa fuligitiosa Hauck was collected at Trieste and has been examined by us as mentioned above. Further remarks on this type will be found under P. entophysaloidcs S. and G. The result of our study has been to retain the Seattle plant under this name, for the present at least, since it resembles the type material veiy closely. We did not, however, find any of the larger colonies described and figured by Hauck and the cells, with thick teguments, measure up to 30/Li in diameter, which is half again greater than the maximum measurements given by Hauck. For reasons given later we feel uncertain as to the exact form and development of the gonidangia and gonidia in this species. 2. Pleurocapsa gloeocapsoides S. and G. Plate 5, figs. 15, 16 Colonies associated into soft, glistening, gelatinous masses, 1-2 mm. thick; cell divisions regularly in three planes; cells globose when single, angular from mutual pressure in colonies; protoplast 4-8/i, diam., homogeneous, pale blue-green ; cell wall conspicuous, brownish ; colonies of 2-8 cells enclosed in an ample, homogeneous, hyaline, soft, gelatinous tegument; gonidia 2-4 formed in unchanged vegetative cells, 2.5-3.5/* diam. Growing on a water-soaked log, at the margin of a salt marsh. Alameda, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918a, p. 465, pi. 39, figs. 15-17. Gloeocapsa crepidinum Collins, Ilolden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1151 (not of Thuret). The material of the above mentioned distribution was collected in 1913 in the same locality in which the type material of /'. gloeooap- soides was collected in October, 1917. The gonidia, if present in the original collection, were overlooked, and the close resemblance of the species in the vegetative stage to Thuret 's Gloeocapsa crepidinum, so well and amply figured in Bornet and Thuret (Notes Algol. I, 1876, pi. 1), led the authors of the above mentioned exsiccatae to place it in that species. Now that well formed, typical gonidia are found in great abundance it has seemed best to remove it from the Chroococ- caceae and place it in tlic Chamaesiphonaceae, if we are to adhere to tlie well recognized distinction between these two families. The 38 Universitij of California Publications in Botany [Vol.8 formation of gonidia is not nnifjue in this species. It is similar to that reported a.s taking place in Plenrocapsa entoph ysaloides, and in other undoscribed species which we have observed. In all of these species the contents of all of the cells of a colony seem to divide simultaneously. Any and all of the vegetative cells may produce gonidia without change in size. This is also true of all species of Demiocarpa, Gomphosphaeria, etc. The cell being small the number of gonidia from a cell is small, viz., two to fovir, and it has not been determined positively whether the two divisions necessary- to form four gonidia take place successively or simultaneousl3\ In most of the species in other genera which we have studied the divisions take place successively, and this method may possibly be the one followed by all species. Wille (1906, p. 21) has described and figured what appears to be the same method of gonidial formation in the European Glococapsa crcpidinnm Thur., which he finds near the biological station at Droutheim. He does not look upon this stage in the life history as being the gonidial stage comparable to that of the Chamae- siphonaceae, but speaks of it as the " Aphanocapsa-^iaidmm.'" He concludes that these small cells float away, finally lodge in tide pools, and become the so-called marine species of Aphariocapsa, e.g., A. nvarina Hansg. The facts as we find them here seem hardlj^ sufficient to warrant such conclusions concerning our species. There are certain difficulties in the way of a satisfactory placing of this form that have led to a disposition of it as a species of Plenro- capsa. Were it not for the presence of gonidia, it might be placed fairly satisfactorily under Gloeocapsa crepidinum Thuret. The dis- covery of similar gonidia in what Wille refers to Gloeocapsa crepi^ dinum in Norway, strengthens this position. There are, however, pos- sibilities that Wille 's plant may not be the same as that of Thuret and that ours may be different from both. It may be that all Gloeocapsa species may be found ultimately to form gonidia, but it does not seem very probable. In view of the various uncertainties, it seemed best for the time, at least, to refer the California plant to Pleurocapsa. 3. Pleurocapsa entophysaloides S. and G. Plate 4, figs. 9, 10; plate 7, fig. 30 Plants forming a dark colored, pulverulent, somewhat mucilaginous stratum, 1-4 mm. thick; single cells spherical, 8-1 0/x diam., in colonies very angular, 4— 8/t diam., forming spherical or variously lobed, fre- 1919] Setchell-Gardncr : Myxophyceae 39 quently entophysaloid colonies, 40-60/1, up to 200/i, diiim., by cell divisions witliont rupturing the origiiuil tegument ; teguments firm, slightly mucilagenous on the surface, j'ellowish brown, 2ix thick ; proto- plast homogeneous, light blue-green ; gonidia formed in unchanged vegetative cells of either the small or the large colonies, 3-3. 5ja diam. Growing on rocks in th(^ upper littoral belt. Carmel Bay, ]\Ion- terey County, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918a, p. 463, pi. 41, fig. 30. Plrurocapsa fuUginosa Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 704 (not of Hauck), Pleurocapsa entopJujsaloidcs is closely related to P. fulUjinuaa Ilauck (1885, p. 515, fig. 231) but differs from it in having slightly larger colonies which are often entophysaloid (pi. 7, fig. 30), in hav- ing a blue-green protoplast, a yellowish brown tegument, in having slightl}^ larger vegetative cells and in having gonidia develop in the small vegetative cells. In this last statement concerning the size of the cells, we are assuming that Hauck intended to include the large spherical cells which he figures, and which would ordinarily be con- sidered gonidangia, in his measurement "Zellen 5-20|U, dick." We have examined a bit of the type material of his P. fuUginosa and find that the vegetative cells of our species are slightly larger than the cells which we consider to be the vegetative cells of the type. Hauck does not mention gonidangia but he figures, in addition to groups of two, four, to many cells, four large spherical cells, one of which is filled witli undoubted gonidia. The presence of these two forms and sizes of cells brings up the question as to whether or not we are dealing with a single species or with two species, and if the latter, the two species probably belong to different genera. We have been puzzled with several similar mixtures collected on our coast. We are of the opinion that we have to reckon with two species in tliese eases and in the case of P. fuUginosa. Now that we have discovered gonidia in these colonies of small vegetative cells in at least two species of Pleurocapsa, viz., P. cntophysaloidcs and P. gloeocapsoides, the evidence in favor of considering that such mixtures as mentioned above belong to two species is stronger. Either we may take this view of the matter or we may note that we have two lines of development in a single species. One starts with a single cell, e.g., a gonidium, and, after enlarging to mature size, divides in three planes succes- sively, more or less at right angles to each other, the process continuing until a smaller or larger colonj^ is built up, according to the species, 40 r diversity of California Pnhlic-ations in Botany [Vol.8 the cells all yeniaining witliin a common tegument; then at maturity each small coll of the colony divides into a few gonidia, the whole mass of teguments and cell walls dissolves, thus setting free the gonidia. The other line of development starts likewise witli a single cell. This continues to increase in size without division until maturity is reached when it is many times larger than the vegetative cells in the other method of development, after which the whole protoplast divides into gonidia, either by successive or by simultaneous divisions. , These questions need further observation and study before any decision of value can be made concerning them. 11. Hyella B. and F. Plants forming tangled masses of indefinite expansion, boring into shells of mollusks or into other algae ; primary or basal filaments mainly extending horizontally, one or more rows of cells enclosed within a sheath, often very much crumpled and contorted, with frequent true branching, composed of a series of cells practically independent of one another ; short secondary filaments composed principally of longer and narrower cells enclosed in a separate sheath arising from the basal filaments ; cell divisions in all directions ; reproduction is accomplished by the escape of vegetative cells from the sheaths, and by gonidia formed by the successive divisions of the contents of gonidangia devel- oped on short branches of the basal filaments or by the modification of cells of the basal filaments. Bornet and Flahault, Note sur deux nouveaux genres d'algues perforantes, 1888, p. 163 (p. 3, Repr.). The type species is Hyella oaespitosa B. and F., but the type speci- men is not definitely designated. The two localities explicitly indi- cated are those of Croisic in Brittany, on the Bay of Biscay and Cette in Languedoc, on the Gulf of Lyons. Since the locality mentioned especially as the source of the material is Croisic (Bornet and Flahault, Sur quelques plantes vivant, 1889, p. 3), we have assumed this as the type locality. The genus Hyella is dimorphous and presents an interesting and, to some extent, puzzling morphology. It is distinctly filamentous and in general appearance suggests the Stigonemataceae. At first a layer is formed at the surface of plant or shell, which appears chroococcoid but which seems really to be filamentous of the complex type of Stigo- nema. From the inner face of this layer branches are given off which 1919] Setchell-Gardncr : Myxophijceae 41 penetrate into the substratum and whicli are more simple in their structure. These in turn give off true branches. The structure tlius far is stigonemataceous. There are no hormogonia, however, but seem- ingl}^ coccogonia (cf. Bornet and Flahault, loc. cit., p. 22). There are also distinct gonidangia whose contents divide into gonidia, sucli as are found in the Chamacsiphonaceae. While the general appearance of Hyella caespitosa B. and F. differs very much from that of RaclouM Gomantmna Sauv., yet it is by no means a simple matter to place certain Californian plants recently described. Gardner (1918, p. 432) has stated these difficulties and has outlined his reasons for placing some under Hyella, as follows : "These forms with erect filaments, more or less branched and dis- torted, arising from basal filaments on the surface of the substratum, and growing into it, and having gonidangia at their bases near the surface of the host, have been assigned to Hyella." The genus Hyella is credited by Forti (1907, pp. 124-127) with five species, the type (//. caespitosa.) and three others being shell borers, while the fifth burrows ( ?) into certain red algae. Of the four species thus far detected on the Pacific Coast of North America, two are shell borers and two burrow into membranous red algae. Key to the Species. 1. Boring into shells 2 1. Partially endophytic on larger algae 3 2. Erect filaments usually less than lOft in diam 1. H. caespitosa (p 41) 2. Erect filaments 10-14/u. in diam 2. H. Littorinae (p 42) 3. Filaments branching dendroidally 4. H. socialis (p 44) 3. Filaments seldom branching 3. H. linearis (p 43) 1 . Hyella caespitosa B. and F. Colonies appearing at first as minute discolorations on shells, later becoming much expanded and confluent, frequently covering the entire outer part of the shell, causing it to be very rough ; erect fila- ments usually parallel, 5-6/t, even up to lO^u, diam., lOO-200/i long, lower cells shorter, and ujipcr (mes several times longer than the diameter and sometimes branching; sheaths hyaline; horizontal filaments much branched, composed of spherical or angular cells, often several rows in a sheath ; cell contents yellowish olive green or blue- green; gonidangia formed by the modification of cells towards the base of the filaments into large oval to pyriform gonidangia, gonidia numerous, spherical, about 2/a in diameter. 42 TJniversitij of Calif ornia Puhlications in Botany [Vol. 8 Boring into the shells of oysters and other molliisks. Central to soutliern California. Bornet and Flahanlt, Note sur deux nouveaux genres d'algues perforantes, 1888 (p. 2, Ropr.), Sur quelques plantes vivant, 1889, vol. 36, pi. 10, figs. 7-9, and pi. 11 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsiec.), no. LI. In placing this species among our Pacific Coast algae, we do so with some hesitation. The specimens of oyster shells distributed (Phyc. Bor.-Amer., Exsiec, no. LI) as well as others from the same locality at other dates, show definitely a Hyella and some even with young gonidangia, but no such typically well-fruited specimens as is desirable for certainty. Specimens possibly ^ the same have also occurred at San Pedro, California, but unfortunately^ without goni- dangia. This species is, therefore, listed in the hope that further information mav be obtained. 2. Hyella Littorinae S. and G. Plate 3, figs. 19, 20 Erect filaments numerous, straight, parallel, simple or sparsely branched, 75-85ju, long, 10-14/a diam. ; growth in length by division of apical cell; basal cells of filaments angular, 4-6/a diam., divisions in all planes ; terminal cells of erect filaments cylindrical, 20-30/u. long ; cell contents blue-green, homogeneous ; cell wall or sheath hyaline, homogeneous; 2.5-3.5/x thick; gonidangia unknown. Growing on Littorina planaxis Nutt. along high-tide level on rocks. Common along the coast of California, but probably grows wherever this species of Littorina occurs. The type material is from Carmel, Monterey County, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 441, pi. 37, figs. 19, 20 ; Collins, Holden and Setchell, Phyc. Bor.- Amer. (Exsiec), no. 2255. Reproduction by gonidia has not been observed in this species, but the vegetative characters are so similar to those of Hyella caespitosa, growing on the shells of oysters and other mollusks as to leave room for little doubt as to its close affinity with that species. Tlie prostrate filaments, characteristic of Hyella caespitosa, have not been observed. Gonidangia may not develop and reproduction may be wholly vege- tative in the same manner as vegetative reproduction is reported to occur in Hyella caespitosa. We base our opinion on the fact that we 1919] Setchell-Gardner : Myxophyceae 43 have examined shells at all seasons of the year and from different localities and have not found gonidia. Tlie basal cells divide in several planes into numerous small, angular cells approximating gonidia. The filaments resulting from these divisions resemble those figured by Bornet and Flahault (1889, pi. 11, fig. 2). The small, angular cells probably escape and develop into new plants. They can hardly be considered as having formed in gonidangia, because a few cells just above the basal cells divide likewise though progressively to a less degree, forming clavate filaments at maturity (pi. 3, fig. 19). 3. Hyella linearis S. and G. Plate 2, fig. 8 Thalli dark blue-green, penetrating into the host, 350— 450/^ long; cells of the inner ends of the filaments smallest, 4-6/x, diam., 3.5-4,5/u. long, gradually increasing in size to 12ju, in diam. toward the periphery of the host ; cell walls thin, hyaline ; cell divisions in one plane at first, building, up more or less tortuous, rarely branched filaments ; later cell divisions in three planes, often decidedly oblique, most abundant toward the periphery of the host, building up clavate filaments ; goni- dangia at the surface of the host, 14-20/* diam. ; gonidia numerous, Ifi diam. Growing on Prionitis sp. Sunset Beach, near the mouth of Coos Bay, Oregon. This is the type locality and only one plant of Prionitis has been found infested by this species of Myxophyceae. Setchell and Gardner, m Gardner, New Pac. Coast Alg. II, 1918, p. 442, pi. 36, fig. 8. This species seems closely related in form to Hyella socialis S. and G., but differs principally in the size of the cells, and in having the filaments nearly straight and rarely branched. The earl.y stages in the development have not been observed. There is probably a prostrate layer of cells developed first, characteristic of the genus Hyella, and the erect penetrating filaments arise from that. The discovery of Hyella socialis was made by observing the presence of small warts or excrescences growing on Prionitis. Hyella was found to be uniformly associated only with the warts. We presume that the presence of a foreign plant may have stimulated the cells of Prionitis thus produc- ing the abnormal growths at the points of infection. The rapid growth of the cells of Prionitis would have the esffect of disturbing the hori- zontal layer of Hyella and of dispersing its erect filaments. 44 University of California Puhlications in Botany [Vol. 8 4. Hyella socialis S. and G. Plate 2, fig. 5 Filaments penetrating into the host, 200-300/^ long, tortuous, branching dendroidally, at first cell divisions only in one plane, later dividing in all directions, producing groups of cells within the original sheath ; each group resulting from the divisions of a single cell in the filament, becoming practically independent, similar to groups of Gloeoc-apsa cells, the largest groups being nearest the surface of the host; cells very angular, irregular in shape and size, 4^6/^ diam., terminal penetrating cell 7-9/a long, decidedly conical ; cell walls hyaline, soft; cell contents bright blue-green; gonidangia unknown. Growing in the stipitate portion of Iridaea minor J. Ag. in the lower littoral belt. Carmel Bay, Monterey County, California, May, 1916. Setchell and Gardner, in Gardner, New Pac. Coast Alg. 11, 1918, p. 443, pi. 36, fig. 5. The basal filaments of the plants, if present at all, cannot be thor- oughly worked out with the material at hand. Further study will be required to elucidate this point. The early stages of the development of this species are unknown. No gonidangia were present and the host plant was nearing maturity. It is possible that no gonidia are developed, and that the dissolution of the sheath of the groups of vegetative cells free them at the time that the host is beginning to disintegrate and these vegetative cells locate on younger hosts. "We have placed this species in the genus Hyella on account of its close similarity in some of its vegetative characters and in its penetrating habit to those of H. oaespitosa B. and F. (1888), the orig- inal species of the genus. They represent cell divisions as taking place in all directions at the base of the erect filaments. In surface view the cells arising from divisions of the cells in the basal filaments appear in more or less isolated groups in their illustrations. The few cells near the base of the erect filaments are less divided, and the terminal cells of the erect filaments remain undivided. The erect filaments thus become somewhat isolated, and clavate in form. The filaments of H. soci^alis appear to be formed in the same manner although they are crooked and branched. In the absence of knowledge concerning the prostrate portion of the thallus, characteristic of the typical Hyella, and in the absence of gonidangia, this species must remain somewhat in doubt as to its generic positon. 1919] Setchell-Gardner : Myxophyceae 45 12. Radaisia Sauv. Plants formino; small, compact masses of cells on the surface of the host, consisting of a more or less parenchj-matous basal layer formed by repeated divisions in vertical planes of a single cell, and of simple or complex, erect, more or less branched filaments arising from the basal layer by horizontal divisions and usually very com- pact and more or less coalcscent; gonidangia arising by modification of terminal cells of the erect filaments. Sauvageau, Sur le Radaisk, 1895, p. 373 (p. 2, Repr.), pi. 7, fig. 1. The genus Radaisia vv^as founded hy Sauvageau {loc. cit.) to receive two species, R. Gmnontiana Sauv. and R. Cornuana Sauv., of which the first, both because of its position in the article and because it is described and figured with gonidangia, may be taken as the type. It is a marine species, epiphytic upon species of Fucks, and was found in the southwest of France, at Biarritz and at Guethary. The type shows a minute cushion, composed of vertical and slightly radiating filaments which are simple or occasionally fastigiately dicho- tomously branched, whose terminal cells are transformed into large, spherical, ovoid or pyriform gonidangia. Of the development, and manner of the cell divisions Sauvageau says nothing. The second species is an inhabitant of fresh water, growing on submerged stones in rapidly flowing springs, but was not provided with gonidangia. From the figures and description of the adult stages of Radaism Gomontiana and from the study of our R. Laminariae, which seems certainly to be referred to the same genus, it appears that the divisions of the cells take place variously and successively in one, two, and three directions. Apparently a cushion may and does arise, as a rule, from a single cell (gonidium). By divisions taking place in two directions, perpendicular to the substratum, a layer of cells is formed. The cells of this layer divide, after a time, in the third direction, i.e., parallel to the substratum, producing the filaments which form a cushion out of the layer. The filaments by occasional division in other directions than parallel to the substratum initiate branches and consequently the radiate structure of the cushion arises. The transformation of the terminal cells into large and conspicuous gonidangia completes the structure of the typical species. We have followed the distinction set forth by Gardner (1918, p. 432) in distinguishing Rad-aisia from Hyella. Rad-aisM, then, will include those forms with erect filaments, simple or complex, closely 46 University of California Puhlications in Botanii [Vol.8 compact, more or less parallel, not at all or but slightly branched, arising from basal filaments on the surface of the host and extending away from it, and with the gonidangia on the outer free ends. Key to the Species. 1. Gonidangia simple, each terminating a trichome 2 1. Gonidangia compound, i. e., in groups within a common sheath 4. R. epiphytica (p 49) 2. Gonidangia spherical to ovoid 3 2. Gonidangia hemispherical 3. R. clavata (p 48) 3. Gonidangia splicrical to ovoid, 8-9/* in diam 1. R. Laminariae (p 46) 3. Gonidangia spherical, 4-6/a in diam 2. R. subimmersa (p 47) 1. Radaisia Laminariae S. and G. Plate 3, figs. 14-16 Prostrate portion of the plant consisting of compact, radiating filaments, dichotomously or subdichotomously branched, forming a closely compact thallus circular in outline, up to 300/* diam. ; cells of prostrate filaments quadrate, 4-4. 5/a diam., giving rise by horizontal divisions to closely compact, erect filaments ; the whole thallus 30-40a thick ; gonidangia terminal on the erect filaments, spherical, or slightly oval, 8-9/u. diam. ; gonidia 0.8/* diam. formed by simultaneous division ; color bright blue-green. Growing on the terminal portion of the blades of Laminaria Sin- clairii. Fort Point, San Francisco, California. This locality, so far as we know, is the only one in which this species has been observed. It probably has a much wider distribution. The host plant extends from Vancouver Island, British Columbia, to the vicinity of Point Conception, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 444, pi. 37, figs. 14-16; Collins, Holden and Setchell, Phyc. Bor.- Amer. (Exsicc), no. 2254. Radaisia Laminariae we have taken to represent a typical form of the genus, having a single layer of cells for the base which gives rise to perpendicular, parallel, unbranched filaments extending away from the host, and each bearing a single terminal gonidangium. The whole cushion or colony is in reality a single plant resulting from the growth of a single gonidium. The plants of this species start from a single cell, and by a few divisions a small group of cells is formed ; around the margin the cells begin to arrange themselves radially in rows, and by divisions in two planes; radial and tangential, a circular disk, one layer of cells deep, is formed. The marginal cells enlarge tan- 1919 J Setchell-Gardner : Myxophyceae 47 gentially and are cut into two cells by a radial wall; the resulting: "filaments" are of ecpial growth i\s a rule, and the forking thus becomes dichotomous (pi. 3, fig. 16). Plants often become so closely associated as to form a continuous layer over the surface of the host. Even under this condition they have no effect upon the host, so far as death and disintegration of the cells are concerned, and hence they are strictly epiphytic. The erect filaments result from the horizontal division of the prostrate or basal cells. They form very dense, com- pact masses, their cell walls adhering firmly (pi. 3, fig. 15). The gonidaiigia are numerous, spherical or slightly oval, being transformed terminal cells of the erect filaments (pi. 3, fig. 14). 2. Eadaisia subimmersa S. and G. Plate 3, figs. 12, 13 Thalli small, inconspicuous, irregular in outline on the surface of the host, growing on the cuticle, or in small surface cavities ; prostrate or basal layer composed of angular cells -3-5/* diam., arranged irregu- larly, giving rise to erect filaments, parallel at first, later spreading somewhat at the free distal ends, 35-45ju, long; cell division on the free surface portion in one plane, within the host in three planes, building up oval masses ; cells in erect filaments 3-5/a long, 1.5-2.5/x wide, older cells frequently becoming pear-shaped ; cell contents homo- geneous, blue-green ; gonidangia terminal, spherical, 4-6/t diam., pro- ducing 6-8 gonidia by simultaneous division. Growing on Khodymenia sp. Carmel Bay, Monterey County, California. The host plant was collected by Gardner (no. 3350). It is a Rhodymenia and possibly R. Palmetta, at least it belongs to the Palmetta group. It w^as cast ashore and slightly faded, thus making the Radaism groups appear distinct, which led to their discoverj\ The host is not uncommon along the California coast, and the epiphyte is to be expected in other localities. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 446, pi. 37, figs. 12, 13. This species of Radaisia, like others, seems to be epiphytic at first until the ba.sal layer of cells is produced. Plants start from a single cell on the cuticle of the host, at least some of them have been so observed. By repeated divisions, sometimes perpendicular to the long diameter of the cell, but usually quite oblique, a single layer of cells of varying shapes and sizes is built up (pi. 3, fig. 13). The cell walls of this basal layer are transparent, seem to be gelatinous, so that the 48 University of California Puhiixxitions in Botany [Vol.8 cells soon become more or less freed and independent of each other. Horizontal divisions begin and short filaments, three to five cells long, are foraied above the surface of the host. Meanwhile it seems povssible that the prostrate layer has begun to dissolve the cuticle and the under- lying cortical cells, and division of the basal cells may have begun forming filaments which push into the host, completely dissolving the host cells as they penetrate (pi. 3, fig. 12). The plants upon which this species is founded are scarcely mature, the gonidangia being \ery rare. The depth to which they may pene- trate the host is thus far rather uncertain. It is not at all unlikely that they may penetrate to a greater depth than that reported in the diagnosis above. It certainly seems that the whole of the cells of the host is actually absorbed, or at least destroyed, as far as the parasite travels. Radaisia suhimmersa may be looked upon as being on the border line between Radaisia and Hyella so far as its relation to the host is concerned, being partially internal and partiall}^ external, and pos- sibly growing in both directions from the original basal layer. The filaments, however, being more or less parallel, and having the goni- dangia on the outer free ends, are characters which have led us to place it in the genus Radaisia. 3. Radaisia clavata S. and Q. Plate 3, figs. 17, 18 Plants forming microscopic, deep blue-green cushions on the surface of the host, up to 100/a diam., more or less fan-shaped in median sec- tion; filaments very closely compact, 70-100/a long, sparsely branched near the outer ends ; cell walls 4-5/a diam. at the base, 7-8/x above, 3-4/i, long, cell divisions often irregularly^ oblique, cell walls thin, hj^aline; protoplast homogeneous; gonidangia 8-9/x diam., terminal, hemispherical ; gonidia angular, 1-1. 5/x diam., formed by simultaneous division. Growing on Gymnog&tigrus linearis, in the lower littoral belt. Lands End, San Francisco, California. This is the only known locality in which this plant grows. The host plant is common along the Cali- fornia coast and extends as far north as the Straits of Juan de Fuca. It is not at all unlikely that it may be found on the same host in other localities. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 445, pi. 37, figs. 17, 18. 1919] Setchcll-Garclner : Myxophyceae 49 Radaisia clavata departs slightly from K. Laminnriac in having the filaments occasionally branched, and the cross cell divisions often decidedly irregnlarh' oblique. 4. Radaisia epiphytica S. and G. riate 3, figs. 10, 11 Thalli forming cushions on the surface of the host, nearly circular in outline as seen from above, 250-350/i, across, 50-60/x thick ; prostrate or basal layer formed by dichotomous or subdichotomous branching around the margin ; erect filaments loosely adherent, composed of groups of angular cells, 3-5^ diam., produced by cell divisions in three planes ; protoplast homogeneous, blue-green ; terminal and subterminal cells of the vertical groups transformed into gonidangia with slight increase in size; gonidia angular, 1.8-2.4/x diam., foi'ined by simul- taneous division of the protoplast. Growing on Iridaea minor J. Ag. in the lower littoral belt. Carmel, Monterey County, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. II, 1918, p. 447, pi. 37, figs. 10, 11. Only a single antheridial i)lant of Iridaea has been observed with tliis epiphyte growing upon it, but doubtless it is common and prob- ably- grows on other forms of the same species. Iridaea minor is usually rather dark colored, which makes the presence of the Radaisiu somewhat obscure, and probably accounts for its not having been observed previously'. The gonidangia of R. epiphytica depart somewhat from the typical form of the genus. Since the erect filaments are complex in each sheath, resulting from vertical as well as horizontal divisions, often irregular and oblique, the gonidangia are also complex, consisting of a group of transformed terminal cells instead of a single terminal cell as is usually the case. The original cell wall or sheath persists as the erect filaments elongate and become complex. Likewise when the terminal cells metamorphose into gonidangia the original sheath of a group of cells persists, and a compound gonidangium is the result. 13. Gomphosphaeria Kuetz. Cells associated into definite, small, irregularly more or less .spherical, solid, floating masses ; cells usually obovoid, tapering within, rounded or, at the l)eginning nf division, obcordate without, supported 50 rniversity of California Puhlicatiom in Botany [Vol. 8 oil radiatinjr. die-hotomous, gelatinous stalks; ])i-utuplast blue-green, yellowish or reddish, homogeneous; gonidia numerous, arising in the otherwise unaltered cells (gonidangia) through successive divisions. Kuetzing, Alg. Decade XVI, 1836, no. 151. The type of the genus Gamphosphaeria is G. aponiim Kuetzing collected at Abano near Padua, in waters of 36° R. (45°C). The structure of the colonies lias not been generally understood, but has been clearly described and illustrated by Schmidle (1901, pp. 16-20, pi. 1, figs. 1-5). We have been able to confirm the account of tliis structure and the development of the colony. The structure and development seem to relate this genus rather to Xenococciis and other Chamaesiphonaceae than to ain- of the Chroococoaceae and the dis- covery of gonidia (cf. Schmidle, loc. cit., and Zukal, 1894, p. 259, pi. 19, figs. 9, 10), which we, however, have not as yet observed, gives additional reason for placing it in the Chamaesiphonaceae as we have done. There are, at present, three species referred to Gomphosphaeria, of which the type, G. aponina Kuetzing, is regarded as being the most common and widely distributed. Gomphosphaeria aponina Kuetz. Plate 1, figs. 2, 3 Cells associated into microscopical blue-green colonies up to 90ix diam., tegument hyaline, moderately thick, slightly lamellate, cells clavate or pear-shaped to obcordate, radially arranged in the colonies, 10 fi long, 4-5/x diam., pedicellate with radiating, short, thick stalks, dividing in two directions; gonidia numerous, globular, about 2/^ in diameter, successively formed. Floating among other algae in a pool in a salt marsh. Whidbey Island, "Washington. Kuetzing, Alg. Decade, XVI, 1836, no. 151, Tab. Phyc, vol. I, 1846-1849, p. 22, pi. 31, fig. 3 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 180. Gomphosphaeria aponina is found in warmer and cooler fresh waters as well as in brackish water of pools in salt marshes and may be rather widely distributed along our coast although we are able to cite definitely only one locality. The specimens agree perfectly with those distributed by Kuetzing in his Decades (no. 151), as cited, and also with the type material in Kuetzing 's herbarium. 1919 J Setchell-Gardner : Myxophyceae 51 Order 2. IIORMOGONALES atkixson Thallus pluricellular, filamentous, with or without a sheath, cylin- drical, or tapering to a hair, unbranched, or with false or true branch- ing; filaments single, or several within a common sheath, or united into a more or less gelatinous mass; all of the cells of the filaments similar, or with occasional specialized cells called heterocysts; multi- plication by the filament breaking into segments a few cells long, called hormogonia, through the death of certain cells, and by the formation of resting spores. Atkinson, A college text book of botany, ed. 2, 1905, p. 163. Hoi'mogoneae Thuret, Essai Class. Nost., 1875, p. 377. As previously stated under Coccogonales, Thuret was the first to divide the Myxophyceae into two groups and it seems best to consider these as orders. The Ilormogonales differ from the Coccogonales in being uniformly filamentous, either with or without branches, and reproducing vegetatively by short pieces of two, to three, to many cells instead of separating single cells for this purpose. The hormo- gonia are formed by the definite splitting off of these small lengths of the filaments, usually in a series, the hormogonia being separated from one another by the death of intermediate cells. Spore formation, when present, is by means of cells changing their shape and size to a greater or less extent and forming a thick, smooth, or at times variously roughened, outside coat. Gonidia formation is described for certain of the Hormogonales, but needs further observation and study before being accepted as equivalent to that of the Chamaesiphonaceae. After careful consideration of the various views, it has seemed best, for reasons given below, to divide the Hormogonales into two sub- orders, Homocystineae and Heterocystineae. Key to Suborders and Families. 1. Cells alike, neither differentiated into hair cells nor heterocysts (Suborder 1. Homocystineae) Family 3. Oscillatoriaceae (p 53) 1. Cells of two sorts, vegetative and either hair cells or heterocysts, or Ixith (Suborder 2. Heterocystineae) 2 2. Trichomes alike at both ends, branching wanting Family 4. Nostocaceae (p 89) 2. Trichomes unlike at opposite ends 3 3. Branching false, hairs usually present, abundant Family .5. Rivulariaceae (p 93) 3. Branching true, hairs (in our genera) present, occasional or al)uii(l,iiit Family G. Stigonemataceae (p 109) 52 University of California rtihJications in Botany [Vol.8 Suborder 1. IIOMOCYSTINEAE nobis Filaments either floating free or in layers, usually not attached to the substratum at either end; trichomes of cells very little different from one another, not provided with heterocysts or tapering into a hair, simple or branched, with or without a sheath enclosing one or more trichomes; propagation by hormogonia; spores unknown; goni- dia ?. Ilomocysteae Bornet and Flahault, Tab. syn. d. Nost. fil. liet., 1885, p. 197, Rev. I, 1886, p. 325 ; Gomont, Monogr. des Oscill., 1892, p. 289 (1893, p. 27, Repr.). It has seeemd best to continue the practice, introduced by the French phycologists, of separating the Hormogonales into two sub- orders, the Homocystineae and the Heterocystineae. The presence or absence of heterocysts is so nearly an exact dividing character and the exceptional cases so few and so readily dealt with, that it seems unnecessary, as well as decidedly undesirable, to change the desig- nations. Gomont (1899, pp. 30-33) has discussed the question, and further details will be given in the discussion of the Heterocystineae. The Homocystineae, as here defined, include all the Hormogonales having neither heterocysts nor terminal hairs. It fonns a compact, well defined, seemingly natural group. FAMILY 3. OSCILLATORIACEAE harvey Trichomes pluricellular, straight, arcuate, more or less uncinate at the apices, or spirally twisted, simple, or rarelj^ with false branch- ing, cylindrical, or slightly tapering at the apices, all of the cells similar in shape and in function, with or without a sheath, single or plural within a sheath; multiplication by means of motile (?) hormo- gonia. Harvey, Ner. Bor.-Amer. Ill, 1858, p. 96 (in part) ; Kirchner, Schizophyceae, in Engler and Prantl, Natiirl. Pflanzenfam. I, lo, 1898, p. 61. Oscillarideae Graj^ Nat. Arr. Br. PI., vol. 1, 1821, p. 80. It seems best to recognize a single family under the Homocystineae and this was done in 1898 by Kirchner {loc. cit.) who is quoted above, therefore, as final authoritj^, although the name in its present form was used as early as 1858 by Harvey {loc. cit.), but in much more extended sense. In the sense of Kirchner, Oscillatoriaceae include both the Vaginarieae and the Lyngbyeae of Gomont (1893, p. 28. 1919] Setchcil-Gard )i( r : Myxophyceae 53 Repr.). The family of tlio Oscillatoriaceae may be subdivided into several subfamilies, such a.s the Schizotricheae, Lj^ngbyeae, Oscilla- torieae, and Spirulineae. Key to the Genera. 1. TricIiDinos (lo8titiito of a sheath 2 1. Trichoines provided with a sheath 4 2. Trichomes twisted into a distinct spiral (Subfamily 1. Spirulineae).,.. 3 (p 53) 2. Trichomes straight or, at times, in a loose and irregular spiral (Subfamily 2. Oscillarieae) 16. Oscillatoria fp .58) 3. Dissepiments distinct, spiral, loose 14. Arthrospira (p 53) 3. Dissepiments indistinct, spiral, loose or tight 15. Spirulina (p 55) 4. Trichomes solitary within the sheath (Subfamily 3. Lyngbyeae).... 5 (p 67) 4. Trichomes two to many within a common sheath (Sul)family 4. Schizotricheae) 9 (p 83) 5. Trichomes simple 6 5. Trichomes branched 8 6. Sheaths distinct, not diffluent. 7 6. Sheaths diffluent into an enclosing jelly 17. Phormidium (p 68) 7. Forming caespitose expansions 18. Lyngbya (p 72) ■ 7. Forming fasciculatcly tufted layers '. 20. Symploca (p 80) 8. Filaments free 19 Plectonema (p 78) 8. Filaments ascending and fasciculate, forming tufted layers 20. Symploca (p 80) 9. Trichomes few in a sheath 21. Hydrocoleum (p 84) 9. Trichomes several to many in a sheath 22. Microcoleus (p 85) SUBFAMILY 1. SPIEULINEAE FORTI Filaments without a sheath, more or less regularly or irregularly coiled in a laxer or closer spiral. Forti, in De-Toni, Syll. Alg., vol. 5, 1907, p. 145. Spirulinmdeac Gomont, Monogr. des Oscill., 1892, p. 248 (1893, p. 116, Repr.) (lim. mut.). We have followed Forti {loc. cit.) })oth as to the form of the name of this subfamil}' and as to including Arthrospira as well as Spirulina although Gomont {loc. cit.) includes only Spirulina. From our point of view, both these genera closely approach species of Oscillatoria as will be shown in detail below. 14. Arthrospira Stizenb. Trichomes multicellular, cylindrical, evaginate, loosely and regu- larly coiled, usually of relatively large diameter and large spirals, and comparatively short and with few coils; dissepiments distinct, apices slightly or not at all tapering, terminal cell rounded, calyptra absent. 54 University of California ruhlications in Botany [Vol.8 Stizeubergor, Spiruli}ui und Arthospira, in Hedwigia, vol. 1, 1852, p. 32. Tlie type species is Arthrospira Jenncri (Hass.) Stizenb., a fresh water plant from Tunbridge. Arthrospira is intermediate between Oscilhtoriu and Spirnlina. Some species of Oscillatoria, sucli as 0. Bonnemai-so'iiii Crouan are loosely, but regularly, spiral. The coarser species of Arthrospira approach these. On the other hand, the looser and laxer species of Arthrospira, e.g., Arthrospira niiniata (Hauck) Gomont which is slender and with the dissepiments obscure, approach Spirulin-a. In certain slender but straight species of Oscillatoria, e.g., 0. amphihiu Ag., the dissepiments are as obscure as in species of Spirulina until they are revealed by treatment with strong solutions of chromic acid (cf. Gomont, 1893, pi. 7, figs. 4, 5). In the same fashion, treatment with chromic acid reveals the dissepiments in species of Spirulina (cf. also Gardner, 1917, p. 377). Key to the Species. 1. Cells 7-9/A in diam., 5-7/a long 1. A. maxima (p 54) 1. Cells 14.5-16/A in diam., 2.5-3.5/a long 2. A. breviarticulata (p 5.5) 1. Arthrospira maxima S. and G. Plate 8, fig. 3 Trichomes 7-9/^, diam., forming an open regular spiral of 3-8 turns, 40-60|U diam., 70-80/a between the turns, slightly tapering at the ends ; cells 5-7fjL long, not constricted, with numerous, coarae, angular, refringent granules frequently crowded at the partitions; end walls of terminal cells rounded, slightly thickened; color verdigris green. Found floating among other species of Myxophyceae in a warm salt-water pond. Known only from a single locality, viz., in a hot, salt-water pond. Key Route pool, in Oakland, California, on the shore of San Francisco Bay. Setchell and Gardner, in Gardner, New Pac. Coast Alg. I, 1917, p. 377, pi. 33, fig. 3 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 2259. The salt water of this pond was pumped from the bay and used for condensing the steam of a power house, the same water being used repeated!}^, thus it became alternately heated and cooled. This treatment subjected the floating algae to the unusual condition of extremes of heat and cold under which it thrived abundantly. 1919] Setchell-Gardner : Myxophyceae 55 2. Arthrospira breviarticulata S. and G. Plate 7, fig. 26; plate 5, fig. 18 Trichomes very loosely twisted into a more or less regular spiral, and much knotted and contorted, 14.5-16fi diam., comparatively short, slightly torulose, not tapering at the apices; cells 2.5-3. 5)it long; proto- plast pale steel-blue, with few scattered, somewhat angular granules; cell walls thin, distinct, terminal cell very convex, outer wall not thickened. Growing on rock.s and among CUidopJiora trichotom-a in tide pools along high-tide level. Lands End, San Francisco, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918a, p. 466, pi. 39, fig. 18, and pi. 41, fig. 26; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 2258. Arthrospira hreviarticulata is distinguished from all other species of the genus by its much greater length, and greater diameter, by its being loosely coiled, and by its relatively much shorter cells. It approx- imates the spirally coiled species of Oscillatoria, yet seems to be refer- able rather to Arthrospira. 15. Spirulina Turp., emend. Gard. Trichomes multicellular, cylindrical, evaginate, loosely or tightly coiled into a more or less regular spiral ; apex of trichome usually not tapering ; dissepiments obscured ; terminal cell rounded, without calyptra ; protoplast homogeneous or granular, Turpin, in Diet, des sciences nat. de Levrault, vol. 50, 1827, p. 309 ; Gardner, New Pac. Coast Alg. I, 1917, p. 379. It has been shown (Gardner, 1917, pp. 377-379) that there is no fundamental difference between the genera Spirulina and Arthrospira, both having multicellular, spirally twisted filaments. We have retained the two genera as a matter of convenience, since the species are few in each genus and well known, and since they fall rather naturally into two groups as regards size. We have retained Spirulina to include the small, more or less tightly coiled forms with inconspicu- ous cross walls, usually described as "unicellular," and Arthrospira to include the large, comparatively short, loosely coiled forms with more or less conspicuous cross walls. 56 University of California Publications in Botany [Vol. 8 The genus Spirulina was fouudod by Turpin in 1827 {loc. cit.) with the type species named Spirulina oscillarioidcs, a name placed among tlie "Species inquirendae" by Gomont (1893, p. 275, Repr.). Judging from his figures {loc. cit. Planches, 2«. partie, regne organise, "oscillariees," figs. 3, 3a., 36, 3c) Turpin 's plant was a mixture of fresli water species of Spirulina, although some of his figures resemble species of Spirogyra, but without cross walls. This appearance is doubtless due to the idea of Turpin that the spiral trichome is enclosed in a tube or thread of mucilage. Gomont (1893, p. 269, Repr.) has adopted the name Spirulina of Turpin (1827) instead of the earlier Spirogyra of Link (1809, p. 20) which seems to have been founded on a species of Spirulina Turpin. giving his reasons in full. Since Gomont 's Monographie des Oscil- lariees has been made the starting point for the nomenclature of "Nostocaceae homocysteae" by the Brussels Congress (cf. Actes de Illme. Congres Intern, de Botanique, Bruxelles, 1910, vol. 1, p. 103), and since also the Spirogyra of Link 1820 has been placed by action of the same body {loc. cit., p. 109) among the "nomina conservanda" as against the " Conjugaia" of Vaucher 1803, it seems necessary as well as desirable to follow Gomont. Key to the Species. 1. Spiral regular, loosely coiled 1. S. major (p 56) 1. Spiral regular, tightly coiled 2. S. subsalsa (p 57) L Spirulina major Kuetz. Plate 1, fig. 5 Plants in mass bright blue-green, trichomes pale blue-green, more or less flexuous, 1.2-1. 7/x diam., twisted into a fairly loose, regular spiral, 2.5-4/A diam., with a distance of 2.7-5/x between the turns. Growing in brackish water. Puget Sound, Washington, to central California. Kuetzing, Phyc. Gen., 1843, p. 183 ; Gomont, Monogr. des Oscill., 1892, p. 271, pi. 7, fig. 29 (1893, p. 271, Repr.) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 182. The species of Spirulina are to be distinguished from one another by four different criteria : (1) by the varying diameter of the trichome ; (2) by the horizontal amplitude of the spiral; (3) by the distance of the turns of the spiral from one another, i.e., by the looseness or tight- 1919] Setchell-Gardncr : Myxophyceae 57 ness of the spiral ; and (4) by the regularity or irregularity of the spiral. Usuallx' tlif Iriclionu-s show decided uniformity within the species, but occasionally certain trichomes are found showing varia- tion of a profound and jierplexing character. Spirulina major, for example, is usiiallx- to be distinguished from Sp. Mcneghiiimna Zanard., which approaches it closely in dimensions, by its regular spiral, which is, however, lax in both species. From Sp. suhsalsa CErst., Sp. viajor is to be distinguished by its lax spiral, which is tight in Sp. suhsalsa. A specimen from the warm salt waters of the Key Route pool in Oakland (Gardner, no. 3237) shows tightly coiled and regular loosely coiled turns in the same trichome, seemingly being partly Sp. major and partly Sp. suhsalsa. Such specimens throw doubt on the usual criteria of species. 2. Spirulina subsalsa f. oceanica (Crouan) Gomont Trichomes forming a thin blue-green or yellowish green stratum on mud, or floating among other algae, 1/x diam., twisted into a nearly straight, regular, tightly coiled spiral. Growing in pools of brackish water. AVhidbey Island, Washing- ton, and San Francisco Bay, California. Gomont, Monogr. des Oscill., 1892, p. 254, pi. 7, fig. 32 (1893, p. 274, Repr.) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 182; Collins, Holden, and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 954. Oscillaria oceanica Crouan, Algues marines du Finistere, no. 324 (in part). The smaller form of the species is the onl}^ one" which has occurred to us in our territory, but seems typical and is probably widespread in shallow pools of brackish water. SUBFAMILY 2. OSCILLATOEIEAE forti Trichomes always simple, straight or at times in a loose more or less regular but not especially distinct spiral, destitute of a distinct sheath. Forti, in De-Toni, Syll. Alg., vol. 5, 1907, p. 147. "We have followed Forti in the name and limits of this subfamily. It is decidedly more restricted than the subtribe Oscillarioideae of Gomont (1892, p. 95, 1893; p. 115, Repr.). 58 University of Calif urniu Puhlioations in Botany [Vol. 8 16. Oscillatoria Gomont Trichomes free, often forming into dense tangled masses, cylin- drical, without a sheath, or at times with a delicate, more or less mucous sheath, smooth or constricted at the partitions, not moniliform, straight or arcuate, not spirally twisted; apices straight or uncinate, more or less tapering, terminal cell of some species with thickened membrane. Gomont. Faut il dire Oscillatoria on Oscillaria, 1891, p. 273. Oscillatoria Vaucher, Hist, des Conferv., 1803, p. 165 (lim. mut.). Gomont (1891, p. 273) has apparently discussed the generic name and its relation to Oscillaria so thoroughly as to demand no especial consideration here. As used at present and generally accepted its limits are considerably changed from those proposed by Vaucher. The type of the genus seems clearly to be Oscillatoria princeps Vaucher {loc. cit., p. 190) arid the type locality (of this species) is Crevin, near Geneva, Switzerland. Of the other eleven species assigned by Vaucher to this genus Gomont (1893, pp. 256-266, Repr.) lists nine as doubtful, and two, one each, to be referred to the genera Beggiatoa and Microcoleus respectively. Oscillatoria is a genus containing somewhat over one hundred recognized species, the great majority of which are inhabitants of fresh water or growing in moist situations. The species usually listed in a marine flora are largely, at least, to be found in brackish water and consequently in the pools or other bodies of water in salt marshes. In such situations the water is warmed by the air and by the sun and is of decidedly higher temperature than that of the adjacent ocean or larger body of strictly salt water. The species of Oscillatoria are to be distinguished from those of Phormidiiim and of Lynghya by being destitute of a sheath and, in general, this method of distinguishing them is both certain and satis- factory. Certain species seemingly of Oscillatoria, however, show (or develop?) a sheath under certain circumstances (especially 0. sancta and 0. limosa) while the trichomes of Lynghya, and even more so those of Phormidimn, escaping from the sheatli, take on for a time exactly the appearance of being trichomes of Oscillatoria. The naked trichomes of certain species of Phonniditmi as well as those of Micro- coleus, not only imitate the appearance of trichomes of Oscillatoria but also possess the power of movement characteristic of certain species of Oscillatoria. 1919] Setchell-Gardner : Myxophyceae 59 Key to the Species. 1. Trichomes not attenuate at the apex 2 1. Trichomes phunly attenuate at the apex (Attenuatae) 7 2. Trichomes thick to very thick, cells very short (Principes) 1. O. limosa (p o9) 2. Trichomes moderately thick to thick, cells short (Margaritiferae) 3 2. Trichomes slender (not over 11/a) cells at least V:t as long as broad to equally long (Aequales) G 3. Trichomes twisted into a regular spiral 2. O. Bonnemaisonii (p 60) 3. Trichomes long, arcuate, at times straight 4 4. Trichomes 17-29/a in diam 3. O. margaritifera (p 61) 4. Trichomes 6-11/a in diam 5 5. On mud and rocks; trichomes straight 4. O. nigro-viridis (p 62) 5. Epiphytic; trichomes flexuous 5. O. Corallinae fp 02) 6. Trichomes not torulosc, 2-3/a in diam., dissepiments obscure 6. O. amphibia (p 63) 6. Trichomes decidedly torulose, 2.3-4/a in diam., dissepiments pellucid 7. O. geminata (p 63) 7. Trichomes more or less abruptly attenuate 8 7. Trichomes long and gradually attenuate 11. O. Okeni (p 66) 8. Slightly or not at all constricted at the dissepiments 9 8. Not at all constricted at the dissepiments 10. O. brevis (p 65) 9. Trichomes very slender, 3-5/a in diam 10 9. Trichomes coarser (8-13/i in diam.) 12. O. chalybea (p 67) 10. Cells subquadrate, apical cells obtuse or subacute... 8. O. laetevirens (p 64) 10. Cells mostly longer than broad, rarely subquadrat(\ apical cell quasi mucronate 9. O. acuminata (p 65) Section 1. Princij)es Gomont Trichomes straight, curved or spiral at or toward the upper end, slightly, if at all, attenuated, apices obtuse ; cells very short. Gomont, Monogr. des OscilL, 1892, p. 201 (1893, p. 221 Repr.) 1. Oscillatoria limosa Ag. ]. Oscillatoria limosa Ag. Trichomes aeruginous or mon; or less olive green, in a blackish- aeruginous layer, on drying often a steel-blue black, straight, on drying rigid and fragile, not at all torulose, 11-20/i., commonly IS-lQfi thick, apices straight, slightly if at all attenuate, not capitate; cells 3-6 times shorter than the diameter, 2-5ju, long; dissepiments frequently granulate ; apical cell convex above showing a sliglitly thickened membrane. Chiefly in fresli water, but occasionally found floating in pools or ditches in salt marshes where the water is slightly brackish. Whid- bey Island, AVashington. 60 riiirirsity of Calif ornm Puhlicatians in Botany [Vol. 8 Agardli, Disp. Alg. Suec, 1812, p. 35 ; Gomont, Monogr. des Oscill., 1892, p. 210, pi. 6, fig. 13 (1893, p. 230, Repr.) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 183. This species has only a slight claim to being considered marine, at least so far as our territory- is concerned. It has occurred to us in the locality noted above, but it may possibly be met with among 0. nigro- viridis, Lynghya scmiplena, species of Microcoleus, etc., as it was in the Whidbey Island localitj'. It may l)e that young and naked trichomes of Lynghya acstuarii ma^' be mistaken for this species. Oscillatoria ornata (Kuetz.) Gomont has been credited to the marine flora of our coast on the strength of a specimen distributed in the Phycotheca Boreali-Americana (no. 1604). There has been some confusion of specimens under this number, the locality being undoubt- edly correct, but the statement on the label reads : "Among CladopKora sp.," referring to another specimen collected at the same general locality. Neither specimen, however, shows, upon careful reexam- ination any filaments of 0. ornata, and we seriously doubt the existence of 0. ornata at the locality mentioned. Our specimens under no. 1604 Phj'cotheca Boreali-Americana show two hormogonial species, viz., Hydrocoleum lynghyaceuni Kuetz. and Microcoleus confluens S. and G. Section 2. Margaritiferae Gomont Trichomes constantly torulose, apex obtuse, scarcely attenuated, very long arcuate, rarely either straight or totally spiral; maritime species, diameter moderate to thick. Gomont, Monogr. des Oscill., 1892, p. 202 (1893, p. 222, Repr.). 2. 0. Bonnemaisonii Crouan 3. 0. niargaritifera (Kuetz.) Gomont 4. 0. nigro-viridis Thwaites 5. 0. Corallinae (Kuetz.) Gomont 2. Oscillatoria Bonnemaisonii Crouan Trichomes usually intermixed with various other aquatic Myxo- phyceae, somewhat regularly or loosely twisted, very flexible, slightlj^ torulose, 18-36/ia diam., dilute olive green; apices not at all or only slightly tapering, with end wall of terminal cell convex and not thickened; cells 3-6/a long; protoplasm with fine granules uniformly distributed. 1919J Setchcll-GarchKr: Myxophyceae 61 Growing on mud in salt marshes and floating in pools of salt water. Puget Sound, Washington, to central California. Crouan, in Desmazieres, PI. cr.Ypt. de France, 2 ser., no. 537, 1858 (fide Gomont) ; Gomont, Monogr. des Oscill., 1892, p. 215, pi. 6, figs. 17, 18 (1893, p. 235, Repr.) ; Setchell and Gardner, Alg. N.W. Auier., 1903, p. 183 (small form) ; Collins, Ilolden, and Setchell, Phyc. Bor.- Amer. (Exsicc), no. 1707. According to Gomont {loc. cit.) this species has a considerable variation in diameter, viz., from 18/i to 36/a, although not so great as that given for 0. princeps, which is IQjx to QO/x (Gomont, 1892, p. 207). In general, no single collection shows any such variation in the diameter of the filaments and it seems possible that there may be necessity- for more careful study of these seemingly polymorphous species. What seems to be good 0. Bonnemaisonii has occurred at Whidbey Island, Washington (cf. Setchell and Gardner, 1903, p. 183) and about San Francisco Bay, California (cf. Ph^'c. Bor.-Amer., nos. 1707a., h, and d). 3. Oscillatoria margaritifera (Kuetz.) Gomont Trichomes bright olive green, forming dark agglomerated masses, or intermixed with other algae, very flexible, torulose, 17-29)U, diam., straight, arcuate at the ends and slightly attenuate, obtuse; length of cells 3-6/a; apical cell capitate, furnished with a slightly convex calyptra ; protoplasm with numerous large granules distributed along the crass walls. Growing on mud and in pools in salt marshes. San Francisco Bay, California. Gomont, Monogr. des Oscill., 1892, p. 161, pi. 6, fig. 19 (1893, p. 236, Repr.) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1708. Oscillaria margaritifera Kuetzing, Tab. Phyc, vol. 1, 1846, p. 31, pi. 43, fig. 10. What seems to be this species has been encountered several times in tlie salt marshes about San Francisco Bay, California. The calyp- trate tip is well shown in our specimens. Under no. 1604 in Phycotheca Boreali-Americana this species is said to occur in the specimen distributed. We fail to find it in the specimens in our copies, there having been some confusion and mis- takes of identification as already indicated above under 0. ornnta. 62 I'liinrsity of California Fuhlications in Botany [Vol.8 ■4. Oscillatoria nigro-viridis Thwaites Plants forming extensive dark olive green layers; trichomes olive green, of moderate length, nearly straight, fragile, torulose, T-ll/x diani., sliglitly curved at the extremities; apex slightly tapering; end cell wall very convex, sliglitly thickened; cells 3-5/* long, witli two rows of granules at the cross walls. Growing in pools in salt marsh, Whidbey Island, Washington, and on the shores of San Francisco Bay, California. Thwaites, in Harvey, Phyc. Brit., Synopsis, vol. 3, 1849, p. xxxix, no. 375, pi. 251, fig. A ; Gomont, Monogr. des Oscill., 1892, p. 217, pi. 6, fig. 20 (1893, p. 237, Kepr.) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 183. This is another more or less puzzling species of the "Margariti- ferae" section, but certain specimens both from Puget Sound and from the San Francisco Bay region seem referable to it. There is some departure from the descriptions in some specimens. In filaments whose cells are actively dividing, the length of the cells may be as short as one-sixth as long as broad, but are mostly one-third the diameter. The filaments are mostly short arcuate in the California specimens, and while some filaments show distinctly the transverse rows of granules at the dissepiments, others seem nearlj^, if not quite, to lack them. 5. Oscillatoria Corallinae (Kuetz.) Gomont Trichomes aggregated into a thin, dark, olive green stratum or intermixed with other small algae, aeruginous, densely intertwined, flexuous, torulose, 6-10/a diam., apices long and moderately arcuate, very slightly attenuate ; cells 2-3 times shorter than the diameter, protoplast sometimes with sparsely scattered granules, not crowded at the cross walls; apical cell subcapitate, with slightly thickened convex terminal wall. Forming a thin stratum on rocks and on or among other small algae. Lands End, San Francisco, California, Gardner, no. 1634; Moss Beach, San Mateo County, California, Gardner, no. 2978 ; Pacific Grove, Monterey County, California, Setchell, no. 5490&. Gomont, Essai Class Nost., 1890, p. 356 (in part), Monogr. des Oscill, 1892, p. 218, pi. 6, fig. 21 ( 1893, p. 238, Kepr.). Leibleinia Corallinae Kuetz., Sp. Alg., 1849a, p. 276. 1919] Setchell-Gardner : Myxophyceue 63 Oscillaforia Corallinae resembles the other members of the same section of OsciUatorm, but it is smaHer tliaii any except the last, from which it differs by not liaving granular dissepiments. Its general appearance is tiiat of a very small 0. Bonnemaisoiiii, but it is much smaller than even the most slender forms referred to that species. It is usuall}', if not always, epiphj-tic. Section 3. Aequales Gomont Trichomes not attenuate above, straight or arcuate ; cells at least one-third as long as broad up to equally long; slender species of not over llfx. in diameter ; largely fresh water. Gomont, Monogr. des OscilL, 1892, p. 202 (1893, p. 222, Repr.). 6. 0. amphihia Ag. 7. 0. geminata Menegh. 6. Oscillatoria amphibia Ag. Trichomes forming a thin layer at the bottom of quiet water or floating on the surface, color pale copper acetate, straight or some- what contorted in age, fragile, not constricted at the partitions, 2-3/i, diam. ; terminal cells not attenuate nor capitate, with outer cell wall rounded ; cells 2-3 times as long as the diameter, up to 8/x long ; proto- plast homogeneous except with usually 2 granules at the dissepiments wliieh are obscure. Growing in pools in salt marshes, usually in company with other species of Oscillatoria. Puget Sound, Washington and San Francisco Bay, California. Agardh, Aufziihlung, in Flora, vol. 10, 1827, p. 632; Gomont, Monogr. des OscilL, 1892, p. 221, pi. 7, figs. 4, 5 (1893, p. 241, Repr.). Judging from the figures of Gomont {loc. citJ), Oscillatoria, am- phihi-a does not show dissepiments until the protoplasts are dissolved out with strong acids. What seems to be this species, although in some cases var3ang slightly from it, has occurred to us in salt marshes. The species usuallj^ occurs in few or isolated filaments intermixed with other homocysted forms. 7. Oscillatoria geminata ]\Ienegh. Trichomes pale aeruginous color, matted together into a tliin, sordid, j'ellowish green stratum, occasionally circinate, slightly fragile, constricted ratlier deeply at the dissepiments, 2..3-4/X diam., 2.3-1 6/x 64 University of California Puhlications in Botany [Vol.8 long; protoplaist with a few large, scattered, refriiigent granules; dissepiments conspicuous, non-granular, apical cell convex, calyptra none. Growing among other species of OscHlatorin in a salt water pond, B street, Oakland, California. Meneghini, Consp. Algol. Eugan., 1837, p. 9 ; Gomont, Monogr. des Oseill., 1892, p. 222 (1893, p. 242, Repr.). The type specimens of 0. geniinata were from the thermal waters of the Euganean springs, and what seems to be the same species or, at least, very close to it, occurs also in thermal waters in the Yellow- stone National Park. The brackish water specimens referred here have the cells short, yet within the proportions given. Otherwise they seem typical. They were mixed with Oscillatoria hrevis var. neapoli- tana (Kuetz.) Gomont. Section 4. Attenuatae Gomont Trichomes decidedly attenuate above, more or less acutely uncinate or flexuous, not definitely spiral (0. chalyhea at times excepted) ; cells longer or shorter than the diameter, never very short; plants commonly slender, not over 13/i, thick, inhabitants of fresh and thermal, more rarely of saline waters. Gomont, Monogr. des Oscillar., 1892, p. 203 (1893, p. 223, Repr.). 8. 0. laeteviretis (Crouan) Gomont 9. 0. acuminata Gomont 10. 0. hrevis Kuetz. 11. 0. Okeni (Ag.) Gomont 12. 0. chalyhea (Mert.) Gomont 8. Oscillatoria laetevirens (Crouan) Gomont Trichomes associated into a delicate membrane of deep blue-green color, the single filaments being of a yellow-green color, straight, deli- cate, slightly constricted at the dissepiments, 3-5ju. diam. ; apices straight or uncinate, with the terminal cells obtuse or subacute ; cells 2.b-bjx long; protoplasm with fine, evenly dLstributed granules. Growing in salt marsh pools. San Francisco Bay, California. Gomont, Monogr. des Oseill., 1892, p. 226, pi. 7, fig. 11 (1893, p. 246, Repr.). Oscillatoria laetevirens Crouan, Liste des algues marines Finistere, 1860, p. 371 (nomen nudum), Fl. du Finist., 1867, p. 112 (descr.). 1919] Setchell-Gardner : Myxophyceae 65 This species approaches 0. hrevis Kuetz. but is somewhat smaller, with proportionally longer cells and a different arrangement of gran- ules. It never has the occasional swollen cells so fairly characteristic of 0. hrevis. It is present in seemingly typical form in salt marsh pools about San Francisco Bay. The plant from Whidbey Island, referred here with some doubt (cf. Setchell and Gardner, 1903, p. 184), on further examination seems to be referable rather to 0. hrevis var. neapolitaiia. D. Oscillatoria acuminata Gomont Plate 1, fig. 11 Trichomes entwined in a dense thin layer of a verdigris color, delicate, straight, slightly constricted at the partitions, 3-6//, diam. ; a few apical cells attenuated to a sharp point, not uncinate ; length of cells 5-8/A ; protoplast finely granular, with the granules frequently crowded at the dissepiments. Floating in warm salt water. Oakland, California. Gomont, Monogr. des Oscill., 1892, p. 227, pi. 7, fig. 12 (1893, p. 247, Repr.) ; Collins, Holden and Setchell, Phj'c. Bor.-Amer. (Exsicc), no. 1303. The type specimen of Oscillatoria acuminata was collected at the Euganean springs, but has since been reported from other waters in several widely separated localities. Our specimens from warm or almost hot pools of brackish waters agree too nearly with the descrip- tion and figures of Gomont to allow of separation. The plants dis- tributed under no. 1303 of the Phycotheca Boreali-Americana, which are from the vicinity of hot salt waters, have shorter cells than the type. 10. Oscillatoria brevis Kuetz. Filaments fonning dense olive green layers or intermixed with other species of algae, of blue-green color, comparatively short and straight, rather fragile, 4-6. S/x diam., not constricted at the dissepi- ments, briefly and subacutely attenuate, uncinate or slightly twisted; cells very short, 1.5-3/i, long, with an occasional refringent torulose cell interspersed; protoplasm with small granules evenly dispersed throughout the cell. Growing among other algae in salt mai*sh pools. San Francisco Bay, California. 66 University of Calif orniu Puhlicatians in Botany [Vol.8 Kuetziii«r. Pliyc. Gen., 1843, p. 186 ; Gomont, Monogr. des OscilL, 1892, p. 215, pi. 6, figs. 17, 18 (1893, p. 235, Repr.) ; Collins, Holdeu and Setchdl, Pliyc. Bor.-Amer. (Exsicc), no. 1158. This species seems to be represented with us, in brackish water, by the typical form, although more frequently by the var. neapolitann (Kuetz.) Gomont. Gomont {loc. cit.) describes 0. hrevis as having "dissepimenta non granulata, " but his figures show them granulate. 10a. Oscillatoria brevis var. neapolitana (Kuetz.) Gomont Trichomes larger than the type, 5-6.5/* diam. ; with uncinate or twisted apices. Growing in salt marshes. San Francisco Bay, California. Gomont, Monogr. des Oscill., 1892, p. 229, pi. 7, figs. 14, 15 (1893, p. 249, Repr.) ; Collins, Holden and Setchell, Phj^c. Bor.-Amer. (Exsicc), no. 1304. OsciUaria neapolitana Kuetzing, Phyc. Gen., 1843, p. 185. 0. laetevirens Setchell and Gardner, Alg. N.W. Amer., 1903, p. 184 (not of Gomont). This variety is the more common form of 0. hrevis with us and is found in characteristic form. 11. Oscillatoria Okeni (Ag.) Gomont Trichomes forming a dark blue-green mass, straight, manifestly constricted at the joints, 5.5-9/* diam. ; apices long and gradually tapering, uncinate-arcuate with blunt apical cells ; length of cells 2.7- 4.5/t; end cell up to 8/x, neither capitate nor calyptrate; protoplasm filled with fine granules. Growing in hot salt water. Oakland, California. Gomont, Monogr. des Oscill, 1892, p. 232,. pi. 7, fig. 18 (1893, p. 252, Repr.) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 184; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1605. OsciUaria Okeni Agardli, Aufzahlung, in Flora, vol. 10, 1827, p. 633. The type specimen of Oscillatoria Okeni came from thermal waters at Carlsbad. The specimen from the hot salt waters of the Key Route pool seems typical. A reexamination of the specimens from Whidbey Island referred to this species (Setchell and Gardner, 1903, p. 184), shows them to be 0. chalyhea (Mert.) Gomont. 1919] Setchell-Gardner : Myxophyceae 67 12. Oscillatoria chalybea (Mert.) Gomont Trichomes pale steel-blue, dark blue-green in mass, fragile, usually straight, but at times slightly spirally twisted ; moderately constricted at the joints, 8-13/x diam. ; briefly, or long and gradually attenuate, one to a few apical cells uncinate ; cells quadrate to 2-3 times shorter than the diameter, protoplast finely granular, with few, scattered, angular, ref ringent granules ; dissepiments non-granular ; apical cells obtuse, non-capitate, non-calyptrate. In ponds of brackish water. Wliidbey Island, Washington and West Berkeley, California. Gomont, Monogr. des Oscill., 1892, p. 232 (1893, p. 252, Repr.). OscillarM chalybea Mertens, in Jiirgens, Algae aquaticae, Decas XIII, no. 4, 1822 (determined by Gomont). 0. Okeni Setchell and Gardner, Alg. N.W. Amer., 1903, p. 184 (not of Agardh). This species is widely distributed, occurring in fresh waters, thermal waters, and brackish waters. It is found in salt marshes both in the Puget Sound region and in the region of San Francisco Bay. The form found in both these regions is the typical form (var. genuina Gomont). The tip, while characteristic, varies in its more sudden or more gradual attenuation, and the cells are frequently equally long and thick. Certain filaments seem straight at the tip and bear some likeness to 0. simpUcissima Gomont. SUBFAMILY 3. LYNGBYEAE kuetz. Trichomes simple or branched, each enclosed within a more or less firm or diffluent gelatinous sheath. Kuetzing, Phyc. Gen., 1843, p. 179 (char, emend.) ; Forti, in De- Toni, Syll. Alg., vol. 5, 1907, p. 217 (lim. mut.). Lynghyoideae Gomont, Monogr. des Oscill., 1892, p. 95 (1893, p. 115, Repr.). We have quoted Forti under the subfamily Lyngbyeae because his idea of the limitations of the subfamily is nearest to, although not exactly, ours. We include the genus Plectonema in addition to those named by Forti. Our subfamily differs from the subtribe Lj^ng- byoideae Gomont by the inclusion of Phormidimn. 17. Phormidium 18. Lynghya 19. Plectonema 20. Symploca 68 University of Calif arnia Publications in Botany [Vol. 8 17. Phormidium Kuotz. Trichomes many celled, single witliin a sheath, simple, frequently attenuate and uncinate at the apices; sheatli distinct, hyaline, some- times mucous, more or less diffluent, in a few species obscure. Kuetzing, Phyc. Gen., 1843, p. 190. Kuetzing enumerated twenty-eight species under his genus Phor- midinm, not designating any particular one as the type. Certain species (about three) are not retained by Gomont, but most of them are and there can be no question as to the main ideas of Kuetzing which have been retained by Gomont. These are, first, the possession of sheaths less firm than those of Lynghya, and second, the diffluence and coalescing of these sheaths into a membrane or layer of jelly enclosing a large number of filaments. In some species admitted to the genus hy Gomont there is little if any trace of a sheath. These species are approximate to Oscillatoria. During the period, or stages, of hormogonial production, the hormogonia, or even whole trichomes, escape from the sheaths and enclosing jelly. In this stage they are exactly like the trichomes of Oscillatoria. The majority of the species of Phormidium are inhabitants of f resli water, but a few occur also in brackish water, while a very few are exclusively marine. Key to the Species. 1. Trichomes distinctly torulose (Moniliformia) 2 1. Trichomes rarely or scarcely torulose (Euphormidia) 3 2. Trichomes attenuate at the apices, terminal cell acutely conical 1. Ph. fragile (p 69) 2. Trichomes not attenuate at the apices, terminal cell swollen, subspherical 2. Ph. hormoides (p 69) 3. Apices of trichomes neither attenuate nor capitate 3. Ph. ambiguum (p 70) 3. Apices of trichomes both attenuate and capitate 4 4. Trichomes slightly and abruptly tapering at the apices, terminal cell rounded, calyptrate 4. Ph. lucidum (p 71) 4. Trichomes gradually tapering at the apices, terminal cell with depressed conical calyptra 5. Ph. submembranaceum (p 71) Section 1. Moniliformia Gomont Trichomes distinctly torulose, even moniliform in some cases, neither curved nor capitate at the apices. Gomont, Monogr. des Oscill., 1892, p. 159 (1893, p. 179, Kepr.). 1. Ph. fragile (Menegh.) Gomont 2. Ph. hormoides S. and G. 1919] Setchcll-Gardner : Myxophyceae 69 1. Phormidiiim fragile (Menegh.) Gomont Filaments forming a thin A'clluwish or dark blue-green stratum, at times lamellate ; trichomes more or less fiexuous, bright blue-green, moniliform, 1.2-2. 3/Lt diam. ; apices attenuate, acute conical, without calyptra ; protoplasm homogeneous. San Francisco Ba}-, California. Gomont, Monogr. des Oscill., 1892, p. 163, pi. 4, figs. 13-15 (1893, p. 183, Repr.) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1609. Anabaena fragilis Menegliini, Conspectus Algol. Eugan., 1837, p. 8. Tlie t^'pe locality for this species is the thermal water of the Euganean springs, but, as seemingly often happens, the species reappears in shallow brackish waters. The specimens referred here agree with the description of Gomont so far as aggregation and diameter and torulosity of the trichome are concerned, but the trichomes are not so attenuate as that represented on plate 4, figure 14, but fully as much so as that represented by figure 15. It agrees also with a specimen from Kiel collected by Reinbold and determined by Gomont. 2. Phormidium hormoides S. and G. Plate 6, fig. 23 Filaments forming a thin, expanded, gelatinous stratum ; tri- chomes short, somewhat fiexuous, moniliform, 2.4— 2.7/i, diam. ; sheaths hyaline, ample gelatinous, confluent ; cells quadrate or subquadrate, extremely constricted at the dissepiments, terminal cell larger, sub- spherical, end wall not thickened. Forming a thin layer on glass aquaria of salt water from the Pacific Ocean. Physiological Laboratory, University of California, Berkeley, California, 1905. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918rt, p. 467, pi. 40, fig. 23. Phormidium hormoides is very closelj^ related to Ph. foveolarum (Mont.) Gomont, which was found growing in small pits in calcareous rock on the coast of France, and from which it differs in habitat, in the size of the filament and in the shape of the terminal cell. The filaments as viewed under the microscope are not uniformly dis- tributed in the stratum but seem to have a tendency to aggregate into fascicles which anastomose freely, giving the stratum somewhat the 70 University of Calif ornia Piihlicatians in Botany [Vol.8 appearance of a very delicate net, although many short filaments crawl out into the interstices. In the specimen collected, Phormidium hormoides is mixed with another undetermined filamentous species of Myxophj^ceae, about 0.8/* diam., with cylindrical cells longer than the diameter and with con- spicuous cross walls. Ph. hormoides has some re&emblance to the young filaments of a very delicate species of Anahaena on account of the pronounced moni- liform trichomes, but there is no indication of heterocysts or spores. Section 2. Euphormidia Gomont Trichomes rarely or scarcely torulose, straight or curved at the apices, in many species capitate. Gomont, Monogr. des. Oscill., 1892, p. 159 (1893, p. 179, Repr.). 3. Ph. amhiguum Gomont 4. Ph. lucidum (Ag.) Kuetz. 5. Ph. suhmenibrmiaceum (Ard. and Straff. ) Gomont 3. Phormidium ambiguum Gomont Stratum more or less expanded, dark or yellowish green or at times aeruginous, filaments long and flexuous ; sheath either firm or mucous and diflSuent, somewhat thick and lamellate; trichomes aeruginous, slightly constricted at the dissepiments, 4-6/i, diam. ; cells one-fourth the diameter long, occasionally granular at the cross walls ; apices neither attenuate nor capitate ; terminal membrane slightl}" thickened. Growing on wood and on stones in the upper littoral belt. Bridge across an estuary to Bay Farm Island, Alameda, California, Septem- ber, 1903. Gomont, Monogr. des Oscill., 1892, p. 178, pi. 5, fig. 10 (1893, p. 198, Repr.). We are inclined to refer to Phormidium amhiguum a specimen collected in Alameda, California, which forms a distinct dark green layer, with sheaths fairly thick, firm and distinct, but only slightly, if at all, stratified. The cells are very short (only 1.5/a at times) and there are no granules on the dissepiments. The apical cell is rounded or even, at times, almost conical, with a very slightly thickened mem- brane. 1919J Sctchell-Gardner : Myxophyceae 71 4. Phormidium lucidum (Ag.) Kuetz. Plate 1, fig. 4 Trichomes bright blue-green, floating separately while in the free motile stage, later forming dense entangled flocculent masses of dull blue-green color, attached to soil along the margin of a pond or float- ing, slightly but definitely constricted at the joints, 7-8/a diam. ; sheaths quite mucous and more or less diffluent, apices straight, very sliglitly tapering; cells 2-2.5|U. long; end cell rounded, calyptrate and with thickened end walls; protoplast with two layers of fine granules at the cross walls. Growing in warm salt water. Oakland, California. Kuetzing, Phyc. Gen., 1843, p. 194; Gomont, Monogr. des Oscill., 1892, p. 179, pi. 5, figs. 11, 12 (1893, p. 199, Repr.). OscUlatoria liicida Agardh, Aufzahlung, in Flora, vol. 10, 1827, p. 633. The type of Phormidium lucidum is credited to Carlsbad and as having grown on walls exposed, at least intermittent!}^, to steam. The specimens referred to the species from our coast grew in warm salt water in the Key Route pool at Oakland, California, and are per- haps rather thermal than marine. The species also has been found in a salt marsh near the Key Route pool, in shallow ditches made warm by the sun. The description given above has been framed to fit our plant, but differs from that of Gomont only in the matter of color and thickness of the layer. In ours the color is bright blue and the layer thin. In both these respects no. 127 of Kuetzing 's Decades {Oscillaria lucens Kuetz.), which Gomont has cited as genuine Ph. lucidum, agrees fairly well with our plants. 5. Phormidium submembranaceum (Ard. and Straff.) Gomont? Stratum membranaceous, coriaceus, dark green, trichomes without sheath, embedded in an amorphous mucus, constricted at the joints, 5/i, diam. ; apices of trichomes straight, long and gradually tapering, capitate ; cells 4— 10/x long ; terminal cell provided with a depressed conical calyptra; protoplasm homogeneous. Upper littoral belt. San Francisco Bay, California. Gomont, Monogr. des Oscill., 1892, p. 180, pi. 5, fig. 13 (1893, p. 200, Repr.) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no, 1162. Oscillaria suhmcmhroinacea Ardissone and Straf- forello, Enumer. d. Alg. di Lig., 1877, p. 66. 72 University of California Piihlic-ations in Botany [Vol.8 This species is one of the truly marine species, the type locality being Porto Maurizio in Liguria on the northwestern coast of Italy. The plants from Alameda, on San Francisco Bay, formed a layer on the wall of the buttress of a bridge. In habit, diameter of trichomes, and proportion of cells our plant corresponds with Gomont's descrip- tion. The trichomes, however, are not so gradually attenuated, not quite so capitate, and not quite so constricted at the dissepiments as Gomont's figure indicates. In the absence of opportunity of con- sulting either the type or an authentic specimen, it seems best to refer our specimens provisionally to this species. 18. Lyngbya Ag. Filaments with a sheath, simple, either free or aggregated into dense, floccose, caespitose or pannose masses, attached or free-float- ing; sheath thin and homogeneous or thick and at times lamellate, either hyaline or of a sordid j'ellow or brown color ; trichome not con- stricted at the dissepiments, not tapering, or only slightly so at the apex, terminal cell wall often thickened. Agardh, Sj'st. Alg., 1824, p. xxv. The genus Lynghya is usually given as having been described by C. A. Agardh in 1824 (Syst. Alg., p. xxv, p. 73), but Pfeiffer (1874, p. 184) gives the date 1820, viz., the Aphorismi botanici (p. 98). The name Lynghya is given in the Aphorismi (D. VII, p. 98) as contain- ing thirteen species but without description or synonymy. Pfeiffer also refers with doubt to C. A. Agardh 's Species Algarum, I, giving the date as 1820 and not quoting a page number. The Species Algarum is dated 1820 to 1828, and in no part of it do we find reference to Lynghya. In 1824 C. A. Agardh referred seven species and three varieties to Lynghya. Of these Gomont identifies four as either wholly or in part Lynghya in the proper sense, four as "species inquirendae, " and the remaining two as wholly made up of other things. As now established, Lynghya contains about sixty species, largely marine. Key to the Species. 1. Filaments caespitose, fixed (epiphytic) at the center and free at both ends (Leibleinia) 2 1. Filaments not caespitose, free or with attached base (Eulyngbya) 4 2. Filaments spirally twisted about other filamentous algae 2. L. epiphytica (p 74) 2. Filaments not spirally twisted 3 3. Trichomes 5-8/a thick 1. L. gracilis (p 73) 1919] Setchell-Gardner : Myxophyceae 73 3. Trichomes 1 5-2/i. thick 3. L. Willei (p 74) 4. Sheaths finally j-ellow brown 4. L. aestuarii (p 75) 4. Sheaths always hyaline 5 5. Trichomes 9-25/u. thick, apices never attenuate-capitate 5. L. confervoides (p 77) 5. Trichomes 5-12/i. thick, apices often attenuate-capitate ...6. L. semiplena (p 78) Section 1. Leibleinia (Kuetz.) Gomont Filaments caespitose, fixed when submerged, attached by the cen- tral portion and intertwined, erect at both ends ; sheaths thin, hyaline, not evidently lamellate ; trichomes not attenuated at the apices ; marine species of the aspect of Calothrix. Gomont, Essai Class. Nost. Horn., 1890, p. 354; Kuetzing, Phyc. Gen., 1843, p. 221 (as genus, char. mut. et sp, excl.). The species referred to the subgenus Leibleinia are epiphytic, attached at the middle and free at both ends. They seem to be wholly marine. y /Ar i n t? t 1. L. gracilis (Menegh.) Kab. 2. L. cpiphytioa Hieron. 3. L. Willei S. and G. 1. Lyngbya gracilis (Menegh.) Rab. Tufts extended, dense, floecose, slippery, purple violet, often losing color on drying and becoming dirty yellow, up to 1.5 cm. high ; fila- ments elongated, flexible, angularly flexuous ; sheath thin, smooth, does not turn blue with chlor-zinc iodine; trichomes rose-red, torulose (in dried specimens), 5-8ju, thick, not attenuated at the apices; cells quad- rate or twice shorter than the diameter, 2.8-4.6/a long; protoplast finely granulate ; apical cell rounded, with the membrane slightly thickened above. On Chaetomorpha aerea in pool. Pacific Beach, southern California. Mrs. M. S. Snyder. Rabenhorst, F\. Eur. Alg. II, 1865, p. 145 ; Gomont, Monogr. des Oscill., 1892, p. 124 (1893, p. 144, Repr.) ; Collins, Ilolden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 853. Leihleinia gracilis Meneghini, Alg. Spec. Nov., 1844, p. 304 {fide Gomont). The only specimen known to us is that mentioned above, dis- tributed as no. 853, in the Phycotheca Boreali-Americana. It is cer- tainly of the subgenus Leibleinia and seems to be very close to L. gracilis so far as answering to the description is concerned. The determination is l)y Frank S. Collins. It is accompanied by other epiphytes. 74 University of California Puhlications in Botany [Vol.8 2. LjTigbya epiphytica Hieron. Filaments adhering firmly to the surface of other filamentous algae, often regularly, spirally twisted around them, commonly having the ends free ; triehomes aeruginous ; cells 1-1. 5/u, diam., 2/x long with non-granular protoplasts; sheath \Qvy thin, hj-aline; terminal cell not attenuate and neither capitate nor calj^ptrate. Growing on Lynghya confervo-ides Ag. in tide pools along high-tide level. Cannel Bay, Monterey Count}', California. Hieronymus, in Kirchner, in Engler and Prantl, Natiirl. Pflanzen- fam., 1898, p. 67 (nomen nudum) ; Lemmermann, Plankton, schwed. Gewasser., 1903, p. 103, pi. 1, fig. 10; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 2206. This is one of the most curious members of the genus, growing tightly coiled about other filamentous algae, first found by Hieronj^- mus at Berlin growing on Oedogonium and Tolypothrix, and later by Lemmermann who had it from a garden pond in Stromsberg in Sweden. It is also given as occurring in a lagoon on Chatham Island. It is curious to find it so far away from its type locality, but our plant seems to fit the description and figure most exactly. 3. Lyngbya Willei S. and G. Filaments epiphytic on larger algae, either attached at one end with the other end free or attached in the middle with both ends free, solitary or aggregated into small caespitose masses; sheath very deli- cate, hyaline, adhering closely; triehomes pale blue-green or grayish green, torulose, 1.5-2yu, diam. ; cells quadrate or one-half the diameter long ; apices not attenuate and neither capitate nor calyptrate ; ter- minal cell wall convex, not thickened ; protoplasm homogeneous. Growing on Rhizoclonium riparitim var. polyrhizum Rosenv. Near the mouth of Tomales Bay, Marin County, California. August, 1916. Setchell and Gardner, in Gardner, New Pae. Coast Alg. Ill, 1918a, p. 468. Lynghya epiphytica Wille, Algol Notizen XXII-XXIV, 1913, pp. 22-25, pi. 1, figs. 14-17 (not Hieronjonus). The type, Lynghya epiphytica Wille, was discovered on the coast of Norway at Trondhjem, growing on Rhizoclonium hieroglyphicum (Ag.) Kuetz. "What seems to be exactly the same plant has been detected on the coast of California growing on Rhizoclonium riparium var. polyrhizum Rosenv. The latter species was distributed under 1919] Setchcll-Gardner : Myxophyceae 75 no. 2238a. of tlie Phycotheca Boreali-Americana. The epiphyte is rather sparsely represented on our material of Rhizoclonmm. The identification was made after the distribution of the Rhizoclonium and hence is not certainly known to be represented in all of the speci- mens of the distribution. The specific name, cpipJujtica, having already been occupied by Hieronymus (1898, p. 67) to designate a small, unique species coiling around the filaments of larger Myxophyceae, it became necessary to rename the species of the Leihleinia type found later by Wille, and the species was consequently dedicated to him. Subgenus 2. Eulyngbya Gomont Filaments intertwined into a floccose or woolly expanded mass or tufted with attached base, or even floating free ; sheaths, as they become older, often thick and lamellate, at times j'ellowisli brown; trichomes sometimes attenuate at the apices; marine, fresh water or thermal species, found on rocks, but very rarely epiphytic. Gomont, Essai Class. Nost. Hom., 1890, p. 354. 4. L. aestuarii (Mert.) Liebm. 5. L. confcrvoides Ag. 6. L. semiplena (Ag.) J. Ag, 4. Lyngbya aestuarii (IMert.) Liebm. Filaments forming dense, dark olive green or blue-green strata on mud, or more or less floccose floating masses, elongated, very flexuous, densely interwoven, occasionally false-branched ; sheath at first hyaline, thin, smooth, increasing in thickness with age, becoming rough, lamel- late, or of yellowish or brownish color; trichomes blue-green or olive green, not constricted at the dissepiments; apices slightly attenuate, capitate, with slightly thickened end wall, rarely subacute, conical, 8-24/i diam., length of cells up to six times shorter than the diameter, 2.7-5.6/A long; protoplasm finely granular, usually with a laj-er of granules at the cross walls. Floating in lagoons and pools of salt and brackish water, probably along the entire coast from Puget Sound southward. Liebman, Bemark. tilliig danske Algenflora, 1841, p. 492. Co-n- ferva aestuarii Mertens, in Jiirgens, Algae aquaticae. Decas II, no. 8, 1816 {fide Gomont). 76 University of California P 1(1)1 icatiwis in Botany [Vol.8 I-'l/fW^yfi acstiMrii, as commonly understood, is a widespread and, to some extent, polymorphous species, yet generally readily recognized in a normal form. It occurs in shallow ditches and pools of brackish water all over tlie world except in the polar regions. It varies con- siderably as to the color and stratification of the sheath as well as in habit. Lynghya acstuaril is pr()i)erly a species of tlie tropical (or at least warmer) waters and is an excellent example of how such a species may invade zones of cooler waters, by finding in shallow pools and ditches waters warmed by the sun to the temperature favorable to their growth and reproduction. The following forms have been detected on our coast: Lyngbya aestuarii f. aeruginosa (Ag.) Wolle Plate 1, fig. 16 Plant mass pale blue-green; sheatlis moderately thin, hyaline. Floating in lagoons, salt water. Whidbey Island, Washington, and probably common in similar habitats along the Pacific Coast to the south. Wolle, in Wittrock and Nordstedt, Alg. Aq. Dulc, no. 282 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 187 ; Gomont, Monogr. des Oscill., 1892, p. 130 (1893, p. 150, Repr.) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 902. Lynghya aeruginosa Agardli, Syst. Alg., 1824, p. 74. Lyngbya aestuarii f. ferruginea Gomont Plants forming dense floating masses, of dark or ferruginous color ; sheaths thick, lamellate, deep yellowish brown color. Floating in pools, salt marsh, Wliidbey Island, Washington. Gomont, Monogr. des Oscill., 1892, p. 130 (1893, p. 150, Repr.) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 187. Lyngbya aestuarii f. limicola Gomont Plants inhabiting moist soil, occasionally inundated, forming rather thin compact strata; filaments closely interwoven and very tortuous. Growing on mud in salt marsh, Whidbey Island, Washington. Gomont, Monogr. des Oscill., 1892, p. 129 (1893, p. 149, Repr.) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 186; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 903. 1919] Setchell-Gardner : Myxophyceae 77 Lyngbya aestuarii f. natans Gomoiit Plate 1, fig!. 15 Plants at first forming- layers on the mud at the bottom of salt mai*sh pools, later floating ; filaments elongated, flexuons or nearly straight and loosely intertwined. Floating in pools, salt marsh, Whidbey Island, Washington. Gomont, Monogr. des Oscill., 1892, p. 129 (1893, p. 149, Repr.), Setchell and Gardner, Alg. N.W. Amer., 1908, p. 187 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc.), no. 904. Lyngbya aestuarii f. spectabilis (Thur.) Gomont Sheaths up to 14/a tliiek, hyaline on the exterior, changing to yel- lowish golden color on the interior. Growing in salt marsh, Whidbey Island, Washington. Gomont, Monogr. des Oscill., 1892, p. 130 (1893, p. 150, Repr.) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 187. Lynghjja spectabilis Thuret, in Holmes and Batters, Rev. List Brit. Mar. Alg., 1890, p. 68 {fide Gomont, loc. cit.). 5. Lyngbya confervoides Ag. Filaments attached, caespitose, at times twisted into small, rope- like fascicles, mucous, 1-5 era. high, dark olive green or yellowish brown with age ; sheath hj^aline, homogeneous or slightly lamellate, more or less roughened on the surface, 3.5-5/x thick; trichomes olive green or aeruginous, not constricted at the dissepiments, not attenuate, 9-25/x, usually 10-1 6/a diam., cells 2-8 times shorter than the diameter ; dissepiments generally granular; terminal cell wall convex, not thickened. Growing in shallow rock pools along high-tide level. Central California. Agardh, Sp. Alg., 1824, p. 73 ; Gomont, Monogr. des Oscill., 1892, p. 136 (1893, p. 156, Repr.); Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 2206, as the host of Lyngbya epipliytica Hieron. The type localitj^ for the species is Cadiz, Spain, but it is generally recognized as occurring in the warmer water all over the globe. Thus far it has been found only on the central coast of California, l)ut is probably of wider distribution. The specimen distributed under 78 University of Californi.a Publications in Botany [Vol.8 no. -2206 of the Phycotheca Boreali-Americana agrees with the descrip- tion, but is twisted above into a rope-like strand. It is also infested with Lynghya cpiphytica Hieron. 6. Lyng-bya semiplena (Ag.) J. Ag. Plant mass caespitose, mucous, about 3 cm. high, dull yellowish green, sometimes becoming dark violet on drying ; filaments ascending from a decumbent, entangled base, flexuous; sheaths hyaline, sub- mucous, lamellate with age, 3/a thick; trichomes blue-green or yellow- ish green, slightly attenuate at the apices, capitate, not constricted at the joints, 5-12/x diam. (commonly T-lO/x,), cells 2-3/i, long, with granules at the cross walls; apical cell provided with a depressed, conical cah^ptra. Growing on rocks and on mud in the littoral belt. Puget Sound, "Washington and San Diego County, California. J. Agardh, Alg. Mar. Medit. et Adriat., 1842, p. 11; Gomont, Monogr. des. Oscill., 1892, p. 138 (1893, p. 158, Repr.) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1905; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 187. Calothrix semipleoia Agardh, Aufzahlung, etc., in Flora, vol. 10, 1827, p. 634. The type locality is Trieste at the upper end of the Adriatic Sea, where it was found on rocks at the upper limits of the littoral belt. As now recognized it is of wide distribution. It bears a close resem- blance to Lynghya aestuarii especially to the narrower forms with hyaline sheaths. Our specimens agree well with descriptions and published specimens. 19. Plectonema Thuret Trichomes provided with sheaths, with false lateral branching in pairs or singly, caused by rapid growth in certain regions in the fila- ments rupturing the sheaths, frequently constricted at the joints; apices straight, rarely tapering, without calyptra ; sheaths hyaline, or rarely colored. Thuret, Essai Class. Nost., 1875, pp. 375, 379. Thuret names Plectonema mirahile (Dillw.) Thuret first, and this may be taken as the type of the genus. He also includes P. tenue Thuret as the second member of the genus. Thuret {loc. cit.) places Plectonenia between Symploca and Lynghya, on the one side, and Scytonema and Tolypothrix, on the other. Gomont (1890, p. 5) places 1919] Setchell-Gardncr : Mxjxophyccae 79 it in his subtribe Lj-ngbyeae, next to Lyncjhya. Ilansgirg (1892, p. 39) places it near Tolypothrix and Scytonema. In this he is fol- lowed by Kirchner (1898, pp. 77, 78) and Forti (1907, p. 488). West (1916, p. 43), however, follows Gomont. Since occasional false branching is known in Symploca and even rarely in Lynghya, and since some species of Plectancnm have few branches and none of them have heterocysts, it seems best to place this genus as has been done by Gomont and West. Key to the Species. 1. Layer blackish or brownish green, trichomes 2-3. 5/a thick 1. P. Battersii (p 79) 1. Layer rose colored or reddish brown, trichomes 1.2-2/a thick 2. P. Golenkinianum (p 80) 1. Plectonema Battersii Gomont Plate 1, fig. 1 Filaments forming a black or dark green stratum, elongated, flex- uous, abundantly and repeatedly false-branched ; branches usually in pairs and smaller than the primary filaments; sheath hyaline, thick- ened slightly in the primary filaments ; trichomes pale blue-green, torulose, 2-3. 5/a diam., with long and gradually tapering apices ; the older trichomes often very densely contorted within the sheath ; cells up to four times shorter than the diameter, with homogeneous con- tents; apical cell rounded. Growing on rocks near high-tide limit. Golden Gate, San Fran- cisco, California. Gomont, Sur quelq. Oscill. nouv., 1899, p. 36; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1712. The two members of the genus Plectonema credited to our coast were found in the same localit}' and it is difficult at times to separate them. Plectonema Battersii, as represented in no. 1712 of the Phyco- theca Boreali-Americana, has slightly thicker trichomes and is de- scribed as forming a black or brownish green layer. Unfortunately the color of our specimens is not, at present, discernible. The branch- ing in our specimens, while present, is not plentiful. But this species and the next twine about other filamentous Myxophyceae and then stream outward. The branching seems more common in younger speci- mens and toward the base of the cluster of entangled filaments. This is shown in specimens from the same locality but of another collection than that distributed. 80 University of California Puhlicatiwis in Botany r^^ou 8 2. Plectonema Golenkinianum Goniont Rose colored or reddish yellow, forming an expanded layer on rocks, or distribnted among other algae ; filaments intricate, elongated, flexuons, repeatedly false branched; false branching in pairs, very evident, smaller than the primary filaments, snbflagelliform, sheath hyaline, somewhat thickened; trichomes rose colored, with short articu- lations, torulose, 1.2-2/i, diam., articulations up to three times shorter ; protoplasm homogeneous; apical cell rounded. Growing on rocks near high-tide limit. Golden Gate, San Fran- cisco, California. Gomont, Sur quelq. Oscill. nouv., 1899, p. 35, pi. 1, fig. 11 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1713. The specimen distributed under no. 1713 of the Phycotheca Boreali- Americana shows no trace of rose or rosy brown color, but the fila- ments are more slender than those of P. BattersH as issued under no. 1712 of the same distribution. No branching has been made out with certainty but in other respects the plant resembles closely the specimens under no. 603 of the Phycotheca Boreali- Americana, dupli- cates of which were determined by Gomont. 20. Symploca Kuetz. Filaments loosely attached at the base, forming prostrate or erect, pointed, dense fascicles; trichomes single within a sheath, sparingly false branched, straight at the apices, branches solitary; sheaths thin, hyaline, firm or slightly mucous. Kuetzing, Phyc. Gen., 1843, p. 201, Phyc. germ., 1845, p. 167 (as '' Synploca," orthographic error) ; Sp. Alg., 1849a, p. 270 (cor- rected to "Symploca"). The original spelling of the name of this species was " Synploca" (cf. Kuetzing, 1843 and 1845, as noted above). This was undoubtedly an orthographic error and was changed by Kuetzing himself to "Sym- ploca" in 1849 {loc. cit.) Originally seven species were referred to it, of which four still remain, two are doubtful, and one is now assigned to Schizothrix {Sch. Friesii (Ag.) Gomont). The type may be con- sidered to be Symploca miiralis Kuetz. There are twenty-six additional species referred to the genus, at present, by far the greater number being terrestrial or of fresh water. Certain species are distinctly and exclusively marine. 1919] Setchell-Gardncr : Myxophyceae 81 Species of Symploca maj' usually be readily recognized by tlieir habit of occurring in more or less extended layers with the filaments at first prostrate, but soon forming erect fascicles which give the sur- face the effect of ])eing covered b}- more or less crowded tooth-like tufts. In certain stages, however, and even under certain conditions, these fascicles are not formed. In such cases it may be difficult to distinguisli the species from those of Phormidium. The symplocoid habit is also found in certain species of Schizothrix, Scijtonema, and Calothrix, and one of us ("W. A. S.) has found, particularly among thermal algae, undoubted species of Phormidium assuming a symplo- coid habit under certain conditions. Key to the Species. 1. Apical cell rounded, not calyptrate 2 1. Apical cell convex, calyptrate 3. S. aeruginosa (p S3) 2. Apical cell slightly swollen, trichomcs 6-8/a thick 1. S. hydnoides (p 81) 2. Apical cell not at all swollen, trichonies 3-3. 5/^ thick 2. S. funicularis (p 82) 1. Symploca hydnoides Kuetz. Plate 1, figs. 12, 13 Filaments forming erect, sordid, or dark blue-green, sharply pointed fascicles, 1-2 cm. high, in age often discolored at the base, sparingly- false branched; sheaths thin, slightly mucous; trichomes blue-green, 6-8/i, diam., slightly torulose near the apex ; length of cells variable, 5-14/a long; protoplasm filled with large granules, par- ticularl}^ near the cross walls; apical cell slightly inflated, without calyptra. Growing on logs in the littoral belt. Whidbey Island, Washington. Kuetzing, Sp. Alg., 1849a, p. 272; Gomont, Monogr. des Oscill., 1892, p. 107, pi. 2, figs. 1-4 (1893, p. 126, Repr.) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 188 ; Collins, Ilolden and Setchell, Phyc. Bor.-Amer. (Exsiec), no. 905 (under var. genuiim Gomont). We have retained the name Symploca hydnoides for this species, since this was the final decision of Gomont. We note, however, that Gomont {loc. cit., p. 108; p. 129 of Repr.) states that the first name given to this species was Blennothrix elegant Kuetz. (1845, p. 181) and that this was referred by Kuetzing later (1849rt, p. 272) to Symploca as S. elegans. In the same account (1849o, p. 270), how- ever, occurs also a description of the earlier Symploca elegans Kuetz. described in 1843 (p. 201). In the Tabulae Phycologicae (vol. 1, 82 University of California Publications in Botany [Vol. 8 p. 44, volume dated 1846-1849, this part certainly, then, of 1849) Kuetzing rectifies his error, bestowing on this species the new name of Symploca pulchra. It seems that this last name ought to have been chosen by Gomont for the species, since, according to Bornet and Flahault (1886, p. 356) tlie Calothrix hydnoides of Harvey (in Hooker, 1833, p. 368), upon which Kuetzing founded Symploca hydnoides, is referred to Calothrix pulvinata (Mert.) Ag., but without indication as to this opinion being borne out by examination of the tj'pe or other authentic specimen. The inclusion of Symploca hydnoides among our Pacific Coast algae rests upon a single specimen distributed under no. 905 of the Phycotheca Boreali-Americana. This seems too close to the descrip- tion and too nearly in agreement with other distributed specimens to be safeh' separated, but the trichomes are somewhat slender, even for var. genuina Gomont and the dissepiments are usually obscure. It may possibly prove to be an undescribed species. 2. Symploca funicularis S. and G. Plate 7, fig. 29 Filaments twisted into fine anastomosing rope-like fascicles 3-4 mm. high ; trichomes aeruginous, slightly torulose, 4.5-5. 5/^ diam., cells quadrate or up to two times as long as the diameter, 5-8yu, long ; sheath hyaline, gelatinous, and diffluent in the fascicles ; terminal cell slightly longer, convex, with small convex calyptra. Growing on moist soil and on other plants in a salt marsh. Bay Farm Island, near Alameda, California. Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918a, p. 469, pi. 41, fig. 29. Symploca atlantica Collins, Holden and Setchell, Phj'c. Bor.-Amer. (Exsicc), no. 1356 (not of Gomont). S. funicularis differs from S. atlantica in having a somewhat dif- fluent sheath, in having the filaments often tightly twisted into rope- like threads, in having smaller trichomes, less torulose, and with slightly longer cells; and particularly in the character of the terminal cell, which has a small, depressed, convex calyptra covering only about one-third of the end cell, instead of being "depressed conical" as is the case of S. atlantica as described and figured by Gomont (1892, p. 109, pi. 2, fig. 5; p. 129, Repr.). 1^19] Setchell-Gardncr : Myxophyceae 83 3. Symploca aeruginosa S. and G. Filaments 4-4. 5/^ diam., forming an aeriiginous stratum of erect, loose fascicles, 1 mm. high ; trichomes decidedly torulose, 3-3. 5/i, diam. ; cells quadrate, terminal cell much rounded, neither capitate nor cah'ptrate ; protoplast homogeneous, pale aeruginous, dissepiments obscure; sheath very thin, colorless, close, at first smooth, later becom- ing roughened on the outside. Growing on mud covered rocks, near the upper-tide limit. St. Michael, Alaska. Setchell and Gardner, m Gardner, New Pac. Coast Alg. Ill, 1918a, p. 469. Symploca laeteviridis Setchell and Gardner, Alg. N.W. Amer., 1903, p. 188 (not of Gomont). In the Algae of Northwestern America the plant described above was referred to Symploca laeteviridis Gomont with the statement that ' ' it certainly seems strange to find a plant, hitherto known only from the tropical locality of Key West, so far north." Since then we have been able, through the kindness of Professor W. G. Farlow, to examine an authentic specimen of Gomont 's species. It is heavily incrusted with lime and has a decidedly conical apical cell, while the cells of the trichome are almost always decidedly longer than broad. The diameter of the cells is 1.5-2/x and the dissepiments are comparatively broad and transparent. In all of these respects it differs from our Alaskan plant, although that comes within the limits of thickness assigned by Gomont to his species. The Alaskan plant is more slender than Symploca atlantica Gomont, with less distinct sheath, and more rounded terminal cell, which is not at all thickened above. It differs also in having inconspicuous dissepiments. On account of these vari- ous differences it seemed necessary to separate the Alaskan plant and consider it an independent species. SUBFAMILY 4. SCHIZOTRICHEAE forti Trichomes in well developed filaments, two to many within a com- mon sheath ; sheaths in many species colored (yellowish brown, red or blue). Forti, in De-Toni, Syll. Alg., vol. 5, 1907, p. 315. Vaginarieae Gomont, Essai Class, Nost. Hom., 1890, p. 351. We have preferred to follow Forti in choosing the designation of this subfamily, since the genus Vaginaria has, justly and b}^ common consent, been relegated to synonymy (cf., however, Otto Kuntze, 84 l')iiv< rsit}/ of California Publications in Botany L^'o^-S 1891, p. 926, and below, under Microcoleus). With the exception of Porphijrosiphon, the genera referred to the subfamily Schizotricheae consist of species whose individuals always show a fair proportion of more than one trichome in a sheath. Key to the Genera. 1. Trichomes few in a sheath 21. Hydrocoleum (p 84) 2. Trichomes many in a sheath 22. Microcoleus (p 85) 21. Hydrocoleum Knetz. Plant mass forming a compact, smooth or caespitose cushion on the substratum, at times encrusted with lime ; filaments with hyaline, cylindrical, sublamellate sheaths, sparingly false branched, more or less mucous, at times completely diffluent; trichomes few and loosely aggregated in a sheath, apices straight, more or less attenuate and capitate, with terminal cell wall thickened. Kuetzing, Phyc. Gen., 1843, p. 196. It has seemed best to retain the original spelling of the name of this genus, although, of late, it is being written " Hydrocoleus" (cf. Forti, 1907, p. 315, and others). The assumption is, presumably, that "Hydrocoleum" is an orthographic error. The change may also be made to make it agree with Microcoleus. There seem to be two words in Greek, or even three, meaning sheath, viz., 6 Ko\e6. Gakon'Ek. UNIVERSITY OF CALIFORNIA PUBLICATIONS IN BOTANY Vol. 8, No. 2, pp. 139-374, plates 9-33 July 14, 1920 THE MARINE ALGAE OF THE PACIFIC COAST OF NORTH AMERICA PART 11 CHLOROPHYCEAE BY WILLIAM ALBERT SETCHELL AND NATHANIEL LYON GARDNER --'iWN Subclass 2. CHLOROPHYCEAE kuetzing Tliallopliytes containing only the pigments, chlorophyll and xantho- pliyll ; thalhis varying from strictly single cells (uninucleate^, or more or less simple or complex colonies (as in the Protococcales), to multicellular individuals which are either made up of cells (i.e., uninucleate divisions, as in the Ulvales, Schizogoniales, and the Ulotricales) or are coenocytes (i.e., of multinucleate divisions), the latter being either septate (i.e., provided with partitions, as in the Siphonocladiales) or destitute of septa (as in the Siphonales), and ranging in size from microscopic forms to individuals of more than a meter in at least two dimensions; cell walls varying in structure and composition, mostl}' of cellulose but sometimes largely of pectose, occasionally more or less externallj^ mucilaginous, generally simple, moderately thick and structureless, but at times thick and variously stratified, occasionally incrusted with lime ; nuclei well developed ; chromatophores usually distinctly differentiated, of varying shape and number, often containing stareh centers, or pyrenoids, and colored b}' chloroplijdl and xanthophyll, the former usually in excess; reproduction vegetative, by non-sexual spores, and by zygotes ; vege- tative reproduction by cell division, fragmentation, and bj^ gemmae 140 Univcrsiti/ of California ruhliclla (p. 296) 32. P.seu(l()i)ringsheimia (p. 299) 33. Gomontia (p. 300) Family 13. — Trpntopohliaceae (p. 305) 34. Trentopohlia (p. 305) Series 1. ISOKONTAE blackman and tansi.ey Unicellular, multicellular and coenocytic Chlorophyceae, repro- ducing by means of zoospores or planogametes provided with two or four equal cilia or, when multinucleate, with the cilia arranged in pairs (Vaucheriaceae) or exceptionally in a circle (Derbesiaceae). Isokontae Blackman and Tansley, Revis. Class. Green Algae, 1902, p. 20; West, Algae, vol. 1, 1916, p. 156. It has seemed best to adopt the classification as outlined by West (1916, p. 153), dividing the Chlorophyceae into four series according to the character and arrangement of the cilia of the zoospores and the planogametes. West adopts four series, viz., Isokontae, Akontae, Stephanokontae and Heterokontae. Of these, our marine flora has to deal only with the first, the Isokontae, where the cilia are equal and arranged in twos or fours. The other groups are not represented. Only two seeming exceptions need explanation. In the Vaucheriaceae the zoospore is large and covered with cilia. They are, however, arranged over the surface in pairs. The other, and only real, excep- tion is the Derbesiaceae, where the cilia are arranged in a circle as in the Stephanokontae. It has seemed best to leave the Derbesiaceae with the Isokontae in this account, since this is the usual arrange- ment, but it is done with some reservation of opinion. Key to the Orders 1. Thallus of true cells (uninucleate segments) 2 1. Thallus coenocytic (of multinucleate segments) 6 2. Cells solitary or in non-filamentous colonies 1. Protococcales (p. 143) 2. Cells in filaments or membranes 3 3. Thallus filamentous 4 3. Thallus membranaceous 5 4. Filaments .simple or, more often, branched; chromatophore parietal 6. Ulotrichales (p. 281) 4. Filaments simple; chromatophore axile 5. Schizogoniales (p. 275) 5. Chromatophores parietal 4. Ulvales (p. 233) 5. Chromatophores axile 5. Schizogoniales (p. 275) 6. Thallus septate 3. Siphonocladiales (p. 179) 6. Thallus non-septate 2. Siphonales (p. 153) 1920] Seichellr-Gardner : ChIoi-ophycca>e 143 Order 1. PROTOCOCCALES (meneghixi) oltmaxns Unicellular isokontae, motilo or nonmotile, often occurring singly or in larger or smaller, definite oi- indefinite eoloiiies or eoenobia, or even simple coenocytes, often provided witli mucilaginous teguments of more or less ample dimensions and of various shapes, never properly multicellular; number and shape of chromatophores (chloroplasts) various; pyrenoids often present: i"('i)i'oductivf methods various as outlined for the series Isokontae. Prolococcalfs Oltmanns, Morph. und Biol, der Algen, vol. 1, 1904, p. 169; West, Algae, vol. 1, 1916, p. 160. Protococcoideac Meneghini, Cenni sulla organ, e. fisiol. delle Alghe, 1838, p. 4 (of reprint) ; Black- man and Tansley, Revis, Class. Green Algae, 1902, p. 21 ; Wille, in Engler and Prautl, Natiirl. Pflanzenfam., Nachtr. zum 1 Th., 2 Al)t., 1909, p. 3. The Protococcales, or Protococcoideae as they have long been designated, form a rather large and seemingly heterogeneous order. They are mostly iniiabitants of the fresh waters and, although unicel- lular in the broad sense, are varied in their form, aggregation and methods of reproduction. Our marine species are few so far as known, hut undou])tedly a considerable number yet I'emain to be detected. This is i)articularly true of the endophytic species of our coast whose presence and development are very little understood at present. Key to the Families 1. Thallus of larger or smaller colonies (or aggregations of cells) 1. Palmellaceae (p. 143) 1. ThaUus strictly unicellular 2. Chlorochytriaceae (p. 146) FAMILY 1, PALMELLACEAE (decaisne) naegeli Cells united into larger or smaller colonies by mueihiginous modi- fication of the outer walls, usually provided with a single parietal chromatophore (chloroplast) containing a single pyrenoid ; repro- duction by bieiliated zoospores or by isoplanogametes; fragmentation of colonies often takes place. Palmellaceae Naegeli, Die neuern Algensyst., 1847, p. 123; West, Algae, vol. 1, 191 (i, p. is:!. Palmelleae Decaisne, Essai snr nne classe des Algues, etc., 1842, p. 327. 144 University of California Puhlicntions in Botany [Vol.8 The names Palmellaceae and Palnielleae are used with different intent and to different extent by various writers and are interchange- able wholly or in part with other family designations. It has seemed best to follow West as to the usage in this account. The fundamental idea is that of the colony the cells of which are held together hy means of the mucilaginous material produced by tlie transformation of the outer walls. Some of the colonies are microscopic while others are of considerable size reaching a length (e.g., in some species of Tetraspora) of 15 to 20 centimeters. The mucilaginous modification ma\' be general or it may be localized on each cell wall, and the shape, as well as the size, of the colony may thereby be influenced. The cells possess a single parietal chromatophore with a single pj^renoid. Colonies may split up and multiply the plant. Reproduction hy zoospores and planogametes is the rule. In zoospore formation several (4 or 8) may arise in a zoosporangium or an ordinary cell may be transformed directly into a zoospore. This latter method, as well as the general cell structure and colony formation, points directl}' toward relationship with the Volvocaceae. 1. Collinsiella S. and G. Frond gelatinous, solid or later hollow, composed of pj^riform cells, on dichotomous, gelatinous stalks tapering downward from the cells; all enclosed in the general gelatine ; chromatophore band-shaped, with one large py renoid ; the terminal cells become the zoosporangia ( 1 ) Setchell and Gardner, Alg. N.W. Amer., 1903, p. 204. There is a reason for difference of opinion as to whether Collins- iella is to be retained as an independent genus or merged with the genus Echallocystis Bohlin. It has seemed best to place the discussion under the single species known from our coast. Collinsiella tuberculata S. and G. Plate 10, figs. 4-10 Colonies rugose-tuberculate, 2-4 mm. diam., dark green, gelatinous, firm, attached hy a broad base ; cells pyriform, 5-12/x. diam., 12-20/a long; branches repeatedly dichotomous, proceeding in two planes per- pendicular to each other and to the surface of the colony, some of the cells of the dichotomies pu.shing forward, forming the cortex, leaving behind the translucent, stalklike, gelatinous cell walls, while growth 1920] Setchell-G-ardner : Chlorophyc&ae 145 of other cells of the dichotomies is suppressed and they remain within the colony; the cell stalks show strong cellulose reaction to Chloriodide of Zinc ; the cortical cells are changed into zoosporangia( ?) containing 8-16 or occasionally more zoospores. Growing on rocks and pebbles in tide pools in the middle and upper littoral belts. West coast of Whidbey Island, AVashington, Port Renfrew, Vancouver Islaiul, Farallones Islands and Point Carmel, California. Setchell and Gardner, Alg. N.W. Amer., 190:^ p. 204, pi. 17, f. 1-7 ; Collins, Green Alg. N. A., 1909, p. 141; West, Algae, vol. 1, 1916, p. 188; Collins, Ilolden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 909. EchaUocijstis WiUeana Yendo, Three species of marine Echallo- cysths, 1908, ]). 199. Ecballocystis tuberculata (S. and G.) Wille, Nachtriige, 1909, p. 28 (in part). Wille (1909, p. 27) places Collinsiplla as a synonyni utider Echollo- cijsfis Bolilin, ])iit Collins (1909, p. 141 j and West (1916, p. 188) keep it distinct. It seems to differ from Echallocjjstis in forming an extended and definite gelatinous thallus, in tlie more vertical and regular division of the cells, and in the longer gelatinous stalks to the cells. Because of the first of these differences, West {he. cit.) places it in the subfamily Palmophylleae of the Palmellaceae and next to Palmophijlhini. This disposition of the genus seems to be the most satisfactory and is adopted here. Collins (1909, p. 141) assigns the EchaJlocystk WiUcana Yendo, from Port Renfrew, British Columbia, to CoUinsiclla tnhrrcnlata S. and (t. as a synonjTu, and draws liis description from both those of Yendo and of Setchell and Gardner. Yendo, however, in his remarks (1908, j). 204) states that it seems to him highly probable that Collinsiella tuberculata may be a young and sterile form of a plant closely related to his EcbaUocijstis WiUeana, if not the same species. We have not had the opportunity of examining a plant of EebaJlocijstis WiUeana, but judging from Yendo 's description and plates, there are some differences. In the Whidbey Island plant there is a sort of basement membrane from whicii bullate swellings rise as indicated in the' habit figure of Setchell and Gardner (1903, ])1. 17, f. 1). Yendo figures isolated, much folded thalli (1908, pi. 8, f. 1) attached by rhizoidal outgrowths on the underside {loc. cit., pi. 8, f. 2, 6, 12). No such outgrowths have been detected in the plant from Whidbey Island oi- in any others of our collections. These are, perhaj)s, minor and unessential differences, l)ut they indicate that there is a reason to feel uncertain as to the absolute 146 Vnivcrsity of California Publications in Botany [Vol.8 identity of the two plants. The specimens from tlic central Californian coast, on tlie other hand, resembU^ more closely tlic Yciido plant in habit but show no attaeliintr fibrils. FAMiiA- 2. CHLOROCHYTEIACEAE num. nov. Tliallns unicellular, not united into colonies, or single unseptate coenoeytes, reproducing solely by zoospores and by isoplanogametes. Planosporaceae West, Algae, vol. 1, 1916, p. 209. Endosphaeraceae Klebs, Orgran. einig. Flagellaten-Gruppe, 1883, p. 344; Ilansgirg, Prodr. d. Algeufl. v. Bohmen, II, 1888, p. 124; Blaekman and Tansley, Rev. Class. Green Algae, 1902, p. 95. This is a small but fairly natural family including- a number of genera which are, however, mostly inhabitants of the fresh waters. West (1916, p. 212) has reduced a number of genera under Chloro- chytrinm, as indicated elsewhere, among them being Enclosphaera. West has, consequently, set aside the family name Endosphaeraceae, as adopted by Blaekman and Tansley, and substituted the designation "Planosporaceae." Since this does not embody one of the genera of the family as reorganized it seems best to consider it inapplicable under the present rules of nomenclature and to adopt "Chloro- chj'triaceae " as a fitting family name. As stated by West, "this family is established to include all those non-coenobic members of the Protocaccales which are reproduced solely by zoogonidia or isoplanogametes." The great majority of the mem- bers of this family are either epiphytic or endophytic. Key to the Genera 1. Cells spherical to more or less ovoid 2. Chlorochytrium (p. 146) 1. Cells cylindrico-oblong with a more or less elongated stipe '6. Codiolum (p. 151) 2. Chlorochytrium Cohn Thallus unicellular, rounded, with chromatophore covering more or less of the outer wall and continuous or with radial prolongations, containing one to several pyrenoids; asexual reproduction by akinetes or by 2- or 4-ciliated zoospores escaping singly or enclosed in a gela- tinous mass; sexual reproduction by 2-ciliated isogametes escaping in a gelatinous utricle mass and conjugating before separation, or escap- ing singly and conjugating in the water; zygote, 4-ciliated, at first motile, later coming to rest and penetrating the host plant. Cohn, Ueber parasitische Algen, 1872, p. 102, diagnosis. 1920] SctchcU-Gardner: Chlorophijceue 147 West reduces Endosphaerti Klebs, Scotinosph06?; Collins, Green Alg. N. A., 1909, 11. 147 (in part) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsiec), no. 514?; Tilden, Amer. Alg. (Exsicc), no. 389?. The description, given above, is a fairly literal translation of the Latin diagnosis of Kjellman, who adds certain details in his remarks. The original host is Dilsea Integra (Kjellm.) Rosenv. (Sarcophijllis arctica Kjellm.). The cells of the Chlorochytriinii are placecl. in most 148 Z^nivcrs^ity of Californm Puhli^xitions in Boianri [Vol.8 cases, near the surface of the host phmt but sometimes occur in the middle layer. In vejretative condition the cells are from 80/* to IOO/a in diameter, the cell wall is thin and of equal thickness throughout, while the ehromatophore is thin and spread over the whole wall. The wall becomes thicker and apiculatc at the outer end as the cell passes into the reproductive stages, the apiculatc wall piercing the outer cortical tissues of the host. Kjellman states that the contents divide into a large number of closely packed zoospores which escape through an opening formed by the dissolution of the wall at th^» tip of the cell. These latter statements are evidentl}^ inferences because he distincth' says that he had only dried specimens for examination. In an authentic specimen of the host plant distributed by Kjell- man, young cells of the Chlorochytrium were found nearl^y spherical in shape, with uniformly thin walls, and with a ehromatophore thin and dotted with numerous large pyrenoids. These cells are about 80^1 in diameter. Upon examining various specimens referred to this species, the conclusion has been forced upon us that there is some variety of species and possibly even of genera among the Pacific Coast plants referred to Chlorochytrium inclusiim and it seems practically demon- strated that no one of those accessible to us is clearly the plant of Kjellman. Very little can be accomplished from the study of dried specimens, but living specimens should be studied to obtain more exact informa- tion as to structure and development. Our present knowledge, even of the type, is so slight as to admit of little certainty, and Kjellman 's statements as to the formation and emission of "zoospores" need to be carefully verified. On reexamining the various specimens referred to this species from our coast, we are able to make only a few general statements. Freeman (1899, p. 186) describes a plant which he provisionally refers to Chlorochytrium inclusum, but he found only vegetative stages. It was endophytic in the blades of Constantinea suhidifera Setchell. In the Algae of Northwestern America (1903, p. 206), we referred several specimens to the same species. Of these we may dis- tinguish, at least, two very different kinds of endophytes. The first kind includes what are probably species of Chlorochytrium, possessing a single ehromatophore with numerous starch centers, while the second is made up of plants seemingly possessing neither chromatophores nor chlorophyll and certainly devoid of starch. No. 290, N. L. Gardner, 1920] Sctchell-Gardiicr: Chlorophyceae 149 on Iridaea from the west coast of Whidbey Island, Washington, shows small plants (40/a x 80/i,), broadly pyriform and with thick walls. It is to be referred provisionally to Chlorochijtrium, but does not agree with Kjellman's description. No. 514, of Collins, lloldcu and Setchell's Phycotheca Boreali-Americana, shows large, thin walled cells, depressed vertically and measuring about 160/i, by 240/x, seem- ingly a Chlorochytriiwi, but not in accord with the descriptions of either Kjellman or Freeman. The other references given bj' us, with the exception of Tildeu's no. 389, which is Freeman's plant, are to be rejected. They are found to be based upon plants of the second type, whicli is probably Chytridiaceous, possibly being near to Rhodo- chytrium. The}' are probably the so-called gland cells mentioned by Schmitz as occurring in Tunierella Mertensiana (P. and II.) Schmitz (1896, p. 372) and figured as occurring in Iridaea affinis P. and R. (Postels and Ruprecht, 1840, pi. 40, f. 93). We have selected for illustration (pi. 13, f. 1) plants occurring endophytic in Wecksia Fryeana Setchell collected by Gardner near Sitka, Alaska. These seem to correspond more nearly than any of our other speci- mens with the description and figures of Kjellman. 2. Chlorochytrium Schmitzii Rosenv. Cells clavate or ovoid, with rounded apex, without cone-shaped thickening of the cell wall, and witli i)ointed base ; up to 370/x. long by 90ju, diam. ; chromatophore single, occupying the greater part of tlie cell wall, and with two ])yrenoids. Growing in various incrusting marine algae, e.g., Petrocelis. Alaska. Rosenvinge, Groenl. Havalg., 1893, p. 964, f. 56; Collins, Green Alg. X. A., 1909, J). 147; Setchell and Gardner, Alg. N.W. Amer., 1903, ]). 206 (in part). In our Algae of Northwestern America (1903, p. 206), we referred two specimens to this species, one from Harvester Island in Uyak Bay, on the Island of Kadiak, Alaska, and another from the west coast of Wliidbey Island, Washington. On reexamination of these speci- mens it seems best to retain the former under this name, in spite of certain differences between it and the figures and descriptions of the Greenland plant as given by Rosenvinge. Certain of the cells in our specimens are rounded above and pointed below, seemingly in vegeta- tive condition. Olhcr cells hav(^ pajiillate swellings at one or both 150 University of California Pnhlicutions in Botany [Vol. 8 ends and aro jirobably reproducing: since the contents seem more or less broken u]). There is no trace of a stalk (or tail) as in Codiolum, nor is the shape that of the cell (or clava) of that genus. Therefore it seems best to retain our Ala-skan jilant in Chlorochytrinnt and to refer it to C. ScJunitzii pending further investigation of living material. The "VVhidbey Island plant referred here has also been carefully reexamined. In the shape of the "clava" and in the occasional possession of a stalk (or tail), it shows itself to be a Codiolion and is discussed below under that geinis. The Alaskan i)Iant referred to this species varies in height from 123/A up to 220/t, and in width from 54/i, to 66/x, thus coming within the measurements as given by Rosenvinge for Chlorochytrinm Schmitzii. 3. Chlorochytrium Porphyrae S. and G. Plate 15, fig. 1 Cells spherical, 40-60/x diam., embedded within the host on l)oth sides ; chromatophore, single, at first small, covering the upper part of the young plant, then increasing in size by sending out several radiating arms and finally covering the cell wall ; pyrenoid, single, large, embedded within the chromatophore toward the upper part of the cell; cell wall 2-3ft diam., hyaline, not laminated; color, grass green ; sexual reproduction by 2-ciliated isogametes, 3-4/x diam., fusi- form to almost spherical, escaping singly through the oval opening in the outer wall; asexual reproduction by zoospores and akinetes unknown. Growing completely embedded within the outer membrane of Porphyra perforata f. segregata Setchell and Hus. Washington (Cape Flattery) to central California (San Francisco). Setchell and Gardner, in Gardner, New Pac. Coast Mar. Alg. I, 1917, pp. 379-384, pi. 32, f. 6; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 2280. This species M^as discovered at Lands End, San Francisco, Cali- fornia, but since the first publication of its discovery it has been observed in the vicinity of Cape Flattery, Washington, where it grows in abundance on the same host as at San Francisco. It probably extends along our coast wherever the host plant grows. A full account of the morphology and development of this species, as well as an extended discussion of the status of Chlorochytrinm and the various plants referred to C. Cohnii, will be found under the refer- ence to Gardner given above. 1920] Setchell-Gardncr : Chlorophyccae 151 ."i. Codiohim A. Bra mi Frond unieelhilar, ovoid to elavate or subcylindrical, the cell wall prolonji:ed below into a lonjici* or sliorlci- slipe, attached ])y a simple or forked expansion ; chromatophore covering the cell wall or more or less lirokcii, with several pyrenoids ; asexnal reproduction hy 4- ciliated zoospores, many in a cell. A. Brann, Alfianiiii Tnic, 1855, p. 19. This genus was first mentioned in 1852 hy Braun before the '29th Congress of naturalists and pliysiciaiis at Wiesbaden (cf. Flora, 1852, p. 755) and was excellently described and illustrated in full in 1855 in his "Algarum Unicellularum Genera nova et minus cognita" (p. 19). The type species is Codiohim (/re(/(iriiiiii A. Braun, and the t3'pe locality is Helgoland. The species of Codiolum are all very similar and consist of a color- less stipe of longer or shorter dimensions bearing above a sw^ollen cell Avhieh is elongated ovoid in shape and which is termed the "clava." The dimensions of both stipe and clava differ somewhat even in tlie same species, but in the endophytic species the stipe may be al>i)re- viat( d or even, most commonly, wanting. Key to the Species 1. Cells with ii long stipe not endophytic 1. C. gregarium (p. 151) 1. Cells with stipe short or wanting, endophytic 2. C. Petrocelidis (p. 152) 1. Codiolum gregarium A. Braun Plate 15, fig. 2 Clava narrowly elliptical in median section, definitely delimited from the long narrow stipe, up to 500/a long, and l()0;a wide; stipe hyaline, unbranched, nearly cylindrical but slightly enlarging upward, 600-10()()/j. long, 20-30/Li wide, somewhat disk-shaped at the base. Reported from a single locality in our region, growing on an ifon buoy near Friday Harbor, San Juan County, Washington. A. Braun, Alg. Unic, 1855, p. 20, pi. I, f. 1-17 ; Collins, Green Alg. N. A., 1909, p. 152. There have been described several species of Codiolum beside the endophytic species and these species have been dependent largely upon differences in various dimensions, but particularly on length of stipe. Borgesen, however, in his "Marine Algae of the Faeroes" (1902, 152 University of California Puhlications in Botany [Vol.8 p. 517) conies to the conclusion that two species, or groups of species, stand out with fair distinctness, viz., Codiolum greyariiDn A. Rraun, in which species (or group) the clava is definitely constricted at tlie line of union with the stipe, and C. pusillum (Lyng.) Kjellman, where the stipe passes insensibly into the clava. Our specimens are to be arranged witli C. gregarium A. Braun and while their dimensions dilfer from those given by various authors for this species, yet it seems best not to attempt any separation at present. Our specimens vary in hnigth of clava from 160ju, to 240/a, and in width from 32/a to 64ju,, while the stipe varies from 250ju, to 55()/i, in length and from IG^a to 28/x, in diameter. 2. Codiolum Petrocelidis Kuckuck Clava ovoid or obovoid, 65-90/x long, 20-30/i, wide ; stipe relatively short or sometimes absent, often tapering abruptly below into a sharp point. Growing within the thallus of Petrocelis franciscana, central Cali- fornia, and of P. Middendorffii, Whidbey Island, Washington. Kuckuck, Bemerk. zur mar. Algenveg. Wiss. Meeres., vol. 1, 1894, p. 259, f. 27 ; Collins, Green Alg. N. A., 1909, p. 152 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 2281. Chlorochytrium, Schmitzii Setchell and Gardner, Alg. N. "W. Amer., 1903, p. 206 (in part). Codiolum Petrocelidis was described by Kuckuck from specimens growing in Petrocelis Hennedyi at Helgoland, where it had first been detected many years previously by Ferdinand Cohn. It has also been described as growing in Petrocelis on the coast of New England. Two specimens of Codiolum growing in species of Petrocelis have been collected on the Pacific Coast of North America, one in P. Midden- dorffii on the west coast of Whidbey Island, Washington, and the other in /'. franciscana on the coast of central California at Fort Point, San Francisco. These two sets of plants differ somewhat from one another and also both differ in dimensions from C. Petrocelidis as described by Kuckuck. Kuckuck gives (as in description above) 65ju, to 90/A long and 20/* to 30/x wide as the dimensions of his type. The Washington plant varies from 136f(, to 180/x long and from 20/* to 44/i, wide for the clava, while the Californian plant shows clavae from 80/x to 140/1, long and 28/x, to 42/i wide. It seems best, however, to refer them both to Codiolum Petrocelidis Kuckuck, at least for the present. 1920] Sctchell-aardncr: Chlorophyceae 153 As to the stalk (or stipe) it is very distinct in some specimens while absolutely wantino: in most of the others, but the shape of the cell is, in general, sufficiently distinctive to permit of the ready separation of tliese specimens from those usually referred to Chloro- chiifriuni. Order 2. SIPIIONALES (grev.) oltmanns Fronds filamentous, either simple or variously entan<2:led or inter- woven, sometimes producing- complex individuals, devoid of septa (or very nearly so) in the activelj^ vegetative portions, but septa appear- ing in the reproductive portions, multinucleate and with many small chromatophores ; multiplication vegetative, by non-sexual spores, and b}' zygotes; vegetative by abscission of proliferous shoots or frag- mentation ; non-sexual spores, either aplanospores or zoospores, produced usuall.y in specialized zoosporangia ; zygotes from either isogametes or heterogametes. Siphoiialfs Oltmanns, Morph. und Biol. d. Algen, vol. 1, 1904, pp. 134, 291 ; Blackman and Tansley, Revis. Class. Green Algae, 1902, p. 114; Collins, Green Alg. N. A., 1909, p. 385; West, Algae, vol. 1, 1916, p. 222. Siphoneae Greville, Alg. Brit., 1830, p. 183. There is a very considerable variety both in the structure of the frond and in the methods of multiplication to be found among the Siphonales. From the simple globular but i)edicellate Halicystts or the dichotomously filamentous Vaucheria or Derhesia, through the more or sometimes less specialized species of Bryopsis, to the elab- orately constructed fronds of the Codiaceae, which are, however, made up of interwoven filaments with or without calcareous incrustation, there is a series of increasing complexities. In sexual multiplication there is also a series of increasing complexities from the isoplano- gametes of Bryopsis through the heteroplanogametes of Cod {urn to the condition in Vaucheria, where the female gamete is large and motion- less and the male gamete is small and motile. Complexity of form and differentiation of gametes do not proceed along the same lines, e.g., Vaucheria has a frond of simple structure, while its male and female gametes are most widely different from one another. Key to the Families 1. Thallus filamentous 2 1. Thallus not filamentous 3. Protosiphonaceae (p. 154) 2. Filaments free 3 2. Filaments densely interwoven to form a complex thalliip 6. Codiaceae (p. 166) 154 University of California Puhlimtions in P>otan\j [Vol.8 3. Filamoiits piiinatoly branched 4. Bryopsidaceae (p. 156) 3 Filaments irregularly or dichotomously branched 4 4. Sexual reproduction anisogamous; zoospore single, covered with cilia 7. Vaucheriaceae (p. 177) 4. Sexual reproduction unknown; zoospores several in a sporanjiiuiii, provided with a crown of cilia 5. Derbesiaceae (p. 163) FAMILY 3. PROTOSIPHONACEAE blackman and taxsley Thallus small, more or less globular, with or without colorless rhizoids or pedicels, unseptate in vegetative condition ; nuclei several ; chromatophore single and reticulate, or several, with or without pyre- uoids; multiplication vegetative, by aplanospores, through micro- and macro-zoospores, and possibly also through isoplanogametes. Blackman and Tansley, Rev. Class. Green Alg., 1902, p. 315; Collins, Green Alg. N. A., 1909, p. 153; West, Algae, vol. 1, 1916, p. 223. A small famil}- separated by Blackman and Tansley from the Botrydiaceae to contain particularly^ Protosiphon Klebs as a segregate from Botrydiutn Wallroth which, in turn, was removed from the Isokontae to the Heterokontae. Besides Protosiphon, it is usually made to include Blastophysa Reinke and Halicystis Aresch. The result is a not over homogeneous assemblage and one not readily or satisfactorily to be defined. Our only representative is Halicystis ovalis (Lyngb.) Aresch, which is described further on. 4. Halicystis Aresch. Thallus globular to ovoid, unseptate, multinucleate, with penetrat- ing rhizoidal portion; chromatophores small, disk-like, destitue of pyrenoids; asexual reproduction by 2-ciliated zoospores without stigma, escaping through one or more openings ; similar but smaller zoospores or zoogametes( ?) formed in separate individuals; after the emission of the spores the openings close and several new generations of spores can be similarly produced. Areschoug, Phyc. Scaiid., ])art II, 1850, p. 446; Collins, Green Alg. N. A., 1909, p. 372. A genus of two marine species of the northern oceans, seemingly occurring in both the north Atlantic and the north Pacific. It has been separated from Valonia because the vegetative body consists of an unseptate coenocyte of an ovoid shape with short pedicel and 1920] 8etchell-Gard)ier: Chlorophyceae 155 rliizoidal portion. It is now placed near to I'roiosiphon, wiiieli it more closely resembles than any other genus. The description given above is adapted from Collins {loc. cit.) and expresses well the general characters. Halicystis ovalis (Lyngb.) Aresch. Plate 14, fig. 3 Thalhis solitary or gregarious, obovate-ovoid, 0.5-1 cm. high, about half as wide; membrane tough, 10-12/* thick; basal prolongation penetrating the substratum; zoospores 12-14/x long, 7-8/x wide; gametes ( ?) 7-8/x long, 2-3/i wide. Growing on Lithothamnion and on other crustaceous corallines adhering by means of the rhizoidal portion penetrating deeply into the host. Vancouver, British Columbia, to Monterey, Califoi'nia. Areschoug, Phyc. Scand., part II, 1850, p. 447 ; Kuckuck, Abhandl. Meeresalg., 1907, p. 189, pi. Ill; Collins, Green Alg. N. A., 1909, p. 372. Vulonid oralis (Lyngb.) Agardh, Sp., vol. 1, part 2, 1822, ]). 4:]1; Saunders, Four Siphon. Alg., 1899, ]). 2, i)l. 350, f. 2 a, b; Setchell and Gardner, Alg. N. W. Amer., 1903, p. 232. Gastridium ovale Lyngbye, Hydr. Dan., 1819, p. 72, pi. 18 B. This very curious and interesting species has been most carefully studied, deserilx'd and illustrated by Kuckuck (1907) and seems to be the same as tluit found on our own coast. Very little material is available for study, neither of the present writers has had the oppor- tunity of collecting it, and only one of tlunn (Setchell) has had the privilege even of examining a living plant. In general aj)pearance and structure, however, the Pacific Coast plant agrees thorougldy with tlie descriptions of the European writers. It was first credited to our coast by Saunders (1899) who found it at "Point Lobos" (or Point Carmel) in Monterey County, Califor- nia. Later it was found in successive years at a locality near Point Cj'press, only a few miles north of "Point Ijobos" by Professor Harold Heath of Stanford ruiversity, and Ihc third and last locality is Port Renfrew in British Columbia, where it was collected by Misses J^uller and l'()ih'\-. It is always found growing on living crustaceous coral- lines into tlie tluillus of which it bores its way. It will probal)ly be found at othci" points along the coast, since it undoubtedly escapes observation as it is small and grows at. or just below, the lowest tide mark. 156 XJnivcrsit]) of CaUfornia Puhlicntions in Botany [Vol.8 FAMILY 4. BRYOPSIDACEAE (bory) de-toni Thallus a more or less braiiehed, unseptate eoenocyte, arising from rootlike, creeping:, often rhizome-like filaments which originate as lowermost branches ; branching more or less regularly or irregularly pinnate and lateral pinnules of definite growth arranged pinnately, and either distichous or polystichous, never interwoven ; wall thin, neither incrusted nor provided with trabeeulae (as in the Cauler- paceae) ; chromatophores and nuclei numerous and small, the former elliptically discoid and provided with a single pyrenoid each ; vege- tative reproduction by a detachment of pimiules or breaking off of proliferations or the creeping rhizome ; zoospores unknown ; sexual reproduction by 2-ciliated anisogametes produced in gametangia which are slightly modified pinnules {Bryopsis) or ovoid or pyriform out- growths from the pinnules (Pseudohryopsis) ; monoecious or dio- ecious ; female gamete the larger, with large posterior chromatophore, male gamete smaller, brownish-red with reduced chromatophore ; zygote germinating at once. Bryopsidaceae De-Toni, Syll. Alg., vol. 1, 1889, p. 427 ; Collins, Green Alg. N. A., 1909, p. 402; West, Algae, vol. 1, 1916, p. 225. Bryopsideae Bory, Voyage Coquille (Duperrey), Bot., 1828, p. 203; Thuret, Rech. sur les zoosp. et les antherid. des Crypt., 1850, p. 217 (sul) "Bryopsidees"). The genus Bryopsis is the only representative of the family Bryopsidaceae on our coast. The family closely resembles the Der- besiaceae, from which it is distinguished hy its method of branching and the possession of 2-ciliated, motile, reproductive bodies, the Codiaceae, from which it is distinguished by not having its branches interwoven to form a complex frond, and the Caulerpaceae, from which it is distinguished readily by the thin wall and lack of internal reenforcing plates or trabeeulae. The fernlike fronds of our species distinguish them at a glance from all our other filamentous Chloro- phyceae. The name Bryopsidaceae, as first used by Bory, included other Siphonales as well as Bryopsis, particularly species of Caiderpa and Vaucheria. The present concept of the family dates from about 1850 when Thuret published his classic paper on zoospores and anthe- ridia. The account of the reproduction is adopted from Oltmanns (1904, p. 304 ct seq.) and has not been verified, as yet, in our species. 1920] Setchell-Gardner : Chlorophyceae 157 '■). Bryopsis Lamour. Thallus iiiisej)tately coeiiocytic, much brauelied ; t'liromatopliores nuiucroiis small disks, each with one pyrcuoid ; the axis producing rhizoids below and branches above both of unlimited and limited growtii ; in the latter large, 2-eiliated, green, female gametes, and on separate individuals, smaller, brown, 2-eiliated male gametes are formed; by the union of the two a zygote is formed germinating immediately. Lamouroux, Observ. sur la, i)liysi()l. des alg. mar., 1809, p. 333, Mem. sur trois nouv. gen. dc la famille des alg. mar., 1809a, p. 133; Collins, Green Alg. N. A., 1909, p. 402. The above description, taken largely from Collins, expresses the technical characteristics of the family and of the genus Bryopsis. In this genus the gametes are produced in the branchlets of limited growth which are little changed, but are shut oif from the axis on which they are borne when they are transformed into gametangia. The genus contains about twenty-five species and inhabits warmer waters, but a few species proceed northward into decidedly cold water, e.g., B. plunwsa (Huds.) J. Ag. being credited even to the icy waters of Baffin Bay. Most of the species have woiidci-fully >,yni- nicti-ical fern-like fronds of a beautiful dark green which, when spread out on jiapcr, adhere closely to it and produce a very pleasing picture. Our Pacific Coast species are nowhere common, and are in need of more careful study to determine their habits of growtli and reproduc- tion, as well as their specific differences and identities. The species of Bryopsis present problems of determination of exceeding complexity and difficulty. The specific limits do not seem to be at all well ascertained and the actual identity and limits of the described species must remain uncertain until some monographer, wi1h ani)il(' facilities and patience, shall have unusual opportunities for study and illustralion. Much remains to be determined as to the stability of the various characters of these plants. A preliminary study leads us to believe that many characters, even of minor morpho- logical importance, may prove stable and suitable for use in distin- guishing species. The general habit, the number of orders of branch- ing, the distinctness or lack of it of the "plumes," or feather-like divisions, the distichous, tetrastichous, or polystichous arrangement of the ultimate branchlets, or "pinnules," are characters now gen- erally employed. "We suggest also comparison of the exact shape and 158 rnivcrsity of California PulylicaUons in Botany [Vol.8 proportions of the i)iiiiiuk's and, especially, the shape of the bases of the older ])iiinules, as important characters. The bases of branches and branchlets, especially below on the main or secondary axes, may produce rhizoid-like, almost corticating, structures, and these seem to present differences, possibl}' of diagnostic value. M. A. Howe has particularly called attention to this in his "Marine Algae of Peru" (1914, p. 38 et seq. and pi. 7, f. 6-9). They were also made part of the distinction in B. corticulans Setchell, but they exist in many, or possibly all, species, varying in their shape and distribution. Key to the Species 1. Thallus small, more or less simple 1. B. pennatula (p. 158) 1. Thallus 8-14 cm. high, much branched 2 2. Pinnules arising; on all sides of the branches 2. B. hypnoides (p. 159) 2. Pinnules distichous 3 3. Base of pinnules abruptly constricted and unequally rounded 3. B. corticulans (p. 160) 3. Base of pinnules gradually tapering and not appreciably rounded 4. B. plumosa (p. 161) 1. Bryopsis pennatula J. Ag. Thallus more or less simple, sublinear in outline, distichously pinnate ; pinnules nearly equally long, cylindrical, obtuse. Known only from the type localitj^ ' ' St. Augustin, ' ' on the Pacific coast of Mexico, where it was collected by Professor Liebmaiiti of Copenhagen. J. G. Agardh, Nya alger fran Mexico ("Algae Liebmannianae"), 1847, p. 6 ; Kuetzing, Spec. Alg., 1849, p. 492, Tab. Phyc. vol. 6, 1856, p. 27, pi. 76, f. II. Bryopsis pennata var. minor J. G. Agardh, Till Alg. Syst., 1886, part 5, p. 23. Bryopsis pennata Collins, Green Alg, N. A., 1909, p. 405 (in part). The only information available concerning this species is derived from Agardh 's description and Kuetzing 's figure. The latter seems to have been drawn from a specimen of the type collection. Agardh, later, as may be seen from the references above, reduced this species to a form of Bryopsis pennata Lamour. Comparing figiires and speci- mens of B. pennata, there seems to be a close resemblance in habit and even in the shape of the pinnules, but the Mexican plant is very small and slender, as compared with typical B. pennata, and it seems best to us to keep it distinct until additional collections throw further light 1920] Setchell-Gardncr: Chlorophyceac 159 upon the relationships of the two plants. Concerning the type locality, wiiicli is also the type locality for other species published by J. G. Agardh in the same paper, it seems probable it is on the coast of the state of Oajaca in the vicinity of Pochiitla and Pt. de lluatidco. (See Oersted in Liebmann, Clienes de rAmeri(|no Tropicale, 1869, p. viii.) 2. Bryopsis hypnoides Lamoiir. Tlialliis 5-10 cm. high, flaccid, rather pale green, profusely and variously branched ; branches in no definite order, growing smaller in the successive series, and with no sharp division between the lesser branches and the pinnules tliat clothe them on all sides, the latter themselves being frequently more or less branched; pinnules usually long autl slender, gradually attenuate at the apices, suddenly con- stricted and symmetrical 1\" rounded at the bases. Growing on logs, floats, shells, stones, etc. Ranging from N'ictoria, British Columbia, to San Pedro, California. Lamouroux, Mem. sur trois nouv. genres., 1809('/, vol. "2, \). 135, pi. 1, f. 2 a, b; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 230; Harvey, Phyc. Brit., 1846, pi. 119 ; Vickers, Phyc. Barb., 1908, p. 30, pi. 53, f. 1, 2; Collins, Ilolden and Setchell, Phyc. Bor.-Amer. (Exsiec), no. 1028. Oiil\- three illustrations of this species are available to convey an idea of the characteristics of tiie species. The first, and only strictly authentic illustration, is that of Lamouroux (1809a, pi. 1, f. 2a, b). Figure 2a represents the habit, while figure 2b shows the enlarged tip of a pinnule. The plant is evidently polystichous with the ultimate branchlets gradually attenuated in the lower third, or even half. The second is that of Harvey in the Phycologia Britannica (pi. 119), which does not represent the plant with sufficient detail to make as certain as desirable tlie shape of the base and apex of the pinnules. It is very evident, however, that the conception of Harvey was of a much branched, poly.stichous plant with long slender pinnules which are more or less constricted at the base and with the base itself unsym- metrical. The third illustration is that given by Aniui Vickers in her Phj'cologia Barbadensis (pi. 53). The piniudes of this species, both as to proportions and as to branching, seem very different from those of both the others. The illustrations of the plumules {loc. cit., f. 2) seem also to indicate that the gametes ( ?) are formed in restricted basal segment.s of the ])iniudes. 160 Umversity of Calif urn la Publications in Botany [Vol.8 The braneliiiig: of Bryopsis elegans Menegh. figured by Zanardini (1S60-76, pi. 72) referred to by J. G. Agardh (1886, p. 28) as being possibly of B. hypnaidcs is different in detail, at least, from all the othere. The specimens from the Pacific Coast, referred here until more study and careful comparison with the type s'pecimens can be made, seem reasonably uniform. They are much branched plants, poly- stiehous, with less definite distinction between axes and with less regular plumes than B. corticulans shows. The pinnules are compara- tively long and slender, long attenuate at the apex, but suddenly con- tracted to a broad, rounded base, and attached to the axis by a narrow neck. The older pinnules are verj^ symmetrically rounded at the base and without an}- appearance of the production of rhizoidal outgrowths above, but possessing stout, rather long and branched rhizoids at the bases of the main branches (cf. M. A. Howe, 1914, p. 40, and Phyc. Bor.-Amer., no. 1028). The Pacific Coast plants referred here vary somewhat in coarseness and may ultimately be found to belong to more than one species. 3. Bryopsis corticulans Setchell Plate 15, figs. 4, 5, and plate 27 Thallus rather stout and coarse, 8-14 em. high, main stem 1 mm. diam. ; dark green in the growing parts, glossy throughout ; main stems not much divided, lower part naked, upper part, usually about half of the whole length, with abundant, patent, generally opposite branches constricted at the bases, naked below, above with rather stout, distichous pinnules, decreasing in length towards the tip of the branch and abruptly contracted at the unequal base ; general outline of frond of individual branches pj^ramidal ; conspicuous tufts of coarse, descending, slightly branched, rhizoidal filaments found at the bases of the branches and branchlets. Growing on rocks in the lower littoral belt, from Vancouver, Brit- ish Columbia, to southern California. Observed at Vancouver Island, British Columbia, Puget Sound, Washington, and also at Santa Cruz, Pacific Grove, Carmel, and San Pedro in California. Setchell, in Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), 1899, no. 626; Collins, Green Alg. N. A., 1909, p. 404; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 230. Bryopsis plumosa Tilden, Amer. Alg. (Exsicc), no. 371 (not of C. Agardh). 1920] Setchell-Gardner: Chlorophyceae 161 Bryopsis corticulans is a coarse, dark green species, fairly regu- lai'ly (listiclious and with piiiiiulcs little reduced in size from tlie axis whence they spring. It lias, in the older plants at least, small clusters of short rhizoidal outgrowths at the bases of the lower (or even of the upper) branches. Tluis far it has been observed only in winter and spring on the coast of California, but in Puget Sound it seems to occur also in mid-summer. It is closelj' related to B. phimosa, but it is coarser, with more regularly occurring corticulatiug rhizoids, and with the pinnae more elongated lanceolate. It is still a question whether we have true B. phimosa or not. and it is not absolutely certain that />. corticulaits differs sufficiently from it to be always distinguishable. The pinnules of B. corticulans, however, are coarser, more robust, and more abruptly and unequally rounded at the base than those of any of the plants usually referred to B. plumosa. The lower plumules are not only abruptly and extremely constricted at the base, but possess bases which bulge out on the lower side where the rhizoidal growths issue. Thus far the great majority of the stricth' distichous Bryopsis from our coast seem referable to B. corti- culans rather than to B. plumosa. 4. Bryopsis plumosa (Huds.) Ag. Plate 14, fig«. 1, 2 Thallus not more than 10 cm. high, deep green and shining, more or less branched once or twice, seldom more, the ultimate branches forming plumes with distichous, slender pinnules gradually narrowed above and to a base which is slightly, if at all, rounded; bases of the lower branches showing several short lobes. On floats, Puget Sound Marine Station, Friday Harbor, San Juan Island, Wa.shington, collected by Annie M. Hurd. Agardh, Sp. Alg., vol. 1, part 2, 1822, p. 448; Collins, Green Alg. N. A., 1909, p. 403. Viva plumosa Hudson, Flora Anglica (2nd Ed.), 1778, p. 571. The type locality of Bryopsis plumosa^ is Exmouth in Devoi; on the south coast of Ejigland, and no type specimen seems to be available. The species is widespread, as far as report goes, but it is very doubtful whether by any means all the plants, even of Europe, assigned to it, really are properly referred. It is distichous, as generally defined, ami has broad triangular plumes. More investigation is needed to determine exactly the original application of the name, if possible, and 162 University of California Piihlications in Botany [Vol.8 also, as to how many varieties or even species are to be properly referred under it. The illustrations by Kuetzing (1856) both under B. phimma (pi. 83, f. 1) and under B. ahietina (p. 80, f. I) are usually referred to B. plnnwsa. On comparinor these illustrations with those of Harvey (1846, pi. 3), Greville (1830, pi. 39) and of Bryopsis Lynghyci Hornemann (1818, pi. 1603) and its reproduction by Lyngbye (1819, pi. 19, f. B), it seem>s evident that there is con- siderable variety among the European plants referred to B. plnmosa. Unfortunately the figure of B. arhuscula Lamouroux (1809, pi. 5, f. 1) is only of the habit of the plant. Without opportunity of examining a distinct type, or any speci- mens from the type locality, it is impossible to determine with any certainty just what the Ulva phimosa Hudson may be. However, judging by specimens from Debray from the neighboring coast of France, it seems likely to prove to be a plant very similar to that figured by Kuetzing (1856, pi. 83, f. II), viz., a distichous plant with pinnules gradually tapering to both base and apex. This grad- ually tapering base of the pinnule is not found in any of our speci- mens of B. corticulans or B. kypnoides. It may possibly be that this is characteristic of only younger stages of the European plant, but this does not seem likely. An illustration which seems to be reasonably authoritative, and one that mav serve as a basis for discussion is that of TJlva pluniosa of the English Botany (vol. 33, 1814, pi. 2375). This seems also to be the basis for the figures of plate 19 of Greville 's Algae Britannicae (1830). The agreement of these figures with that of Kuetzing is very close. As to whether Bryopsis phmiosa is represented on the Pacific coast of North America, or not, there is little to be said. The name appears in certain local lists and Tilden (Amer. Alg., no. 371) has distributed a plant from Tracyton, "Washington, in the Puget Sound region which seems rather to be B. c-orticidans Setchell. There is a single specimen collected by Miss Hurd (Herb. Univ. Calif., no. 200726) which seems to agree fairly closely with the illustration in the "English Botany" and we refer this to B. plumosa with some hesitation. The shape of the pinnules seems to be fairly characteristic. In this specimen the bases of the lower branches show several short, blunt lobes. Older specimens might show that these grow out into short rhizoids such as are found abundantly in Atlantic Coast and European plants referred to this species. The description given above was drawn up with especial reference to our plant. 1920] Setchell-Gardner: Chlorophyceae 163 FAMILY 5. DERBESIACEAE (thuret) kjellm. Thallus of erect, simple or sparingly' branched coeiiocytic filaments, arising from more slender creeping filaments which are attached to the substratiini by sliort, branched, rhizoid-like holdfasts; chromatophores small, discoid, oval or elliptical in sliape without or with one or two pyrenoids; non-sexual reproduction by zoospores provided with a crown, or circlet, of cilia, produced in special, lateral, globose to pyri- form zoosporangia, sexual reproduction unknown. Derhesiaccae Kjellman, Algae Arctic Sea, 1883, p. 316. Derbesiees Thuret, Rech. sur les zoospores des algues, etc., 1850, p. 231 (p. 22 Repr.). Dcrhesieae Thuret, in Le Jolis, Liste des alg. mar. de Cher- bourg, 1863, p. 14. The family of the Derbesiaceae differs from all others of the Isokontae in the possession of zoospores with a circlet of cilia similar to those of the Stephanokontae. In spite of this seemingl}^ funda- mental difference, all writers have placed it among the Isokontae rather than among the Stephanokontae. Davis, in his paper on "Spore formation in Derhesia" (1908), has followed out the nuclear behavior during zoospore formation and its relation to the development of a blepharopla-st as well as the resulting circle of cilia. Unfortunately the development of the zoospore and of the circlet of cilia is not as yet known for Oedogonium or any other of the Stephanokontae. Davis {loc. cit., p. 16) states that the zoovspores of Dcrbesiu and of Oedogonium- are of similar structure and ventures to predict that those of Oedogonium will be found to develop a blepharoplast closely similar to that of Derbesia. Nevertheless, he warns against the danger of classifying the algae on the basis of the structure of zoospores and gametes and expresses as his idea that Derbesia should not be removed from the Siphonales. Davis also expresses the opinion that no one will be bold enough to suggest a relationship between Derbesia and Oedogonium on account of the resemblances of the zoospores. It seems to us, however, that in the Stephanokontae, there exists a peculiar tyjie which may be as early, or as primitive, as any of those under the Isokontae. Possibly there may have existed many forms of Stephanokontae, now lost, or possibly not yet discovered. We may assume then that as the Isokontae have advanced along several lines from multicellular to septate and then to unseptate coenoeytic condition, the Stephanokontae may have done the same. It seems to us neither impossible, nor wholly* inconsistent with what we find 164 Vniro-sity of California Publications in Botany [Vol.8 among the Isokontae, to coiisidor Derhesiu as a coenocytic genus of the Stephanokontae. For general convenience, however, connected with the fact tliat this account deals with marine species only, we leave it in tiic j)lac(' usually assigned to it. There are only two genera to represent this family, Derhesia Solier and Bryohcsia Weber-van Bosse. Of these Derhc»ia alone has been found, thus far, on our coast. 6. Derbesia Sol. Filaments unseptate, or with occasional partitions, multinucleate, simple or branched, with no diiferentiation of axis and branches; chromatophores numerous, discoid, with or without pyrenoids ; non- sexual reproduction by large, multiciliate, stephanokont zoospores, each with a single nucleus, formed in lateral globose to pj-riform zoosporangia ; sexual reproduction unknown. Solier, Sur deux alg. zoosp. form, le nouv. genre Derhesia, 1846, p. 453 (cf. also Bot. Zeit., vol. 4, 1846, p. 497), Mem. sur deux algues, 1847, p. 158. Little remains to be said of the genus Derhesia after the de- scription of the famil}', since there are only two genera included in Derbesiaceae. The genus Derhesia was founded on D. marina and D. Lamourouxii, of which the former is given first, and may properly be considered as the type. D. marina Solier, however, is judged not to be identical with Vaucheria marina Lyngbye and is now known as D. tenuissima (De Not.) Crouan. The genus at present consists of eight to ten species widely distributed chiefly in tropical and sub- tropical waters. It differs from Bryohesia in having the sporangia ( ?) lateral. In Bryohesia after the terminal sporangium is emptied it is forced to one side by the continued growth of the filament beneath. Unfortunately we have had no opportunity of studying any of our Pacific Coast species of Derhesia in the living condition and must draw upon the publications of others for all details. Key to the Species 1. Filaments 50-70^ in diameter 1. D. mariaa fp. 165) 1. Filaments 100-000/^ in diameter 2. D. Lamourouxii (p. 165) 1920] Setchell-Gardner : Chlorophyceae 165 1. Derbesia marina (Lyngb.) Kjellm. Plate 15, fig. 3 Filaments arisiii'z from a creeping base, bright green, 50-7()/x diam., simple or usually with a few lateral branches similar to the axes, continuous l)ut with a short segment separated by partitions near the base of a brancli or occasionally in the axils just above a l)raneh, little smaller than the branch itself and about as long as broad ; sporangia occupying tlie place of branches, ovoid to subspherical, 150-250/x long, 90-200/^ broad ; pedicel varying from 30-70^ in length, 30-35/x in diameter, about as long as broad; spores 20 or more in a sporangium. Alaska to southern California. Kjellman, Alg. Arctic Sea, 1883, p. 316 (not of Solier, fide J. G. Agardli, Till. Alg. Syst., 5th part, VIII, 1886, p. 34) ; Saunders, Alg. Harriman Exp., 1901, p. 415; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 230; Collins, Green Alg. N.A., 1909, p. 407. Derbesia tenuis- sinm Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 574. Vaucherm marina Lyngbye, Hydr. Daji., 1819, p. 79, pi. 22 A. We suspect that the Derbesia vmicheriaeformis of Saunders (1899, p. 3, pi. 350, f. 4 a-d) from "Point Lobos" (really Point Cannel) near Monterey, California, is to be placed rather under I). iiKirina as understood by J. G. Agardh. Saunders describes his species as pos- sessing filaments from 30^ to 40/a broad and elliptical, obovate or pyriform sporangia 140/I, to 200/a long and 50^ to SO/n wide. The sporangia are distinctly pedicellate but the diameter of the pedicel is not given. Judging from his figure 4a, the pedicel is one half the diameter of the filament, or 15/a to 20/a broad. The zoospores, also judging from the same figure, number decidedly more than twenty. The branching is represented as dichotomous. Saunders, also, in the Algae of the Harriman Expedition to Alaska (1901, p. 415) refers a plant from Yakutat Bay to D. vmicheriaeforniis, but did not oliserve mature zoosporangia. 2. Derbesia Lamourouxii (J. Ag.) Sol. Filaments arising from a creeping ba.se, a few centimeters to 2 dm. high, 100-600/A diam., dark green, rather stiff, sometimes simple, some- times with more or less numerous irregular branches; sporangia spherical, 300-550/a diam., sessile or on sliort and slender pedicels. Southern California. 166 Vnivcrsity of CalifoniUi l'ublicatio)is in Botany [Vol.8 Solier, Mem. sur deux Algues, 1847. p. 162, pi. 9, f. 18-30; Collins, Green Alg. N. A., 1909, p. 407. Bryopsis Balhismna var. Lamouroiixii J. Agardli, Aleious or occasionally monoecious. Stackhouse, Nereis Brit., 1797, p. xvi. Lamarckki Olivi, ('/( Olivi, Zool. Adriat., 1792, p. 258, and in Usteri, Ann., part 7, 1794, p. 76. Spongodium Lamouroux, Essai, 1813, (p. 72 repr.). The designation of this genus presents certain difficulties. The earliest name proposed seems undoubtedly to be Lamarckia of Olivi (1792, p. 258 and 1794, p. 76). There are, however, several other genera dedicated to Lamarck and the generic names have been spelled in various ways. The first of these was proposed by Medicus in 1789 (p. 28), but is now regarded as a synonym of the Malvaceous genus Sida. Lamarkia of Monch, proposed in 1794 (p. 201) is still recog- nized as a genus of grasses, and has been adopted by the International Botanical Congress at Vienna as a nomen conservandum (cf. Briquet, 1906, p. 73, and 1912, p. 79). Codium was proposed by Stackhouse in 1797 in the first edition of tlie Nereis Britannica (2d fascicle, p. xvi), but in tlie second edition (1816, p. xii) evidently abandoned in favor of " Leniarkea." There is an earlier generic name, Codia (Forster and Forster, 1776, p. 59), still used for a genus of Saxi- fragaceae, and CodiaeiDii of Rumphius (1743, p. 65) is still current among the Euphorbiaceae. Otto Kuntze (1891, p. 900) argues for "Lamarckia" as the propi^r designation, but Codium, properly diag- nosed (for the period), has been in almost universal use for nearly, if not quite, a century, and has the right of way now that llic status of the name of Lamarkin has been settled as indicated above. The genus Codium contains somewhat over twenty-five described species agreeing closely in microscopic structure, but differing very decidedly in habit. Some are flat expansions, some are expanded but ciLshion-shaped, some are spherical and hollow, while some are either cylindrical or flattened but erect and l»i'anching. J. G. Agardh (1886, p. 35 et seq.) has suljdividcd the genus according to these differences. After habit, good characters for distinction of the species have been 168 TJniversiiy of California Puhlicatio-ns in Botany [Vol.8 sought fur in tlie varying size, shape, proportions, and niodifieatiou of the tips of the utricles. Further and more careful study in this direction, not only of plants of different species, but also of plants of varying ages of the same species is very much to be desired to determine the limits of these variabilities. The reproduction of Codiuni is known in detail onl}' for the European C. tomcntosum (cf. Oltmanns, 1904, p. 301, and West, 1916, p. 241). In this species the spore reproduction is exclusivel}' sexual. There are two kinds of gametangia giving rise respectively to larger motile 2-ciliated female gametes, and smaller but similar male gametes. Conjugation has been observed and a thick walled zygote is formed which germinates later. Nothing has been undertaken, thus far, towards the study of the reproduction of our species. Gametangia ( ?) have been seen, in most species credited to our coast, but further stages have not been observed. Key to the Species 1. Thallus prostrate 2 1. Thallus erect 3 2. Thallus applanate, flat 1. C. SetchelUi (p. 168) 2. Thallus cushion-shaped, rounded 2. C. Ritteri fp. 169) 3. Utricles more or less mucronate 3. C. fragile (p. 171) 3. Utricles never mucronate 4 4. Thallus cylindrical or flattened only below the axils 5 4. Thallus cylindrical only at base, decidedly flattened above 6. C. latum fp. 175) 5. Utricles 400m or more in maximum diameter 4. C. decorticatum (p. 172) 5. Utricles 250/i or less in maximum diameter 5. C. tomentosum (p. 174) 1. Codium Setchellii Gardner Plate 30, and plate 9, figs. 10, 11 Thallus forming dense, compact, spongy, irregular cushions, 6-10 mm. up to 15 mm. thick, adhering firmly to rocks ; color dark glo.ssy green ; medullaiy filaments 12-30/x diam. ; utricles variable in shape, clavate, cylindrical, or sometimes constricted below the apex, truncate or slightly rounded above, 65-75/i, wide, walls thin throughout when young, the outer ends 6-1 6/i, thick and lamellose when older; game- tangia cylindrical or slightly fusiform, 300-330/x long, 45-55/x diam., growing singly on the utricles; trichomes wanting. Growing on rocks in the lower littoral belt. Central California (possibly extending to southern California) and northward to Sitka, Alaska. 1920] Setchell^Gardner: Ckloroplujceae 169 Gardner, New Pac. Coast Mar. Alg. IV, 1919. p. 489, pi. 42, f. 10, 11. Coclium adhacrcns Anderson, List of Calif. Mar. Alg., 1891, p. 217 ; Howe, A month on the shores of Monterey Bay, 1893, p. 63 ; McClatchie, Seedless Plants, 1897, p. 351; Saunders, Four Siphon. Alg., 1899, p. 2, pi. 350, f. 3 a, b, c, Alg. Harriman Exp. 1901, p. 416 ; Setchell and Gardner, Alg. N. W. Amer., 1903, p. 231 ; Collins, Green Alg. N. A., 1909, p. 387 (not of Agardh). C odium dimorphiim Hurd, Pug. Sound Mar. Stat. Publ., vol. 1, 1916, p. 211-217, pi. 38, f. 1-13 ; Collins, Green Alg. N. A., Supl. 2, June, 1918, p. 88 (not of Svedelius). C odium Setchellii represents the adhaerens group of J. Agardh (1886, p. 37) on our coast. For many years all the collections of this group from the Pacific Coast of North America passed under the name of C. adJiaerois (Cabr.) Ag. Many different species, however, have been and still are referred to C. adhaerens, and much careful study and comparison will be necessary before they can be satisfactorily separated. Miss Hurd {lac. cit.) was the first to throw doubt on the relation- ship of our plant with the C. adhaerens of the European coast. She, however, concluded from her studies that our plants, particularly from the region of the San Juan Group of Islands, Washington, are identical with C. dimorphum Svedelius (plate 9, figs. 7, 8) from West Pata- gonia. A careful study and examination of authentic material show sufficiently constant differences between that species and our plants to seem to make it necessary to consider ours distinct from that species and from the European C adhaerens as well. It has conse(iuently been described as new by Gardner {loc. cit.), its type locality being Monterey, California, since from that general loealitj- only have fruit- ing specimens been collected. It is highly desirable that material be studied at different seasons throughout its range and fruiting material found with a view of determining whether we have one or more species on h when grow- ing in pools, 48-60 cm. high when growing in deep water, 3-4 mm. thick, cylindrical, often slightly flattened at the axis, dichotomous, surface often very tomentose, becoming smooth with age, color dark green; utricles cylindrical, small, 500-650/x long, 120-170/x, (rarely to 220/i) wide, apex usually distinctly thickened, blunt; smaller utricles sometimes pointed, but never mucronate; gametangia (5) small, 200- 250/i long, 40-70/x wide; gametes 20-22;u long, 10-12^ wide. La Paz, Lower California. Stackhouse, Ner. Brit. (fasc. 3), 1801, p. xxiv; pi. 7; Howe, Phyc. Studies V, 1911, p. 493; Collins, Green Alg. N. A., 1909, p. 388; Harvey, Phyc. Brit., 1846, pi. 93 ; Vickers, Phyc. Barb., 1908, p. 22, pi. 26. Fucus tomentosus Hudson, Flora Anglica, 1778, p. 584. In attempting to arrange the erect branched species of our coast with non-mucronate utricles, we are confronted with a problem of which the solution seems impossible at present. In the first place, the material available to us is slight ; in the second place, the reference of the similar species of Europe and other parts of the world is not at all satisfactory; and in the third place it is impossible at present to examine the types of the hitherto described species of this group. AVhen we add to this a lack of knowledge as to the possible variation in habit and size of utricle of the species of Codium, it seems sufficient to prevent us from presenting any but a tentative, and by no means satisfactory, arrangement. We have decided to refer our plants of this group under two species, viz., C. tomentosum (Huds.) Stackh. and C. decorticatum (Woodw.) Howe. Codium tomentosum was originall}^ described from Exmouth in Devon, on the south coast of England. The type specimen will pre- sumably be found in the Buddie Herbarium in the British Museum, but no account has been published as to its exact nature. Cotton (1912, p. 114) has published an exact description of the Clare Island plant which, presumably, is true C. tomentosum, and we have adopted this in our diagnosis. We may assume that the typical form is a slender, much branched plant, of varying length, cylindrical, or often slightly flattened just below the axils and with slender utricles, "120- 170/A (rarely to 220/a) wide," with apex distinctly thickened and blunt or at times pointed, but never mucronate. We have never seen a plant from our coast answering to this description. Howe {loc. cit.) has referred here a plant from La Paz, Lower California. He also 1920] Setchell-Gardner: Chlorophyceae 175 seems to be inclined to refer here no. 628 of the Phyc. Bor.-Amer. from La Jolla, California, which was distributed under the name of Codium Lindenhergii (cf. plate 31). We have examined the specimens of no. 628 in our copies of the distribution. Altogether there are three specimens available and all are much branched, rather broad (up to 1.5 cm.) plants which seem distinctly flattened. The utricles vary more than we have foimd to be the case in European C. tomcn- tos^(m. In fact there is almost a "dimorphism" and the occasional larger type of utricle reaches a diameter of 150-330/^ while the diam- eters of the smaller, somewhat differently shaped, utricles range from 45-80/x or more. The walls of both sorts of utricles may be thickened at the top, even to 28/x. The gametangia (?) are broadly fusiform and measure close to 200/x long and lOO^a wide. More information is needed concerning these plants and it is hoped that further collections may be made. They do not seem to belong to C. Lindenhergii since they, although flattened, differ decidedly in details of branching and in breadth. The utricles of C. Lindenhergii, as described and figured by Kuetzing, are probably at lea.st 250/a in maximum diameter, and in specimens distributed by Tyson (no. 55) occur up to at least 880/x, in diameter, while the gametangia ( ?) are 20(V to 228/i, long and 76ju, to 95/A A\nde. It should be mentioned, however, that there are tliree flattened species described from Cape Colony, viz., C. Linden- hergii Kuetz., C. danmecorne (Bory) Kuetz., and C. platylohiiim Aresch., usually combined (cf. J. G. Agardh, 1886, p. 46) under the name of the first species, but possibly without good reason. Bornet (1892, pp. 216, 217) discusses at length a similar problem connected with Schousboe's plants from Tangiers and refers C. Lin- denhergii as a form with smaller utricles under C. elongatum Ag. More has been said of this under C. decorticatum. In conclusion, we may say that we are not satisfied in referring the plant of southern California (as represented by no. 628, Phyc. Bor.-Amer.) to C. tomentosum and feel that it is probably an unde- scribed species. More experience with the living plant is needed, however, satisfactorily to determine its exact status. 6. Codium latum f^ur. Plate 15, fig. 6 Thallus arising from a small, spongy disk, 15-25 cm. high, or more, the lower stipitate portion cylindrical, 3-5 mm. diam., 2-3 cm. long, more or less branched and abruptly' flattened into broad, di-trieho- tomonsly branched lo])os rnundrd at the apices; lobes 2-3 mm. thick 176 University of California l^iihlications in Botanjj [Vol.8 and up to 5 cm. or more wide; utricles 500-60(V long, 50-110/x, up to 160/1, diam., nearly cylindrical when young, with a constriction just below the rounded apex, at maturity, with a decided shoulder below the constriction bearing a whorl of 4-6 hairs, membrane usually thick- ened at the apices, up to 25/1 tliick; gametangia (?) borne below the middle of the utricles, fusiform, 220/^ long, 60-75/x diam., membrane thin. Guadalupe Island, Mexico. Suringar, Algae Japonicae, 1870, p. 22, pi. 7 ; Okamura, Icon, Japan. Algae, 1915, vol. 3, no. 9, p. 158, pi. 142. The inclusion of Codium latum Sur., a Japanese species, in our account is based u])on several specimens in the Daniel Cady Eaton Herbarium of Yale University. These specimens were collected on the shores of Guadalupe Island by E. Palmer in 1875. The specimens are nearh' cylindrical and dichotomous or dichotomo-fastigiate below, but soon expand into long, broad, flattened lobes or branches. The particular character which makes the reference of these specimens to C. latum seem plausible, is the existence of a distinct whorl or verticil of hairs (shown in older specimens hy projecting scars) a little below the broad apex of each utricle. These are distinctly represented in the illustrations of the species by Okamura (1915, pi. 142, f. 4, 6). The specimens resemble those of the C. Lvndenhergii complex, but differ decidedly in the shape and size of the utricles as well as the arrange- ment of hairs upon them. The Guadalupe plants do not approximate the extremes of either length or breadth given by Okamura {loc. cit.) for his Japanese specimens but are very similar to the dimensions given by Suringar {loc. cit.). 8. Halimeda Lamour. Fronds jointed, freely branching from near the base, attached by. a dense mass of rhizoidal filaments usually strongly calcified except at the nodes; segments from slightly to very much flattened and expanded, flattened cylindrical, cuneate, orbicular or reniform, entire or variously lobed; medullary tissue a strand of longitudinal, slender, branched, unseptate filaments, expanding in the segments by lateral branchlets whose terminal cells (utricles) cohere more or less tightly to form a continuous layer, but unchanged, although often anastomos- ing, at the nodes and at the apex; reproduction b}^ globose or ovoid sporangia (?) borne on slender filaments projecting beyond the sur 1920] Setchell-Gardner : Chlorophyceae 177 face of segments and producing 2-ciliated zoospores ( ?) whose further development has not been followed. Lamouroux, Class. Polypes, 1812, p. 186. The genus Ilalimeda is very well marked on account of its calcified, jointed structure, most of the species are strongly calcified, but in the single species thus far detected on our coast the calcification is slight. The species are strictlj' tropical, occurring in abundance on coral reefs and assisting materially in their formation. Otto Kuntze (1891, p. 908) has urged the substitution of the earlier name Opuntiodcs of Ludwig (1737, pi. 138), but since HaUmeda has been in practically undisputed use for over a century, it seems best to retain it as a "nomcn conservandum" if necessary. Halimeda discoidea Dec'ne Plate 13, fig. 3 Fronds branched in one plane, up to 15 cm. high, nearly orbicular in outline, very slightly calcified, color bright green, fading on drying ; segments mostly quadrangular-oblong or cuneate-obovoid, the longer axis longitudinal rather than transverse, thin, smooth ; central fila- ments fused in twos, rarely threes, at the nodes; utricles of subcortical layer 68-175/a diam., larger than the interlocked, often fused, peri- pheral utricles. La Paz, Lower California. Deeaisne, Mem. sur Corall., 1842a, p. 102; Howe, Phyc. Studies III, 1907. pp. 495-500, pi. 25, f. 11-20, pi. 26, Phyc. Studies V, 1911, p. 492. Only a single species of Halimeda has as yet been credited to our coast and from a single locality, viz.. La Paz in California Baja (or Lower California), Mexico. From this locality it is reported by Plowe {loc. cit.), and we have also specimens collected at the same locality by Dr. and Mrs. Marchant. It is to be distinguished fairly readily from other flat, jointed species by its slight calcification and by the large rounded utricles of the subcortical layer. Other species are to be looked for along the tropical portion of our coast. FAMILY 7. VAUCHERIACEAE dumort. Filaments simple or usually more or less dichotomously branched, cylindrical throughout or witli frequent constrictions, without septa, often gregarious into expanded tufted oi- feltlike masses, attached at first by colorless rhizoidal branches; chromatophores numerous, small. 178 University of California PnhIic()o liiie (about 11.3/>t) in diameter (main filaments 75-80/a). C. cohaerens also differs particularly from C. saxatilis Rupr. in its intertwined filaments and its lower, more slender and shorter branch- lets. The type specimen of C. cohaerens in the Herbarium of the Imperial Academy of St. Petersburg has the appearance and habit of Spongomorpha arcta, but it is very desirable that it be carefully examined microscopically before being finally referred. 2. Spongomorpha Hystrix Stroemf. Plants rich green, in rather dense tufts, filaments straight, very erect, except those at the base of the tuft, which are somewhat more open; about 100-300/x diam. at the base, 200-500/a diara. at the tip ultimate segments blunt or clavate, not attenuate ; segments up to 4 diam. long at the tip, 0.5-1.5 diam. long below ; rhizoidal branches fairly common in the older parts, 40-70/x diam., segments 3-10 diam. long. Forming a dense mass on rocks in the littoral belt. From Agattu Island to Sitka, Alaska. Stroemfelt, Om Algvegt. vid Island Kuster, 1887, p. 54; Collins, Green Alg. N. A., 1909, p. 358 ; not Setchell and Gardner, Alg. N.W. Amer., 1903, p. 226. Spongomorpha Hystrix seems to be a high northern species of the arcta group, differing primarilj^ from Spongomorpha arcta in the greater diameter of the filaments. The specimens referred by us in our final disposition of the species, have much larger filaments than 1920] Sctchcll-Gardncr: Chlorophyccae 225 those of S. arcta (uj) to 200/a or over at the tips), but we have seen none approximating the maximnin diameter (500^1 at the tips) given for the Atlantic-Arctic plants. The Tihlen specimens (American Algae, no. 374), issued as Cladx>phora arcta form h, and a.ssigned to C. Ilijstrix by Setchell and Gardner (1903, p. 226), prove on exam- ination to have compound hooked branchlets and have been assigned, consequently, to Spongomorpha- coalita in this account. Specimens from Karluk and from Uj'ak Bay, Alaska, assigned by Setchell and Gardnei- to Cladophora arcta and its form conglutinata are now referred here, after careful examination. The status of this species on our coast, however, is subject to careful revision as soon as more abundantniaterial for study and comparison is available. Spongomorpha Hystrix might be compared with 8. duriuscula, so far as description goes, but the species are very different in aspect, tlie former being closel}' matted together below, while the latter shows so loose an intermingling of the filaments as to suggest tlie possibility of its belonging rather to Cladophora than to Spongomorpha. The segments also in *S^. duriuscula are usually shorter and those of the main filaments are horizontallv striate. 3. Spongomorpha duriuscula (Rupr.) Collins Tufts 15-25 cm. high, erect, loose, main filaments firm, straight, with thick, horizontally striate walls, 200-250/a diam. below, 300/.1 at the tip; segments 0.5-1.5 diam. long, 2-3 diam. at the blunt tips; branches similar, erect, scattered or in secund series of two or more ; near the base of the tuft more slender, 150-200/i. diam., with thiinier walls, not striate, with numerous short, patent ramuli, scattered or secund. Growing on rocks in the upper sublittoral and lower littoral belts. Alaska (Pribilof Islands to Karluk). Collins, Green Alg. N. A., 1909, p. 357. Cladophora ala.skana Collins, in Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 917 (nomen nudum), in Setchell and Gardner, Alg. N.W. Amer., 1903, p. 228 (description). Conferva duriuscula Ruprecht, Tange, 1851, pp. 401-404. Conferva cartilaginca Ruprecht, Tange, 1851, p. 404 (fide Yendo). Acrosiphonia duriuscula Yendo, Notes on algae new to Japan, V, 1916, p. 246. The type locality of Conferva duriuscula Ruprecht is Unalaska, where it was collected by Wosnessenski (no. 108) as the type specimen 226 Uuivnsif]/ of California ruNications in Botany [Vol.8 shows. The type speeiincn is of exactly the same habit and appearance as the specimens distributed under no. 917 of Collins, Holden and Setcheirs Phycotheca Boreali-Americana, which are topotypes, prob- ably collected at the very same spot whence "VVosnessenski obtained the type. Spongomorpha duriiiscuhi is a coarse, lax species whose filaments are so slightlj" bound together that the plant seems much less like a Spongomorpha than either of the preceding species. There are some slender rhizoidal branches, however, and the main filaments increase in diameter towards their summits. The walls of the segments of the main filaments and longer branches are thick and horizonally striate as Ruprecht has stated. It seems to be a very distinct species of the Upper Boreal Zone. Yendo (1916, p. 246) has placed this species under Acrosiphonia and, after examining the tj-pes, has united with it Conferva cartila- ginea Ruprecht (1851, p. 404) whose type locality is also Unalaska. He also refers here Tilden's no. 373 (Amer. Alg.) under Cladophora arcta. The two ("a" and "b") specimens in our copy are, however, clearly Spongomorpha coalita, both as to habit and as to the possession of compound hooked branchlets. Yendo states that Kjellman (1889, p. 55) included plants of this species under his Cladophora diffusa from Bering Island, Siberia. 4. Spongomorpha saxatiUs (Rupr.) Collins Plants dense but not much matted together ; filaments 80-120;U, diam., about the same diameter throughout, segments below 1-3 diam. long, above 3-6 diam., terminal segments sometimes 10-12 diam. ; branching di- trichotomous, with occasional lateral branches, divisions erect, somewhat acute or tapering, but usually with rounded tip ; older parts with descending rhizoidal filaments, about half the diameter of the filaments from which they spring, and with longer segments some- times 10-12 diam. long. On rocks in the lower littoral belt. Alaska to San Francisco, Cali- fornia. Collins, Green Alg. N. A., 1909, p. 360, Mar. Alg. Vancouver Island, 1913, p. 104. Conferva saxatiUs Ruprecht, Tange, 1851, p. 403. Cladophora saxatilis (Rupr.) De-Toni, Syll. Alg., vol. 1, sect. I, 1889, p. 311 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 223 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 921. Clado- phora arcta Tilden, Amer. Alg. (Exsicc), no. 279 (not of Kuetzing). 1920] Setchell-Gardncr: Chlorophyceae 227 Spongomorpha saxatilis var. Chamissonis (Kupr.) Collins Filament.s 40-6()/x diam., cells 3-4 diam. long, nodes constricted; cells slightly shorter towards the base. Alaska to Washington. Collins, Green Alg. N. A., 1909, p. 360. ClMophora Chamissoms (Rupr.) De-Toni, Syll. Alg., vol. 1, sect. I, 1889, p. 333; Collins, Holden and Setchell, Phyc. Bor.-Anier. (Exsicc), no. 920. Conferva Chamissonis Ruprecht, Tange, 1851, p. 403. Sponcjomorpha saxatilis resembles looser conditions of S. arcta, but is even more lax, as a rule, than any condition of that species. It resembles >S'. spinescens in having very much attenuated branches and even moderately sharp branchlets, but it never has hooked, acute, tipped branchlets. It is also more lax and less split up into symplocoid tufts than is usual with the S. spinescens of our coast. The tj'pe of Conferva saxatilis Ruprecht was found at ''Cap Nichta" in the Sea of Ochotsk, and the other specimens referred to it seem to differ from it and among themselves in coarseness and pro- portions of segments. Yendo, who has examined the type specimens of Ruprecht 's species of Conferva, refers (1916, p. 245) Conferva Chamissonis and C. saxatilis to the same species, as Collins had already done. Collins, however, was inclined to add Conferva Mertensii and C. viminea as well, but Yendo says that while the type specimens in St. Petersburg show that the two latter are identical they also show that they are quite distinct from the two former. We, also, have felt it necessary' to keep C. Mertensii separate from C. saxatilis. 5. Spongomorpha Mertensii (Rupr.j S. and G. Plants up to 11 cm. high, erect, moderately rigid, lax, bright green; branching alternate, branches erect, angles acute ; main filaments and branches 110-160/x diam. above, 80-110/x diam. below; segments 0.5- 2.5 times as long as the diameter, terminal rounded or gradually taper- ing, even prolonged into long spinous rhizoids, up to 5 times as long as the diameter; spiny branchlets absent; short, ])luiit, l)ranched, hooked branchlets generally present. Alaska (Unala.ska and Sitka) to California (San Francisco). Setchell and Gardner, Phyc. Cont. I, 1920, p. 280. Conferva Mertensii Ruprecht, Tange, 1851, p. 403. Canferva viminea Ruprecht, 228 University of California Publications in Botany [Vol. 8 loc. cit. (fide Yeiido). Cladophora Mertensii De-Toni, Syll. Alg., vol. 1, 1889, p. 317. Cladophora riminca De-Toni, loc. cit., p. 318. Spongomorpha arcta var. limitanea Collins, Green Alg. N. A., Suppl. I, 1912, p. 97, in Collins, Holden and Setchell, Phyc. Bor.-Anier. (Exsiec), no. 1736. Acrosiphonia Mertensii (Riipr.) Yendo, Notes on algae new to Japan, V, 1916, p. 246. Collins (1909, p. 360), on evidence furnished by authentic speci- mens in Herbarium Farlow, unites not only Canferva Mertensii Rupr. with C. viminea Rupr., but also unites with them C. Chamisso)iis Rupr. and C. saxatilis Rupr., placing all these names as sj'nonj-ms under Spongomorpha saxatilis. Yendo (1916, p. 245), however, as a result of study of the type specimens preserved in the Herbarium of the Imperial Academy of Sciences of St. Petersburg, is of the opinion that Conferva saxatilis and C. Chaniissonis are simply forms of one species and that C. Mertensii and C. viminea are also forms of one species, but that the two latter are quite distinct from the two former. Yendo does not, however, point out in what this difference consists. We are inclined to refer here provisionallj' and with considerable doubt, a specimen (no. 3288 of Setchell and Lawson) collected at Amaknak Island in the Bay of Unalaska. It is somewhat coarser than specimens of Spongomorpha saxatilis and of even more lax habit. It has no spines, but has occasional inrolled, circinate, yet blunt, branch- lets, very different, however, from the hooked branches of either of the two succeeding species. The general aspect, the dimensions, and these inrolled branchlets are all indicated in Ruprecht's description of Conferva Mertensii and assist in distinguishing this species from C. saxatilis. Very similar to the Unalaska plant is that distributed under no. 1736 of the Phycotheca Boreali-Americana. It has no spiny branches or branchlets but it usually shows circinate, often branched, branchlets. The terminal segments vary from verj^ blunt and dilated to extremely attenuated and in some plants are prolonged into curious long and sinuate rhizoids. The last character has been noticed only in summer plants. We may add that the description of this species has been drawn up largely from our Califomian specimens. The type locality for Conferva Mertensii Rupr. is given as Sitka, while C. viminea Rupr. is given as occurring at both Sitka and Unalaska. 1920] SetchcU-Gardncr: Chlorophyceae 229 6. Spong-omorpha spinescens Kiietz. Plants orbicular in outline, with short symplocoid divisions; fila- ments about 80/i, diam. below, lOO/x diam. at tip; segments 0.5-1 diam. long below, 2 diam. long at tip ; normal, erect, somewhat obtuse branches abundant ; also patent and acute branches, either short and spine-like, or long, hooked, revolute and eircinate, uniting the filaments into branching symplocoid tufts; descending rliizoidal branches slen- der and abundant. Growing on the tips of algae and sponges along the upper tide limit in exposed places. Bay of Unalaska, Alaska, to Coos Bay, Oregon. Kuetzing, Tab. Phyc, vol. 4, 1854, p. 16, pi. 75, II ; Collins, Green Alg. N. A., 1909, p. ."360. Cladophora spinescens Kuetzing, Sp. Alg., 1849, p. 418; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 227. CUidophora saxatilis Setchell and Gardner, loc. cit., p. 223 (in part). Cl-adophora arcta f. pulvinata Collins, in Setchell and Gardner, loc. cit., p. 225. Spongomorpha arcta f. pulvinata Collins, Green Alg. N. A., 1909, p. 360 (not of Foslie). Cladophora arcta f. conglutinuta Collins, in Setchell and Gardner, loc. cit., p. 225 (in large part). Spongomorpha arcta f. canglutinata Collins, Green Alg. N. A., 1909, p. 359. Cladophora arcta Harvey, List N.W. Alg., 1862rt, p. 176 (at least in part). Cladophora scopaeformis Setchell and Gardner loc. cit., p. 227 (in part). Spongomorpha spinescens was founded on a specimen sent by Lenormand to Kuetzing from the coast of Morbihan, a department of France on tlie northern short of the Bay of Biscay. A topotype of this species, if not possibly a cotype, exists in the Herbarium of the University of California (no. 145264), i.e., it is from the same locality and sent out by Lenormand. It also answers in full to Kuetzing 's description. Spongomorpha spinescens is characterized by abundant acute branches and branchlets with some of the short, simple, acute branch- lets curved into definite hooks. In looking over our Alaskan and Puget Sound materials, we find a number of specimens which corre- spond well in habit and other characters with the descriptions and figures of S. spinescens as well as with the specimen mentioned above. We feel fairly certain in referring them to Kuetzing 's species. We have also compared our specimen w'ith the descriptions of Acrosiphonia albescens Kjellman and A. hamiilosa Kjellman as well as with speci- 230 TJnivers^ity of California Puhlicatioiis in Botany [Vol.8 mens of the former from both Iceland (J(3nsson) and the Faeroes (Borgesen). Our plants do not agree completely with the description of either of Kjellman's species nor do they correspond to either of the specimens of A. albescens which specimens, in their turn, seem to us to belong to different species. We find that our specimens, seeming to belong to this species, have been variously referred in our previous paper (1903) as will be seen from the s^-nonymy given above. It is to be easily distinguished from the next, both in habit and in the unbranched, simple, hooked branch- lets. The fertile segments are all intercalary, usually one or two together, and rarely three to four in a series, and generally distributed over the plant. 7. Spongomorpha coalita (Rupr.) Collins Plate 16, fig. 4, and plate 32 Plants elongated, at first loosely tufted, but soon forming long, dense, ropelike, branching tufts, up to 30 cm. long: at first bright, later dull or yellowish green ; filaments 100-250/* diam. in the terminal segment; branching dichotomous below, irregularly alternate above, all branches of this class erect, with blunt, truncate, or, at times, acute ends; also present, except in very young plants, abundant, patent, tapering, very acute, compound, or branched, sharply and abruptly hooked branches by which all the older parts are densely matted together; segments 0.3-1 diam. long in the lower part of the older plants, 2-3 diam. in the younger plants, and even 6-25 diam. in the active terminal segment. Growing on rocks and on other algae in the middle and lower littoral belts. Very abundant along the entire Pacific Coast from southeastern Alaska (Sitka) to central California (San Luis Obispo County). Collins, Green Alg. N. A., 1909, p. 361. Cladophora scopaeformis Setchell and Gardner, Alg. N.W. Amer., 1903, p. 227 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), nos. 819 and 922; Farlow, Anderson and Eaton, Alg. Exsicc. Amer.-Bor., no. 203. Cladophora coalita Setchell and Gardner, loc. cit., p. 227. Cladophora Hystrix Setchell and Gardner, loc. cit., p. 226 (not of Stroemfelt). Conferva coalita Ruprecht, Tange, 1851, p. 404. Cladophora arcta form a, Tilden, Amer. Alg., no. 373, and form h, no. 374; Collins, Mar. Alg. Vancouver Island, 1913, p. 104, as to no. 374. 1920] Setchell-Gardncr: Chlorophijcme 231 Spongomorpha coalita, as it usually occurs, is readily recognizable, both by its habit and by the possession of compound, strongly hooked branchlets. It seems reasonably certain that the Conferva scopae- formis Ruprecht represents only a younger stage of C. coalita Ruprecht, with somewhat more slender filaments and longer terminal segments (cf. Collins, 1909, p. 361). The plants are distinctly elongated and their filaments are combined into ropelike masses. The recurved branchlets usually show either three or four sharply recurved and pointed tips or a less number, sometimes only one, with one or more longer straiglit branchlets arising from them. We have seen nothing like this in any other of our species of Spongornorpha, nor is any branching of this sort described for any of tlie species of this genus, or of Acrosiphonia, except that Kjellman figures compound recurved branchlets in his Acrosiphonia hamulosa (1893, pi. 1, f. 5). This species, however, is of very different habit, and ha.s more slender filaments as well as more slender recurved branchlets than Spongo- rnorpha coalita, resembling more closely S. spinescens, but seemingly distinct from it. There is considerable variation in the dimensions of the filaments and in the proportions of the segments in different individuals. The walls of the segments also vary much in thickness, up to as great as 40jLt, e.g., in a specimen collected on the west coast of AVhidbey Island, "Washington (Gardner, no. 467). A seemingly' young, but unusual plant, collected on June 3 at Carmel Bay, California (no. 5418 Setchell), is about 200/^ in diameter at the tips, but the terminal segment is often as much as 3 mm. long. Below, the hooked branchlets are often simple, but some are com- pound. If separated, these specimens might be referred under Con- ferva scopaeformis Rupr. 15. Microdictyon Dec'ne Plant a sessile, membranaceous network, formed of monosiphonous filaments, densely branching in one plane in a radiate manner, the tips of the branches attaching themselves to the sides of other branches by a terminal thickening, producing irregular, angular, open spaces between the segments ; reproduction by zoospores formed in any segment. Decaisne, PI. de I'Arab., 1841, p. 115. 232 University of California Publications in Botany [Vol.8 Tlie genus Microclicfyon comprises species which are totally differ- ent in habit from any of the other Cladophoraceae, and possesses a thallus of a leaflike form and general appearance. The species may, however, be considered to represent opposite branched Cladophorae whose branchlets anastomose to produce a plane, reticulate thallus, the main filaments and branches giving the appearance of veins, while the branchlets form the general groundwork. The species are all tropical or subtropical, one species only being credited to our coast. Microdictyon Agardhianum Dec'ne Plants delicateh' membranaceous, filaments 50-200/1, diam., main veins rather distinct, radiate, branches patent ; segments usually 2-4 diam. long. Guadalupe Island, Lower California. Decaisne, PI. de I'Arab., 1841, p. 115. Collins (1909, p. 366) refers under the name Microdictyon Agardhianum a plant from Guadalupe Island off the coast of Mexico. Since we have not seen specimens of this, we have not attempted to consider whether the Guadeloupe plant is the same as M. Agardhianum Decaisne of the Red Sea or M. umtilicatum (Velley) Zanard. from southwest Australia, but have left our reference under the name used by Collins. 16. Boodlea JMurray and De-Toui Boodlea composita (Harv.) Brand (1904, p. 187, pi. 6, f. 28-35) is a tropical species, the type locality of which is the island of ]\Iau- ritius. This species has been credited to our coast (ef. Setchell and Gardner, 1903, p. 226; Collins, 1909, p. 367; Yendo, 1916, p. 247; Collins, Holden and Setchell, Phyc. Bor.-Amer., no. 722). An exam- ination of the specimens upon which this representation is based shows, however, that none of them is really the Conferva composita Harv. (1834, p. 157). Collins (1918, p. 85) states that what has been said concerning Boodlea composita in his Green Algae of North America (1909, p. 367) is to be cancelled. Boodlea, consequently, can not be said to have been found on our coast. 1920] Setchell-Gardncr: Chlorophyceae 233 Order 4. UL VALES blackman and tansley Fronds membranaceous of one or two layers of cells, or tubular with wall of a single layer of cells, or filamentous of two or more vertical rows of cells, simple or branched, attached by rhizoids either free or united into a disk; cells with a single nucleus and a single parietal chromatophore containing usually one, but, occasionally, two or three pyrenoids; multiplication vegetative, non-sexual and sexual; vegetative, by abscission of proliferous shoots, by accidental rupture, by gemmae or by akinetes; non-sexual, by 2- or 4-ciliated zoospores; sexual by 2-ciliated isoplanogametes forming a zj'gote capable of germinating at once. Blackman and Tansley, Rev. Class. Green Algae, 1902, pp. 20 and 136; West, Algae, 3916, vol. 1, p. 275. FAMILY 9. ULVACEAE greville Characters of the order. Greville, Alg. Brit., 1830, p. 168 (lim. mut.). Ulvacees Lamouroux, Essai, 1813, p. 59 (in part) ; Thuret, Note sur la Syn., 1854, p. 27. Key to the Genera 1. Frond tubular even at maturity 2 1. Frond expanded at maturitj' 4 2. Frond parenchymatous (except E. groenlandica) 19. Enteromorpha (p. 244) 2. Frond not parenchymatous 3 3. Cells gloeocai)soid in longitudinal strij)s 17. Capsosiphon (p. 238) 3. Cells neither gloeocapsoid nor in longitudinal strips Enteromorpha groenlandica (p. 248) 4. Frond narrow, 1-4 cells wide 21. Percursaria (p. 273) 4. Frond broad, meml)ranaceous 5 5. Mature frond of a single layer of colls 18. Monostroma (p. 235) 5. Mature frond of two layers of cells, united wholly or in part 2U. Ulva (p. 260) 17. Capsosiphon Gobi Plants filamentous, hollow, gelatinous, tlie cells mostly in twos and fours, enclosed witliiii the Avails of the mother cell, and arranged in distinct longitudinal series, the series loosely connected laterally. Gobi, Ber. Alg. Forsch. im Finn. Meer., 1877, etc., 1879, p. 88. Ilea Fries, Syst. orb. veg., pt. 1, pi. homon, 1825, p. 336 (in part) ; J. G. Agardh, Till Alg. Sys., pt. 3, 1883, p. 114. 234 University of California Publications in Botany [Vol.8 "We have preferred to use the generic name Capsosiphon of Gobi (1879) rather than Ilea J. Ag. for several reasons. Fries founded the genus Ilea in 1825 (p. 336) to contain various species which were later found to belong to Entermnorpha Link (1820). The genus Ilea was refounded by Fries in 1835 (p. 321) to contain two species, viz., /. Fascia (Muell.) Fries and /. foeniculaceus (Huds.) Fries. If the genus ZZc-fl. is to be retained at all, it ought to be retained for Ilea Fascia (Phyllitis Fasci^a Kuetz.), since Fries states (1835) that the character of /. Fascia was the one upon which the genus was really founded. Finally the genus Capsosiplwn Gobi (1879) was founded two to three years before J. G. Agardh (1883, p. 114) resurrected the name Ilea to confer it upon the Viva aureola Ag. (1835, no. 29, pi. 29). Capsosiphon fulvescens (Ag.) S. and G. Fronds 1-5 cm. up to 8 cm. high, thread-like, later becoming tubular, up to 2 cm. diam., cjdindrical or somewhat compressed, with an occasional swelling, unbranched, or in age slightly proliferating; cells roundish or oval with a thick membrane resembling the cells of Gloeocapsa, 4-5/a diam., arranged in long rows, 2-4 rows grouped together. Growing on muddy rocks. St. Michael, Alaska. Setchell and Gardner, Phyc. Cont. I, 1920, p. 280. Ulva fulvescens Agardh, Sp. Alg., 1821, p. 420. Ilea fulvescens, J. Agardh, Till Alg. Syst., part 3, 1883, p. 115, pi. 4, f. 95-99; Collins, Green Alg. N. A., 1909, p. 206, f. 71. E nteroniorpha aureola Kuetzing, Tab. Phyc, vol. 6, 1856, p. 14, pi. 40; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 214. Capsosiphon aureolvm (sic!) Gobi, loc. cit. Ulva aureola Agardh, Icon. Alg. Eur., 1835, no. 29, pi. 29. Capsosiphon fulvescens, better known perhaps as Enteromorpha aureola, was included in our previous account (1903, p. 214) as having been found at St. Michael, Alaska by one of us (Setchell) intermixed with Rhizoclanium riparium. The specimen, on reexamination, fails to show a single filament of the Capsosiphon, hence its proper inclusion in our flora must remain, for the present, a matter of doubt. We have chosen the specific name fulvescens rather than that of aureolvm, because J. G. Agardh (1883, p. 115) has stated that it be- longs to this species, Ulva fulvescens Ag. being a younger condilion, while U. aureola Ag. is more developed. 1920] Seichell-Gardner: ChloropJujceae 235 18. Monostroma Thur. Frond at the beginning a closed sack or tube, at times splitting very early or again retaining the saccate or tubular shape until late, ill almost all cases, however, finally becoming a flattened or crisped membrane of a single layer usually parench^Tiiatous but occasionally of gloeocapsoid cells, except at the base where thickening occurs by the descent of elongated rhizoidal cells fi)rming several layers; vege- tative multiplication b}' gemmation or proliferation, non-sexual repro- duction by 2- or 4-ciliated zoospores and sexual reproduction by 2-ciliated isoplanogametes all originating in unchanged cells; zygote usually germinating immediately. Thuret, Note sur la Syn. des Ulv., 1854, p. 13. The genus ]\ronostroma comprises those members of tlie T^lvaeeae which, at maturity, form an expanded membrane of a single layer of cells. Certain species of Monostroma develop nearl}- to full size as sacks which then split open by one or more slits and become expanded membranes. There are still other species, however, which seem to consist of expanded membranes of a single layer of cells almost, if not quite, from the beginning. We have some reason to suppose that these species are tubular or saccate only in their very youngest stages, splitting early and becoming, therefore, one-layered almost from the beginning. In some of the species of Monostroma the cells are closely placed, witli thin, or even thicker, firm walls, giving a parenchymatous appear- ance, while in others the intercellular substance is ample and more or less gelatinous causing the cells to stand off from one another, usually in small groups {2-A or more) after the fashion of Gloeocapsa or Chroococms. The relative sizes of the cells in different dimensions, as well as the abundance or scarcity of intercellular substance, added to the size, development, and shape of the frond, furnish characters which may be used for the separation of the species. The species of Monostroma are marine, and also found in brackish and fresh water. At times what appears to be the same species may be found in both salt and fresh water. The thirty-five species credited to the genus are known only with certainty from the Northern Hemi- sphere, where they occupy, for the most part, the colder waters, intnul- ing into warmer zones only in winter and spring when the temperature of the water is lowered. 236 University of California Puhlications in Botany [Vol.8 Key to the Species 1. Frond saccate until late, then rupturing 2 1. Frond expanded very early 3 2. Membrane 15-20^ thick, delicate in texture 1. M. Grevillei (p. 236) 2. Membrane 25-45^ thick, tougher 2. M. arcticum (p. 238) 3. Frond light green on drying, adhering well to paper 4 3. Frond darkening on drying, not adhering well to paper 8. M. fuscum (p. 242) 4. Membrane 40-.50ai thick 7. M. orbidulatum (p. 242) 4. Membrane less than 30m thick 5 5. Frond T-lO/x thick 6 5. Frond 20-25m thick 7 6. Membrane distinctly areolate, cells distinctly grouped 4. M. areolatum (p. 240) 6. Membrane not areolate, cells slightly, if at all, grouped 3. M. zostericola (p. 238) 7. Cells arranged in distinct groups of 4-6, rounded 5. M. quaternarium (p. 240) 7. Cells not in distinct groups, angular 6. M. latissimum (p. 241) 1. Monostroma Grevillei (Thur.) Wittr. Frond attached, at first saccate, then opening at the top, and ultimately splitting- to the base ; soft and delicate, pale green ; mem- brane 15-20/x thick, cells quadrate with rounded angles, closely set, horizontally oval in cross section, 12-14jx high ; sporif erous cells enlarged, vertically' elongate in cross section ; cell wall dissolving after emission of spores. On stones in the upper sublittoral and lower littoral belts, Alaska. Wittrock, Monostr., 1866, p. 57, pi. 4, f. 14; Collins, Green Alg. N. A., 1909, p. 209; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 208. Enteramorpha Grevillei Thuret, Note sur la Syn. Ulv., 1854, p. 25. Certain of the species of Manostrmna retain the saccate habit until late, or rather until the sack has reached considerable size, before splitting. Two vspecies, at least, on our coast do this; one is Mono- stroma Grevillei and the other is M. arcticum. In M. Grevillei, especially if obtained in position, the saccate habit is usually easily observed or inferred, even when the plant is split to the base into segments. When detached fragments, especially of some size, are collected, the saccate habit may not be in evidence. Monostroma Grevillei is of delicate consistency and lubricous, differing in both these characters from any of the forms of 31. arcticum. It is also decidedly thinner than M. arcticum. Otherwise the two species are much alike. Rosenvinge (1893, p. 949 and 1894, p. 152) has united them as varieties of one species. We are inclined, however, to follow 1920] Setchell-Gardner: Chlorophyceae 237 Collins (1909, pp. 209, 210) and keep them separate, at least for the present, for the reasons given above. On the Atlantic coast of North America, Munostroina Grei'lUci is a summer plant in the Greenland waters (Upper Boreal Zone), but invades the North Temperate Zcme in spring-time. On tlie Pacific Coast, our only specimens are from Bering Sea but Collins (1903, p. 13) states that it descends to Montere\% California, which is much above its accustomed temperature. The reference of Collins to Monterey is based on two small speci- mens found attached to Gloiosiphonia verticillaris Farl., collected by Mrs. J. ]\I. Weeks. Reexamination of these specimens, although not convincing, leads as to the opinion that the}- may be nearer Mono- stroma zostericolu than to any forms of M. GreviUei. Collins gives, in addition to the typical form, the two following varieties as found on our coast. Since we have access to very scanty material we follow liim and otlicr authorities as to their disposition. Monostroma Grevillei var. lubricum (Kjellm.) Collins Frond up to 15 cm. long, j^ale or whitish green, delicate, very lubricous and flaccid, of irregular outline, laciniate, plicate, margin often crisped and lacerate ; frond 18-22ju, thick ; cells seen superficially, circular or rounded angular, often in twos or fours, cell wall thick; in cross section horizontally ovate or oblong, 4.5-8/*, high. Floating in shapeless masses in ([uiet waters. Alaska. Collins, Green Alg. N. A., 1909, p. 209. Monostroma luhricum Kjellman, Spetsb. Thall., 1877, j). 48, pi. 4, f. 8, 9 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 207. Monostroma Grevillei var. Vahlii (J. Ag.) Rosen v. More slender in form, often cyliiidrieal, retaining its saccate shape longer, and with cells arranged in more or less distinct longitudinal series. An early spring plant. Alaska (Kukak Bay, Saunders, Sitka, Gardner). Rosenvinge, Groenl. Havalg., 1893, p. 949 ; Collins, Green Alg. N. A., 1909, p. 209. Monostroma Vahlii J. G. Agardh, Till Alg. Syst., VI, 1883, p. 109, pi. 3, f. 84-89 ; Saunders, Alg. Harriman Exp., 1901, p. 410; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 208. We have seen only a fragment collected by one of us (Gardner) at Sitka. This seems, however, to l)e clearly the Monostroma Vahlii of J. G. Agardh. 238 University of California Puhlicrttions in Botany [Vol.8 2. Monostroma arcticum AVittr. Frond attached, at first saccate, later splitting into a few broad laciuiae; siibradiately plicate, witli crisped margin; pale green, becom- ing yellowish in (hying; membrane 25-45fi thick; cells 4—6 angled, closely set, irregularly placed; in cross section either vertically or horizontally oval, 10-30/<. high. On stones, in shallow pools of the middle littoral belt. Known only from Alaska. Wittrock, Monostr., 1866, p. 44, pi. 2, f . 8 ; Collins, Green Alg. N. A., 1909, p. 210; Setcliell and Gardner, Alg. N.W. Amer., 1903, p. 208; Collins, Holden and Setchell, Phj'c. Bor.-Amer., (Exsicc), no. 910. Monostroma latissimum Setchell and Gardner, Alg. N.W. Amer., 1903, p. 207 (in part). Kosenvinge (1893, p. 949, 1894, p. 152) unites Monostroma arcticum with M. Grevillei, keeping it as a variety. Much may be said in favor of such a disposition, especially in view of the treatment usually accorded M. fuscum, M. splendens and M. Blyttii. Collins (1909, p. 210), however, decides to keep them separate, although acknowledging the close relationship, on the ground that M. arcticum is a somewhat tougher and thicker plant than typical M. Grevillei. It seems best to us, also, to keep them separate. We follow Kosen- vinge, however, in uniting with Monostroma arcticum, M. angicava, M. cylindraceum and M. saccodeum of Kjellman (1883, pp. 295-297). These last species seem to differ only in general habit and this is prob- ably due to earlier or later splitting of the saccate frond. We find in carefully examining some specimens from Bering Sea and northwestern Alaska, previously referred (cf. Setchell and Gard- ner, 1903, p. 207, as to nos. 4020 and 5077) to Monostroma latissium, that they agree better with M. arcticum. 3. Monostroma zostericola Tilden Plate 14, figs. 12, 13 Frond more or less cucullate, cuneate-obovate or divided into segments of that form; cells angular, in more or less distinct series, longitudinal and transverse ; margins plane, often ragged ; membrane 7-10|U, thick, cells quadrate to vertically oblong in cross section, 5-8/* high. 1920] Sctchell-Gardncr: Chlorophyccae 239 In the sublittoral belt, growing on Zostcra. Known definitely only from the waters of the Puget Sound region. " Monostroma zostericolum" Tilden, Amer. Alg. (Exsicc), no. 388, 1900. Monostroma leptodermum Collins, Green Alg. N. A., 1909, p. 213; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 209 (prob- ably not of Kjellman). Monostroma zostericola is known thus far from tlic original collec- tion by Tilden from the waters between Brown and San Juan Islands, Washington ; from Port Renfrew, Vancouver Island, British Colum- bia, collected by Butler and Policy (cf. Collins, 1913, p. 103, under M. leptodermiim) ; and from near Victoria, British Columbia, collected by one of us (Gardner). There is some reason for referring here, although doubtfully, young specimens from Monterey previously placed under M. Grevillei. The specimens of all collections agree in showing sessile plants, attached and split in such a way as to suggest their earlier saccate form and grownng on Zostcra. The species is very delicate and its membrane very thin. The only species of this genus on our coa.st witli anj-thing like so thin a membrane is our Monostroma areolatum which differs decidedly in size, undulate and crisped lobes, areolate surface and cells in definitely delimited and separated groups. Collins, in various papers, has been inclined to refer the Tilden plant to Monostroma leptodermum of Kjellman (1877a, p. 52, f. 23, 24). Kjellman 's plants, unfortunately, were not found attached, but were floating fragments, the largest of which was 10 cm. long and about 6 cm. wide. We have seen no entire plants among the considerable number examined from our coast which approach these dimensions. Kjellman also states that his larger frag- ment had the margins undulate and crisped which is not the ease in any of the specimens from our coast. The cells in ours seem to agree fairly w^ell with the description and figures of Kjellman except in being more elongated vertically than horizontally in cross section. Rosenvinge (1893, p. 944, f. 49, 1894, p. 148, f. 49) and Jonsson (1904, p. 63) refer a very different plant from ours to the Monostroma leptodermum Kjellm. Their plant has a long, slender, tubular stipe and the membrane is undulate and ruffled. It seems best to us, there- fore, to consider that their plant is more likely to represent Kjellman 's species and to place ours under the name bestowed upon it by Tilden. 240 University of California Publications in Botany [Vol. 8 4. Monostroma areolatum S. and G. Plate 25 and Plate 26, fig. 2 Frond very delicate, lubricous, 20-35 cm. high, sessile, saccate when young, soon splitting and forming numerous, long, broadly ovate or obovate, undulate, plicate and much crisped lobes, pale green; mem- brane distinctly and finely areolate, 9-12/1. thick ; cells with rounded angles, S-lfx diam., subspherical in cross section, grouped witliin eacli areole. Growing on Zostera in quiet waters. Sitka, Alaska. Setchell and Gardner, Phyc. Cont. I, 1920, p. 281, pi. 30 and pi. 31, fig. 2. This species of Monostroma is exceedingly beautiful and among the most delicate and flaccid of the genus. The frond remains saccate for a brief period only, attaining a height of but a millimeter or two. The sack then breaks and the membrane spreads out at once, early developing small lobes. Finally a few primary lobes are established and these develop numerous secondary lobes. The growth on the whole margin greatly exceeds that of the interior, which results in the production of a great number of folds, making the margin very much crisped. In the thickness of the frond and shape of the cells M. areolatum closely approximates M. zostericola Tilden. The cells of the latter are, however, more angular and more closely placed, and the frond is not divided into areolae. There is a marked difference in the size of these two species as well as in their method of develop- ment. M. zostericola is diminutive, remains saccate for some time, and then splits longitudinally, forming several lobes broadening out- ward. M. areolatum very closely resembles the genus Prasiola in the grouping of the cells as seen in surface view. 5. Monostroma quaternarium (Kuetz.) Desmaz. Frond at first attached, soon becoming free, soft and delicate, irregularly lobed and folded, 20-23ju, thick; cells rounded, when actively dividing set closely in threes and fours within the mother cell wall; in cross section semicircular or oval, 15-17/a high. Floating in brackish and in fresh water. Washington to southern California. 1920] Setchell-Gardner: Chlorophijceae ' 241 Desmazieres, Plantes Cr3'pt. de France, 3 Ser., no. 603, 1859; Collins, Green Alg. N. A., 1909, p. 212; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 207. Ulva quaternaria Kuetzing, Tab. Phye., vol. 6, 1856, p. 6, pi. 13, f. 2. Monostrama qiuiternarium resembles M. ltivcrsity of California Publications in Botany [Vol.8 •iO/A thick at about the middle and tlie cells in section are circular or oblong and but very slightly elongated vertically in section even when fertile. The substance of the membrane is soft and slightly lubricous. Taken in this narrower sense, we find specimens both from our own coasts and those of Europe in agreement. This leads us to include this species as defined above, but not in the broad sense, as including Ulva rigida Ag., TJ. latissim-a L., and other species as has been the customary usage of recent writers. On this account, it is impossible, at present, to give an extended synonymy under the species. Vickei*s (1908, pi. 1) has figured what seems to be a tropical form of true Viva Lactuca and Hauck has distributed a specimen from Trieste (cf. Hauck and Kichter, Phj'k. Univ., no. 17). 5. Ulva latissima L. Frond ample, broader than long, usually soon free and expanded, often reaching a considerable size, yellowish green ; membrane 35-40/x thick ; cells, in section, nearly square or elongated horizontally. On mud flats and in quiet bays sometimes completely covering extensive areas. Alaska (Juneau). Linnaeus, Sp. Plant., vol. 2, 1753, p. 1163 (in part?). Ulva Lactuca var. latissima De Candolle, Flore Francaise, ed. 3, vol. 2, 1805, p. 9; Collins, Green Alg. N. A., 1909, p. 215 (in part). Mar. Alg. Vancouver Is., 1913, p. 103 (in part?) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 210 (in part). Ulva Lactuca myriotrema Saunders, Alg. Harriman Exp., 1901, p. 410 (not of Le Jolis). Ulva latissima of the Species Plantarum (Linnaeus, 1753, p. 1163) may or may not be the same as that of the Flora Suecica (Linnaeus, 1755, p. 433) and the questions as to whether either of these is the U. latissima of other authors, whose conceptions also have varied, are not to be solved by us. We infer that the specimen of Ulva latissima in the Linnaean Herbarium is not labeled either in Linnaeus' own hand or those of any known amanuensis (cf. Benjamin Daydon Jack- son, 1912, p. 147). It is apparently (cf. Turner, Fuci, vol. 3, 1811, p. 72 and English Botany, vol. 22, 1806, text under pi. 1551) a frag- ment of the blade of Laminaria saccharina. The plant upon which the name given in the Species Plantarum is based was collected by Lin- naeus on his trip into West Gothland, Sweden (Linnaeus, 1753, p. 1163, "iter w. gotl. 160"). 1920] Setchcll-Gardncr: Chlorophyceae 2W We have followed the conception of J. G. Agardh (1883, pp. 164- 166) as to the proper nature of the Linnaean species and have referred here those ample floating forms, with thin membranes, and cells which are cubical or horizontally elongated in section. AVe find very few such plants on our coast, their place as ample, expanded, floating membranes being taken by U. expansa. One specimen, however, col- lected near Douglas, Alaska, bv Mi'. Eldred Jenne seems clearly to belong here, and otlicr specimens may be expected in quiet waters. The specimen from Douglas, Ala.ska, agrees fairly well with no. LXXVI of the Pliyeotlu'ca Boreali-Americana, but is somewhat thinner. 6. Ulva fenestrata P. and K. Frond ample, usually soon free and expanded, yellowish green, completely, and more or less uniformly, perforated with larger and smaller round or elongated openings with undulate edges, margins often wavy ; membrane up to 60/a thick ; cells in section nearly square or slightly vertically elongated (about 20/a high by 16/x broad in thicker sections) ; chromatophore cucullate at outer end of cell. Growing on rocks in the lower littoral and upper sublittoral belts. Alaska (Sitka) to Puget Sound, Washington. Postels and Ruprecht, 111. Alg., 1840, p. 21, pi. 37. The question as to the origin of the perforations found apparently regularly in some species of Ulva and occurring more or less sporad- ically in many or all species, has not, as yet, been at all carefully investigated. Greville (1830, p. 172) speaks of the frond of Viva lati^sima as being "frequently much perforated by marine animals." On the other hand, J. G. Agardh (1882, p. 171) in speaking of U. rigida and its forms, states that the holes found in this species, as well as in U. reticulata Forsk., are not the work of animals, but due to inequalities of growth. We find holes fre(iuently in considerable numbers in various of the Ulvae, as well as of the Porphyrae, of our coast and we feel certain that in manj- cases, at least, they are the work of mollusks, but we also find specimens of a large species of Ulva, which seems likely to be U. fenestrata, in which the holes are so numerous and so regular, and so constantly found that we are inclined to believe them to be the results of groMh of the uninjured frond. We have, conse^iuently, referred them here, although with much doubt, since other than as to perforations, they agree well with specimens of Ulva expansa. Some of the specimens in our possession are as long as 4 meters and up to 13 decimeters wide. As to details of perforation, our specimens agree with those figured b}'' Postels and Ruprecht. 268 rnivcrsity of California Publications in Botany [Vol.8 7. Ulva expansa (Setchell) S. and 6. Frond ample, pale green, orbicular or broadly elongated, margin deeply ruffled; frond 60-70/a thick in the middle, 38-45/a on the margins; cells, in section, vertically elongated in the middle of the frond (up to 28-30/x long, 10-12/a wide), nearly square in the margins. Growing on rocks in the lower littoral belt. Washington (Puget Sound) to Mexico (La Paz). Setchell and Gardner, Phyc. Cont. 1, 1920, p. 284. Ulva fasciata f. expansa Setchell, in Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. LXXVII; Collins, Green Alg. N. A., 1909, p. 216. We find along the coast of central California a broad species of Viva, often also long, something like Viva latissima in appearance, yet of a more vivid green color, thicker in the center of the frond and with distinct, broad, ruffled margins. The cells of the thicker center of the frond are distinctly palisade-like in section, while on the thinner margins they are nearly square. A younger specimen of this plant was distributed by one of us as Viva, fasciata f. expansa (Phyc. Bor.-Amer., no. LXXVII), but it has seemed, on further study, to belong neither to Viva fasciata Delile nor to the Viva fasciata f. taeniata also distributed by one of us (Phyc. Bor.-Amer., no. 809), but described later in this account as Viva taeniata. We have there- fore described it (Setchell and Gardner, 1920, p. 284) as an indepen- dent species under the name of Viva expansa. Viva expansa, so far as we have observed it, remains attached only for a short time. It soon becomes free and floats or drifts, increasing in size, becoming at times at least 3 meters long and varying in width from 18 cm. to 75 cm. In form and structure it differs from Viva latissima and from all the other species of Viva of our coasts. It comes nearest to Viva fenestrata as we have described that species, but is little, if at all, perforate. Plants of what appears to be the same species have been found in the Puget Sound region and Howe (1911, p. 490) is inclined to credit here some from La Paz, Mexico. 8. Ulva lobata (Kuetz.) S. and G. Frond dark green, of moderate size (up to about 30 or more cm. long and 10-15 cm. broad), more or less deeply lobed or divided, attenuate to a cuneate, crisped, often more or less twisted base, 1920] Setchell-Gardner: Chlorophyceae 269 margins plane or slightly undulate; membrane 45-90/j. thiek, thicker in the center and thinner near the margins; cells elongated vertically, up to two and one half times as high as broad in the thicker central portion, nearly square at the margins. On rocks in the lower littoral belt. Central California (San Fran- cisco) to southern California (Pacific Beach). Setchell and Gardner, Phyc. Cont. I, 1920, p. 284. Phijcoscris lohata Kuetzing, Spec. Alg., 1849, p. 477, Tab. Phyc, vol. 6, 1856, p. 10, pi. 27. Ulva fasciata f. lohata Setchell, in Collins, Ilolden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 863; Collins, Green Alg. N. A., 1909, p. 216. Among the Ulvae of the Californian coast is one of moderate size (up to 30 cm. or more long and to 15 or more cm. broad) which is distinct in general appearance. It is attenuate at the crisped base, broadening above and usually lobed or divided into several broad divisions. The margins are either plane or slightly undulate. Like U. expansa it is thicker in the center with palisade-like cells (in sec- tion) and thinner on the margins where the cells are nearly square (in section). It bears a striking likeness in every way to Kuetzing 's figure (1856, pi. 27) of his Phycoseris lohata from Cliili. We have, therefore, referred it to his species with some doubt. lira lohata belongs to the same group of species as U. expansa but is generally firmer in substance, slightly thicker, never reaches a great size, and is less deeply or conspicuously ruffled. It is well repre- sented by the specimens distributed in the Phycotheca Boreali- Americana (under no. 863). The most typical plants are those of the central Californian coast (San P^'rancisco to ]\Ionterey). We have referred here also one plant from southern California, but with some doubt. 9. Ulva rigida Ag. P'rond low, at first lanceolate or ovate-lanceolate, firm and stiff, with distinct stipe, later broader and irregularly deeply divided; membrane 60-110/* thick, varying with age and position in the frond; cells, in section, vertically elongated, one and one half to three times as high as broad. Growing attached to rocks and other algae, upper littoral ])elt. Alaska (Uyak Bay) to Slexico (La Paz). 2(0 University of California Publications in Botany [Vol.8 Agardli, Sp., vol. 1, part 2, 1822, p. 410. UlvO' Lactuca var. rigida Le Jolis, Alg. Mar. Cherb., 1863, p. 38; Collins, Green Alg. N. A., 1909, p. 215 (in part), Mar. AJg. Vancouver Is., 1913, p. 103 (in part) ; Saunders, Alg. Harriman Exp., 1901. p. 410 (in part) ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 209 (in part) ; Howe, Phyc. Studies, V, 1911, p. 490. Ulva rigida must needs be carefully studied and redescribed from the type specimen before any exact knowledge is possible as to the nature of the species. Agardh (1822, p. 410) describes it as from 3 or 4 up to about 9 inches long, split to the base into curved and crisp laciniae. J. G. Agardh (1883, p. 168) describes it as having cells vertically elongated in section to 2 to 3 times their width. He, how- ever, refers as typical the figure of Ulva Lactnca of Thuret and Bor- net's Etudes Phycologiques (1878, pi. 2, e). Yendo (1916, p. 244) says that J. G. Agardli has taken a broader view of the species than did C. Agardh. Yendo refers to U. rigida, in the sense of its founder, the Ulva conglohata Kjellm. and its f. densa as well as the Ulva fasci- ata f. caespitosa Setchell (Phyc. Bor.-Amer., no. 809). Yendo does not, however, state definitely just the characters of the type of U. rigida Ag. The Ulva conglohata' Kjellm. seems to us to agree well with the U. fasciata f. caespitosa Setchell (Phyc. Bor.-Amer., no. 809, nom. nud.), both as to habit and as to structure. The cells in each are only slightly, if at all, elongated vertically in section. We are inclined to refer both of these plants to Ulva Lactnca as small forms. The Ulva conglohata f. densa, however, seems different in its structure. Judg- ing b}^ Kjellman's figure (1897a, pi. 3, f. 15), the cells are decidedly vertically elongated in cross section, and this form probably, therefore, belongs to U. rigida in the sense of J. G. Agardh. We have, in the light of what has been written, considered the Ulva rigida to be a low plant, rigid, deeply divided, rather thick and with cells vertically elongated in section. The membrane usually shows a rather thick hyaline layer under each surface, and another between the layers of cells. We have found that certain of our speci- mens conform to these characters and are to be distinguished by them from any other species of Ulva. 1920] Setchcll-Gardncr: Chlorophyceae 271 10. Ulva stenophylla S. and G. Plate 21, fig. 2, and plate 24 Frond simple, linear-laiiceolate, taperinj^ abruptly at the ba.se to a very short, flattened, cuneate stipe, 5-8 dm. hit diam., seen superficially ; in cross section oblong or palisade-form, 11-14/x high; aplanospores probably numerous within each aplanosporangium, in groups of 8. Growing on rocks just above high water mark. Alaska. Reed, Two new ascomyeetous Fungi, 1902, p. 160, pi. 15, f. 7 ; Collins, Green Alg. N. A., 1909, p. 220; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 215; Trelease, Tlie Fungi of Alaska, 1904, p. 34, pi. 7, f. 1, 5. Pradola horcalis has been found only on the Alaskan coast (Unala.ska, Kadiak and Baranof Island) and always infested with a fungus {Guignardia al^skana Reed), thus resembling the Mastodia iessellata Hook, and Harv. (cf. J. D. Hooker, 1847, p. 499, pi. 194, II) 278 University of California Publications in Botany [Vol.8 whose alf,'al portion was later referred to Prasiola tcssellata by Kuetz- inr (not over 38-40m diam.) 3. U. pseudoflacca (p. 285) 1. Ulothrix implexa Kuetz. Plants light green, forming soft masses, cells 6-15/1, diam., some- times slightly swollen at the middle, nearly quadrate, chromatophore, wlioii young, occupying onlj^ the middle part of the cell, often an incomplete ring ; fertile cells nearly quadrate, not swollen or increased in width. Growing on rocks near the mouths of streams, and on wood in quiet water, in tlic littonil belt. Alaska (St. Michael) to Califoniia (San Francisco). Kuetzing, Sp. Alg., 1849, p. 349 ; Collins, Green Alg. N. A., 1909, p. 185 ; Setch.'ll and Gardner, Alg. N.AV. Amer., 1903, p. 217. Ulothrix suhfJaccida Wille, Stud. ueb. Chloroph., I-VII, 1901, p. 27, pi. 3, f. 90-100 ( ?) ; Collins, Green Alg. N. A., 1909, p. 186; Collins, Ilolden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1275. 284 University of Californw Publications in Botany [Vol. 8 "NVille (1901, p. 22) has raised the question as to the exact nature of the type of this species and as to the status of other plants referred to it. Hazen (1902, p. 155) thinks, however, that AVille's doubts are not founded on sufficient basis for rejecting the name and that tlie type of U. iniplcxa may be reckoned among the marine species. "We have followed the usual fashion of referring here our most slender species whose cells are usually as long as, or often longer than, broad. The chromatophore in young cells in active vegetative con- dition forms a more or less complete band about the middle of the outer cell wall. IMany of our specimens, however, seem to have a complete chromatophore clothing the entire outer wall. We are inclined to consider the cells of such specimens as probably passing over into the fertile condition, but not, as yet, having undergone divi- sion to form zoospores or gametes. The fertile cells in these species are neither enlarged (i.e., broadened) nor swollen. A careful study of living material in various stages will be very helpful in clearing up these matters. We follow Hazen in placing the Ulothrix suhflaccida Wille Hoc. cit.) as a synonym under U. implexa. 2. Ulothrix flacca (Dillw.) Thur. Plants forming bright or dark green, often much entangled, masses or skeins; cells 10-25|U, diam., 0.25-0.75 as long as broad, when pro- ducing spores up to 50/a diam., and swollen in the middle ; chromato- phore occupying the whole of the cell wall with 1 to 3, occasionally more, pyrenoids. Growing on other algae, on rocks and on wood, in the littoral belt. From Alaska to California. Thuret, in he Jolis, Liste Alg. Mar., 1863, p. 56; Collins, Green Alg. N. A., 1909, p. 185 ; Saunders, Alg. Harriman Exp., 1901, p. 412 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 217 ; Hazen, Uloth. and Chaetoph. U. S., 1902, pi. 20, f. 7-9. Conferva flacca Dillw., Brit. Conf., 1809, pi. 49. We can not feel certain whether the Ulothrix flacca, as it has been finally limited by Wille (1901, p. 18 et seq.) is the Conferva flacca of Dillwyn (loc. cit.) or not. There is a certain strong suggestion to our minds of Ulothrix psetidoflacca Wille in both the figures and the description of Dillwyn. It seems best, however, to follow the present conception of the species and assign under U. flacca marine Ulotriches 1920] Setchell-Gardnrr: Chlorophyceae 285 which, while comparativeh' slender (10-25/x diam.) in the vegetative condition, thicken very considerably (up to 60/a or even 80/tx,) when producing zoospores or gametes. The cells when younger may be almost or quite quadrate, but become in the fertile condition very much shorter than the diameter. 3. Ulothrix pseudoflacca Wille Filaments 8-32/x diam., free from one another, attached by an ehmgated, downwardly gradually tapering cell ; cells from 0.25 as long as broad to nearly quadrate; cell walls thin; chromatophore parietal, completely covering the outer cell wall, thickened in the region of tlie single pyrenoid, fertile cells not exceeding the vegetative in diameter, from flattened to nearly globular. On rocks and algae, upper littoral belt. Alaska (Sitka) to Cali- fornia (San Francisco). Wille, Stud. ueb. Chloroph., 1901, p. 22, pi. 2, f. 64-81. Ulothrix pseudoflacca varies as follows: f. minor Wille {loc. cit., p. 23, pi. 2, f. 67-69), 8-16/. diam.; f. major Wille (loc. cit., p. 23), 10-22/x diam.; f. maxima Setchell and Gardner {in Gardner, 1919, p. 488, pi. 42, f. 6), 28-32/t, up to 40jLt diam. Plate 9, fig. 6 A, B. Of these f. iuinor has been collected at Sitka, Alaska, f. major and f. iiKi.ri 111(1 cit Lands End, San Francisco, California (all by Gardner). Ulothrix pseudoflacca bears a considerable resemblance to U. flacca except that in its fertile condition it does not reach so considerable a diameter and the fertile cells are usually more or less rounded. The chromatophore in U. pseudoflacca is a broken ring while that of U. flaccu is a complete ring. Ulothrix pseudoflacca varies much in diameter and, as shown above, may be separated more or less readily into three overlapping forms, the f. minor approximating forms of U. implexa in slenderness, while f. maxima approaches forms of U. flacca.. As filaments of U. pseudoflacca approach the fertile condition, it is difficult to detect the gap in the chromatophore. Jonsson (1904, pp. 55-57) has reviewed this species as well as others of the genus and has made valuable suggestions. He has also described a related new species [loc. cit., pp. 57-60, f. 8, 9), Ulothrix scutaid, wliich has not been thus far detected ani()iii diani., 2-3 times as long as the diameter, tenninal cells long, conical. Growing within the membrane of Chaetomorpha calif ornica Wille. Southern California (Ocean Beach, near San Diego). Setchell and Gardner, Phyc. Cont. I, 1920, p. 292, pi. 23, fig. 7. The plants of this species seem to be nearing maturity in December, since a few empty cells in the center of the thallus were found from which reproductive bodies probably had escaped. Aside from this condition, nothing further is known of its method of reproduction. Entocladm cingens is placed in tliis genus on account of the resemblance of the vegetative development to that of the type species, E. viridis Reinke, and because of the same endophytic habit as that species. It differs from E. viridis in having the branching filaments more closely coalescent, the enlarging cells in the main part of the thallus soon forming a pseudo-parencliymatous tissue, leaving only a few free marginal filaments. E. viridis, E. codicola, and E. cingens form a well connected series, using the vegetative characters as a basis. The first named species has a rather wide-spreading thallus, composed of relatively sparsely branching filaments, scarcely, if at all, coalescing in the center. In the second, the filaments coalesce freely in the center so that at least 292 University of California Piihli cat ions in Botany [Vol.8 half of the thallus is formed into a pseudo-parenchymatoiis tissue at the time of reproduction, but leaving an abundance of free branching marginal filaments. The thallus of the third is almost wholly trans- formed into a pseudo-parenchymatous tissue at maturity, leaving only a few free marginal filaments. 27. Endophyton Gardner Filaments sparingly and irregularly branched within the medulla of tlie host, but branching more freely near the surface, sending off in addition to horizontal branches many short, erect branches perpen- dicular to the frond, the end cells of the perpendicular branches becoming the sporangia and growing out to the surface of the host; chromatophore band-shaped ; each cell containing a single pyrenoid ; zoospores pyriform, 2-cyliated. Endophytic within the fronds of various species of red algae. Gardner, New Chlorophyceae, 1909, p. 371 ; West, Algae I, 1916, p. 304. This is a form genus, whose cytology is at present too little known. In its habit, it is more thoroughly endophytic than any other genus of the Chaetophoraceae, since its filaments traverse the medullary as well as the cortical tissues of its hosts. The absence of hairs and specialized zoosporangia seem to mark it as distinct. Endophyton ramosum Gardner Plate 11, figs. 3, 4 Filaments 4-6/x, diam., tortuous, often very irregular in shape ; cells 6-8 times longer than broad, cross-walls distinct ; sporangia club- shaped, tapering to a point at the outer end, when young 10-12/x diam. ; zoospores numerous, 3/i. diam., escaping through openings in the upper ends of the sporangia which grow to the surface of the host ; plants occupy small areas a few millimeters in diameter, usually near the base of the frond of the host, but may spread promiscuously over the entire area of the host. Endophytic within the fronds of various species of red algae, e.g., Iridaea laniinarioidcs, Gigartina exasperata, etc. Central California (San Francisco) and probably farther north. Gardner, New Chlorophyceae, 1909, p. 372, pi. 14, f . 3, 4 ; Collins, Green Alg. N. A., 1909, p. 282; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1627. 1920] Setchell-Gardncr: Chlorophyceae 293 Tlie presence of this endophyte in the fronds of species of Iridaea, Crigartina and possibly also of NitaphyUuDi is indicated externally by spots of a much redder color than that of the uninfested portions of the host. Its detection at other points than abovit San Francisco will probably follow careful search for it on similar hosts. . 28. Pseudodictyon Gardner Thallus much branched, the main filaments comparatively long and tortuous, creeping among the cells of the cortical layer of the host plant {Laminarm sp.), branching freely; the branches, usually aris- ing at right angles to the main filaments and bending backward among the cortical cells, unite into a sort of net; a very short erect branch composed of two or three cells arises from practically every cell of the horizontal filaments in the central portion of the thallus; the uppermost cell of each erect branch becomes a sporangium and grows to the surface of the host; each cell contains a single peripheral chromatophore with one pyrenoid ; reproduction unknown. Gardner, New Chlorophyceae, 1909, p. 874; West, Algae I, 1916, p. 304. Since neither the cj'tology nor the reproduction of the type and onh' species thus far referred to this genus, has been studied, it exists merelj^ as a form genus of probably close relationship to Entocladi-a. It is to be hoped that some one having favorable opportunity may add much that is desirable to our knowledge of this seemingly' very distinct endophytic genus. Pseudodictyon geniculatum Gardner Plate n, figs. 5, 6 The young, creeping filaments 3— 4yu, diam., becoming larger with age ; tips of the geniculate filaments seem to coalesce with neighboring cells, giving the young plant the appearance of a fine net, the meshes enclosing 4-8 cells of the host plant; sporangia 8-12/a diam.; cell walls thin and cross walls distinct. Growing in abundance in the terminal parts of tlu^ blade of Laminaria Sinclairii. San Francisco Bay, California. Gardner, New Chlorophyceae, 1909, p. 374, pi. 14, f . 5, 6 ; Collins, Green Alg. N. A., 1909, p. 283; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1628. 294 University of California Puhlications in Botany [Vol. 8 The host plant of "a" of the above distribution is Laminaria Sin- cl-airii; and the host of "b'' of the same distribution is Dictyoneuron calif or nicum. The plants under "b" are not quite typical, but with our present knowledge seem too closely related to the typical form to warrant separation from it. Its life history has not been studied. The "net" character of the thallus is much less regular than in the typical form. This may be due to the character of the cells of the host plant. 29. Internoretia S. and G. Thallus endophytic, consisting of profusely branched filaments, at first of a single series of cells increasing by apical divisions per- pendicular to the long diameter, but later, by oblique and longitudinal divisions, building up cjdindrical threads composed of numerous cells in cross diameter; branching at right angles, anastomosing, forming a network; chromatophore parietal, with one pyrenoid; reproduction unknown. Setchell and Gardner, Phyc. Cont. I, 1920, p. 294. The genus Internoretia was proposed for a peculiar endophyte found by Professor T. C. Frj^e, growing within the membranes of Porphyra. Its reproduction not having been determined, it is added to the numerous form genera of uncertain position and placed pro- visionally among the Chaetophoraceae. It resembles Pseudodictyon Gardner and Zygoiniitus B. and F. From the former it differs in forming solid filaments several cells in thickness. From Zygomitus, Internoretia differs in the greater regularity of its solid portions, and in the more uniform network brought about by the regular giving off of branches at right angles. Internoretia Fryeana S. and G. Plate 18, figs. 3-6 Cells of the terminal filaments 3.5-5/a diam., 3-5 times as long, apical cell conical; cells of the older part of the thallus isodiametric, angular; otherwise as the genus. Growing within the membrane of Porphyra Naiadum. Friday Harbor, Washington. Setchel land Gardner, Phyc. Cont. I, 1920, p. 295, pi. 23, figs. 3-6. This most interesting little plant is as yet known only from the collections and observations of Professor T. C. Frye. It generally occurs in such abundance as to discolor the host plant. In some years 1920] Setchell-Gardncr : Chlorophyceae 295 it is very common, discoloring most of the plants of Porphyra in the neighborhood of the Puget Sound Marine Station, while in other years it is difficult to find any plants at all. .'^0. Ulvella Crouan Thalli forming small disks on larger plants or other objects, firmly attached by the under surface, unistratose at first, later, at times, pluristratose, of radiating, laterally united, dichotomous filaments; segments multinucleate, with parietal chromatophore and no pyre- noid ; 2-ciliated zoospores formed in the central cells, 4-8-16 in a cell, escaping by an opening at the top. Crouan, Notice sur quelq. nouv. algues mar., 1859; p. 288, pi. 22, f. E ; Wille, Nachtrage, 1909, p. 89. The genus Ulvella is based upon Ulvella Lens, found growing upon bits of porcelain and glass at Brest, France. The original specimens have been examined by Huber (1893, p. 295), who has figured the type {loc. cit., pi. 11, f. 4-6) and added to our knowledge of its morphology and cell structure. It is a prostrate, unistratose or paucistratose, discoid plant composed of radiating filaments with no trace of hairs and whose terminal cells fork before dividing. The chromatophore is single and devoid of a pyrenoid. Nothing is known of the reproduction of the type of the species. It has come to be generally accepted that Dcrmatophyton radians Peter, a species inliab- iting the carapaces of fresh water tortoises in southwest(^rn Europe, is also to be referred to Ulvella (cf. Schmidle, 1899, Wille, 1909, p. 89) and the characters of multinucleate "cells" and 2-ciliated zoospores considered to be characteristic for the genus. Unfortunately, we do not know whether these characters hold for the type species, Ulvella Lens. We also unfortunately do not know whether they hold for the single species of our coast which we are inclined to refer under this genus and also to Ulvella Lens. It is to be hoped that further information may be obtained at some favorable opportunity. Ulvella Lens Crouan Plate 33 Thallus orbicular, briglit green, 150-250/x, up to 1.5 mm. diam. ; marginal segments usually cuneate, 3.5-4.5/i, diam., 15-25/x long with terminal growth, central segments 8-15/i, diam. Growing firmly attached to Laurencia sp. in the upper sublitloral belt. Central California (Pacific Grove). 296 University of California Publications in Botany [Vol.8 Crouan, loc. cit.; Iluber, Contributions des Chaetophorees, 1892, p. 294 et seq., pi. 11, f. 4-6; Collins, Green Alg. N. A., 1909, p. 286; Wille, Nachtrage, 1909, p. 89. We feel compelled to refer here a plant found in abundance on a species of Ixiiirencia at Pacific Grove, California, in July. In gen- eral appearance, in structure, in dimensions of the cells and manner of peripheral growth, the specimens correspond exactly with the figures and description of Huber (loc. cit.) for the type material of Ulvella Lens. Our plants, however, have only been detected, thus far, as epiphytes. "We have seen, in our preserved material, the central cells both empty and divided into 8 rounded bodies, probabh' zoo- spores. Unfortunately we have not preserved specimens in a con- dition suitable for the study of the number of nuclei in the cells. 31. Pseudulvella Wille Thalli forming small disks, composed of radiating filaments closely placed, coalescent and finally more or less loosely pluristratose towards the center, unistratose and more or less free and dichotomous towards the periphery ; cells uninucleate, with a single parietal chromatophore containing a single pj^renoid; zoospores 4-ciliated. Wille, Nachtrage, 1909, p. 90. Ulvella Snow, Ulvella americana 1899, p. 309 (in part). The genus Pseudulvella is said to differ from Ulvella in that the cells of its species have onl}^ a single nucleus, the chromatophore has a single pyrenoid and the zoospores are 4-ciliated. It is said to differ from Pseudopringsheimia in the lack of rhizoid-like filaments which penetrate the host. It is placed by Wille {loc. cit., p. 79) among the genera whose species lack hairs, although Snow (1899, p. 310) says that ''in quite a number of cases, long gelatinous hairs extended from the surface" in the type species, Ulvella americana Snow. This state- ment as to hairs undoubtedly led Collins (1909, p. 289) to refer the Ulvella americana Snow to Chaetopeltis. Since Snow does not figure the hairs and the statement seems little convincing, we are inclined to follow Wille in presuming that no hairs are present. Key to the Species 1. Basal layer of more or less distinctly radiating filaments 2 1. Basal layer distinctly parenchymatous 3. P. applanata (p. 298) 2. Radiating filaments loosely coalescent ....1. P. prostrata (p. 297) 2. Radiating filaments closely coalescent 2. P. consociata (p. 297) 1920] Setchell-Gardner: Chlorophyceae 297 1. Pseudulvella prostrata (Gardner) S. and G. Plate 11, figs. 1, 2 Thallus 2-3 mm. diam. consisting of 2-3 layers of cells in the center, but of a single layer at the margin, formed by branching fila- ments growing out radially on the host, coalescing in the central part of the thallus but free from each other around the margin, and adhering very firmly to the host ; filaments branched, 6-7 /x diam., nearlj' uniform in diameter throughout their entire lengtli ; cells quadrate in the center of the thallus, those at the outer ends of the filaments 1.5-2.5 times as long as broad ; color very dark green ; end cells blunt, each containing a single peripheral chromatophore and one pyrenoid. Growing on the basal portion of Iridaea laminarioides. Central California (Lands End, San Francisco). Setchell and Gardner, Phyc. Cont. I, 1920, p. 295. Ulvella pros- trata Gardner, New Chlorophyceae, 1909, p. 373, pi. 14, f. 1, 2 ; Collins, Green Alg. N. A., 1909, p. 287 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1629. Although we know too little of the Ulvella prostrata Gardner both from the point of view of its cytology and of the nature of its zoo- spores, it cannot remain in Ulvella because of the presence of a pj-renoid in the chromatophore. It does not possess the penetrating rhizoidal filaments supposed to be characteristic of Pseudopring- sheimia. It does, however, resemble Pseudxdvella ameriaina (Snow) AVille sufficiently closely in its general structure to be referred to the same genus for the present at least. 2. Pseudulvella consociata S. and G. Plate 19, figs. 4-6 Thallus irregular in size and in outline, 100-140/i, thick, increasing by irregular and obscurely radiating filaments early coalescing and becoming parenchymatous ; color dark green ; erect filaments firmly coalescent, 7-10/i diam., cells nearly cjdindrical, slightly irregular in form, 1-2 times as long as the diameter; zoosporangia (?) terminal, l\vriform to spherical, producing 8 zoospores. Growing on the shells of Ilyanassa ohsoleta Say. Central Cali- fornia (Bay Farm Island, Alameda). Setchell and Gardner, Pliyc. Cont. I, 1920, p. 296, pi. 24, fig. 4-6. 298 rniversity of California Publications in Botany [Vol.8 Tlie shells of Ilyanassa obsoleta were introduced some years ago along with oysters from the Atlantic coast of North America, and possibly the plant here described was introduced with the host. The comparison of this species with others will be found included in the discussion under P. applanata. 3. Pseudulvella applanata S. and G. Thallus thin, parenchymatous, spreading by marginal growth, expanded to several mm. in diam., smooth and glossy, 45-55/x thick; color grass green ; cells in fairly regular vertical rows nearly iso- diametric, sharply angled, 6-7. 5ju, diam. ; chromatophore covering the cell wall, provided with one pyrenoid; zoosporangia ( ?) slightly modi- fied surface cells ; reproduction imknown. Growing on the shells of Littorina planaxis Nutt. Central Cali- fornia. Setchell and Gardner, Phyc. Cont. I, 1920, p. 295. Littorina planaxis is very abundant in small tide pools and in moist places along high-tide level from Sitka to San Diego. Pseudul- vella applanata has been studied only on material found along the coast of central California, but it is presumed to have a much wider distribution. Its presence on the host is readily recognizable by its expanded, grass green, glossy appearance. Microscopically it may readily be distinguished from all other described species of the genus by its very small, closely compact, parenchymatous cells, and its seeming absence of radiating filaments composing the basal layer. It spreads over the host by tangential and by radial divisions of the peripheral cells, at least it can thus be stated when the plant is of considerable size. It probably starts on the very young host, and doubtless many plants early coalesce to form a confluent thallus. We have never been able to ascertain the nature of the early developmental stages, although even very small shells have been examined. Reproductive bodies have been seen to escape from the surface cells. Wliether they are zoospores or gametes, the number of cilia they posses, and their behavior after escaping are subjects for furth(;r investigation. The three species of Pseudulvella treated of in this paper may be arranged, so far as the basal layer is concerned, in the follow- ing sequence : P. prostrata, with distinctly radiating basal filaments 1920] Setchell-Gardner: Chlorophyceae 299 which branch rather frequently and which are comparatively loosely coalescent; P. consociata, with indistinctly radiating basal filaments closely coalescent; and P. applanota, with a parenchymatous basal laj^er. 32. Pseudopringsheimia Wille Thallus cushion-shaped, epiphytic, often penetrating the hosts at intervals, or growing upon the shells of mollusks; increase in diameter produced by terminal growth of radiating filaments branching fre- quently and coalescing to form a parenchymatous basal layer; increase in thickness produced by horizontal divisions of the cells of the basal layer forming a mass of erect filaments sometimes branching in turn; cells without hairs containing one chromatophore in the outer end, and one pyrenoid ; zoosporangia mostly terminal on the erect filaments or occasionally subterminal as well. Wille, Nachtriige, 1909, pp. 88, 89. The genus Pseudopringsheimia was founded on the two species, UlveU-a conflucns Rosenv. and V. fucicol-a Rosenv. The particular characteristic separating the genus, especially from Pseicdulvella Wille is the presence of rhizoidal outgrowths from the base penetrating the host plant. In other respects the species of Pseudopringsheimia closely resemble those of Pseiidulvella. It is a question as to how important such structures as penetrating rhizoids should be estimated as being in separating genera, but since AVille has separated the two genera and since we have altogether too little knowledge of their reproductive processes, it seems best to recognize both for the present, Pseudopring-sheimia apiculata S. jiiid G. Plate 17, ligs. 1, 2 Thallus minute, 145-160/a thick, hemispherical when alone, but often with many crowded closely together forming a continuous stratum 2-3 mm. diam. ; color bright green ; erect filaments 8-12/^ diam., composed of 9-12 cylindrical or slightly swollen cells; rliizoids aggregated into short conical fascicles; zoosporangia ( ?) producing 8 zoospores, terminal, slightly swollen, varying from convex to de- cidedly apiculate; zoospores (?) 4-ciliated. Growing on the rhachis and the cysts of Egrecjia Menzi^sii. Cen- tral California. Setchell and Garndor, Phyc. Cont. I, 1920, p. 297, pi. 22, figs. 1, 2. 300 University of Californm Puhlic^tiojis in Botany [Vol.8 Pseudopringsheimia apicidata is closely related to P. conflucns (Rosenv.) "Wille. The most conspicuous difference is to be foiuid in the shape and size of the zoosporangia, if the terminal reproductive cells are to be designated as such. Those of P. confluens are long and comparatively narrow, and produce 30^0 zoospores, while in P. apiculata they are shorter, somewhat swollen, mostly with a pro- nounced terminal projection, and produce about 8 zoospores. These reproductive bodies are very small, and 'it is exceedingly difficult to determine the number of cilia. On one occasion four cilia were observed but the reproductive bodies seemed a little larger and some- what more irregular in form than the average. These may have been the zj^gotes formed by the fusion of 2-ciliated gametes, but had not yet come to rest. 33. Gomontia Born, and Flah. Thallus consisting of creeping, freely branched, septate filaments, from the under side of which many erect, more or less branched fila- ments arise ; cells irregular in shape and size, uninucleate, occasionally multinucleate, with parietal, band-foi^m or shield-shaped chromato- phore covering the whole or part of the cell, or a network extending through the cell, with one or two pyrenoids ; reproduction by zoo- sporangia, producing a few egg-shaped zoospores with 4 cilia, by large, irregularly shaped, thick walled, gametangia (?) with rhizoidal outgrowths, producing 2-ciliated gametes (?) whose conjugation is unknown, and by similar large cells producing aplanospores. Bornet and Flahault, Note sur deux algues, 1888, p. 163 (Repr., p. 5) ; Sur quelq. pi. viv. dans le test calc, 1889, pp. clii-clx, pi. 6-8, 10, fig. 3. The genus Gomontia is composed of species having the peculiar and presumably distinctive habit of boring into calcareous material. They are usuall}^ to be found boring into shells of mollusks, chiefly lamellibranchs, of both fresh and salt waters. One species {O. codio- lifera (Chodat) Wille), however, bores (?) into limestone rocks. We have considered, as chief characteristic of this genus, the formation of large "sporangia" (gametangia ( ?) and aplanosporangia) which are usually provided with one or more rhizoid-like appendages. In some species, however, there seem to be no such appendages (e.g., G. arrhiza Hariot). The "sporangia" arise as segments of the branch- ing filaments. These segments enlarge and give off processes, finally 1920] Seichell-Gardner: Chlorophyce-ae 301 the walls thicken more or less and the "rhizoids" often thicken so as to become entirely solid or, at least, throughout the greater portion. The "sporangia" varj- considerably in shape and size, even in speci- mens inhabiting the same shell, and at times exhibit extraordinary differences, but at other times closely follow a particular type. It has been puzzling to us to interpret this variation. As a result of considerable experience, how^ever, we are inclined to lay more stress on distinctions of form and- size in the "sporangia" than has been done by otliers. In connection with any attempt to examine carefully and critically the various specimens of Gomantia as to their identity with, or dis- tinctness from, the eight or more species already described, it has become neeessarj^ to examine carefully the type of the species, viz., Gomontia polyrhiza (Lager.) B. and F. We have two sources of information as to tlie type species, viz., tlie original description and figures of Lagerheim (1885) and the careful and detailed description and figures of Bomet and Flahault (1888). For reasons which we shall give below, we are inclined to suspect that the plant of Bornot and Flahault is a different species from that of Lagerheim, and our suspicion is so strong that we have felt it necessary (cf. Setchell and Gardner, 1920, p. 298) to bestow upon it a new specific name, viz., G. Bornetii S. and G. In carrying out the idea that the "sporangia" furnish diagnostic characters, we have separated several species which present difficulties, to be sure, in narrow diagnosis, but which seem rather more satisfying than the attempt to lump all under the one name. The explanation of the variability may possibly be that the different texture of the various species of shells, or of different portions of the same shell, affect the size and shape, but there does not seem to be evidence forthcoming to support this idea. It seems possible that two, or even more, species may be inhabitants of the same shells and thus cause an intermingling of different types of "sporangia." In our attempt to clear up the situation, we have a.ssumed tlie possibili- ties of distinct species, at times, intermingled. Key to the Species 1. "Sporangia" with 2 to several rhizoids 2 1. "Sporangia" usuallywith a single rhizoid 4. G. caudata (p. 304) 2. "Sporangia" longer than broad (Codiolum-type) ...1. G. polyrhiza (p. 302) 2. "Sporangia" broader than long (Acarid-type) 3 3. Rhizoids nearly simple, stout, blunt 2. G. Bornetii (p. ,302) 3. Rhizoids branched, slender, acute 3. G. habrorhiza (p. 304) 302 Fnivcrsitij of California ruhlications in Botany [Vol.8 1. Gomontia polyrhiza (Lagerh.) B. and F. Plate 19, fiff. 1 "Sporangia" irrogularl}- and bi'oadly clavate to nearly cylindrical, up to 150/x diam., and 240/i, long, producing usually several blunt, at times sliglitly branched rhizoids at the smaller (proximal) end. Growing in clam shells. Neah Bay, Washington. Bornet and Flahault, Note sur deux nouveaux genres d'algues per- forantes, 1888, pp. 161-163, Sur quelq. pi. viv. dans le test, calc, 1889, pp. clii-clx, pi. 6-8 (as to combination onl}') ; Setchell and Gardner, Phyc. Cont. I, 1920, p. 298, pi. 24, fig. 1. Codiolum polyrhizum Lager- heim. Cod. poly. n. sp. etc., 1885 (at least in greater part). The above description is taken in part from the original of Lager- heim and in part from the material collected at Neah Bay. The material from which Lagerheim drew his description was apparently in the sporangial stage exclusively, as least he did not recognize a sterile, or vegetative stage. The Neah Bay material, collected in May, is likewise in a reproductive stage, or if the vegetative stage is present, it and the sporangial stage could not be identified as belonging to the same species, hence the incompleteness of the description. The "sporangia" approximate so closely to the figures (especially figs. 10, 11) and the description of Lagerheim as to make it sufficiently safe to ally our plant with his and to keep it distinct from the G. poly- rhiza of Bornet and Flahault {G. Bornetii S. and G.). The filaments of this species have been examined by us in a speci- men distributed by Reinbold from Keil. Reinbold's specimens have "sporangia" largely of the Codiolum-type, both old and young, but it also has an occasional "sporangium" of the Acrid-type (apparently good G. Bomeivi). Since Reinbold's locality is not far distant from Lagerheim 's type locality, it seems extremely probable that his plant is true G. polyrhiza. The filaments in Reinbold's specimens are so close to those of G. Bornetii as figured by Bornet and Flahault {loc. cit.) as to be indistinguishable. 2. Gomontia Bornetii S. and G. Horizontal filaments irregular, much branched, erect filaments with clavate ends, less branched ; cells 4-12/x, most frequently Gfi diam., 15-55//, long, cylindrical to more or less swollen and crooked; "sporan- gia" variable and irregular in form, 80-125/a wide, 150-200/x long. 1920] Setchell-Gardner: Chlorophyccae 303 having numerous blunt, mostlj' simple rhizoids arising principally on one side, but oceasionallj' promiscuously scattered all over the sporangia ; zoospores of two sorts, one 3.5/a wide and 5fi long, the other 5-6/4 wide and lO-12/i long, development unknown ; aplanospores 4/i diam. Growing in clam shells. Neah Bay, Washington. Setchell and Gardner, Phyc. Cont. I, 1920, p. 298. Gomontia polyrhiza Bornet and Flahault, Notes sur deux nouveaux genres d'algues perforaaites, 1888, pp. 161-163 (pp. 3-5, repr.), Sur quelq. pi. viv. dans le test, ealc, 1889, pp. clii-clx, pi. 6-8 (not Codi- olum polyrhiza Lagerheim). Bornet and Flahault (1889) distinctly state (p. civ) that the greatest dimensions of the "sporangia'' in their specimens are 120ju, for the height and 75/i for the width and mention that Lagerheim found "sporangia" in his specimens up to 240/a in height and 60jU, in breadtli. We judge, therefore, that the Codiolum-type of "sporan- gium" which Lagerheim figures (1885, pi. 28, figs. 10, 11 in particu- lar) and describes {"pleriimque plus mimts elongatis," loc. cit. p. 22) was not to be found in the French material and certainly is not illustrated by Bornet and Flahault, unless figure 9 on plate 7 may represent it. The type of "sporangium" illustrated by Bornet and Flahault (1889, pi. 7, 8) belongs to the shorter and broader type, the Acarid-type as it may be called, and has blunt, simple or slightly branched rhizoids. Lagerheim (loc. cit., pi. 28, figs. 7, 8, 12, 13) has also figured "sporangia" of the true Acarid-tj^pe and probably found a mixture of species in the shells he examined. Since, however, he emphasizes the elongated, or Codiolum-type of "sporangia," it seems best to reserve his specific name for the species with the Codiolum-type of "sporangium" and assign the new specific name (Bornetii S. and G.) to the species having the Acarid-type of "sporangium" and with blunt, rather stout, simple or, at most, slightly branched rhizoids. The filaments of G. Bornetii are well represented by Bornet and Flahault (1889, pi. 6, figs. 1-8) and by their usually large number of short blunt or almost bulbously enlarged branchlets and their com- pact massing, make a characteristic appearance after decalcification. They are very similar to tliose of G. polyrhiza so far as we may deter- mine, but somewhat different from those of G. hahrorhiza, although this difference is not readily described. While we find what seems referable to G. Bornetii in the Puget Sound region and that of central California, we desire more abundant and more decisive material to make us certain. 304 Vnivcrsity of California Puhlications in Botany [Vol.8 3. Gomontia habrorhiza S. ami G. Plato 19, ligs. 2, 3 Filaments repeatedly and irreo:ularly branched ; cells very variable in form and size, typically cylindrical, 4-7/i. diam., 2-8 times as long; chromatophore without pyrenoids, filling the cell; "sporangia" nar- row to wide, bluntly conical, 50-70/x high, 25-60/a wide, developing many very slender, attenuate, dendritically branched rhizoids from the lower side; reproduction unknown. Growing in dead clam shells. Neah Bay, Washington. Setchell and Gardner, Phyc. Cont I, 1920, p. 299, pi. 24, figs. 2, 3. In certain shells from Neah Bay we have found all the "sporan- gia" of the Acarid-type and with the processes or rhizoids slender, branched, and attenuated to a point. The "sporangia" seem so distinct from those of G. Bornetii that we described the plant possess- ing them as new. In some shells, we have found the "sporangia" of this species intermingled with others. The vegetative filaments of G. habrorhiza seem less entangled and slightly larger than those of either G. polyrhiza or G. Bornetii. 4. Gomontia caudata S. and G. Plate 18, fig-s. 1, 2 Filaments short, sparsely branched ; cells 5.5-6.5/i, diam., 2-12 times as long; chromatophore covering the terminal cells and young "sporangia," broken in the older cells; pyrenoids inconspicuous; "sporangia" clavate, 50-70/x diam., 160-200ju, long, tapering to a single rhizoid below with thick, hyaline, homogeneous wall at maturity; rhizoid often becoming much thickened and striated. Growing in shells of Mytilus c-alifornictis. Neah Bay, Washington. Setchell and Gardner, Phyc. Cont., 1920, p. 300, pi. 23, figs. 1, 2. We have found in shells of the larger edible mussel of our coast a Gomontia with filaments seemingly less abundantly branched and "sporangia" (aplanosporangia?) with very thick walls and with a single long rhizoid (cf. pi. 18, figs. 1, 2). These "sporangia" bear a certain resemblance to the "cells" figured by Lagerheim (1885, pi. 28, fig. 4, 6) but are, at least, thicker walled. The fact which seemed to indicate distinctness was that only this type of "sporangium" was found in the shells examined. 1920] Setchell-Gardncr : Chlorophyceae 305 FAMILY 13. TRENTEPOHLIACEAE de-toni Tlmlli tilamentous, brauclied, forming cUtl'use or felt like tufts or expansions, in some genera compact and discoidal ; cells with one to several nuclei ; ehromatophore single and band-shaped or several and lenticular, the chlorophyll masked by haematochrome ; zoosporangia borne on geniculate or hooked cells, usually deciduous and producing 2-ciliated zoospores; gametangia terminal or intercalary producing 2-ciliated gametes. De-Toni, Consp. gen. Chloroph., 1888, p. 449 ; llansgirg, Ueber Gatt. Herposteiron, etc., 1888, p. 222 ; Collins, Green Alg. N. A., 1909, p. 315; West, Algae I, 1916, p. 305. Chroolepidaceae Borzi, Stud. Alg., fasc. 1, 1883, p. 25 (in part). More recent authors agree in separating Trentepohliaceae from Chaetophoraceae, principally on account of habitat and the presence of haematochrome in the cells, masking the green of the chlorophyll and giving an orange-red or yellow color to the members of this family. The plants belonging to Trentepohliaceae are usually epiphytic, or partially endophytic, but some species of Trentepohlia grow upon rocks. Only one member of the family aifects, at times, a habitat subject to the direct action of the sea water. Since that member has been found in a marine situation on our coast, we feel compelled to include an account of it. 34. Trentepohlia ]\rart. Frond composed of dichotomously or irregularly branched, erect filaments of a single series of cells, arising from irregularly branched creeping filaments; branches arising either from the middle or from the upper ends of the cells; color greenish at times in active vegetative condition, changing to yellowish or red, fading to white wlnii dried and dead; cells cylindrical to spherical with thick hyaline walls; ehromatophore without pyrenoid, band-shaped oi- broken; reproduc- tion by 2-ciliated zoospores in sporangia borne on special hooked oi- curved cells, and by 2-ciliated gametes in lateral, termiiuil or inter- calary transformed vegetative cells. Martins, Flora Cryptog. Erlang., 1817, p. 351. The members of this genus are usualh' found upon wood or the trunks of trees, although certain species are found upon rocks. The rock-inhabiting species as well as those found upon trees, are of 306 Vniversitij of Californm Piihlications in Botany [Vol.8 frequent occurrence in the maritime region, especially where fogs are frequent. Only one species, however, is said to be found where actually immersed at high tide and that grows upon wood. The aerial species on rocks and wood are often conspicuous, forming broad patches of j-ellow or deep orange-red upon the rocks or tree trunks. Those visiting the shore in search of marine algae are very likely to encounter some of these species. Trentepohlia odorata var. umbrina (Kuetz.) Harlot Filaments forming a more or less dense, at times pulverulent or tomentose stratum, without marked distinction between prostrate and erect positions, flexuous, somewhat torulose, with short branches ; color green, varying to brownish or orange-red ; cells varj- ing from cylin- drical to ovoid, 10-30ju. diam., 1-1. 5/i, times as long; cell wall thin when young, becoming thick and lamellate with age ; gametangia spherical to ellipsoid, lateral, terminal or intercalary, 20-30/a diam. ; sporangia similar to gametangia. Growing on piles of Douglas Fir (Pseudotsuga taxifolia) along high-tide level. Breakwater, San Pedro Harbor, Los Angeles County, California. Hariot, Notes sur le genre Trentepohlia, 1889, pp. 400-403; Col- lins, Green Alg. N. A., 1909, p. 319. Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 2288. Chroolepns umbrinum Kuetz- ing, Phyc. Gen., 1843, p. 283, pi. 7, f. 2. Trentepohlia umbrina var. quercina Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 662. One of us (Gardner) has found what certainly seems to be this species growing on piles of Douglas Fir {Pseudotsuga taxifolia) along high-tide level and above, but where frequently immersed in or splashed by the sea water. The zone affected by the tide was of green color, but above, where contact with salt water was less frequent, the color was deep orange. The locality was observed on two occasions several years apart, and the Trentepohlia found persisting. The filaments are to be found mostly within the empty wood cells of the piles. 1920] Setchell-Gardner: Chlorophyceae 307 BIBLIOGRAPHY Agardh, C. a. 1817. Synopsis algarum Scandinaviae, adjeeta dispositione univcrsali alganim. Luud. 1817-1825. Aphorismi botanici. Decades I-XVI. Lund. 1820-1828. Species algarum rite cognitae cum synonyinis, differentiis specificis et doseriptioiiibus succiuetis. 1820. Vol. 1, part I, pp. 1-268. 1822. Vol. I, part II, pp. 269-531. 1828. Vol. II, part I, pp. i-lxxvi and 1-189. 1824. Systema algarum. Lund. 1828-1835. Iconcs algarum europaoarum. Representation d' algues euro- peennes suivi de colle des especes exotiques les plus remarquables recemment decouvertes. Leipzig. 1828. Vol. 1, pis. 1-10. 1828 (or 1829?), vol. 2, pis. 11-20. 1829. Vol. 3, pis. 21-30. 1835. Vol. 4, pis. 31-40. ["Literatur Bericht zur Linnaea, fiir das Jahr 1830," p. 86, has a notice of the Avork: "Livraisous 1-3, nos. 1-30, Leipsic 1828 u. 29." This seems to us to imply that part 1 was issued in 1828, covering plates 1-10, part 3 in 1829 covering plates 21-30, while part 2, plates 11-20 may be either 1828 or 1829. Collins in a letter of June 16, 1919, where he writes us the above information, says also, "safe to assume that part 4 was issued in 1835," i.e., plates 31-40.] Agardh, J. G. 1842. Algae maris Mediterrauei et Adriatiei, observationes in diagnosiu specierum et dispositionem generum. Paris. 1846. Anadema, ett nytt slagte bland Algerne. Kongl. Sv. Vet.-Akad. Handl., pp. 1-16. Stockholm. 1847. Nya Alger fran Mexico. Oefvcrs af Kongl. Vet.-Akad., Fbrhaudl. Arg. 4, no. 1. Stockholm. [Often quoted as "Alg. Lieb. " Volume 4 of the "Oefversigt" is dated on title page and final page, 1848, but the individual part-s are all dated "1847" on the title page; the exact date of imprint, however, is given at the bottom of the final page of each number. Numbers 1-9 were issued in 1847, but number 10 and the title page and index were delayed until 1848.] 1873-1890. Till Algernes' systematik, Xya bidrag. 1873. Forsta afdelningen, vol. 9. Lunds Univ. Arssk. 1882. Andra afdelningen, vol. 17. Lunds Univ. Arssk. 1883. Tredje afdelningen, vol. 19. Lunds Univ. Arssk. 1885. Fjerde afdelningen, vol. 21. Lunds Univ. Arssk. 1887. Femte afdelningen, vol. 23. Lunds Univ. Arssk. 1890. Sjette afdelningen, vol. 26. Lunds Univ. Arssk. Ahlxer, K. 1877. Bidrag till Kannedomen om de Svenska formerna af Algsliigtet Entero- inorpha. Akademisk aufhandling. Stockholm. 308 University of California Puhlications in Botany [Vol.8 AXDEKSON, C. L. 1891. List of Califoruia marine algae with notes. Zoe, vol. 2, pp. 217-225. ArdissoJJE, F. 1883-1886. Phycologia mediterranea. Part I, Floridee. 1883. Mem. Soc. Critt. Ital., vol. 1. Ihid. Part Ila, Ooosporee, Zoosporee, Schizosporee. 1886. Ibid., vol. 2. Areschoug, J. E. Algae seandinavicae exsiccatae. 1840. Edition 1. 1861-1879. Series nova, Ease. I-IX. Upsala. 1843. Algarum (Phyeearum) minus rite cognitarum pugillus secundus. Linnaea, vol. 17, pp. 256-269, pi. 9. 1850. Phyceae Scandinaviae marinae, sive Fucacearum nee non Ulvacearum, quae in maribus paeninsulam scandinavicam affluentibus crescunt, descriptiones. (Fucaceae, ex Act, Upsal., vol. 13. Ulvaceae, ex Act, Upsal., vol. 14.) Upsala. 1866. Observationes* phycologieae. Die confervaceis nonnullis, part 1. Upsala. Batters, E. A. L. 1891. Hand-list of the algae in the algae of the Clyde Sea area. Journal of Botany, vol. 29, pp. 212-214; 229-236; 273-283. Ibid. Eeprinted, with additions, from the Journal of Botany for 1891, pp. 1-25. 1894. New or critical British algae, Grevillea, vol. 22, p. 114. Bentham, G. 1843. Tetrnnema mexicnnum , in Lindley, Edwards's Botanical register or ornamental flower-garden and shrubbery, consisting of coloured fig- ures of plants and shrubs cultivated in British gardens, accompanied by their history, best method of treatment in cultivation, propagation, etc. Vol. 6, new series. London. Blackman, F. F., and Tansley, A. G. 1902. A revision of the classification of the green algae. The New Phytolo- gist, vol. 1, pp. 17, 47, 67, 89, 114, 133, 163, 189, 213, 238. Bonnemaison, T. 1822. Essai d 'un classification des Hydrophytes loeulees ou plantes marines qui croissent en France. Joum. de Phys., vol. 94, pp. 174—203, 6 pi. BORGESEN, F. 1902. The marine algae of the Faeroes, in Warming, Botany of the Faeroes, part II, p. 339. Copenhagen. BORNET, E. 1892. Les algues de P.-K.-A. Sehousboe, recoltees au Maroc & dans la Medi- terranee de 1815 a 1829. Mem. Soc. Nat. Sci. Nat et Math, de Cherbourg. Vol. 28, p. 165. Paris. BoRNET, E., and Flahault, C. 1888. Note sur deux nouveaux genres d 'algues perforantes. Journal de Botanique, vol. 2, p. 161. 1889. Sur quelques plantes vivant dans le teste calcaire des mollusques. Bull. Soc. Bot. de France, vol. 36, p. cxlvii, pis. 6-12. 1920] Setchell-Gardncr: Chlorophycece 309 BoRY DE Saint Vincent, J. B. (M. A. G.) 1804. Voyage dans Ics quatre principales ilcs des mors d' Afrique, fait par ordre du gouvernment pendant les anndes IX et X de la republique (1801 et 1802), avec riiistoire de la travers6e du Capt. Baudin jusqu'au Port Louis de 1 'isle Maurice. 3 vols. Paris. 1827-1829. Cryptoganiie, in Voyage autour du monde — sur la Corvette de Sa Majcste, La Coquille, par M. L. I. Duperrey, pp. 1-96, 1827; 97-200, 1828; 201-300, 1829; according to Shcrborn and Woodward, in Jour- nal of Botany, vol. 39, p. 206. The title page is dated 1828. (Atlas, 1826.) 1828rt.. In Dictionaire classique d'histoire naturelle, vol. 13. Paris. BoRZi, A. 1883. Studi algologici saggio di ricerche snlla biologia delle alghe. Fasc. 1. Messina. Brand, F. 1904. Ueber die Ahuheftung der Cladophoraceen und ueber verschiedene polynesischon Formen dieser Familie. Beihefte Bot. Centralb., vol. 18, pp. 165-193, pis. V, VI. 1908. Zur Morphologie und Biologie des Grenzgebietes zwischen den Algen- gattungen Bliizoclonium und CJadopJwra. Hedwigia, vol. 48, pp. 45-73. Braun, a. 1855. Algarum unicellularum genera nova et minus cognita. Leipzig. Briquet, J. 1906. Regies Internationales de la nomenclature botanique adoptees par le congres international de botanique de Vienne, 1905. 1912. Ibid. Deuxieme edition mise au point d'apres les decisions du congrfes international de botanique de Bruxelles, 1910. Jena. Chodat, R. 1902. Algues vertes de la Suisse. Beitrtige zur Kryptogamcn-flora der Schweitz. Vol. 1, part 3. COHN. F. 1872. Ueber parasitische Algen. Beitr. Biol. Pflanzen., vol. 1, part 2, p. 87. Collins, F. S. 1902. The marine CUidophoras of New England. Rhodora, vol. 4, no. 42. 1903. The Ulvaceae of North America. Rhodora, vol. 5, p. 1, pis. 41-43. 1906. New species, etc., in the Phycotheea Boreali-Americana. Rhodora, vol. 8, no. 90, pp. 104-113. 1907. Some new green algae. Rhodora, vol. 9, p. 155. 1909. The green algae of North America. Tufts College Studies, vol. 2, no. 3, Scientic Series. Mass. 1909a. New species of Cladoplwra. Rhodora, vol. 11, pp. 17-20, pi. 78. 1912. The green algae of North America, Supplement I. Tufts College Studies, vol. 3, no. 2, Scientific Series. Mass. 1913. The marine algae of Vancouver Island. Canada Geological Survey. Victoria Memorial Museum, Bulletin no. 1, pp. 99-137. Victoria, B. C. 1918. The green algae of North America, Supplement II, Tufts College Studies, vol. 4, no. 7, Scientific Series. Mass. Collins, F. S., Holden, I., and Setchell, W. A. 1895-1917. Phycotheea Boreali-Americana. Fasc. 1-45 and A-E. (Exsiec). Maiden, Mass. 310 University of California Piihlications in Botany [Vol.8 COTTOK, A. D. 1912. Clare Island Survey, part 15, Marine Algae. Proe. Boy. Irish Acad., vol. 31, pp. 1-178, pis. 1-11. Dublin. Ck)viLLE, F. v., and EoSE, J. N. 1898. List of plants collected by Dr. and Mrs. Leonard Stejneger on the Commander Islands during 1895-1897, in Jordan, Fur seals and fur seal islands, vol. 4, p. 352. Crouax, p. L., and H. M. 1859. Not«s sur quelques especes et genres nouveaux d'algues marino de la rade de Brest. Ann. Sci. Nat.', 4 ser., Bot., vol. 12, p. 288. Davis, B. M. 1908. Spore formation in Derhesia. Annals of Botany, vol. 22, p. 1. Decaisxe, J. 1841. Plantes de I'Arabie heureuse recueilles par M. P. E. Botta. Arch. du. Mus., vol. 2, p. 89. Paris. 1842. Essai sur une classification des algues et des polypiers calciferes de Lamouroux. Ann. Sci. Xat., 2 ser. Bot., vol. 17, p. 297. 1842a. Memoire sur les corallines ou polypiers calciferes. Ann. Sci. Nat., 2 ser. Bot., vol. 18, p. 96. De Candolle, A. P. 1801. Extrait d 'un rapport sur les Conferves, fait a la Societe Philomathique par C. C. DecandoUe. BulL Sci. Soc. Phil., no. 51, p. 17. Paris. Delile, a. R. 1813. Flore d 'Eg}'pte. Paris. De Notaris, G. 1846. Novita algologiche {Prospetto delJa Flora Ugustica nella Descrizione di Genova e del Genm-esato, publicata per cura del Municipio di Genova in occasione del Congresso degli scienziati italiani tenuto in questa citta nell'anno 1846), con 1 tav. Genoa. DESMAZlilRES, J. B. H. J. 1825. Plantes cryptogames du nord de la France. Fasc. 1 (Exsicc). Lille. Desvaux, N. a. 1813-1814. Journal de botauique appliquee a 1 'agriculture, a la pharmacie, a la medecine et aux arts. 4 vols. Paris. De-Toni, J. B. (or G. B.) 1888. Conspectus generum Chlorophycearum omnium hucusque cognitorum. Notarisia, ann. Ill, no. 10, pp. 447-453. Venice. 1889. Sylloge Algarum. Vol. 1, sec. I, II, Chlorophyceae. 1895. Phyceae Jajonieae novae, addita enumeratione algarum in ditione mari- tima Japoniae hucusque coUectarum. Mem. R. 1st. Veneto, sci. lett. ed arti. Vol. 25, no. 5. Venice. De-Toni, J. B. (or G. B.), and Litvi-Morenos, D. 1888. Flora algologica della Venezia, part III, Le Cloroficee. Atti R. 1st. Veneto, ser. 4, vol. 5, pp. 1511-1593 ; vol. 6, pp. 95-155 and 289-350. Venice. DiLLENIUS, J. J. 1741. Historia muscorum, in qua circiter sex centae species veteres et novae ad sua genera relatae describunter, et iconibus genuinis illustrantur ; com appendice et indice synonymorum. Oxonii. 1920] Setchell-Gardner: Chlorophijccae 311 DiLLWYN, L. W. 1802-1809. British Confervae or coloured figures and descriptious of the Brit- ish plants referred by Botanists to the genus Conferva- Loudon. [The title page as above is dated 1809, then follow two pages of the "Preface to the First Fasciculus," dated June 1, 1802, which is also a sort of advertisement. There are 87 consecutively niunbcred pages of * ' Introduction, ' ' discussions of the systems of Roth, Vaucher, De Candolle and Hudson, and a ' ' Synopsis of the British Confervae." The five pages of Index of this portion are unnum- bered. These 87 pages, index and title page were issued probably late in 1809. There are 109 plates consecutively numbered, and mostly dated as to issue, together with one or more pages of text for each species figured. The plates and leaflets of text were undoubtedly issued in fascicles, some of wliich were numbered, and at various dates. Finally there are five "supplementary plates," done in a very different style from the others and labelled from A-G. They are not dated neither are they accompanied by leaflets of text as are the other 109 plates. From the dates on the plates and the fascicle numbers at the bottom of some of the descriptive leaflets, the work was probably issued as follows : 1802, June 1, "Preface to the First Fasciculus.' 1802, July 1, Fasciculus 1, text and plates 1-12. 1802, Nov. 1, Fasciculus 2, text and plates 13-20. 1803, June 1, Fasciculus 3, text and plates 21-32. 1803, Nov. 1, Fasciculus 4, text and plates 33-38. 1804, Dec. 1, Fasciculus 5, text and plates 39-44. 1805, Sept. 1, Fasciculus 6, text and plates 45-50. 1805, Dec. 1, Fasciculus 7, text and plates 51-56. 1806, Mar. 1, Fasciculus 8, text and plates 57-62. 1806, June 1, Fasciculus 9, text and plates 63-68. 1806, Sept. 1, Fasciculus 10, text and plates 70-75. 1806, Dec. 1, Fasciculus 11, text and plates 76-81. 1807, Mar. 1, Fasciculus 12, text and plates 82-87. 1807, June 1, Fasciculus 13, text and plates 88-93. 1808, July 1, Fasciculus 14, text and plates 94^99. 1909, (Feb. 20?), Fasciculus 15, text and plates 100-105. 1809, ?, Fasciculus 16, text and plates 69 and 106-109. 1909, ?, Fasciculus 16?, supplementary plates A-G. 1809, Title page, 87 pages of text, and 5 pages of index.] Don, G. 1831-1838. A general history of the diclamydeous plants comprising eomplote descriptions of the different orders, etc. 1831, vol. 1. 1832, vol. 2. 1834, vol. 3. 1838, vol. 4. [The first three volumes are entitled "A general system of gar- dening and botany, etc.," the fourth volume only having the above title. The title of the first three volumes is frequently quoted as "Gen. Syst."] DUMORTIER, B. C. 1822. Commentations botanicae (Observationes botaniques) (1823). Tournay. 1829. Analyse des families des plantcs avec I'indication des priucipaux genres, qui s'y rattachent. Tournay. 312 University of California Puhlications in Botany [Vol.8 English Botany, or coloured figures of Britisli plants with their essential char- 1790-181-4. actcrs, synonymes, and places of growth, to which will be added occasional remarks by James Edward Smith. The figures by James Sowerby. Vols. 1-36. London. Farlow, W. G. 1881. Marine algae of New England and adjacent coast. Eeport of the U. S. Fish Comni. for 1879. Washington. Farlow, W. G., Anderson, C. L., and Eaton, D. C. 1877-1889. Algae Exsiccatae Americae-Borealis. Fasc. 1-5. Boston. FoRSTER, J. R., and G. 1776. Characteres generum plantarum quas in itinere ad insulas maris Aus- tralis collegerunt, deseripserunt delinearunt annis MDCCLXXII- MDCCLXXV. London. FOSLIE, M. 1890. Contributions to the knowledge of the marine algae of Norway I, East- Fiumarken. Tromso Museums Aarshefter, vol. 13. 1891. Ibid., 11. Vol. 14. Freeman, E. M. 1899. Observtaions on Constantinea. Minnesota botanical studies, ser. 2, part 2, pp. 175-190, pi. 2. Minneapolis. 1899a. Observations on Chlorochytrmm. Minnesota botanical studies, ser. 2, part 3, pp. 195-204, pi. 3. Minneapolis. Fries, E. 1825. Systema orbis vegetabilis. Primas lineas novae eonstructionis peri- clitatur Elias Fries. Part I, Plautae homonemeae. Lund. 1835. Corpus florarum provineialium Sueciae. I. Floram Scanicam scripsit Elias Fries. Upsala. 1846. Summa vegetabilum Scandinaviae, Sect. 1. Frye, T. C, and Zeller, S. M. 1915. Hormiscia tetraciliata sp. nov. Puget Sound Marine Station Publica- tions, vol. 1, no. 2, pp. 9-13, pi. 2. Gardner, N. L. 1909. New Clilorophyceae from California. Univ. Calif. Publ. Bot., vol. 3, pp. 371-375, pi. 14. 1917. New Pacific Coast marine algae I. Univ. Calif. Publ. Bot., vol. 6, no. 14, pp. 377-416., pis. 31-35. 1919. New Pacific Coast marine algae IV. Univ. Calif. Publ. Bot., vol. 6, no. 18, pp. 487-496, pi. 42. Gobi, C. 1879. Bericlit ucber die algologischen Forschungen im finnischen Meerbusen im Sommer 1877 ausgefiihrt. St. Petersb. Gesellseh. d. Naturf., vol. 10, p. 83. Gray, J. E. (see S. F. Gray). 1821. A natural arrangement of British plants. Vol. 1. London. Gray, S. F. 1821. A natural arrangement of British plants. Vol. 1. London. [J. E. Gray, son of S. F. Gray, did the systematic Avork in the two volumes which came out under the above title, with S. F. Gray as the author. J. E. Gray is sometimes cited as the author.] 1920] Setchcll-Gardner: Chlorophijceue 313 Greville, R. K. 1823-1829. Seottisli Cryptogamic Flora, or colored figures and descriptions of cryptogamic plants belonging chiefly to the order Fungi, and intended to serve as a continuation of English Botany. Vols. 1-6. Edinburgh. [We have consulted the six volume edition, each volume contain- ing sixty plates and dated as follows: vol. 1, 1823; vol. 2, 1824; voL 3, 1825; vol. 4, 1826; vol. 5, 1827; vol. 6, 1828. (Cf. Pritzel, 1872, p. 128, and Jackson, 1881, p. 240 for dates, 1823-1829.)] 1830. Algae Britanuicae, or descriptions of the marine and other inarticu- lated plants. Edinburgh. Hagem, O. 1908. Beobachtuiigeii ucber die Gattung Vrospora in Kristianiaf, jord. Xyt Mag. fur Natur., vol. 46, p. 289. Cliristiania. Hansgirg, a. 1886-1888. Prodromus der Algenflora von Bohmen. Erster Theil enthaltend die Rhodophyceen, Phaeophyceen und einer Theil der Chlorophyceen. Arch, naturw. Landesdurchf. v. Bohmen. 1886, vol. 5, part 1, no. 6. 1888, vol. 6, part 2, no. 6. 1888. Ueber die Gattungen Herposteiron Nag. und Aphanochaete Berth, non A. Br. ncbst einer systematischen Uebersicht aller bisher bekannten oogamen und anoogamen Confervoiden-Gattungen. Flora, pp. 211- 223. Hariot, p. 1889. Algucs, in Mission scientifique du Cap Horn, 1882, 1883. Vol. 5, Botanique, pp. 1-109, pis. 1-9. Paris. 1889-1890. Notes sur le genre Trentepohlia Martius. Journ. de Bot., vol. 3, and vol. 4. Harvey, W. H. 1834. Notice of a collection of algae, communicated to Dr. Hooker by the late Mrs. Cliarles Telfair from "Cap Malheureux" in Mauritius, with descriptions of some new and little known species. The Journal of Botany (Hooker), vol. 1, p. 147. London. 1838. The genera of South African plants, arranged according to the natural system. Cape Town. 1846-18.51. Phycologia Britannica. London. [According to a memorandum from E. M. Holmes to F. S. Collins, this work Avas issued in parts of six ])lates each, part 1 having ber, Josephine E. 189-1—1909. American Algae (Exsicc). Centuries 1-7, fase. I. Tkelease, W. (with P. A. Saccardo and C. H. Peck). 1904. Tiie Fungi of Alaska (issued by the Harriman Alaska Expedition with cooperation of Washington Academy of Sciences), vol. 5, pp. 11-64, pis. 2-7. Trevisan, V. 1842. Prospetto della Flora Euganea. (Cf. Flora, odcr allgemeine botanische Zeitung, vol. 26, 1843 (July) p. 464, for further information.) Turner, D. 1802. A synopsis of the British Fuci. 2 v(j1s. London. 1808-1819. Fuci sive plantarum fucorum generi a botanicis ascriptarum ieones descriptiones et historia. London. 1808, vol. 1. 1809, vol. 2. 1811, vol. 3. 1819, vol. 4. Tyson, W. 1909-1910. South African marine algae. Fasc. 1, 2. (Exsicc.) VicKERS, Anna. 1908. Phycologia Barbadensis. Tconographie des algues marines recoltees a I'ilo Barbade (Antilles). (Chlorophycecs et Pheophycees). Paris. Weber, F., and Mohr, E. M. H. 1804. Naturhistorische Reise durch einen Theil Schweden. Gottingen. West, G. S. 1904. A treatise on the British freshwater algae. Cambridge. • 1916. Algae I. Myxophyceae, Peridinieae, Bacillarieae, Chloropliyeeae. Cam- bridge Botanical Handbooks. Wiggeks, F. H. 1780. Primitiae florae Holsatiae. Kiliae. WiLLE, N. 1897. Conjugatae and Chlorophyceae, in Engler and Prantl, Natiirl. Pflanzen- fam., 1 Th., 2 Abt. Leipzig. 1890, Lief. 40, pp. 1-48. 1890, Lief. 41, pp. 49-96. 1890, Lief. 46, pp. 97-144. 1891, Lief. 60, pp. 145-175. [The date of the title page of the volume on Algae is 1897.] 1899. Meddelelser om scin Undersogelser angaaende Cellekjaenernes Forhold hos Slaegten Acrosiphonia (J. Ag. ) Kjellm. Botaniska Notiser, p. ■* 281. Lund. 1900. Die Zellkerne bci Acrosiphonia (J. Ag.) Kjellm. Botan. Centralb., vol. 81, p. 238. 1901. Studien ueber Clilorophyceen I-VII. Medd. f. d. Biol. Station Drobak No. 2 Vidensk. Skrifter. I Math, naturv. Klasse, 1900, no. 6. Chris- tiania. 1906. Algologische Untersuchungen an der biologischen Station in Drontheim I-VII. Det Kgl. Norske Vidensk. Selk. Skrifter, no. 3. 1909. Conjugatae und Chlorophyceae, in Engler and Prantl, Natiirl. Pllanzen- fam., Nachtrage zum 1 Th., 2 Abt. 324 University of California Publications in Botany [Vol.8 WiTTROCK, V. B. 1866. Forsok till en monographi ofver algslagtet Monostroma. Akademisk afhandling. 1880. Points-fortekniug ofver Skandiiiaviens vaxter. Part 4. Lund. WiTTROCK, V. B., and Xordstedt, O. 1877-1903. Algae aquae duleis exsiccatae praecipue Sc'andina\ncae quas ad- jectis algis mariuis chlorophyllaceis et phycochromaceis. Upsala. 1877-1889, Fasc. 1-21. 1893-1903, Fasc. 22-35. In 1896 G. Lagerheim was added as one of the distributors. Woodward, T. J. 1797. Observations upon the generic characters of Ulva, with the descriptions of some new species. Trans. Linn. Soc, vol. 3, pp. 46-58. Loudon. Wyatt, Mary. Algae Danmonienses, or dried specimens of marine plants principally collected in Devonshire. 4 vols._ and supplement. Tor Quay. Yendo, K. 1903. Three species of marine Echallocystis. The Bot. Mag., vol. 17, p. 199, pi. 8, figs. 1-15. Tokyo. 1914. Notes on algae new to Japan II. The Bot. Mag., vol. 27, p. 233. Tokyo. 1916. Notes on algae new to Japan V. The Bot. Mag., vol. 30, p. 243. Tokyo. Zanardini, G. 1843. Saggio di classificazione naturale delle ficee. Venice. (Also Botan. Zeit., 1844, pp. 401-408.) 1860-1871. Iconographia Phycologica Adriatica, vols. 1-3. Venice. [From the printed evidence, it is difficult to determine the exact dates of the publication of this large work of Zanardini. The title pages of the volumes bear dates as follows: vol. 1, 1860; vol. 2, 1865; and vol. 3, 1871. These dates are not sufficiently exact for reference as to priority of publication. The three volumes of the Iconographia are made up of reprints from the various parts pub- lished in the ' ' Memorie dell ' I. R. Istituto Veneto, ' ' where they appeared under the title ' ' Scelta di Ficee nuove o piu rare del Mare Adriatico. ' ' The general distribution of pages, plates and approxi- mate dates have been collated by Dr. W. G. Farlow and confirmed, so far as possible, by us. They are as follows : Volume 9 of "Memorie," dated 1860, has part 1, plates 1-8, pages 41-78, was presented April 16, 1860, and is the same as volume 1 of the "Iconographia," plates 1-8, Preface and pages i-iv and 1-34. Vol. 10, 1861, parts 1?, 2?, pis. 9-16, pp. 93-124, presented June 17, 1861, is vol. 1, pis. 9-16, pp. 35-66. Vol. 10, 1861, part. 3, pis. 26-33, pp. 449-484, presented Apr. 23, ^ 1862, is vol. 1, pis. 17-24, pp. 67-102. Vol. 11, 1862, part 2, pis. 11-18, pp. 271-306, presented Apr. 15, 1863, is vol. 1, pis. 25-32, pp. 103-138. Vol. 12, 1864, part 1, pis. 1-8, pp. 9-43, presented May 30, 1864, is vol. 1, pis. 33-40, pp. 139-175. Vol. 12, 1864, part 2, pis. 14-21, pp. 377-410, presented May 22, 1865, is vol. 2, pis. 41-48, preface, index and pp. iii-viii, 1-32. 1920] Setchell-Gardncr: Chlorophyccae 325 Vol. 13, 1866, part 1, pis. 2-9, pp. 143-176, no date of presenta- tion, is vol. 2, pis. 49-56, pp. 33-66. Vol. 13, 1866, parts 2?, 3?, pis. 10-17, pp. 403-434, presented May 27, 1867, is vol. 2, pis. 57-64, pp. 67-98. Vol. 14, 1869, part 2, pis. 4-11, pp. 181-216, presented June 22, 1868, is vol. 2, pis. 65-72, pp. 99-134. Vol. 14, 1870, part 3, pis. 26-33, pp. 437-472, presented June 21, 1869, is vol. 2, pis. 73-80, pp. 135-168. Vol. 15, 1871, part 2, pis. 10-17, pp. 425-460, presented June 20, 1870, is vol. 3, pis. 81-88, pp. 5-36. Vol. 17, 1873, part 3, pis. 14-21, pp. 429-460, presented Dec. 22, 1872, is vol. 3, pis. 89-96, pp. 37-68. Vol. 18, 1874, part 1, pis. 2-9, pp. 255-286, presented Dec. 22, 1873, is vol. 3, pis. 97-104, pp. 69-100. Vol. 19, 1876, part 3, pis. 23-30, pp. 513-544, presented June 18, 1876, is vol. 3, pis. 105-112, pp. 101-132.] EXPLANATION OF PLATES PLATE 9 Hormiscm sphaerulifera S. and G. Fig. 2. A, basal portion of filament showing intramatrical rhizoids. B, vegetative cells in the median portion of the filament. C, an empty sporangium. X 25. Hormiscia grandis (Kyliu) S. and G. Fig. 3. A, basal portion of filament showing numerous intramatrical rhizoids. B, two zoosporangia of moderate size. C, a long typical zoosporangium, empty. D, moderate sized vegetative segments. X 80. Soiitniscia penicilliformis (Roth) Fries Fig. 4. A, sporeling with rhizoid penetrating a filament of Ulothrix flacca. B, basal portion of a young filament, showing a few intramatrical rhizoids. C, characteristic zoosporangia. D, young vegetative segments. X 80. Bhizodonium lubricum S. and G. Fig. 5. A, terminal portion of a young filament with short segments. B, terminal portion of a filament with long, ' ' resting segments. ' ' X 160. Ulothrix pseudoflacca f. maxima S. and G. Fig. 6. A, B, vegetative filaments. C, sporangia. X 250. Codium dimorphum Svedelius Fig. 7. A young utricle with an empty sporangium. X 80. Fig. 8. A terminal portion of a utricle, showing the extremely thick, lamellate and tuberculate end wall. X 100. Codium intertextum var. criTjosum M. A. Howe Fig. 9. Portion of the end wall of a utricle, showing internal modifications. X 100. Codium Setchellii Gardner Fig. 10. Tj^iical utricle and sporangium, showing the scars of three previous sporangia. X 80. Fig. 11. Showing different forms of utricles and sporangia. This plate is from Gardner, New Pac. Coast Mar. Alg. IV, 1919, pp. 487-496, pi. 42. Fig. 9 was labeled Codium adhaerens. [326] UNIV. CALIF. PUBL. BOT. VOL. 8 [ SETCHELL-GARDNER ] PLATE 9 ~^oaa PLATE 10 Prasiola boreaUs Reed Fig. 1. A group of "n-hole plants infested by the parasitic fungus, Guignardia alaskana Eeed. X 3.5. Fig. 2. A cross section of the frond. X 375. Fig. 3. A surface view at the margin of the frond showing the grouping of the cells. X 285. Figures 1-3 are from Eeed, Two new Aseo. Fungi, 1902, pp. 141-16-i, pis. 15, 16. CollinsielJ^ tubercuJata S. and G. Fig. 4. Habit sketch of a group of plants. X 4. Fig. 5. A vertical section through one of the fronds. Fig. 6. Dissection of a part of the vertical section which has been treated with Chloriodide of Zinc to show the branching. The cell contents are much shrunken. Fig. 7. A tangential section at the surface to show the division planes. Fig. 8. A terminal cell showing a diminished chromatophore and two pyre- noids. Fig. 9. A terminal cell showing the vacuolated appearance of the chromato- phore. Fig. 10. A young terminal cell showing a complete parietal chromatophore and one pyrenoid. Figures 4-10 are from Setchell and Garder, Alg. N.W. Amer., 1903, pp. 165- 418, ph 17. [328] UNIV. CALIF. PUBL. BOT. VOL. 8 [SETCHELL-GARDNER ] PLATE 10 PLATE 11 Pseudulvella prostrata (Gardner) S. and G. Fig. 1. Showing a small section of the margin of the thallus on the surface of Iridaca lamdnarioides. Fig. 2. A vertical section of fig. 1, perpendicular to tlie long diameter of the filaments of Ulvella: the drawing is imperfect, it should show a common enclos- ing cuticle. Endophyton ramosuvi Gardner Fig. 3. Showing the narrow filaments within the central part of the host, Iridaea laminarioides, terminating in sporangia at the surface. Fig. 4. Showing pieces of irregularly shaped filaments. Pseudodietyon geniculatum Gardner Fig. 5. A part of a thallus showing a few terminal filaments penetrating among the cortical cells of Laminaria Sinclairii. Fig. 6. A cross section of fig. 5, showing terminal sporangia on short, erect filaments. All highly magnified. This plate is from Gardner, New Chlorophyceae from California, 1909, pp. 371- 376, pi. 14. [330] UNIV. CALIF, PUBL. BOT, VOL. 8 [SETCHELL-GARDNER] PLATE 11 PLATE 12 Ulva Linza L. Fig. 1. A vertical section through the margin of a frond showing the separa- tion of the two layers. Plant from Friday Harbor, Washington. X 250. Fig. 2. A surface view of fig. 1. X 250. Fig. 3. The same view as fig. 1. Plant from Admiralty Island, Alaska. X 250. Fig. 4. A surface view of fig. 3. Gayella constricta S. and G. Fig. 5. Habit sketch of a whole plant. X 30. Fig. 6-8. Showing the development of rhizoids. Fig. 9. Two enlarged segments showing shapes and arrangement of the cells in surface view\ X 100. Fig. 10. A cross section of a large segment showing the radial arrangement of the cells. Figures 5-10 are from Gardner, New Pae. Coast Mar. Alg. I, 1917, pp. 377- 416, pi. 33. [332] UNIV. CALIF. PUBL. BOT. VOL. 8 [SETCHELL-GARDNER] PLATE 12 PLATE 13 Clilorochytrium indusum Kjellin. Fig. 1. A vertical section through the host, sliowing the penetration of the endophyte to the medulla. X 250. Cladophora microcladioides Collins Fig. 2. Showing the method of branching of the terminal ramuli. X 8. Halimeda discoidea Dec 'ne Fig. 3. A habit sketch of a small plant. X 3. I 834 UNIV. CALIF. PUBL. BOX. VOL. 8 [ SETCHELL-GARDNER ] PLATE 13 PLATE 1-i Bryopsis plumosa (Huds.) Ag. Fig. 1. Diagrammatic illustration of a whole plant showing the method of branching. X 1. Fig. 2. A sketch of a branch showing the arrangement, tlie relative length and the constriction of the bases of the pinnules. X 40. Halioystis ovalis (Lyngb.) Aresch. Fig. 3. A habit sketch of a whole plant except the rhizoidal base. X 2. EnteromorpJia tubulosa Kuetz. Fig. 4. A portion of a small frond showing the linear arrangement of cells. X 250. Fig. 5. A section of a frond. X 250. Percursaria percursa (Ag.) Eosenv. Fig. 6. A portion of a frond showing one row of cells at one end and two rows at the other. X 250. Enteromorpha compressa (L.) Grev. Fig. 7. A vertical section through the frond. X 250. Fig. 8. A surface view. X 250. Chnetomorpha aerea (Dillw.) Kuetz. Fig. 9. A group of young plants showing long basal cells with rhizoids. X 35. Figs. 10, 11. Sketches showing different ages of the cells in vegetative stages. X 35. Monostroma sostericoJa Tildeu Fig. 12. A surface view. X 500. Fig. 13. A vertical section. X 500. [ 336 ] UNIV. CALIF. PUBL. BOT. VOL. 8 [SETCHELL-GARDNER] PLATE 14 X^O ZDOCJC^JCDCOOOOCDCpO^. mm ^M0 ^iT';.;-.' 11 ^2 oooo -^nnnooooooooooQQQOQQ 13 -^SQQQQQQpy^ irs /-^ ^■2\ /r^ /-s --~^ ^i C~, 7^ 1?^ ,'?\ /^ /7\i'-~\ z-?"! Jii- vty \iy v:?/ v_/ 7 8 "^W TLATE 15 CMoroclujtrmm Porphyrae S. and G. Fig. 1. A vertical section tlirough the host, showing plants of the endophyte in various stages of development and of embedding. X 140. Codiolum gregarium A. Br. Fig. 2. A group of three plants. X 120. Derhcsia marina (Lyng.) Kjellm. Fig. 3. A part of a filament showing the method of branching, and one sporangium. X 65. Bryopsis corticulans Setehell Figs. 4, 5. Sketches shoAving origin and method of development of the corti- cating filaments. X 25. Codium latum Siu'ing. Fig. 6. Sketch of a single utricle showing the position of the sporangia and of the hairs. X 100. Figure 1 is from Gardner, New Pac. Coast Mar. Alg. I, 1917, pp. 377-416, pi. 32, fig. 6. [338] UNIV. CALIF. PUBL. BOT, VOL. 8 [ SETCHELL-GARDNER 1 PLATE 15 PLATE 1(5 Enteromorpha micrococca var. subsalsa Kjellm. Fig. 1. A habit sketch of a piece of a frond showing the method of branch- ing. X 20. Cladoyhora triclwtoma (Ag.) Kuetz. Fig. 2. A habit sketch of a few terminal ramuli. Enteromorplm compressa (L.) Grev. Fig. 3. A habit sketch of a frond. X 1. Spongomorplia coalita (Kupr.) Collins Fig. 4. Sketch showing the characters of the hooked branches. X 10. CoMum Bitteri S. and G. Fig. 5. A sketch of a group of utricles. X 25. [340] UNIV. CALIF. PUBL. BOT. VOL. 8 [ SETCHELL-GARDNER ] PLATE 16 PLATE 17 Pseudopringsheimia apiculata S. and G. Fig. 1. A section through tlie thallus of a mature plant perpendicular to the host. X 250. Fig. 2. A section through the thallus of a youug plant. X 250. Prasiola delicata S. and G. Fig. 3. a-f. Series of different forms of plants. X 10. Viva vexata S. and G. Fig. 4. A group of plants showing different shapes and sizes. X 1. Fig. 5. A group of mature plants showing the presence of the parasitic fungus, Guignardia TJlvae Eeed. X 3. Fig. 6. A cross section showing the presence of fungal hyphae in the medulla. X 250. Fig. 7. A surface view. X 250. This plate is from Setchell and Gardner, Phyc. Gout. I, 1920, pp. 279-324, pi. 22. [342] UNIV. CALIF. PUBL. BOT. VOL. 8 [SETCHELL-GARDNER 1 PLATE 17 ,/Wv A/SAA/^'^ ' ^ ."^ mm PLATE 18 Gomontia caudate S. and G. Fig. 1. Two pieces of filaments. X 400. Fig. 2. a-d, Different stages and forms of "sporangia." X -400. Internoretia Fryearia S. and G. Fig. 3. A surface view of the host plant, showing the method of permeation and branching of a fcAv terminal filaments. X 375. Fig. 4. A stage slightly in advance of fig. 3, showing cell divisions in planes parallel to the long diameter of the cells. X 375. Fig. 5. A stage in development nearing maturity. X 375. Fig. 6. A cross section of the host cutting the filaments of Internoretia at right angles to their long diameter. X 375. Entoeladia cingens S. and G. Fig. 7. A plant growing in the membrane of Chaetomorplia culifornica and nearing maturity. X 250. This plate is from Setchell and Gardner, Phyc. Cont. I, 1920, pp. 279-324, pi. 23. [344] UNIV. CALIF. PUBL. BOT. VOL. 8 [ SETCHELL-GARDNER ] PLATE 18 .M ooop oooQI rfeoo ^58?Qes mm 3 00 o So' KJ^ PLATE 19 Gomontia polyrhiza (Lagerh.) B. and F. Fig. 1. A group of three "sporangia," the two larger nearing maturity. X 17.3. Gomontia lixibrorliiza S. and G. Fig. 2. A young thallus. X 375. Fig. 3. a-e, Illustrating three forms of the "sporangia." Pseudulvella consoeiata S. and G. Fig. i. A surface view of a young thallus. X 375. Fig. 5. A section of a mature thallus. X 375. Fig. 6. A vertical filament near the surface of a young thallus showing branching. X 225. Entocladia codicola S. and G. Fig. 7. a, A young thallus, showing the method of branching of the fila- ments and of their radiation from a center. X 125. b, A mature thallus with sporangia in the center. X 125. Prasiola delicata S. and G. Fig. 8. A surface view showing typical arrangement of cells. X 500. This plate is from Setchell and Gardner, Phyc. Cont. I, 1920, pp. 279-324 pi. 24. [346] UNIV. CALIF. PUBL. BOT. VOL. 8 [SETCHELL-GARDNER ] PLATE 19 t- (^7 0)^-^c> r3D@E^(2 '^)s^^a ''^& W 8 (^51/% PLATE 20 Prasiola delicata S. and G. Fig. 1. A micro-photograph of a marginal segment, surface view showing the arrangement of the vegetativ^e cells. X 442. Prasiola meridion-alls S. and G. Fig. 2. A micro-photograph of a portion of the surface, showing vegetative cells and interspersed aplanospores (?). X 442. This plate is from Setchell and Gardner, Phye. Cont. I, 1920, pp. 279-324, pi. 25. [348] UNIV. CALIF. PUBL. BOX. VOL. 8 [SETCHELL-GARDNER ] PLATE 20 fe?*-: ■ /*•!• •-■■'1 4»-/ ■ \ \^ PLATE 21 UJva dactyJifera S. and G. Fig. 1. Photograph of a whole plant, Avith the exception of a portion of the base, the type. X 0.75. Ulva stenopliyUa S. and G. Fig. 2. A micro-photograph of a portion of the surface, showing the rounded angles and i-elatively thick walls of the cells. X 442. [350] UNIV. CALIF. PUBL. EOT. VOL. 8 [SETCHELL-GARDNER I PLATE 21 PLATE 22 Ulva angusta S. and G. A photograph of a group of plants, the type. [ 352 ] UNIV. CALIF. PUBL. BOT. VOL. 8 [SETCHELL-GARDNER ] PLATE 22 PLATE 23 Ulva taeniata (Setchell) S. and G. A photograph of a wliole dried plant, showing the extreme crisped nature of the dentate margins at the base. X 0.3. [354] UNIV. CALIF. PUBL. BOX. VOL. 8 [ SETCHELL-GARDNER I PLATE 23 PLATE 24 Ulva stenophylla S. and G. A photograph of a whole plant, the type. X 0.3. [356] UNIV. CALIF. PUBL. EOT. VOL. 8 [ SETCHELL-GARDNF.R 1 PLATE 24 PLATE 25 Monostroma aveolaium S. aud G. A photograph of a whole dried plant, the type. X O.o. [ 358 J UNIV. CALIF. PUBL. BOT. VOL. 8 [SETCHELL-GARDiMER 1 PLATE 25 PLATE 26 Ulva angusta S. and G. Fig. 1. A niicro-photograph of a part of the surface. X 442. Monostroma areolatum S. and G. Fig. 2. A micro-photograph of a part of the surface. Plates 21-2G are from Setehell and Gardner, Phyc. Cont. I, 1920, pp. 279-324, pis. 26-31. [360] UNIV. CALIF. PUBL. EOT. VOL. 8 [ SETCHELL-GARDNER I PLATE 26 PLATE 27 Bryopsis corticulans Setchell A photograph of a whole plant. X 1. [362 ] UNIV. CALIF. PUBL. BOX. VOL. 8 r SETCHELL-GARDNER 1 PLATE 27 u,^yMm^. PLATE 28 Codium fragile (Suring.) Hariot A photograph of an entire dried plant, showing several fronds arising from the same expanded holdfast. X 0.5. [364] UNIV. CALIF. PUBL. BOT. VOL. 8 I SETCHELL-GARDNER | PLATE 28 ■'<>> PLATE 29 Cndium fragile (Suring.) Hariot A photograph of a dried frond, showing long, slender branches and dichotomous branching. X 0.5. [366] UNIV. CALIF, PUBL. BOT, VOL. 8 SETCHELL-GARDNER 1 PLATE 29 PLATE 30 Codium SetchelUi Gardner A photograph of a part of a thallus. X 1. [368] UNIV. CALIF, PUBL. BOT. VOL, 8 SETCHELL-GARDNER 1 PLATE 30 i\ ,jkS .j4rh )wr If- y, 1 I ^ ; '^.U \* PLATE 31 C odium sp. A photograph of a part of a dried plant. [ 370 ] UNIV. CALIF. PUBL. EOT. VOL. 8 f SETCHILL-GARDNER 1 PLATE 31 PLATE 32 Spongomorplia coalita (Eupr.) Collins A photograph of a group of plants showing the method of combining into rope- like masses. X 0.5. [372 ] UNIV. CALIF. PUBL. BOT. VOL. 8 [ SETCHELL-GARDNER ] PLATE 32 PLATE 33 Vlvella Lens Crouan A micro-photograph showing plants in various stages of development. X 200. [374] UNIV. CALIF. PUBL. BOT. VOL. 8 [SETCHELL-GARDNER ] PLATE 33 — V-t<)plior()i(li'ae, 287. Chaiiiarsiplion, 20, 25. Cliaiiiat'siplionaceae, 5, 20. Chlorochytriaceae, 143, 146. Chloiiichyt rium, 146, 147. inclusuin, 147; figure showing, opp. 334. Porphyrae, 147, 150; figure show- ing, opp. 338. Schmitzii, 147, 149. [375] Index Chlorocystis, 147. Chlorogloea, 6, 15. conferta, 16, 17, 23, 26; figure show- ing, opp. 126. lutea, 16, 18 ; figure showing, opp. 126. tuberculosa, 16, 33. Clilorophyeeae, 139-374. Chlorospermeae, 140. Chroococcaceae, 5. Chroococ'c'us, 6, 9, 10. turgidus, 10. f. submarinus, 11; figure showing, opp. 124. Chroolepidaceae, 305. Chroolepus umbrinuni, 306. Cladophora, 180, 181, 207, 208, 221. alaskana, 225. albifla, 208, 218, 219. amphibia, 208, 209. arcta, 223, 229, 230. f. conglutinata, 229. var. pulvinata, 229. Bertoloiiii ' var. hamosa, 208, 218. cartilaginea, 210. Chaniissonis, 227. coalita, 230. Columbiana, 210. composita, 210. delicatula, 208, 220. diffusa, 214. flexuosa, 208, 217. glaucescens, 208, 219. gracilis, 208, 216, 217. graminea, 208, 211, 212. hamosa, 218. hemisphaeriea, 208, 211, 212. Hutchinsiae, 208, 213, 215. var. distans, 211, 213, 214. Hystri.x, 230. laetevirens, 208, 216. lanosa var. uncialis, 223. MacDougali, 208, 213, 214, 215. Mertensii, 228. microcladioides, 208, 212, 215; fig- ure showing, opp. 334. • f. stricta, 212. ovoidea, 208, 213, 214, 215. repens, 210. Eudolphiana, 208, 217, 218. f. eramosa, 218. saxatilis, 229. scopaeformis, 229, 230. spinescens, 229. Stimpsonii, 208, 219, 220. trichotoma, 208, 210; figure .show- ing, opp. 340. f. elongata, 213. viminea, 228. Cladophoraceae, 179, 180. Cladophoreae, 180. Cladophoropsis, 180. Clastidium, 20, 25. Clathrocystis aeruginosa, 13. Coccogonales, 4. Coccogoneae, 4. Codiaceae, 153, 166. Codiaeum, 167. Codieae, 166. Codiolum, 146, 151. gregarium, 151; figure showing, opp. 338. Petrocelidis, 151, 152. polyrhizum, 302. Codium, 166, 167, 168; plate showing, opp. 370. adhaorens, 169. damaccorue, 175. decorticatum, 168, 172, 173. dimorphum, 168, 169, 172, 173. divaricatum, 172. f. hybrida, 172. elongatum, 173. fragile, 168, 171, 172; plates show- ing, opp. 364 and 366. intertextum var. cribrosum, figure showing, opp. 326. latum, 168, 175, 176; figure show- ing, opp. 338. Lindenbergii, 175, 176. maniillosum, 170. mucronatum, 171. platylobium, 175. Eitteri, 168, 169, 170; figure show- ing, opp. 340. Setchelli, 168, 169 ; plate showing, opp. 368 ; figures showing, opp. 326. tomentosum, 171, 173, 174, 175. var. californieum, 172. var. novae-zelandiae, 172. Coleochaete, 289. Coleonema arenifera, 24. Collinsiella, 144. tuberculata, 144, 145 ; figures show- ing, opp. 328. Conferva aestuarii, 75. aggregata, 221. albida, 219. antennina, 203, 204. arcta, 223. cartilaginea, 225. Chamissonis, 227, 228. clathrata, 260. coalita, 230, 231. cohaerens, 224. composita, 232. crinita, 258. distans, 213. duriuseula, 225. flacca, 284. [376] Index Conferva (eont.) flexuosa, 217, 256. glaueoscens, 219. fjracilis, 216. Hutc-liinsiae, 213. implexa, 184. laetevirens, 216. lanosa, 221. melagoiiium, 201. Mcrtensii, 227, 228. oligoc'lona, 207. paradoxa, 259. penicilliformis, 187, 191. perc'ursa, 274. riparia, 183. saxatilis, 226, 228. scopacformis, 231. seopulorum, 97. tortuosa, 184, 186. trichotonia, 210. uncialis, 221. viminea, 227. Wormskiohlii, 197. Crj'ptophvccae, 3. Cyanocystis, 20, 23, 25. Cyanophyceac, 3. Derbesia, 164. Laniourouxii, 164, 165, 166. marina, 164, 165; figure showing, opp. 338. tenuissima, 165. vaucheriaeformis, 165. Derbesiaceae, 154, 163, 164. Dcrbesieae, 163. Dermatophyton radians, 295. Dermocarpa, 20, 21, 22, 24, 25. fucicola, 22, 27, 29; figures show- ing, opp. 138. hemisphaerica, 17, 22, 23, 24, 26; figure showing, opp. 128. Leibleiniae, 26. paeifica, 22, 27, 35 ; figures showing, opp. 128. prasina, 29, 30. protea, 22, 28, 29; figures showing, opp. 130. sphaeriea, 22, 24; figure showing, opp. 132. sphaeroidea, 22, 26; figure showing, opp. 126. suffulta, 17, 22, 23, 26; figure show- ing, opp. 126. Dichothrix, 103. minima, 103, 104. seriata, 103 ; figure showing, opp. 134. Dilsea Integra, 147. Diplonema, 273. pereursum, 274. Efballocystis tubcrculata, 145. Willeana, 145. Ectosperma, 178. Endocladia, 289. cingens, 291. eodieola, 291. Flustrae, 290. viridis, 290, 291. Endoderma viride, 289. Endophyton, 287, 292. ramosum, 292, 293; figures showing, opp. 330. Endosphaera, 147. Endosphaeraeeae, 146. Enteromorpha, 233, 244, 245, 246, 247, 261. acanthophora, 247, 254. aureola, 234. clathrata, 247, 260. compressa, 247, 250, 251, 252, 2.55; figures showing, opp. 330 and 340. f. complanata, 258. f. sub-simplex, 260. crinita, 247, 258, 260. erecta, 259, 260. fascia, 251. flexuosa, 247, 255, 256. Grevillei, 236. grocniandiea, 248. Hopkirkii, 260. intestinalis, 247, 252, 255, 266. f. clavata, 253. f. cylindracea, 252. f. genuina, 253. f. maxima, 253. Linza, 263. marginata, 247, 257. micrococca, 247, 249, 250. f. subsalsa, 247, 249, 250; figure showing, opp. 340. minimd, 247, 249, 250. percursa, 274. plumosa, 247, 259. polvclados, 257. prolifera, 247, 254, 255, 258. var. tubulosa, 256. salina var. polyclados, 247, 257. torta, 258. tubulosa, 247, 255, 256 ; figures show- ing, opp. 336. Entocladia, 287, 288, 289. cingens, 289, 291; figure showing, opp. 344. eodieola, 289, 290; figure showing, opp. 346. viridis, 289, 290. Epicladia, 289. Eulyngbya, 72, 75. Euphormidia, 68, 70. Fucus tomentosum, 174. Fuirena, 85. Gardner, N. L., 1-138, 139-374. Gastridium ovale, 155. [377] Index GayeUa. 275, 279. constrieta, 279, 280, 281; figures showing, opp. 332. polyrhiza, 279. 280, 281. Gloeocapsa cropidinum, 21, 37. Gloeothcce, 7. Gloesipheae, 3. Gloiosiphonia verticillaris, 237. Godlewskia, 25. Gomoiitia, 287, 300, 301. arrhiza, 300. Bornetii, 301, 302, 303, 304. caudata, 301, 304; figures showing, opp. 344. eodiolifera, 300. habrorhiza, 301, 304; figuros show- ing, opp. 346. polyrhiza, 301, 302, 303, 304 ; figure showing, opp. 34G. Gomontieae, 287. Gomphosphaeria, 21, 49. aponina, 50 ; figures showing, opp. 124. Gonidium, 8. Halieystis, 154. ovalis, 155 ; figure showing, opp. 336. Halimeda, 166, 176, 177. discoidea, 177; figure showing, opp. 334. Hammatoidea, 93. Herpyxonenia, 112. Heterocysteae, 89. Heterocystineae, 89. Homocystineae, 51, 52. Hormiscia, 180, 187, 188, 189, 190, 191, 198. coUabens, 190, 193. crassa, 190. doliifera, 191, 193. grandis, 190, 191, 195; figure show- ing, opp. 326. Hartzii, 190. incrassata, 190, 191. penicilliformis, 190, 191, 192, 193; figure showing, opp. 326. sphaerulifera, 191, 196, 198; figure showing, opp. 326. tetraeiliata, 190, 191, 193, 194. vancouveriana, 191, 197, 198. Wormskioldii, 190, 191, 196, 197. Hormogonales, 4, 51. Hormogoneae, 51. Hydrocoleum, 53, 84. lyngbyaceum, 85; figure showing, opp. 124. Hyella, 21, 40. caespitosa, 41. linearis, 41, 43; figure shoAving, opp. 126. Littorinae, 41, 42; figures showing, opp. 128. socialis, 44; figure sho\ving, opp. 126. Ilea, 234. Fascia, 234. foeniculaceus, 234. fulvescens, 234. Intcrnoretia, 287, 294. Frveana, 294; figures showing, opp. 344. Isactis, 104. plana, 104. var. fissurata, 105. var. plana, 105; figures shoAving, opp. 124. Isokontae, 142. Lamarckia, 167. Laniinaria saccharina, 261. Leibleinia, 72, 73. Corallinae, 62. Leptosireae, 287. ' ' Leptothrix lamellosa, ' ' 90. Linckia atra var. coadunata, 107. Literature cited, on, Mvxophyceae, 113-123; Chlorophyceae, 307-325. Lyngbya, 53, 72. aestuarii, 73, 75. f . aeruginosa, 76 ; figure showing, opp. 124. f. ferruginea, 76. f. limicola, 76. f . natans, 77 ; figure showing, opp. 124. f. spectabilis, 77. confervoides, 73, 77. epiphytica, 72, 74, 77. gracilis, 72, 73. semiplena, 73, 78, 99. Willei, 73, 74. Lyngbyeae, 67. Lyngbyoideae, 67. Margaritiferae, 59, 60. Marine Algae of the Pacific Coast of North America: I. Myxophyceae, 1-138. II. Chlorophyceae, 139-374. Mastigocoleus, 110, 112. testarum. 111. Merismopedia, 6, 8. Gardneri, 9; figure showing, opp. 138. Microcoleus, 53, 84, 85. chthonoplastes, 86. contiuens, 86, 88 ; _ figure showing, opp. 134. tenerrimus, 86, 87. Weeksii, 86, 87; figure showing, opp. 134. Microcystis, 13. Microdictyon, 180, 231, 232. Agardhianum, 232. umbilicatum, 232. Microspora, 207. Moniliformia, 68. Monostroma, 235, 236. [378] Index Monostroma (cont.) angieava, 238. arctieuni, 23fi, 238. areolatum, 236, 240; plate showing, opp. 358 ; figure showing, opp. 360. Blyttii, 238, 243. cylindraceum, 238. fnseiim, 236, 238, 242. var. Blyttii, 243, 244. var. splcndens, 242, 243. Grevillei, 236, 237, 238. var. luhriciini, 237. var. Vahlii, 237. groenlandic'uni, 248. latissimuni, 236, 238, 241, 242. leptodermum, 239. lubrifum, 237. orbiculatum, 236, 242. quatornariuni, 236, 240, 241. saeeodeum, 238. splendens, 238, 243. Vahlii, 237. zosterieola, 236, 237, 238, 239; fig- ures showing, opp. 336. !Myxopliyceac, 1-138. Myxophykea, 3. Nitella, 289. Nostoe, 90, 92. Linckia, 92. Quoyi, 111. Nostocaceae, 51, 89. Nostoceae, 89. Nostochopsis, 112. Oedogonium, 163. Oscillaria margaritifora, 61. neapolitana, 66. submoml)ranacea, 71. Oscillarideae, 52. Oscillatoria, 58. acuminata, 59, 65; figure showing, opp. 124. amphibia, 63. Bonnemaisonii, 59, 60. brevis, 59, 65. var. neapolitana, 66. chalvbea, 59, 67. Corallinae, 59, 62. geminata, 59, 63. laetevirens, 59, 64. limosa, 59. margaritifera, 59, 61. nigro-viridis, 59, 62. Okeni, 59, 66. Oseillatoriaceae, 51, 52, 53. Oscillatorieae, 57. Palniclla eoufcrta, 17. Palmclla? tuberculosa, 16. Palmellaceae, 143. Palmelleae, 143. Percursaria, 245, 273, 274. percursa, 274; figure showing, opp. 336. Phormidium, 53, 68. ambiguum, 68, 70. fragile. 68, 69. hormoides, 68, 69; figure .showing, opp. 134. laminosum, 90. lucidum, 68, 71 ; figure showing, opp. 124. submembranaceum, 68, 71. Phycocliroinophyceae, 3. Phycoseris lapathifolia, 265. Linza, 265. lobata, 269. Placoma, 6, 11. violacea, 12; figures showing, opp. 130. Planosporaceae, 146. Plectonema, 53, 78. Battersii, 79 ; figure showing, opp. 124. Golenkinianum, 80. mirabile, 78. Pleurocapsa, 21, 23, 24, 26, 36. amethystea, 24. var. Schmidtii, 31. conferta, 17. entophysaloides, 36, 38; figures showing, opp. 130 and 136. fuliginosa, 36, 39. gloeocapsoides, 36, 37; figures show- ing, opp. 132. Pleurococcus rufescens, 10. Polycystis, 13. Porphyra, 261. Prasiola, 9, 275, 276. borealis, 276, 277, 278; figures .show- ing, opj). 328. calophylla, 276, 277. dolicat^i, 276, 278; figures showing, opp. 342, 346, and 348. furfuracea, 278. meridionalis, 276, 278, 279; figure showing, opp. 348. tesselata, 278. Principes, 59. Pringslieimia scutata f. Cladopborae, 16, 33. Protoeoccales, 142, 143. Protococcoideae, 143. Protococeus rufescens, 10. turgidus, 11. Protosiphon, 154. Protosiphonaceae, 153, 154. Pseudodietyon, 287, 293, 294. gcniculatuiii, 293, 294; figures show- ing, opp. 330. Pseudospringsheimia, 287, 296, 297, 299. apiculata, 300 ; figures showing, opp. 342. confluens, 300. [379] Index Pseudulvella, 287, 296. americana, 297. applanata, 298, 299. cousociata, 296, 297, 298; figures slio^ving, opp. 346. prostrata, 296, 297; figures show- ing, opp. 330. Radaisia, 21, 26, 45. clavata, 46, 48 ; figures showing, opp. 128. epiphytica, 46, 49; figures showing, opp. 128. Gomontiana, 45. Laminariae, 46; figures showing, opp. 128. subimmersa, 46, 47; figures show- ing, opp. 128. Rhizoclonium, 180, 181, 207. implexum, 182, 183, 184. Kerneri, 182, 185. lubricum, 181, 182, 185; figures showing, opp. 326. riparium, 182, 183. var. implexum, 184. var. polyrhizum, 182. f. validum, 185. tortuosum, 182, 185, 186. Eivularia, 105. atra, 106, 107. var. coadunata, 107. var. confluens, 106, 108. var. hemisphaerica, 107; figures showing, opp. 138. Biasolettiana, 106. Contarenii, 97. mamillata, 106, 109; figures show-. ing, opp. 134. nitida, 106, 108. parasitica, 98. Ri^nlla^iaccae, 51, 93. Eivularieae, 93. Schizogoniaceae, 275. Schizogoniales, 142, 275. Schizogonium, 275. laetevirens, 286. Schizophyceae, 3. Schizosiphon eonsociatus, 95, Schizotricheae, 83. Scotinosphaera, 147. Scytosiphon erectus, 259. Setehell, W. A., 1-138, 139-374. Siphonales, 142, 153. Siphonocladeae, 179. Siphonocladiales, 142, 179. Sirosiphoniaceae, 109. Spirulina, 53, 55. major, 56 ; figure showing, opp. 124. subsalsa, 57. f. oceanica, 57. Spirulineae, 53. Spirulinoideae, 53. Spongodium, 167. Spongomorpha, 180, 220, 221, 222. areta, 222, 223, 224. f. conglutinata, 229. var. limitanea, 228. var. pulvinata, 229. coalita, 222, 225, 230, 231; figure showing, opp. 340 ; plate show- ing, opp. 372. duriuscula, 222, 225, 226. Hystrix, 222, 224, 225. lauosa, 221. Mertensii, 227, 228. saxatilis, 222, 226, 228. var. Chamissonis, 227. spinescens, 229, 230, 231. Stigonemaceae, 109. Stigonemataceae, 51, 109. Stigonemeae, 109. Symploca, 53, 80. aeruginosa, 81, 83. atlantica, 82. elegans, 81. funicularis, 81, 82 ; figure showing, opp. 136. hydnoides, 81; figures showing, opp, 124. laeteviridis, 83. Synechoeoccus, 6, 7. curtus, 7 ; figure showing, opp. 124. Synechocystis, 6. aquatilis, 6 ; figure showing, opp. 124. Tetranema, 273. pereursum, 274. Trentepohlia, 305. odorata var. umbrina, 306. umbrina var. quercina, 306. Tubularia, 244. Ulothrix, 282, 283. flacca, 196, 283, 284, 285. implexa, 283, 284. laetevirens, 283, 286. pseudoflacca, 283, 284, 285. f. major, 285. f. maxima, 285. f. minor, 285. subflaccida, 283. Ulotrichaeeae, 281, 282. Ulotrichales, 142, 281. Ulva, 233, 260, 261, 262. angusta, 262, 264; plate showing, opp. 352 ; figure showing, opp. 360. aureola, 234. californica, 262, 264, 271, compressa, 251. conglobata, 270. f. densa, 270. daetylifera, 263, 272; figure show- ing, opp. 350, decorticata, 172. [380] Index Ulva (eont.) expansa, 262, 267, 268, 269. faseiata f. caespitosa, 270. f. costata, 272, 273. f. expansa, 268. f. lobata, 269. f. taeniata, 268, 273. feuestrata, 262, 267. fulvescens, 234. fusca, 242. intestinalis, 252. Lactuca, 261, 262, 263, 265, 266, 270. var. latis.siiiia, 266. var. rigida, 242, 265, 270. nivriotrcma, 266. latissima, 241, 261, 262, 266, 267, 268. Linza, 251, 261, 262, 263; figures showing, opp. 332. lobata, 262, 268, 269. percursa, 274. pluniosa, 161. reticulata, 267. rigida, 269, 270. splendens, 243. stenophylla, 262, 271; figure shoAV- ing, opp. 350 ; plate showing, opp. 356. taeniata, 262, 268, 273 ; plate show- ing, opp. 354. vexata, 262, 271; figures showing, opp. 342. Ulvaceae, 233. Ulvales, 142, 233. Ulvella, 287, 295, 296. americana, 296. eonfluens, 299. fueicola, 299. Lens, 295, 296; plate showing, opp. 374. prostrata, 297, Ulvelleae, 287. Urospora, 187. acrogona, 190. ])angioides, 190, 194. collabens, 194. clavieulata, 190. elongata, 190, 196. grandis, 195. Hartzii, 193. incrassata, 191, 193. mirabilis, 187. penicilliformis, 191, 195. WorniskioMii, 195, 197. Vaginaria, 85. Vaginarieae, 83. Valonia ovalis, 155. Vaucheria, 156, 178. marina, 165. Vaucheriaeeae, 177, 178. Vaucherideae, 178. West, G. S., cited, 146, 147. Xenococcus, 21, 30. acervatus, 31 ; figure showing, opp. 132. Chaetomorphae, 28, 35 ; figures show- ing, opp. 126. Cladophorae, 16, 31, 33 ; figure show- ing, opp. 130. Gilkeyae, 31, 32; figure showing, opp. 132. pyriformis, 31, 34; figure showing, opj). 132. Schoust)oei, 24, 30. Zygoniitus, 294. [381] ERRATA Page 54, Page 85, Page 86 Page 109 Page 114 Page 115 Page 115 Page 143 Page 143 Page 153 Page 156 Page 156 Page 163 Page 163 Page 166 Page 179 Page 207 Page 215 Page 219 Page 219 Page 227 Page 256 Page 260 Page 264 Page 273 Page 275 Page 288 Page 289 Page 302 Page 302 Page 307 Page 307 Page 310 Page 311 Page 311 Page 314 Page 315 Page 319 Page 319 Page 320 Page 326 Page 370 next to last line. For algae read alga. line 35. For Rootb., read Eottb. line 6. For Sirococolcum read Sirocoleum. last line. For Forti read Kirchner. line 26. For Anabaena read Anabaina. line 7. For two read 2. line 38. For cognitariuni read cognitarum. line 1. Delete (meneghini). line 27. Delete (decaisne). line 6. Delete (grev) and add (emend.) after Oltmanns. line 1. Delete (bory). line 32. For Bryopsidaceae read Bryopsideae. line 1. Delete (thuret). line 18. Delete 'out.' line 9. Delete (trevis). line 1. Delete (blackmann and tansley). line 18. For antidates read antedates, line 13. For Ovoidea read ovoidea. line 4. Delete 1732, ed. 1. next to last line. For Ucluet read Ucluelet. line 2. For cells read segments. line 30. At end of line insert (swfe. F. flexuosa). line 27. For filing read filling, line 26. Insert comma after diam. line 5. For teniata read taeniata. line 23. For Blatosporaceae read Blastosporaceae. line 18. For piliferem, read piliferum. line 35. For Stechell read Setchell. line 25. For Keil read Kiel, line 27. For Acrid-type read Acarid-type. line 8. For 1-268 read 1-168. line 9. For 269-531 read 169-531. line 39. For Jajonicae read Japonicae. line 36. For 1909 read 1809. line 38. For ]909 read 1809. line 30. For Ulrothricaceae read Ulothrieaceae. after line 13. Insert 1762. Flora Anglica, ed. 1. London, line 42. For Illutrationes read Illustrationes. line 42. For inprimio read inprimis. line 35. For marine read marines, line 23. For cribosum, read cribrosum. Add (No. 628, Collins, Holden, and Setchell, Phyc. Bor.-Am., referred under Codium LindbergU; cf. p. 175 of text.) [382] UNIVERSITY OF CALIFORNIA PUBLICATIONS IN BOTANY Vol. 8, No. 1, pp. 1-138, plates 1-8 November 29, 1919 THE MARINE ALGAE OF THE PACIFIC COAST OF NORTH AMERICA PART I MYXOPHYCEAE BY WILLIAM ALBERT SETCHELL AND NATHANIEL LYON GARDNER UNIVERSITY OF CALIFORNIA PRESS BERKELEY X7NIVEESITT OF CALIPOBNIA PUBLICATIONS I]-ote. — The University of California Publications are offered in exchange for the publi- cations of learned societies and Institutions, universities and libraries. Complete lists of all the publications of the University will be sent upon request. Tor sample copies, lists of publications and other information, address the MANAGES OF THE UNIVEESITY PRESS, BERKELEY, CALIFORNIA, U. S. A. All matter sent in exchange should bo addressed to THE EXCHANGE DEPARTMENT, UNIVERSITY LIBRARY, BERKELEY, CALIFORNIA, U. S. A. WILLIAM WESLEY & SONS, LONDON Agent for the series in American Archaeology and Ethnology, Botany, Geology, Physiology, and Zoology. BOTANY. — ^W. A. Setchell, Editor. Price per volume, $3.50; beginning with vol. 5, $5.00. Volumes I (pp. 418), n (pp. 360), III (pp. 400), IV (pp. 379), completed. Volumes V, VI, VII, and vm in progress. Cited as Univ. Calif. PubL Bot. Volume 1, 1902-1903, 418 pages, with 27 plates _ $3.50 Volume 2, 1904-1907, 360 pages, with 29 plates 3.50 Volume 3, 1907-1909, 400 pages, with 14 plates .....J^.^^.,.*:. 3.50 VoL 4. 1910-1912. 1. Studies in Ornamental Trees and Shrubs, by Harvey Monroe HalL Pp. 1-74, plates 1-11, 15 text figures. March, 1910 75 2. GracUariophila, a New Parasite on Gracilaria confervoides, by Harriet L. Wilson. Pp. 75-84, plates 12-13. May, 1910 ...„ „ .10 3. Plantae Mexicanae Purpusianae, II, by T. S. Brandegee. Pp. 85-95. May, 1910 „ — _ 10 4. Leuvenki, a New Genus of Flagellates, by N. L. Gardner. Pp. 97-106, plate 14. May, 1910 _ _ .10 5. The Genus Spluierosoma, by William Albert Setchell. Pp. 107-120, plate 15. May, 1910 ..^. - _ _ 15 6. Variations in Nuclear Extrusion Among the Fucaceae, by Nathaniel Lyon Gardner. Pp. 121-136, plates 16-17. August, 1910 15 7. The Nature of the Carpostomes in the Cystocarp of Ahnfeldtia gigartinoides, by Ada Sara McFadden, Pp. 137-142, plate 18. February, 1911 05 8. On a Celacodasya from Southern California, by Mabel Effie McFadden. Pp. 143-150, plate 19. February, 1911 - .05 9. Fructification of Macrocystis, by Edna Juanita Hoffman. Pp. 151-158, plate 20. February 1911 05 10. ErytJirophyllum delesserioides J. Ag., by Wilfred Charles Twiss. Pp. 159- 176, plates 21-24. March,^ 1911 15 11. Plantae Mexicanae Purpusianae, in, by T. S. Brandegee. Pp. 177-194. July, 1911 _ „ — _. „ 15 12. New and Noteworthy California Plants, I, by Harvey Monroe HalL Pp. 195-208. March, 1912 15 13. Die Hydrophyllaceen der Sierra Nevada, by August Brand. Pp. 209-227. March, 1912 .20 14. Algae Novae et Minus Cognitae, I, by William Albert SetchelL Pp. 229-268, plates 25-31. May, 1912 40 15. Plantao Mexicanae Purpusianae, IV, by Townshend Stith Brandegee. Pp. 269-281. June, 1912 _ _ 15 16. Comparative Development of the Cystocarps of Aniiihamnion and Frionitis, by Lyman Luther Daines. Pp. 283-302, plates 32-34. March, 1913 20 17. Fungus Galls on Cystoseira and Halidrys, by Lulu May Estee. Pp. 305-316, plate 35. March, 1913 „.„ 10 18. New Fucaceae, by Nathaniel Lyon Gardner. Pp. 317-374, plates 36-53. April, 1913 _.._ 75 19. Plantae Mexicanae Purpusianae, V, by Townshend Stith Brandegee. Pp. 875-388. June, 1913 _ .16 Index, pp. 389-397. UNIVEESITY OF CALIFOENIA PUBLICATIONS— (Continued) Vol 6. 1912-. 1. Studies in Nicotiana, I, by WlUlam Albert Setchell. Pp. 1-86. December, 1912 _... 1.26 2. Quantitative Studies of Inheritance in Nicotiajio Hybrids, I, by Thomas Harper Qoodspeed. Pp. 87-168. December, 1912 1.00 3. Quantitative Studies of Inheritance in Nicotiana Hybrids, II, by Thomas Harper Goodspeed. Pp. 169-188. January, 1913 J2Q 4. On the Partial Sterility of Nicotiana Hybrids made with N. sylvp.itris as a Parent, by Thomas Harper Goodspeed. Pp. 189-198. March, 1913 10 5. Notes on the Germination of Tobacco Seed, I, by Thomas Harper Goodspeed. Pp. 199-222. May, 1913 25 6. Quantitative Studies of Inheritance in Nicotiana Hybrids, III, by Thomas Harper Goodspeed. Pp. 223-231. April, 1915 _.._ _ 10 7. Notes on the Germination of Tobacco Seed, II, by Thomas Harper Good- speed. Pp. 233-248. June, 1915 15 8. Parthenogenesis, Parthenocarpy and Phenospermy in Nicotiana, by Thomas Harper Goodspeed. Pp. 249-272, plate 35. July, 1915 26 9. On the Partial Sterility of Nicotiana Hybrids made with N. sylvestris as a Parent, II, by T. H. Goodspeed and A. H. Asnres. Pp. 273-292, plate 36. October, 1916 20 10. On the Partial Sterility of Nicotiana Hybrids made with N. syhestris as a Parent, III, An Account of the Mode of Floral Abscission in the F, Species Hybrids, by T. H. Goodspeed and J. N. Kendall. Pp. 293-299. November, 1916 05 11. The Nature of the F, Species Hybrids between Nicotiana sylvestris and Varieties of Nicotiana Tahac^im, with Special Reference to the Conception of P.eaction System Contrasts in Heredity, by T. H. Goodspeed and R. E. Clausen. Pp. 301-346, plates 37-48. January, 1917 „ 45 12. Abscission of Flowers and Fruits in the Solanaccae, with Special Reference to Nicotiana, by John N. Kendall. Pp. 347-428, 10 text figures, plates 49- 53. March, 1918 85 13. Controlled Pollination in Nicotiana, by Thomas Harper Qoodspeed and Pirle Davidson. Pp. 429-434. August, 1918 10 14. An Apparatus for Flower Measurement, by T. H. Goodspeed and E. E. Clausen. Pp. 435-437, plate 54, 1 figure In text. September 25, 1918 .05 15. Note on the Effects of Illuminating Gas and its Constituents in Caiislng Abscission of Flowers in Nicotiana and Citrus, by T. H. Goodspeed, J. M. McGee and E. W. Hodgson. Pp. 439-450. December, 1918 15 16. Notes on the Germination of Tobacco Seed, III. Note on the Relation of Light and Darkness to Germination, by T. Harp«r Goodspeed. Pp. 451- 455. AprU, 1919 .05 Vol 6. 1914-. 1. Parasitic Florldeae, by William Albert Setchell. Pp. 1-34, plates 1-6. April, 1914 _. .36 2. Phytomorula requlariji, a Symmetrical Protophyte Related to Coelastrum, by Charles Atwood Kofold. Pp. 35-40, plate 7. April, 1914 „. .05 3. Variation in Oenothera ovata, by Katherine Layne Brandegee. Pp. 41-50, plates 8-9. June, 1914 _.. 10 4. Plantae Mexicanae Purpusianae, VI, by Townshend Stith Brandegee. Pp. 51-77. July, 1914 25 5. The Scinaia Assemblage, by WUllam Albert Setchell. Pp. 79-152, plates 10-12. October, 1914 „ .75 6. Notes on Pacific Coast Algae, I, Pytniella Postelsiae, n. sp., a New Type In the Genus Fylaiella, by Carl Skottsberg. Pp. 153-164, plates 17-19. May, 1915 _ _ 15 7. New and Noteworthy Califomlan Plants, II, by Harvey Monroe Hall. Pp. 165-176, plate 20. October, 1915 „ 15 8. Plantae Mexicanae Purpusianae, VTI, by Townshend Stith Brandegee. Pp. 177-197. October, 1915 86 UNTVEESITY OF CAIjIFOENIA PUBLICATIONS— (Continued) 9. Floral Relations Among the Galapagos Islands, by A. L. Kroeber. Pp. 199-220, March, 1916 _ — .20 10. The Comparative Histology of Certain Callfornian Boletaceae, by Harry S. Yates. Pp. 221-274, plates 21-25. February, 1916 .50 11. A Revision of the Tuberales of California, by Helen Margaret Gllkey. Pp. 275-356, plates 26-30. March, 1916 _ _ .80 12. Species Novae vel Minus Cognitae, by T. S. Brandegee. Pp. 357-361. May, 1916 _ - .05 13. Plantae Mexicanae Purpusianae, VIII, by Townshend Stith Brandegee. Pp. 363-375. March, 1917 _ .15 14. New Pacific Coast Marine Algae, I, by Nathaniel Lyon Gardner. Pp. 377- 416, plates 31-35. June, 1917 .40 16. An Account of the Mode of Foliar Abscission in Citrus, by Robert W. Hodgson. Pp. 417-428, 3 text figures. February, 1918 10 16. New Pacific Coast Marine Algae, II, by Nathaniel Lyon Gardner. Pp. 429- 454, plates 36-37. July, 1918 ......„.:.....li...i..„ 25 17. New Pacific Coast Marine Algae, HI, by Nathaniel Lyon Gardner. Pp. 455- 486, plates 38-41. December, 1918 85 18. New Pacific Coast Marine Algae IV, by Nathaniel Lyon Gardner. Pp. 487- 496, plate 42. January, 1919 15 19. Plantae Mexicanae Purpusianae, IX, by Townshend Stith Brandegee. Pp. 497-504. November, 1919 10 Vol 7. 1916-. 1. Notes on the Califomian Species of Trillium L. I, A Report of the General Results of Field and Garden Studies, 1911-1916, by Thomas Harper Good- speed and Robert Percy Brandt. Pp. 1-24, plates 1-4. October, 1916 .25 2. Notes on the Califomian Species of Trillium L. II, The Nature and Occur- rence of Undeveloped Flowers, by Thomas Harper Goodspeed and Robert Percy Brandt. Pp. 25-38, plates 5-6. October, 1916 15 3. Notes on the Califomian Species of Trillium L. in, Seasonal Changes in Trillium Species with Special Reference to the Reproductive Tissues, by Robert Percy Brandt. Pp. 39-68, plates 7-10. December, 1916 30 4. Notes on the Califomian Species of Trillixim L. IV, Teratological Varia- tions of Trillium sessile var. giganteum H. & A., by Thomas Harper Good- speed. Pp. 69-100, plates 11-17. January, 1917 SO 5. A Preliminary List of the Uredinales of California, by Walter C. Blasdale. Pp. 101-157. August, 1919 50 6, 7, 8. A Rubber Plant Survey of Western North America. I. Chrysothamnus nauseosus and ts Varieties, by Harvey Monroe HaU. n. Chrysil, a New Rubber from Chrysothamnus nauseosus, by Harvey Monroe Hall and Thomas Harper Goodspeed. III. The Occurrence of Rubber in Certain West American Shrubs, by Harvey Monroe Hall and Thomas Harper Goodspeed. Pp. 159-279, plates 18-20, 8 figures in text. November, 1919. 1.25 Vol. 8. 1919- 1. The Marine Algae of the Pacific Coast of North America. Part I. Msncophyceae, by William Albert Setchell and Nathaniel Lyon Gardner. Pp. 1-138, plates 1-8. November, 1919 $1.50 UNIVERSITY OF CALIFORNIA PUBLICATIONS IN BOTANY Vol. 8, No. 2, pp. 139-374, plates 9-33 July 14, 1920 THE MARINE ALGAE OF THE PACIFIC COAST OF NORTH AMERICA PART II CHLOROPHYCEAE BY WILLIAM ALBERT SETCHELL AND NATHANIEL LYON GARDNER UNIVERSITY OF CALIFORNIA PRESS BERKELEY UKIVEESITT OF OAX.IFOSNIA PUBLICATIONS Ifot«. — The UniversitT of California Publications are offered in exchange for the publi- cations of learned Bocieties and institutions, universities and libraries. Complete lists of all the publications of the University will be sent upon request. For sample copies, lists of publications and other information, address the I4ANAOEB OF THE UNTVEESITT PBESS, BEEKELEY, CAilFOENIA, U. S. A. All matter sent in exchange should bo addressed to THE EXCHANGE DEPARTMENT, UNTVEESITT LIBRAEY, BF.KKF.T.EY, CALIFOBNIA, U. S. A. WILLIAM WESLEY & SONS, LONDON Agent for the series In American Archaeology and Ethnology, Botany, Geology, Physiology, and Zoology. BOTANY.— W. A. Setchell, Editor. Price per volume, $3.50; beginning with voL 5, $5.00. Volumes I (pp. 418), H (pp. 360), III (pp. 400), IV (pp. 379), completed. Volumes V, VI, VII, and VIII in progress. Cited as Univ. Calif. PubL Bot Volume 1, 1902-1903, 418 pages, with 27 plates ■-.--,-—, — -- - --- ?3.50 Volume 2, 1904-1907, 360 pages, with 29 plates ...'.L.l.i...........l_ _. — 350 Volume 3, 1907-1909, 400 pages, with 14 plates — _ 3.50 Volume 4, 1909-1912, 397 pages, with 53 plates 3.50 Vol 5. 1912-. 1. Studies in NicoUana. I, by William Albert Setchell. Pp. 1-86. December, 1912 ~ 1.25 2. Quantitative Studies of Inheritance in Nicotiana Hybrids. I, by Thomas Harper Goodspeed. Pp. 87-168. December, 1912 _ — 1.00 3. Quantitative Studies of Inheritance in Nicotiana Hybrids. II, by Thomas Harper Goodspeed. Pp. 169-188. January, 1913 ..._ .20 4. On the Partial Sterility of Nicotiana Hybrids made with N. sylvestri^ as a Parent, by Thomas Harper Goodspeed. Pp. 189-198. March, 1913 ^ .10 5. Notes on the Germination of Tobacco Seed. I, by Thomas Harper Good- speed. Pp. 199-222. May, 1913 .25 6. Quantitative Studies of Inheritance in Nicotiana Hybrids, in, by Thomas Harper Goodspeed. Pp. 223-231. April, 1915 — _ .10 7. Notes on the Germination of Tobacco Seed. II, by Thomas Harper Good- speed. Pp. 233-248. June, 1915 .15 8. Parthenogenesis, Parthenocarpy and Phenospermy In Nicotiana, by Thomas Harper Goodspeed. Pp. 249-272, plate 35. July, 1915 „ _ „ .25 9. On the Partial Sterility of Nicotiana Hybrids made with N. sylvestris as a Parent. II, by T. H. Goodspeed and A. H. Ayres. Pp. 273-292, plate 36. October, 1916 ~ - — .20 10. On the Partial Sterility of Nicotiana Hybrids made with N. sylvestris as a Parent. Ill, An Account of the Mode of Floral Abscission in the Fj Species Hybrids, by T. H. Goodspeed and J. N. Kendall. Pp. 293-299. November, 1916 ..._ - 05 11. The Nature of the Fj Species Hybrids between Nicotiana sylvestris and Varieties of Nicotiana Tdbacum, with Special Reference to the Conception of Reaction System Contrasts in Heredity, by T. H. Goodspeed and R. E. Clausen. Pp. 301-346, plates 37-48. January, 1917 _ 45 12. Abscission of Flowers and Fruits in the Solanaceae, with Special Reference to Nicotiana, by John N. Kendall. Pp. 347-428, 10 text figures, plates 49- 53. March, 1918 85 13. Controlled Pollination in Nicotiana, by Thomas Harper Goodspeed and Pirle Davidson. Pp. 429-434. August, 1918 _ _ 10 14. An Apparatus for Flower Measurement, by T. H. Goodspeed and R. E. Clausen. Pp. 435-437, plate 54, 1 figure in text. September 25, 1918 .05 15. Note on the Effects of Illuminating Gas and its Constituents In Causing Abscission of Flowers in Nicotiana and Citrus, by T. H. Goodspeed, J. M. McGee and R. W. Hodgson. Pp. 439-450. December, 1918 — ,15 16. Notes on the Germination of Tobacco Seed. Ill, Note on the Relation of Light and Darkness to Germination, by T. Harper Goodspeed. Pp. 451- 455. April, 1919 - .05 UmVEBSITT OF OAUFOBNIA PUBLICATIONS— (Oontlnuod) Vol 6. 1014-. 1. Parasitie Florldeae, by William Albert SetcheU. Pp. 1-34, plates 1-6. April, 19U _ _ ^ 2. Phytomorula regularis, a Symmetrical Protophyte Belated to Coelastrum, by CbaBles Atwood Kofoid. Pp. 35-40, plate 7. April, 1914 _ .06 3. Variation in Oenothera ovata, by Katherine Layne Brandegee. Pp. 41-50, plates 8-9. Jime, 1914 _ _ _ JLO 4. Plantae Mexicanae Purpusianae. VI, by Townshend Stith Brandegee. Pp. 51-77. July, 1914 „ „ _ _ J2B 5. The Scinaia Assemblage, by WlUiam Albert SetchelL Pp. 79-152, plates 10-12. October, 1914 .76 6. Notes on Pacific Coast Algae. I, PylaicUa Postelsioe, n. sp., a New Type in the Genus Fylaiella, by Carl Skottsberg. Pp. 153-164, plates 17-19. May, 1915 _ _ 2B 7. New and Noteworthy Califomian Plants. II, by Harvey Monroe Hall. Pp. 165-176, plate 20. October, 1915 _ _.._ j.6 8. Plantae Mexicanae Purpusianae. VII, by Townshend Stith Brandegee. Pp. 177-197. October, 1915 _ __ „ .JB 9. Floral Relations Among the Qalapagos Islands, by A. L. Kroeber. Pp. 199-220. March, 1916 _ _.._ „ J20 10. The Comparative Histology of Certain Califomian Boletaceae, by Harry 8. Yates. Pp. 221-274, plates 21-25. February, 1916 .50 11. A Revision of the Tuberales of California, by Helen Margaret Gilkey. Pp. 275-356, plates 26-30. March, 1916 _ .80 12. Species Novae vel Minus Cognitae, by T. S. Brandegee. Pp. 357-361. May, 13. Plantae Mexicanae Purpusianae. Vni, by Townshend Stith Brandegee. Pp. 363-375. March, 1917 15 14. New Pacific Coast Marine Algae. I, by Nathaniel Lyon Gardner. Pp. 377- 416, plates 31-35. June, 1917 _ „ 40 15. An Account of the Mode of Foliar Abscission In Citrus, by Robert W. Hodgson. Pp. 417-428, 3 text figures. February, 1918 „ „ .10 16. New Pacific Coast Marine Algae. II, by Nathaniel Lyon Gardner. Pp. 429- 454, plates 36-37. July, 1918 _ 25 17. New Pacific Coast Marine Algae. Ill, by Nathaniel Lyon Gardner. Pp. 455-486, plates 38-41. December, 1918 35 18. New Pacific Coast Marine Algae. IV, by Nathaniel Lyon Gardner. Pp. 487-496, plate 42. January, 1919 :.. 15 19. Plantae Mexicanae Purpusianae. IX, by Townshend Stith Brandegee. Pp. 497-504. November, 1919 10 Vol. 7. 1916-. 1. Notes on the Califomian Species of Trillium L. I, A Report of the General Results of Field and Garden Studies, 1911-1916, by Thomas Harper Good- speed and Robert Percy Brandt. Pp. 1-24, plates 1-4. October, 1916 .25 2. Notes on the Califomian Species of Trillium L. II, The Nature and Occur- rence of Undeveloped Flowers, by Thomas Harper Goodspeed and Robert Percy Brandt. Pp. 25-38, plates 5-6. October, 1916 15 3. Notes on the Califomian Species of Trillium L. in, Seasonal Changes in Trillium Species with Special Reference to the Reproductive Tissues, by Robert Percy Brandt. Pp. 39-68, plates 7-10. December, 1916 30 4. Notes on the Califomian Species of Trillium L. IV, Teratological Varia- tions of Trillium sessile var. giganteum H. & A., by Thomas Harper Good- speed. Pp. 69-100, plates 11-17. January, 1917 SO 5. A Preliminary List of the Uredinales of California, by Walter C. Blasdale. Pp. 101-157. August, 1919 „.. .50 6, 7, 8. A Rubber Plant Survey of Western North America. I. Chrysothamnus nauseosiis and Its Varieties, by Harvey Monroe Hall. II. Chrysil, a New Rubber from Chrijsothamnus nausco.sus, by Harvey Monroe HaU and Thomas Harper Goodspeed. III. The Occurrence of Rubber in Certain West American Shrubs, by Harvey Monroe Hall and Thomas Harper Goodspeed. Pp. 159-278, plates 18-20, 8 figures in text. November, 1919. 1.25 9. Phycological Contributions. I, by William Albert Setchell and Nathaniel Lyon Gardner. Pp. 279-324, plates 21-31. April, 1920 50 UinVEESITY or CALIPOBNIA PUBLICATIONS— (Oontinuod) Vol. 8. 1919- 1. The Marine Algae of the Pacific Coast of North America. Part I. Myxophyceae, by William Albert Setchell and Nathaniel Lyon Gardner. Pp. 1-138, plates 1-8. November, 1919 ?1.50 2. The Marine Algae of the Pacific Coast of North America. Part n. Chlorophyceae, by WiUiam Albert Setchell and Nathaniel Lyon Gardner. Pp. 139-374, plates 9-33. July, 1920 2.75 3 5185 00256