3eWU//] ^o^n fi/J^rr "1:^0-^:11 UNIVERSITY- OF CALIFORNIA PUBLICATIONS IN BOTANY Vol. 8, No. 2, pp. 139-374, plates 9-33 July 14, 1920 /J THE MARINE ALGAE OF THE PACIFIC COAST OF NORTH AMERICA 5: = cr = m — i-R CD- SI D m a \ PART II CHLOROPHYCEAE BY WILLIAM ALBERT SETCHELL AND NATHANIEL LYON GARDNER UNIVERSITY OF CALIFO'RNIA PRESS BERKELEY *J ^? ~» ^ UNIVEESITY or OALIFOSNIA PUBLICATIONS Ifote.— Tbe University of California PutlicationB are oflfered in ezclumge 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. For sample copies, lists of publications and other information, address the MANAGER OF THE UNIVEESITY PEESS BERKELEY, CALIFORNIA, U. S. A. AU matter sent in exchange should be 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), H (pp. 360), III (pp. 400), IV (pp. 379), completed. Volumes V, VI, vn, 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 ..- ~ - — - 3.50 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 Nicotian a. I, by WUUam Albert Setchell. Pp. 1-86. December, 1912 V 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 — _ ^ 4. On the Partial Sterility of Nicotiana Hybrids made with N. sylvestris 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. Ill, 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 ~ - - — •^ 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. KendaU. Pp. 293-299. November, 1916 • 11. The Nature of the Fj Species Hybrids between Nicotiana sylvestris and Varieties of Nicotiana Talacum, with Special Reference to the Conception of Reaction System Contrasts in Heredity, by T. H. Goodspeed dtaid R. E. Clausen. Pp. 301-346, plates 37-48. January, 1917 _ _ .46 12 Abscission of Flowers and Fruits in the Solanaceae, with Special Reference to Nicotiana, by John N. KendaU. Pp. 347-428, 10 text figures, plates 49- 53. March, 1918 - 85 IS. Controlled Pollination in Nicotiana, by Thomas Harper Goodspeed and Pirie 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 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 .05 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 375-382 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 The second part of the Marine Algae of the Pacific Coast of North America, comprising- an account of the Chlorophyceae or Green Algae, succeeding an account of the Myxophyceae, is presented without intro- duction or explanation, pending the publication of the other two 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. Retchell and N. L. Gauoner. lai-Lcr UKin^ eiuier sepiaic V^-*^v piuviueu wiLii |jarLinuiiH, ctrs m Liie 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, mostly of cellulose but sometimes largely of pectose, occasionally more or less externally 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 starch centers, or pyrenoids, and colored bj' chlorophyll and xanthophyll, the former usually in excess ; reproduction vegetative, by non-sexual spores, and by zygotes ; vege- tative reproduction by cell division, fragmentation, and by gemmae 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 CHLOROPHYCEAE f^ /-.^^ V*^ L I K R A r* Y 1 WILLIAM ALBERT SETCHELL AND NATHANIEL LYON GARDNER Subclass 2. CHLOROPHYCEAE kuetzing Thallophytes containing only the pigments, chlorophyll and xantho- phyll; thallus 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 Siphonoeladiales) 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, mostly of cellulose but sometimes largely of pectose, occasionally more or less externally 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 varjdng shape and number, often containing starch centers, or pyrenoids, and colored by chlorophyll and xanthophyll, the former usually in excess ; reproduction vegetative, by non-sexual spores, and by zj^gotes ; vege- tative reproduction by cell division, fragmentation, and by gemmae 140 University of California Piiblications in Botany [Vol. 8 (or cysts) ; non-sexual spores either motile (zoospores, zoogonidia, or planospores) or non-motile (aplanospores, formed inside the wall of the original cell, and akinetes where the outer wall of the original cell is included in the spore formation) ; zj^gotes formed either from isogametes (either isoplanogametes, i.e., both equal and motile, or isoaplanogametes, i.e., both equal and non-motile) or from aniso- gametes (or heterogametes, i.e., unlike gametes) ; germination of the zygote various. Chlorophyceae Kuetzing, Phyc. Germ., 1845, p. 118 ; Wille, in Engier and Prantl, Natiirl Pfianzenfam., 1 Th., 2 Abt., 1897, p. 24; Oltmanns, Morph. und Biol, der Alg., vol. 1, 1904, p. 133; West, Algae, vol. 1, 1916, p. 126. Chlorospermeae Harvey, in Mackay, Fl. Hibern., part III, 1836, p. 163, Genera So. African Plants, 1838, p. 403. Harvey seems to have been the first to propose the classification into green algae, brown or olive-green algae and red algae, as now usually adopted, and coined the names Chlorospermeae, Melano- spermeae and Rhodospermeae. In his Chlorospermeae, he included also what are now separated under Myxophyceae, very few of which, however, were known to him. Kuetzing was the first to use the ending phyceae, but his Chlorophyceae included both the Chloro- spermeae and Melanospermeae of Harvey and is consequently very different in its content from that of more recent writers. There is some difference of opinion, even at present, as to the exact content of the Chlorophyceae. It has seemed best to follow West (1916, p. 126) in including also the Conjugatae as well as the groups with zoospores, although the decision assumes no practical importance in the present account, since none of the Conjugatae is properly marine. The great majority of the marine Chlorophyceae are inhabitants of the littoral belt, a few descending to the upper portion of the sublittoral belt, while those occurring in deeper waters are, so far as the extra tropical portions of the Pacific Coast of North America are concerned, very few indeed. The great majority of the Chlorophyceae are either subaerial or inhabitants of strictly fresh waters, so that a number of the important groups are not found in the salt waters. Unfortunately for this account, also, the strictly tropical waters of the Pacific Coast of North America are, as yet, unexplored, and little is known as to the occur- rence, or non-occurrence, of the more complex forms of the Codiaceae, 1920] Setchell-CUirdiier: Chlorophyceae 141 Valoniaceae and the Caulerpaceae. Undoubtedly many species of these families will be added later when the algal flora of the Pacific coasts of Mexico and Central America is collected and made known. CHLOROPHYCEAE Series 1. — Isokontae Order 1. — Protococcales Family 1.— Palmellaceae 1. Collinsiella Family 2. — Chlorochytriaceae 2. Chlorochytrium 3. Codiolum Order 2. — Siphonales Family 3. — Protosiphonaceae 4. Halicystis Family 4. — Bryopsidaceae 5. Bryopsis Family 5. — Derbesiaceae 6. Derbesia Family 6. — Codiaceae 7. Codium 8. Halimeda Family 7. — Vaucheriaceae 9. Vaucheria Order 3.— Siphonocladiales Family 8. — Cladophoraceae 10. Rhizoclonium 11. Hormiscia 12. Chaetomorpha 13. Cladophora 14. Spongomorpha 15. Microdictyon 16. Boodlea Order 4. — Ulvales Family 9. — Ulvaceae 17. Capsosiphon 18. Monostroma 19. Enteromorpha 20. Ulva 21. Percursaria Order 5. — Schizogoniales Family 10. — Schizogoniaceae 22. Prasiola 23. Gayella Order 6. — Ulotrichales Family 11. — Ulotrichaceae 24. Ulothrix Family 12. — Chaetophoraceae 25. Bulbocoleon 26. Entocladia 27. Endophyton (p. 142) (p- 143) (p. 143) (p. 144) (p. 146) (p. 146) (p. 151) (p. 153) (p. 154) (p. 154) (p. 156) (p- 157) (p- 163) (p. 164) (p. 166) (p. 167) (p. 176) (p. 177) (p. 178) (p. 179) (p. 179) (p. 180) (p- 187) (p. 198) (p- 207) (p. 220) (p. 231) (p- 232) (p. 233) (p. 233) (p- 233) (p. 235) (p- 244) (p. 260) (p- 273) (p. 275) (p- 275) (p. 275) (p- 279) (p. 281) (p. 282) (p- 282) (p. 286) (p. 287) (p. 288) (p- 292) 142 University of California Puhlications in Botany [Vol.8 28. Pseudodictyon (p. 293) 29. Internoretia (p. 294) 30. Ulvella (p. 295) 31. Pseudulvella (p. 296) 32. Pseudopringsheimia (p. 299) 33. Gomontia (p. 300) Family 13. — Trentepohliaceae (p. 305) 34. Trentepohlia (p. 305) Series 1. ISOKONTAE blackman and tansley 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) fi 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 siiuple; 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] SetchelJ^Gardner: Chlorophyceiae 143 Order 1. PROTOCOCCALES (meneghixi) oltmanns Unicellular isokontae, motile or iionmotile, often occurring singly or in larger or smaller, definite or indefinite colonies or coenobia, or even simple coenocytes, often provided with 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 ; reproductive methods various as outlined for the series Isokontae. Protococcales Oltmanns, Morph. und Biol, der Algen, vol. 1, 1904, p. 169 ; West, Algae, vol. 1, 1916, p. 160. Protococcoideae Meneghini, Cenni sulla organ, e. fisiol. delle Alghe, 1838, p. 4 (of reprint) ; Black- man and TaiLsley, Revis, Class. Green Algae, 1902, p. 21 ; Wille, in Engler and Prantl, Natiirl. Pflanzenfam., Nachtr. zum 1 Th., 2 Abt., 1909, p. 3. The Protococcales, or Protococcoideae as they have long been designated, form a rather large and seemingly heterogeneous order. They are mostly inhabitants 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, but undoubtedly a considerable number yet remain to be detected. This is particularly 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. Thallus strictly unicellular 2. Chlorochytriaceae (p. 146) FAMILY 1. PALMELLACEAE ■^^aH^isaE-^ naegeli Cells united into larger or smaller colonies by mucilaginous modi- fication of the outer walls, usuall^^ provided with a single parietal chromatophore (chloroplast) containing a single pyrenoid; repro- duction hy biciliated zoospores or by isoplanogametes ; fragmentation of colonies often takes place. Palmellaceae Naegeli, Die neuern Algensyst., 1847, p. 123; West, Algae, vol. 1, 1916, p. 183. Palmelleue Decaisne, Essai sur une classe des Algues, etc., 1842, p. 327. 144 University of California Puhlications in Botany [Vol. 8 The names Palmellaeeae and Palmelleae 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 by means of the mucilaginous material produced by the 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 may 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 pyrenoid. Colonies may split up and multiply the plant. Reproduction by 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 a^ the general cell structure and colony formation, points directly toward relationship with the Volvocaceae. 1. CoUinsiella S. and G. Frond gelatinous, solid or later hollow, composed of pyriform cells, on dichotomous, gelatinous stalks tapering downward from the cells; all enclosed in the general gelatine ; chromatophore band-shaped, with one large pyrenoid ; the terminal cells become the zoosporangia ( ? ) Setchell and Gardner, Alg. N.W. Amer., 1903, p. 204. There is a reason for difference of opinion as to whether CoUins- 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. CoUinsiella tuberculata S. and G. Plate 10, figs. 4-10 Colonies rugose-tuberculate, 2-4 mm. diam., dark green, gelatinous, firm, attached by a broad base ; cells pyriform, 5-12/^ 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 pushing forward, forming the cortex, leaving behind the translucent, stalklike, gelatinous cell walls, while growth 1920] Setchell-Gardner : Chlorophyceae 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, Washington, Port Renfrew, Vancouver Island, Farallones Islands and Point Carmel, California. Setchell and Gardner, Alg. N.W. Amer., 1903, p. 204, pi. 17, f. 1-7 ; Collins, Green Alg. N. A., 1909, p. 141; West, Algae, vol. 1, 1916, p. 188; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 909. EchaUocystis Willeana Yendo, Three species of marine Echallo- cystis, 1903, p. 199. EchaUocystis tuherculata (S. and G.) Wille, Nachtrage, 1909, p. 28 (in part). Wille (1909, p. 27) places ColUnsiella as a synonjTn under Echnllo- cystis Bohlin, but Collins (1909, p. 141) and West (1916, p. 188) keep it distinct. It seems to differ from EchaUocystis in forming an extencled and definite gelatinous thallus, in the 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 (lac. cit.) places it in the subfamily Palmophylleae of the Palmellaceae and next to Palmophyllum. This disposition of the genus seems to be the most satisfactory and is adopted here. Collins (1909, p. 141) assigns the EchaUocystis WiUeana Yendo, from Port Renfrew, British Columbia, to CoUinsieUa tuherculata S. and G. as a synonym, and draws his description from both those of Yendo and of Setchell and Gardner. Yendo, however, in his remarks (1903, p. 204) states that it seems to him highly probable that CoUinsieUa tuhercidata may be a young and sterile form of a plant closely related to his EchaUocystis WiUeana, if not the same species. We have not had the opportunity of examining a plant of EchaUocystis WiUeana, but judging from Yendo 's description and plates, there are some differences. In the Wliidbey Island plant there is a sort of basement membrane from which bullate swellings rise as indicated in the habit figure of Setchell and Gardner (1903, pi. 17, f. 1). Yendo figures isolated, much folded thalli (1903, 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 Wliidbey Island or in any others of our collections. These are, perhaps, minor and unessential differences, but they indicate that there is a reason to feel uncertain as to the absolute 146 University of California PuhUcations in Botany [Vol.8 identity of the two plants. The specimens from the central Californian coast, on the other hand, resemble more closely the Yendo plant in habit but show no attaching fibrils. FAMILY 2. CHLOROCHYTRIACEAE nom. nov. Thallus unicellular, not united into colonies, or single unseptate coenocytes, reproducing .solely by zoospores and by isoplanogametes. Planosporaceae West, Algae, vol. 1, 1916, p. 209. E ndosphaeraceae Klebs, Organ, einig. Flagellaten-Gruppe, 1883, p. 344; Hansgirg, Prodr. d. Algenfl. v. Bohmen, II, 1888, p. 124 ; Blackman 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- chytrium, as indicated elsewhere, among them being Endosphaera. West has, consequently, set aside the family name Endosphaeraceae, as adopted by Blackman 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- chytriaceae" 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 sphericalto more or less ovoid 2. Chlorochytrium (p. 146) 1. Cells cylindrico-oblong with a more or less elongated stipe 3. Codiolum (p. 151) 2. Chlorochytrium Cohn Thallus unicellular, rounded, with ehromatophore 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 b}^ 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] Sctchell-Gardner: Chlorophyceae 147 West reduces Endosphaera Klebs, Scotinosphaera Klebs, Chloro- cystis Reinhardt and Stoniatochyirium Cunningham to one genus and unites that with Chlorochytrium Cohn. "They all agree in being holophytic, unicellular, spherical or nearlj^ so, wholly or partly endo- phytic plants with a single chromatophore, covering the wall more or less completely and containing one or more pj^renoids. Reproduction is by piano-gametes or by zoospores or by both" (cf. Gardner, 1917, p. 383). It seems best to follow West in his conception of the genus and our species are, consequently, assigned to Chlorochytriuyn in this extended sense. The three species thus far credited to our territory are immersed in the tissues of various membranous or expanded red algae. Key to the Species 1. Cells with apiculate tips 1. C. inclusum (p. 147) 1. Cells without apiculate tips 2 2. Cells spherical, chromatophores with one pyrenoid 3. C. Porphyrae (p. 1.50) 2. Cells clavate or ovoid, chromatophores with two or more pyrenoids 2. C. Schmitzii (p. 149) 1. Chlorochytrium inclusum Kjellm. Plate 13, fig. 1 Cells in the vegetative condition, spherical or subspherical, entirely included within the host plant, at the time of the formation of the zoospores, slightly elongated, depressed conical, ampullaeform, ovoid or ellipsoid, at length exposed through the penetration of the cortical layer of the host by the apiculate tip, emitting the zoospores through an ostiole. Endophytic in the fronds of various membranaceous algae, e.g., Iridaea, Weeksia, Const antinea, etc. Probably common along the coast from Sitka, Alaska, to Puget Sound, Washington. Kjellman, Alg. Arctic Sea, 1883, p. 320, pi. 31, f. 8-17 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 206?; Collins, Green Alg. N. A., 1909, p. 147 (in part) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), 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. {Sarcophyllis arctica Kjellm.). The cells of the Chlorochytrium are placed, in most 148 TJmversity of California PuMioations in Botany \yo\.. 8 cases, near the surface of the host plant but sometimes occur in the middle layer. In vegetative condition the cells are from 80/x to 100/x in diameter, the cell wall is thin and of equal thickness throughout, while the chromatophore is thin and spread over the whole wall. The wall becomes thicker and apiculate at the outer end as the cell passes into the reproductive stages, the apiculate 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 the tip of the cell. These latter statements are evidently inferences because he distinctly 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 nearly spherical in shape, with uniformly thin walls, and with a chromatophore thin and dotted with numerous large pyrenoids. These cells are about SOju, 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 inclusum 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 iiiclusum, but he found only vegetative stages. It was endophytic in the blades of Constantinea suhiilifera 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 chromatophore 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, 1^20] Setchell-Gardner : Chlorophyceae 149 on Iridaea from the west coast of Whidbey Island, Washington, shows small plants (40/* x 80ju,), broadly pyriform and with thick walls. It is to be referred provisionally to Chlorochytrium, but does not agree with Kjellman's description. No. 514, of Collins, Holden and Setchell's Phycotheca Boreali-Americana, shows large, thin walled cells, depressed vertically and measuring about ISOfx by 240jli, seem- ingly a Chlorochytrium, but not in accord with the descriptions of either Kjellman or Freeman. The other references given by us, with the exception of Tilden's no. 389, which is Freeman's plant, are to be rejected. They are found to be based upon plants of the second type, which is probably Chytridmceous, possibly being near to Rhodo- chytrium. They are probably the so-called gland cells mentioned by Schmitz as occurring in Turnerella Mertensiana (P. and R.) Schmitz (1896, p. 372) and figured as occurring ui 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 Fryeaiia 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. Chlorochytrmm Schmitzii Rosenv. Cells clavate or ovoid, with rounded apex, without cone-shaped thickening of the cell wall, and with pointed base ; up to 370/^ long by 90/x, diam. ; chromatophore single, occupying the greater part of the cell wall, and with two pyrenoids. Growing in various incrusting marine algae, e.g., Petrocelis. Alaska. Rosenvinge, Groenl. Havalg., 1893, p. 964, f. 56; Collins, Green Alg. N. A., 1909, p. 147; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 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 Whidbey 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. Other cells have papillate swellings at one or both 150 University of California Publications in Botany [Vol. 8 ends and are probably reproducing since the contents seem more or less broken up. 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 Alaskan plant in Chlorochytriiini and to refer it to C. Schmitzii pending further investigation of living material. The Whidbey 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 Codiolum and is discussed below under that genus. The Alaskan plant referred to this species varies in height from 123/A up to 220//., and in width from 54/a to 66ju,, thus coming within the measurements as given by Rosenvinge for Chlorochytrium Schmitzii. 3. Chlorochytrium Porphjrrae S. and G. Plate 15, fig. 1 Cells spherical, 40-60/x diam., embedded within the host on both 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 2-3/x, diam., hyaline, not laminated; color, grass green; sexual reproduction by 2-ciliated isogametes, 3-4ju, 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 was discovered at Lands End, San Francisco, Cali- fornia, but since the first publication of its discovery it has been observed in the vicinit}^ of Cape Flattery, Washington, where it grows in abundance on the same host as at San Francisco, It probably extends along our eoast 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 Chlorochytrium and the various plants referred to C. Cohmi, will be found under the refer- ence to Gardner given above. 1920] SetcJiell-Gardner : ChloropJiyceae 151 3. Codiolum A. Brann Frond unicellular, ovoid to clavate or subcylindrical, the cell wall prolonged below into a longer or shorter stipe, attached by a simple or forked expansion ; chromatophore covering the cell wall or more or less broken, with several pyrenoids ; asexual reproduction by 4- ciliated zoospores, many in a cell. A. Braun, Algarum Unic, 1855, p. 19. This genus was first mentioned in 1852 by Braun before the 29th Congress of naturalists and physicians 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 Codiolum gregarium A. Braun, and the type 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 swollen cell which is elongated ovoid in shape and which is termed the "clava." The dimensions of both stipe and clava differ somewhat even in the same species, but in the endophytic species the stipe may be abbre- viated or even, most commonly, wanting. Key to the Species 1. Cells with a 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/^ long, and lOO^u, wide ; stipe hyaline, unbranched, nearly cylindrical but slightly enlarging upward, 600-1000/x long, 20-30ju, wide, somewhat disk-shaped at the base. Reported from a single locality in our region, growing on an iron buoy near Friday Harbor, San Juan Count}^ 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 endophj^tic 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 PuUications in Botany [Vol. 8 p. 517) comes to the conclusion that two species, or groups of species, stand out with fair distinctness, viz., Codiolum gregarium A. Braun, in which species (or group) the clava is definitely constricted at the 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 with C. gregarium A. Braun and while their dimensions differ from those given by various authors for this species, yet it seems best not to attempt any separation at present. Our specimens vary in length of clava from 160/^ to 240/^, and in width from 32/x to 64/x, while the stipe varies from 250ja to 550ja in length and from 16/a to 28[x in diameter. 2. Codiohim Petrocelidis Knckuck Clava ovoid or obovoid, 65-90iLi long, 20-30/x 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- dor ffii on the west coast of Whidbey Island, Washington, and the other in P. franciscana on the coast of central California at Fort Point, San Francisco. Tliese 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) 65/a to 90/x long and 20ju, to 30/* wide as the dimensions of his type. The Washington plant varies from 136/x to 180/t long and from 20/a to 44/t wide for the clava, while the Californian plant shows clavae from BOft to 140/t long and 28/x to 42/* wide. It seems best, however, to refer them both to Codiolum Petrocelidis Kuckuck, at least for the present. 1920] Setchell-Cnardncr : Chlorophyceae 153 As to the stalk (or stipe) it is very distinct in some specimens while absolutely wanting in most of the others, but the shape of the cell is, in general, sufficiently distinctive to permit of the ready separation of these specimens from those usually referred to Chloro- chytrium. Order 2. SIPHONALES (gkev.) oltmanns Fronds filamentous, either simple or variously entangled or inter- woven, sometimes producing complex individuals, devoid of septa (or very nearly so) in the actively vegetative portions, but septa appear- ing in the reproductive portions, multinucleate and with many small chromatophores ; multiplication vegetative, by non-sexual spores, and by zygotes ; vegetative by abscission of proliferous shoots or frag- mentation ; non-sexual spores, either aplanospores or zoospores, produced usually in specialized zoosporangia ; zygotes from either isogametes or heterogametes. Siphonales 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. Siphaneae 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 pedicellate Halicystis or the dichotomously filamentous Vaucheria or Derhesia, through the more or sometimes less specialized species of Bryopsk, 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 Codium to the condition in Vaucherm, 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., Vaucherm 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 thallus 6. Codiaceae (p. 166) 154 University of California PuMicatio-ns in Botany L^ol. 8 3. Filaments pinnately 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 sporangium, provided with a crown of cilia 5. Derbesiaceae (p. 163) FAMILY 3. PROTOSIPHONACEAE blackman and tansley 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- noids ; multiplication vegetative, by aplanospores, through micro- and macro-zoospores, and possibly also through isoplanogametes. Blackman and Tansley, Rev. Class. Green Alg., 1902, p. 115; Collins, Green Alg. N. A., 1909, p. 153; West, Algae, vol. 1, 1916, p. 223. A small family separated by Blackman and Tansley from the Botrj^diaceae to contain particularly Protasiphon Klebs as a segregate from Botrydium Wallroth which, in turn, was removed from the Isokontae to the Heterokontae. Besides Protosiphon, it is usually made to include Blast ophysa 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 b,y 2-ciliated zoospores without stigma, escaping through one or more openings ; similar but smaller zoospores or zoogametes( ?) formed in separate indi^'iduals; after the emission of the spores the openings close and several new generations of spores can be similarly produced. Areschoug, Phyc. Scand., part 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] Setchell^Gardner : Chlorophyceae 155 rliizoidal portion. It is now placed near to ProtosipKon, which 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.) Arescli. Plate 14, fig. 3 Thallus solitary or gregarious, obovate-ovoid, 0.5-1 cm. high, about half as wide ; membrane tough, 10-12ja thick ; basal prolongation penetrating the substratum; zoospores 12-14/x long, 7-8/x wide; gametes ( ?) 7-8/a long, 2-3/a wide. Growing on Lithothamnwn and on other crustaceous corallines adhering by means of the rhizoidal portion penetrating deeply into the host. Vancouver, British Columbia, to Monterey, California. Areschoug, Phyc. Scand., part II, 1850, p. 447 ; Kuckuck, Abhandl. Meeresalg., 1907, p. 139, pi. Ill; Collins, Green Alg. N. A., 1909, p. 372. Valonia ovalis (Lj^ngb.) Agardh, Sp., vol. 1, part 2, 1822, p. 431; Saunders, Four Siphon. Alg., 1899, p. 2, pi. 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 ver}^ curious and interesting species has been most carefully studied, described and illustrated by Kuckuck (1907) and seems to be the same as that 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 them (Setchell) has had the privilege even of examining a living plant.. In general appearance and structure, however, the Pacific Coast plant agrees thoroughly with the 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 Cypress, only a few miles north of "Point Lobos" by Professor Harold Heath of Stanford University, and the third and last locality is Port Renfrew in British Columbia, where it was collected by Misses Butler and Policy. It is alwaj^s found growing on living crustaceous coral- lines into the thallus of which it bores its way. It will probably be found at other points along the coast, since it undoubtedly escapes observation as it is small and grows at, or just below, the lowest tide mark. ^ 156 University of California PuMications in Botany [Vol. 8 FAMILY 4. BEYOPSIDAOEAE (boey) de-toni Thallus a more or less branched, unseptate coenocyte, 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 trabeculae (as in the Cauler- paceae) ; chromatophores and nuclei numerous and small, the former elliptically discoid and provided with a single pj-renoid each ; vege- tative reproduction by a detachment of pinnules 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 {sub "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 by its method of branching and the possession of 2-ciliated, motile, reproductive bodies, the Codiaceae, from which it is distinguished bj^ 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 trabeculae. 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 Caulerpa 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 et seq.) and has not been verified, as yet, in our species. 1920] Setchell-Gardner : Chlorophyceae 157 5. Bryopsis Lamour. Thallus unseptately coenocytic, much branched ; chromatophores numerous small disks, each with one pyrenoid ; the axis producing rhizoids below and branches above both of unlimited and limited growth ; in the latter large, 2-ciliated, green, female gametes, and on separate individuals, smaller, brown, 2-ciliated male gametes are formed; by the union of the two a zygote is fonned germinating immediately. Lamouroux, Observ. sur la physiol. des alg. mar., 1809, p. 333, Mem. sur trois nouv. gen. de 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 off 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 decidedlj^ cold water, e.g., B. plumosa (Huds.) J. Ag. being credited even to the icy waters of Baffin Bay. Most of the species have wonderfully sym- metrical fern-like fronds of a beautiful dark green which, when spread out on paper, 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 growth 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, with ample facilities and patience, shall have unusual opportunities for study and illustration. 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 University of California Puhlioations in Botany [Vol. 8 proportions of the piunules and, especially, the shape of the bases of the older pinnules, 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, possibly 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 locality ' ' St. Augustin, ' ' on the Pacific coast of Mexico, where it was collected by Professor Liebmann of Copenhagen. J. G. Agardh, Nj^a 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 figures 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-Gard7ier : Chlorophyceae 159 upon the relationships of the two plants. Concerning the type locality, which 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 Pochutla and Pt. de Huatulco. (See Oersted in Liebmann, Chenes de I'Amerique Tropicale, 1869, p. viii.) 2. Bryopsis hypnoides Lamour. Thallus 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 that clothe them on all sides, the latter themselves being frequently more or less branched; pinnules usually long and slender, gradually attenuate at the apices, suddenly con- stricted and symmetrically rounded at the bases. Growing on logs, floats, shells, stones, etc. Ranging from Victoria, British Columbia, to San Pedro, California. Lamouroux, Mem. sur trois nouv, genres., 1809a, vol. 2, p. 135, pi. 1, f . 2 a, b ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 230 ; Harvey, Phye. Brit., 1846, pi. 119 ; Vickers, Phyc. Barb., 1908, p. 30, pi. 53, f. 1, 2 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsiec), no. 1028. Only three illustrations of this species are available to convey an idea of the characteristics of the species. The first, and only strictly authentic illustration, is that of Lamouroux (1809a, pi. 1, f. 2 a, 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 the shape of the base and apex of the pinnules. It is very evident, however, that the conception of Harvey was of a much branched, polystichous 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 Anna Vickers in her Phycologia Barbadensis (pi. 53). The pinnules 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 segments of the pinnules. 160 University of Calif ornia Piihlications in Botany [Vol. 8 The branching of Bryopsis elegans Menegh. figured by Zanardini (1860-76, pi. 72) referred to by J. G. Agardh (1886, p. 28) as being possibly of B. kypnoides is different in detail, at least, from all the others. The specimens from the Pacific Coast, referred here until more study and careful comparison with the type specimens can be made, seem reasonably uniform. They are much branched plants, poly- stichous, 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 very symmetrically rounded at the base and without any 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 plat© 27 Thallus rather stout and coarse, 8-14 cm. 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 pyramidal; 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] SetcheU-Gurdner : Chlorophyceae 161 Bryopsis corticulans is a coarse, dark green species, fairly regu- larly distichous and with pinnules little reduced in size from the axis whence they spring. It has, in the older plants at least, small clusters of short rhizoidal outgrowths at the bases of the lower (or even of the upper) branches. Thus 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 closely related to B. plumosa, but it is coarser, with more regularly occurring corticulating rhizoids, and with the pinnae more elongated lanceolate. It is still a question whether we have true B. plumosa or not, and it is not absolutely certain that B. corticulans 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 strictly distichous Bryopsis from our coast seem referable to B. corti- culans rather than to B. plumosa. 4. Bryopsis plumosa (Huds.) Ag. Plate 14, figs. 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, Washington, 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 Devon on the south coast of England, 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, and has broad triangular plumes. More investigation is needed to determine exactl}^ the original application of the name, if possible, and 162 University of California Publications 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. plumosa (pi. 83, f. I) and under B. abietina (p. 80, f. I) are usually referred to B. plumosa. On comparing these illustrations with those of Harvey (1846, pi. 3), Greville (1830, pi. 19) and of Bryopsis Lyngtyei Hornemann (1818, pi. 1603) and its reproduction by Lyngbye (1819, pi. 19, f. B), it seems evident that there is con- siderable variety among the European plants referred to B. plumosa. 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 plumosa 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. hypnoides. 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 may serve as a basis for discussion is that of Ulva plumosa 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 plumosa 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. corticulans 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 : Chlorophycme 163 FAMILY 5. DERBESIACEAE (tkl'ret) kjellm. Thalliis of erect, simple or sparingly branched coenocytic filaments, arising from more slender creeping filaments which are attached to the substratum by short, branched, rhizoid-like holdfasts ; chromatcrphores small, discoid, oval or elliptical in shape 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. Derhesiees Thuret, Rech, sur les zoospores des algues, etc., 1850, p. 231 (p. 22 Repr.). Derbesieae 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 seemingly funda- mental difference, all writers have placed it among the Isokontae rather than among the Stephanokontae. Davis, in his paper on ' ' Spore formation in Derhesm" (1908), has followed out the nuclear behavior during zoospore formation and its relation to the development of a blepharoplast 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 Oedogoniuni or any other of the Stephanokontae. Davis {loc. cit., p. 16) states that the zoospores of Derhesia 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 Derhesm. 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 Derhesia should not be removed from the Siphonales. Davis also expresses the opinion that no one will be bold enough to suggest a relationship between Derhesia and Oedogmiimn on account of the resemblances of the zoospores. It seems to us, however, that in the Stephanokontae, there exists a peculiar type 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 coenocytic condition, the Stephanokontae may have done the same. It seems to us neither impossible, nor wholly inconsistent with what we find 164 University of California Puhli oat ions in Botany [Vol. 8 among the Isokontae, to consider Derhesia as a coenocytic genus of the Stephanokontae. For general convenience, however, connected with the fact that this account deals with marine species only, we leave it in the place usually assigned to it. There are only two genera to represent this family, Derhesia Solier and Bryohesia Weber-van Bosse. Of these Derhesia alone has been found, thus far, on our coast. 6. Derbesia Sol. Filaments unseptate, or with occasional partitions, multinucleate, simple or branched, with no differentiation 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 pyriform 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 family, 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 mariiia Lyngbye and is now known as D. tenuissinm (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 Bryobesia 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 50-70m in diameter 1. D. marina (p. 165) 1. Filaments 100-600ju in diameter 2. D. Lamourouxii (p. 165) 1920] Setchell-Cnardner: Chlorophycme 165 1. Derbesia marina (Lvngb.) Kjellm. Plate 15, fig. 3 Filaments arising from a creeping base, bright green, 50-70/1 diam., simple or usually with a few lateral branches similar to the axes, continuous but with a short segment separated by partitions near the base of a branch or occasionally in the axils just above a branch, little smaller than the branch itself and about as long as broad ; sporangia occupying the place of branches, ovoid to subspherical, 150-250/x, long, 90-200)li broad ; pedicel varying from 30-7 Oyu. in length, 30-35/A 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. Agardh, 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-, s'mui Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 574, Vmicherm nmrina Lyngbye, Hydr. Dan., 1819, p. 79, pi. 22 A. We suspect that the Derhesm vmicheriaeformis of Saunders (1899, p. 3, pi. 350, f. 4 a-d) from "Point Lobos" (really Point Carmel) near Monterey, California, is to be placed rather under D. nmrina as understood by J. G. Agardh. Saunders describes his species as pos- sessing filaments from 30jii to 40/t broad and elliptical, obovate or pyriform sporangia 140/i, to 200ja long and 50/x to 80/x 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/* to 20/* 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. vmicheriaeformis, but did not observe mature zoosporangia. 2. Derbesia Lamourouxii (J. Ag.) Sol. Filaments arising from a creeping base, a few centimeters to 2 dm. high, 100-600/t diam., dark green, rather stiff, sometimes simple, some- times with more or less numerous irregular branches ; sporangia spherical, 300-550/i diam., sessile or on short and slender pedicels. Southern California. C/i 166 University of California PuUications in Botany [Vol. 8 Solier, Mem. sur deux Algues, 1847, p. 162, pi. 9, f . 18-30 ; Collins, Green Alg. N. A., 1909, p. 1:07. Bryopsis Balbisiana var. Lamourouxii J. Agardh, Alg. Med., 1842, p. 18. This species is represented in the Herbarium of the University of California by two sterile specimens collected by Mrs. E. A. Law- rence, five miles south of the boundary between southern and Lower California. It is decidedly coarser than any other of the described species of the genus. \ FAMILY 6. CODIACEAE ^i^aevis.)' zanard. Thallus dark green, spongy, subspherical, applanate or erect, cylindrical, flattened, or jointed, simple or dichotomously branched, at times incrusted with lime, composed of intertwined branching fila- ments, the peripheral branchlets forming a palisade or pavement-like external layer; septa (diaphragms) frequent but in connection with formation of reproductive organs or in older filaments; chloroplasts parietal, small, very numerous, especially at the apices of the branches, destitute of pyrenoids; multiplication through fragmentation and by zoospores and anisoplanogametes ; zoosporangia and gametangia differ- entiated and variously situated. Zanardini, Sagg. di class, nat. d. Ficee., 1843 (table opposite p. 17). Codieae Trevisan, Prosp. fl. Eugan., 1842, p. 50, Flora, 1843, p. 465 (in part). The family, originally separated as Spongodiees by Lamouroux (1813, p. 280 or p. 71 of repr.), has long been recognized as distinct among the Chlorophyceae. It contains the most highly differentiated of the genera of the marine Green Algae, both as to complexity of thallus and as to differentiation of the reproductive cells, its only competitors being the Dasycladaceae and the Vaucheriaceae. The thallus is made up of interwoven coenocytic filaments, the peripheral branchlets of which are distinctly and variously differentiated and combined into a distinct external layer. The sporangia and game- tangia are formed from modified lateral branchlets of the coenocytic filaments and the gametes are distinctly unlike in some species at least. Many of the species are heavily incrusted with lime and are important agents in the building up of coral reefs. The majority of the species are strictly tropical but some of the species of C odium are to be found in subtropical, temperate, and perhaps even in frigid waters. Key to the Genera 1. Thallus without joints or calcification 7. Codium (p. 167) 1. Thallus with distinct joints and more or less calcified 8. Halimeda (p. 176) 1^20] Setchell-Gardner : Chlorophycaae 167 7. Codium Stackh. Thallus spongy, not incrusted with lime, applanate, subspherical or cylindrical, simple or dichotomously branched, attached, dark green; medullary filaments vertically intertwined, giving rise to hori- zontal branchlets whose tips, swollen into "utricles," form a con- tinuous external palisade layer; multiplication by fragmentation of the thallus ; sexual reproduction through 2-ciliated anisogametes pro- duced in gametangia situated laterally on the utricles; dioecious or occasionally monoecious. Stackhouse, Nereis Brit., 1797, p. xvi. Lamarckia Olivi, in 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 the Nereis Britannica (2d fascicle, p. xvi), but in the second edition (1816, p. xii) evidently abandoned in favor of " Lemarkea." There is an earlier generic name, Codia (Forster and Forster, 1776, p. 59), still used for a genus of Saxi- fragaceae, and Codiaeum of Rumphius (1743, p. 65) is still current among the Euphorbiaceae. Otto Kuntze (1891, p. 900) argues for "Lamarckia" as the proper 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 the status of the name of Lamarkia 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 cushion-shaped, some are spherical and hollow, while some are either cylindrical or flattened but erect and branching. J. G. Agardh (1886, p. 35 et seq.) has subdivided the genus according to these differences. After habit, good characters for distinction of the species have been 168 University of California Puhlicatians in Botany [Vol. 8 sought for in the varying size, shape, proportions, and modification 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 ag-es 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 only for the European C. tomentosum (cf. Oltmanns, 1904, p. 301, and West, 1916, p. 241). In this species the spore reproduction is exclusively 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 (p. 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 (p. 175) 5. Utricles 400m or more in maximum diameter 4. C. decorticatum (p. 172) 5. Utricles 250m or less in maximum diameter 5. C. tomentosum (p. 174) "SfiMx^c-yn^" 1. Codium Setchellii Gardner /^^ J^ /^ Plate 30, and plate 9, figs. 10, 11 ' yU^UK^zy*^^^^^ Thallus forming dense, compact, spongy, irregular cushions, 6-10"""-^ » mm. up to 15 mm. thick, adhering firmly to rocks ; color dark glossy green ; medullary filaments 12-30/i, 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 6-16/i. thick and lamellose when older; game- tangia cylindrical or slightly fusiform, 300-330/x long, 45-55fi 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 : ChloropJiyceae 169 Gardner, New Pac. Coast Mar. Alg. IV, 1919, p. 489, pi. 42, f. 10, 11. C odium adhaerens 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). Codium diniorphiim 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). Codium 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. adhaerens (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 {loc. 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. d/imorphum 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 consequently been described as new by Gardner {loc. cit.), its type locality being Monterey, California, since from that general locality 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 Math a view of determining whether we have one or more species on our coast. 2. Codium Ritteri S. and G. Plate 16, fig. 5 Thallus spongy, globose when young, becoming flattened, expanded and variously lobed when older, 1.5-2.5 cm. thick, attached by a broad base ; the center and lower portion consisting of tortuous, loosely inter- woven, rhizoidal filaments, 50-65/x diam. ; utricles clavate, usually branching, rarely swollen in the middle and fusiform, mostly truncate, 170 University of California Publications in Botany [Vol. 8 150-250ju, up to 400/A diam. ; 2-4 mm. long, end wall slightly thickened and with a small depression in the center; gametangia unknown. Growing on rocks in the lower littoral and upper sublittoral belts. Extending from Kadiak Island, Alaska, to the west coast of Vancouver Island, British Columbia. Setchell and Gardner, Alg. N.W. Amer., 1903, p. 231, pi. 17, f. 8-11. Codium adhaereiis Tilden, Amer. Alg. (Exsicc), no. 370 (not of Agardli). The type specimen is a small plant about three centimeters in diameter, or possibly it may be a small lobe of an old thallus that had become loosened at the base and by wave action had been torn from the remainder of the thallus. Since the publication of the species, excellent material, several inches across, has come from Alaska to the Herbarium of the University of California through the courtesy of T. C. Frye and G. B. Rigg. These show that the species is con- siderably expanded and variously lobed, though not adhering so firmly and closely to the rock as do other incrusting forms of this genus. The utricles in the upper portion away from the margin are relatively much longer and narrower than those figured for the type (Setchell and Gardner, loc. cit.). New utricles arise from the older one by lateral branching, as many as four and five appearing at a time. The point of origin remains constricted, and a plug cuts off the new utricular protoplast from the old one. In due course these branches may drop off, the old utricle continuing to grow, and later giving rise to others. From their bases the new utricles give rise to several rhizoidal filaments. The species probably fruits in the winter, since all the material thus far collected is sterile, and the collections have all been made in the summer. Setchell and Gardner {loc. cit., p. 232) suggested that possibly the plant distributed by K. Okamura (Algae Japonicae Exsiccatae, no. 49) under C. nmmillosum belong-s under C. Eitteri. Okamura (1915, p. 152) dissents from this suggestion. Since having had opportunity for further study of C. Ritteri, reexamination of the Japanese plant leads us to conclude with Okamura that his plant is not the same as C. Ritteri, but we do not agree with him that it is the same as C. mamillosum of Agardh. We have not seen the specimen of Codium mamillosum of Coville and Rose (1898, p. 353) from Preobrazhenskoye, Copper Island, in the Commander Group, Siberia, but, on account of the low tempera- 1920] Seichell-Oardner : Chlorophyceae 171 ture of the water at that point, we suspect that their plants may belong rather to C. RiUeri than to C. mamillosum which is a sub- tropical species. 3. Codmm fragile (Suring.) Hariot ^' ^^ '^.j^olCZX^ ''^ Plates 28, 29 <:3^I.^Z<^^*^-7'2^^^ ' Fronds one to several from a broad spongy disk, cylindrical, profusely and dichotomously branched, 25-40 cm. high, 2-10 mm. in diameter, glossy, dark green, finely rugose on the surface or, at times, densely" tomentose with long hyaline hairs; utricles cylindric claVate, 150-350/x, (occasionally 630ju.) in maximum diameter, and 5-10 times as long as broad, provided (at least when young) with a more or less distinct mucro; gametangia (2 ?) fusiform, 1-3 to each utricle, 250-450^ long and 75-150yLi in diameter. Growing on exposed rocks and in small pools in the littoral belt. Alaska to Mexico. Hariot, Algues du Cap Horn, 1889, p. 32 ; De-Toni, Phyc. Japon. Novae, 1895, p. 64. Acanthocodium fragile Suringar, Algarum Japonicaeum, Index praec. 1867, ihid., Hedwigia, vol. 7, 1868, p. 55; Algae Japonicae, 1870, p. 23, pi. 8; ibid., Hedwigia, vol. 9, 1870, p. 133. Codium mucronatum J. Agardh, Till. Alg. S^'st., 5th part, 1886, pp. 43, 44; Hurd, Pug. Sound Mar. Stat. Publ., 1916a, vol. 1, pp. 109-135, pi. 19-24 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 232; Saunders, Alg. Harriman Exp., 1901, p. 416. Four Siphon. Alg., 1899, p. 1, pi. 350, f. 1 a, b, c, d ; Collins, Green Alg. N. A., 1909, p. 389; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 229. Codium tomentosum Tilden, Amer. Alg. (Exsicc), no. 281 (not of Staekhouse). The mucronate tip of the utricle of this plant is a prominent specific character, but this character is subject to extreme variation. J. Agardh (1886, pp. 43, 44) separated the species into three varieties based chiefly upon the character of the mucro. We have studied and compared plants from a considerable number of different localities ranging from Alaska to Mexico, and have come to the conclusion that the species cannot be split into varieties based upon that character. Single plants may be found producing mucronate tips covering the entire range of shapes, as regards thickening of the walls and acute- ness of the tip, that have been used to designate the varieties. Miss Hurd (1916o, p. 109) made a critical study of the species as occurring 172 University of California Publications in Botany ["Vol.8 in the vicinity of the Puget Sound Marine Station, and came to the conclusion that they exhibited all the possible variations assigned to the varieties novae-zelandiae and californicnm, both of which have been accredited to our coast. Cotton (1912, p. 114-119, pi. 7, 8, f. 3-5) has discussed the species as found on the coasts of Ireland and of Scotland with remarks on the varieties described by himself and J. G. Agardh. As usually found, Codium fragile gives no impression of being tomentose, but oecasionally plants are found which are covered with a thick coating of hairs. Miss Hurd (1916a, p. 114-116) has dis- cussed the hairs on the utricles of this species in some detail, but did not find the extreme tomentose condition found by one of us (Gardner) at Redondo, California where the hairs were 2 mm. long, and so densely covering the whole plant as to make it seem as if para- sitized. It seems that the conditions causing such extreme growth of hairs have not as yet been definitely ascertained (cf. Hurd, loe. cit., and Oltmanns, 1905, p. 239). There is still a fertile field for obser- vation and experimentation in this subject. Codium fragile seems to be a widespread species. J. G. Agardh described it as occurring on the west coast of North America, in New Zealand, in Australia and in Tasmania. It has been found also in the Cape of Good Hope region and in the region of the Straits of Magellan (Hariot, 1889, p. 33, and Svedelius, 1900, p. 299) and on the coasts of Scotland and of Ireland (cf. Cotton, 1912, p. 115). This is certainly a wide distribution in widely separated waters, but at least the waters have approximately the same temperatures for certain portions of the year. It is interesting to compare in this con- nection Codium divarioatum f. hyhrida Okamura (1915, p. 157, pi. 135, f. 17), which is suggested as being a hybrid between C. divari- catum Holmes and C. fragile (Suring.) Hariot. 4. Codium decorticatum (Woodw.) Howe Thallus sparingly branched, dichotomous, up to 5 dm. or more long, usually decidedly flattened under the dichotomies; peripheral utricles obovoid to broadl}^ clavate, thin walled throughout, obtuse, 135-520/x maximum diameter, 500-700jU, long. La Paz, Lower California, Howe, Phyc. Studies V, 1911, p. 494. Ulva decorticata Woodward, Observations upon the generic characters of Ulva, 1797, p. 55. 1920] Setchell-Gardner: Chlorophyceue 173 Howe {loc. cit.) refers a plant from La Paz, Lower California, to this species, apparently with some confidence, and at the same time he selects Codium decortioatuni as the correct name instead of C. elongatnm. We have not seen Howe's plant, but certain questions arise as to the exact nature of C. decorticatum and of C. eiongatum. The type specimen of Ulva decortiaata Woodward {loc. cit.) is unknown and the tj'pe region is given as the Mediterranean Sea with the statement that the exact locality was unknown to the author. The type locality for C. elongatimi Ag. (1822, p. 454) is Cadiz, Spain. The species is related to C. tomentosum, but differs in being more elongated, witli fewer and longer branches, and in being more or less distinctlj" dilated and flattened just below the axils (or some of them). Such a plant is figured by Kuetzing (1856, pi. 96 b), but his plant came from Rio Janeiro, Brazil, a tropical locality. Bornet (1892, pp. 216, 217) has given his experience with C. eiongatum and his attempts to ascertain the characters upon which separation could be made from C. tomentosum. He considered two sets of characters, viz., the extent of infra-axillary dilation and the magnitude of the utricles. Bornet decided to separate the species according to the presence or absence of dilations, and to subdivide the species with dilations (C. eiongatum) into a variety with large utricles and one with small utricles, since this fulfilled the idea of C. Agardh and also corre- sponded with the geographical distribution. Codium eiongatum with small utricles extends north along the Atlantic coast of France and to England, while C. eiongatum with large utricles does not extend north of Cadiz. In this connection it is interesting to note again that Cadiz is the type locality of C. eiongatum, and to note also that the type specimen of C. eiongatum is, according to Howe (1911, p. 495), provided with slender utricles. The tropical forms referred to C. eiongatum (or C. decorticatumi) have stout utricles as Kuetzing has described and figured {loc. cit.). We suspect that there may be two overlapping species of somewhat similar habit, but differing in utricles and in geographical distribution, represented under C. decorticatum. It may be that C. decorticatum (Wood.) Howe, being a Mediterranean species (subtropical), may finally be separated from C. eiongatum Ag., the more northern (temperate) species which reaches its southern limit near Cadiz and Tangiers, and there intermingles with the large utricled form (C. decorticatum?) as Bornet has found it. Howe's plant from La Paz is described as having large utricles (up to 520/* diam.) and must therefore be arranged with the larger form of Bornet. 174 University of California Puhlioations in Botany [Vol. 8 5. Codmm tomentosum (Huds.) Staekh. Thallus rather slender, much branched, 22-37 cm. high 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/* long, 120-170/i, (rarely to 220/x) wide, apex usually distinct!}^ thickened, blunt; smaller utricles sometimes pointed, but never mucronate; gametangia (5) small, 200- 250/* long, 40-70/* wide ; gametes 20-22/* long, lO-12/i 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. When 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.) Staekh. and C. decorticatum (Woodw. ) Howe. Codium tomentosum was originally 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 tj^pical 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/* (rarely to 220/*) 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 Phye. 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 found to be the case in European C. tonien- tosum. In fact there is almost a "dimorphism" and the occasional larger type of utricle reaches a diameter of 150-330/x 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 28ju,. The gametangia (?) are broadly fusiform and measure close to 200/x long and lOOju, 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. Lindenbergii 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 least 250/a in maximiun diameter, and in specimens distributed by Tyson (no. 55) occur up to at least 380/x, in diameter, while the gametangia ( ?) are 200/a to 228jit long and 76ja to 95;u, wide. It should be mentioned, however, that there are three flattened species described from Cape Colony, viz., C. Linden- hergii Kuetz., C. danmecome (Bory) Kuetz., and C. platylohium 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. tmnentosum 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 Sur. Plate 15, fig. G 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-tricho- tomously branched lobes rounded at the apices; lobes 2-3 mm. thick 176 University of California Puhlicati&ns in Botany [Vol.8 and up to 5 cm. or more wide; utricles 500-600/i, long, 50-110/x, up to 160/A, 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/* thick; gametangia (?) borne below the middle of the utricles, fusiform, 220/* long, 60-75/* 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 Coclium latum Sur., a Japanese species, in our account is based upon 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 nearly 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 (showTi in older specimens by 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. Lindenhergii 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 by globose or ovoid sporangia (?) borne on slender filaments projecting beyond the sur 1920] Setchell-Gardner: Chlorophycme 177 face of segments and producing 2-ciliated zoospores ( ?) whose further development has not been followed. Lamouroux, Class. Polypes, 1812, p. 186. The genus Halimeda 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 strictly tropical, occurring in abundance on coral reefs and assisting materially in their formation. Otto Kuntze (1893, p. 908) has urged the substitution of the earlier name Opiintiodes of Ludwig (1737, pi. 138), but since Halimeda has been in practically undisputed use for over a century, it seems best to retain it as a "nomen 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 ti-ansverse, thin, smooth ; central fila- ments fused in twos, rarely threes, at the nodes ; utricles of subcortical layer 68-175/i, diam., larger than the interlocked, often fused, peri- pheral utricles. La Paz, Lower California. Decaisne, 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 Howe {loc. cit.), and we have also specimens collected at the same locality by Dr. and Mrs. Marchant. It is to be distingiTished 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 with frequent constrictions, without septa, often gregarious into expanded tufted or feltlike masses, attached at first by colorless rhizoidal branches ; chromatophores numerous, small, 178 University of California Puhlications in Botany [Vol. 8 lenticular, destitute of pyrenoids ; akinetes ( ? ) thick-walled formed within the continuity of the filaments ; aplanospores large, ellipsoidal, formed at the ends of the branches; zoospores large, formed at the ends of the branches, provided with many cilia arranged in pairs with a nucleus immediately beneath each pair; sexual reproduction anisogamous ; antheridia tubular, usually curved, emitting many very small uninucleated 2-ciliated male gametes; oogonia swollen, globular to ovoid, sessile or pedicellate, single or several together, producing a single large uninucleate non-motile female gamete amply provided with chromatophores, fertilized in position ; monoecious or dioecious. Dumortier, Comm. bot., 1822, p. 71, Analyse fam. pi. 1829, p. 77. Vaucherideae Gray, Arr. Brit. PL, vol. 1, 1821, p. 288. The family of the Vaucheriaceae, while simple in its coenocytic structure and form of filament, is probably the most complex in its reproduction among the Chlorophyceae. The zoospore is distinctly coenocytic, being large and covered with cilia which, however, are arranged in distinct pairs, each pair associated with its own nucleus. The male gametes, on the other hand, and the female gametes, so far as examined, possess at maturation only a single nucleus. They are very different in size and, while the female gamete or egg is non- motile, the sperms or male gametes are motile, with two equal cilia widely separated and pointing in opposite directions. There are two genera usually included in the family, viz., Vaucheria with continuous and unconstricted filaments and Dicho- toniosiphon with more or less interrupted and constricted filaments. 9. Vaucheria DC. Filaments continuous, without constrictions ; reproduction as indi- cated for the family. De Candolle, Extrait d'un rapport sur les Conferes 1801. The genus Vaucheria includes both fresh-water and brackish-water species. A few are truly marine. There are both marine and brackish water species about San Francisco Bay, but careful search has as yet failed to reveal any trace of sexual reproduction in these. Without a knowledge of the details of this process, it is impossible to be certain of their identification. Specimens of this genus are better preserved for future study in formalin solution or in alcohol, since dried speci- mens are difficult to restore to normal appearance on moistening. Otto Kuntze (1891, p. 926) raises the query as to whether Vaucheria DC. or Ectoaperma Vauch. is the older name. "We are unable to settle this question. 1920] Setchell^Gardner : Chlorophyceae Order 3. SIPHONOCLADIALES (blackman and- tansley-j OLTMANNS Thallus usually of abundantly branched filaments, or of slightly branched sacks, septate, divisions multinucleate ; chromatophores single and reticulate or numerous and lenticular; sexual reproduction by isoplanogametes. Oltmanns, Morph. und Biol, der Algen, vol. 1, 1904, p. 134. SipJionocladeae Blackman and Tansley, Class. Green Algae, 1902, p. 119. The order Siphonocladiales consists of plants with septate coenocj^tes, thus differing from the Siphonales which have unseptate coenocytes and from the Ulotrichales whose filaments are made up of cells in the restricted sense. Siphonocladiales are large, richly branched, filamentous species, although a few are unbranched or branched only slightly, while some species are sack-shaped with few and short segments separated from the main portion of the plant. The larger number and more complex families of this order are tropical and marine, but some families are well represented in fresh water also, and in extra-tropical as well as in tropical waters. Almost nothing is known of the tropical forms of our coast. The recognition of the group of septate coenocytes among the Chlorophyceae as separate from the group of unseptate coenocytes, is due to Schmitz (1878, 1879, p. 273), who designated it as family Siphonocladiaceae. The placing of this group as a subseries (?) and as being made up of separate families is due to Blackman and Tansley as quoted above, although the content was not exactly coincident with that now generally assigned to the order. Although the idea of a separate group originated with Schmitz, Blackman and Tansley were the first to view it as practically a suborder of Siphonales and as made up of families. FAMILY 8. CLADOPHOEACEAE (hass.) de-toni (ampl.) Fronds of simple or branching monosiphonous filaments, free or more or less united laterally; septa frequent, enclosing segments with few to many nuclei; chromatophores broad, reticulate or polygonal- lenticular, but arranged in a network and at times connected by slender strands ; multiplication by fragmentation and by akinetes ; reproduction by 4-ciliated (or possibly 2-ciliated) zoospores and by 2-ciliated isogametes, formed in segments slightly, if at all, differ- entiated. 180 University of California Piiblicatioyis in Botany [^ol. 8 De-Toni, Syll. Alg., vol. 1, part 1, 1889, p. 264. Cladophorem Hassall, Brit. F. W. Algae, vol. 1, 1845, p. 213. The family of the Cladophoraeeae is understood in various ways, but it has seemed best to understand it in the sense used by Oltmanns (1904, p. 255) and by Collins (1909, p. 321). It includes all the forms of the strictly filamentous Siphonocladiales which are either simple or, if branched, have branches which are septate at their bases, usually with no distinct main axis in the branched forms, and with all axes of indefinite growth. Thus we include Microdictyon, Boodlea and Anadyomene. Possibly Struvm also should be included in this family but it has a very distinct main axis and lateral axes of definite growth. In these respects Struvea resembles the Dasycladaceae, but it differs from the members of this family in its lack of calcification and of specialized zoosporangia (or gametangia) while it differs from the members of the Siphonocladiaceae (in the narrower sense) by having septa at the the bases of the branches. In Cladophoropsis, there occur more or less basal septa, but more frequently they are absent. We have followed West (1916, p. 305) in referring Gomontia to the Ulotrichales. Key to the Genera 1. Filaments simple 2 1. Filaments branched 6 2. Filaments usually stiff or rigid 3 2. Filaments flaccid 5 3. Filaments large, over lOOyu diam 12. Chaetomorpha (p. 198) 3. Filaments smaller, under 100/x diam 4 4. Filaments attached 12. Chaetomorpha (p. 198) 4. Filaments unattached, prostrate 10. Rhizoclonium (p. 180) 5. Filaments attached 11. Hormiscia (p. 187) 5. Filaments unattached, prostrate 10. Rhizoclonium (p. 180) 6. Branches free 7 6. Branches anastomosing, forming a network 15. Microdictyon (p. 231) 7. Filaments not held together by special rhizoidal or hooked branchlets 13. Cladophora (p. 207) 7. Filaments held together by special rhizoidal branchlets or by hooked branchlets or by both 14. Spongomorpha (p. 220) 10. Rhizocloiiium Kuetz. Filaments usually prostrate, or slightly ascending, of a single series of segments, unbranched, or occasionally slightly branched, with few to many rhizoidal branchlets composed of one to few segments ; seg- ments with one to several nuclei (rarely one) and a single reticulate, parietal chromatophore with numerous, more or less regularly spaced, 1920] Setchell-Crardner : Chlorophyceae 181 pyrenoids; multiplication by fragmentation and by akinetes; repro- duction by 2-ciliated zoospores with stigmata; gametes unknown. Kuetzing, Phyc. Gen., 1843, p. 261, Ueber syst. Eintheil. der Algen, 1843a, p. 75 (nomen nudum). The genus Rhizoclo7iium, as founded by Kuetzing but without special indication of type species, is one of the simplest of the Clado- phoraceae. It consists ordinarily of species with simple, unb ranched filaments whose segments are provided with comparatively few nuclei. The rhizoidal branches may, or may not, be readily found. In the absence of these it is sometimes difficult to be certain of the genus. The species may usually be distinguished from Chaetomorpha by their characteristically cylindrical, never swollen, segments with a smaller niunber of nuclei in each, as well as by their different texture and tendency to a horizontal habit. The branched species resemble Clado- phora, but the branches push aside the main axis and continue the direction of the main filament. The species of Rhizoclonium inhabit both the fresh and the salt waters. The separation of the species of Rhizoclonium one from another presents certain difficulties which are increased by the fact that very little seems to have been done in the culture of species of this genus. The following characters have been considered : (1) color, (2) texture, (3) straightness or crispate character of the filaments, (4) diameters of the segments, (5) proportions of length to breadth of the segments, (6) varying thickness of the walls of the segments, (7) varying num- ber of nuclei in the segments, (8) presence or absence of long (true) branches, and (9) presence or absence of rhizoids. Of these char- acters, it seems from our present imperfect knowledge that 1, 2, 3, 8 and 9 are the more dependable characters, and that 4, within certain limits, is very helpful. Characters of 5, 6, and 7 will vary within wide limits in the same plants, according to whether they are actively divid- ing or passing into a quiescent condition, as one of us (Gardner) has experienced in growing Rhizoclonium luhricum in the laboratory, and as Brand (1908, p. 66) has stated as the results of his cultures. The principal account of Rhizoclonium of more recent years is that of Stockmayer (1890), but his arrangement of the marine species is not satisfactory to most students. The general disposition of the marine species made by Rosenvinge (1893, p. 911 et seq. and 1894, p. 126-129) seems based on more certain characters and has been generally followed. F. Brand (1908, p. 45 ct seq.) has made some important studies through cultures, testing certain of the characters 182 University of California Puhlications in Botany [Vol.8 mentioned above as to their constancy or variability. After consider- ing all the data possible it has seemed best to take a somewhat nar- rower view of specific limits than has been prevalent and divide our west coast plants among five seemingly distinct species. Key to the Species 1. Filaments flaccid or lubricous, straight or flexuous, light or yellowish green 2 1. Filaments rigid, contorted, dark green 5. R. tortuosum.. (p. 185) 2. Layer fleecy, filaments flexuous, 10-35/i 3 2. Layer lubricous, filaments straight, 25-50^ 4. R. lubricum (p. 185) 3. Rhizoidal branches frequent, often 2-3 septate 1. R. riparium (p. 182) 3. Rhizoidal branches scarce, when present non-septate 4 4. Filaments 10-14^ 3. R. Kerneri (p. 185) 4. Filaments 20-30At 2. R. implexum (p. 183) 1. Rhizoclonium riparium (Roth) Harv. Filaments pale green, expanded on the substratum, flexuous, inter- twined into a fleece ; segments 20-25/x diam., rarely slightly greater or smaller, usually once or twice as long as broad; branches and rhizoids frequent, often 2-3-septate. In skein-like masses on cliffs or hard clay banks, often among other algae in the littoral belt. Alaska to central California. Harvey, Phyc. Brit., vol. 2, 1849, pi. 238 (binomial attributed to Kuetzing) ; Collins, Green Alg. N. A., 1909, p. 327 (in part). Con- ferna riparia Roth, Cat. Bot., vol. 3, 1806, p. 216 ; Dillwyn, Brit. Conf ., 1809, p. 69, pi. E. Rhizoclonium riparium var. polyrhiziim Rosen- vinge, Groenl. Havalg., 1893, p. 913, f . 32 ; Collins, Green Alg. N. A., 1909, p. 328; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 2238. There is no question in our minds that the situation as to species of Rhizoclonium on the Pacific Coast of North America is very similar to, if not perhaps identical with that on the Atlantic Coast of the same continent and on the Atlantic shores of Europe. There are at least two sets, or groups, of plants differing somewhat in dimension and in habit. One of these sets of forms is usually referred to Rhizoclonium riparium and the other to R. tortuosum. This would be reasonablj^ satisfactory, if no previous conceptions existed to be considered. The ■ two species, however, as far as names are concerned, date back to the early portion of the nineteenth century, viz., to the publications of Roth (1806) and Dillwj^n (1809) respectively. Unfortunately no type specimens are available to us and we can simply follow the 1920] Setchell-Gardner : Chlorophyceae 183 custom, with such information as we may glean from the literature. The Ccniferva riparia Roth was known to Dillwyn (1809, p. 69, under no. Ill) by an authentic specimen in Turner's herbarium. Dillwyn says that the English plants referred by him to Roth's species and figured under the name were treated so on authority of an authentic specimen. Dillwyn figures (loc. cit., pi. E) a plant which has shortly fiexuous, but not contorted, filaments and frequent rhizoidal branchlets of several segments each. Harvey (1849, pi. 238) figures a similar plant which he states is certainly that of Dillwyn, since it is drawn from a specimen belonging to Miss Ilutchins (from Bantry Bay) referred to by Dillwyn. The type of Rhizoclonium riparium (Roth) Kuetz., then, may be properly inferred to be the variety with frequent and complex rhizoids which Rosenvinge (1893, p. 913) named var. polyrhizum. This is certainly a Rhizoclonium, being provided with the rhizoidal branches characteristic of the genus. In general the various authors agree that the diameters of the segments vary from 20/^ to 35ju,, but most commonly are from 20/i, to 25^. It seems best to us to keep Rhizoclonium ripariutn as thus char- acterized distinct and separate from other varieties (than polyrhizum) usually referred to it. The var. implexum (Dillw.) Rosenvinge, while very similar to the type of R. riparium in both texture and diameter of its filaments, is to be distinguished by the scarcity and structure of the rhizoidal branchlets and is treated here as a distinct species. The Rhizoclonium riparium var. validum Foslie (1890, pp. 138, 139) is decidedly coarser than the type and is probably to be separated from R. riparium in the more restricted sense, although probably closely related to it. 2. Rhizoclonmm implexum (Dillw.) Kuetz. Filaments simple, 20-30/x, (rarely 40/;t) in diameter, yellowish or light green, forming a horizontal fleecy layer; segments 1.5-2.5 times as long as broad; rhizoidal branches few or wanting, when present short, non-septate and usually continuous with the segments from which they arise. Forming fleecy masses on mud or on various objects in the littoral belt. Alaska to central California. Kuetzing, Phyc. Germ., 1845, p. 206 (at least as to plant of Dill- wyn) ; Batters, Alg. Clyde Sea Area, 1891, p. 230, repr., p. 8. Con- ferva implexa Dillwyn, Brit. Conf., 1805, p. 46, pi. B ; Harvey, Phyc. 184 University of California Pnhlications in Botany [Vol. 8 Brit., vol. 1, 1846, pi. 54 B. Rhizoclonium ripurium var. implexum Rosenvinge, Groenl. Havalg., 1893, p. 915; Saunders, Alg. Harriman Exp., 1901, p. 414; Setchell and Gardner, Alg. N.W. Amer., ]903, p. 222; Collins, Holden and Setchell, Phye. Bor.-Amer, (Exsiec), no. 976 ; Collins, Green Alg. N. A., 1909, p. 328. Rhizoclonium riparium Tilden, Amer. Alg. (Exsice.), no. 379 (not of Roth or Kuetzing). A plant very similar to Rhizoclonium ripariimi, but destitute of, or provided with very few and simple, rhizoids, is found on the shores of the Pacific Coast of North America. This seems to be the same as the plants from both the European and North American Coasts which have passed under the name of Rhizoclonium riparium var. implexum. The filaments are nearly the same in diameter as those of the preceding, but possibly average slightly smaller. The rhizoidal branches are often entirely wanting and in no case are really abun- dant. When present they alway lack septa and generally are not cut off from the segment from which they arise. The growth is generally more entangled and fleecelike than that of the preceding species. It seems best to us to keep this form, which seemingly has a wider dis- tribution along the Pacific Coast than R. riparium, separate. In adopting the name of R. implexum, we are guided by the descriptions of others. The type specimen of Dillwyn is unknown to us, but this seems to be the plant of Harvey and possibly also of Kuetzing and Rosenvinge. Harvey evidently founded his description on Miss Hutchins's specimen from Bantry Bay which is a topotype, possibly even a cotype of Dillwyn 's species. Harvey and Dillwyn give no measurements of Conferva implexa, but Harvey states that the fila- ments are about two-thirds of the thickness of those of C. tortuosa. The latter is probably 40fi to 70^ in diameter. Kuetzing assigns to his Rhizoclonium implexum a diameter of ^oo'"-/45o''' oi* about 11/x to 12/A, which is very much more slender than the Rhizoclonkim riparium var. implexum, of Rosenvinge which is described as being 20/A to 30/x, (or 40/a) in diameter. Our plants agree well with no. 142 and even with no. 190 of Wyatt's Algae Danmonienses, issued under the names of C&nferva implexa and C. tortuosa respectively. No. 142 shows no rhizoids while no. 190 shows frequent unseptate rhizoids. The segments in no. 142 vary from 35/* to 45/*, while those of no. 190 vary from 22/^ to 27/x,. They also agree in general with no. 624 of Wittrock and Nordstedt's "Algae aquae dulcis exsiccatae, " distributed under the name of Rhizoclonium riparium f. valid a Foslie. 1920] Setchell^Crardner : Chlorophyceae 185 3. Rhizoclonium Kerneri Stock. Filaments pale yellowish green, segments lO-14/i, diam., 3-7 diam- eters long, free from rhizoids or branches. Growing in loose masses in tide-pools. Victoria, Vancouver Island, British Columbia. Stockmayer, Ueber die Algengat. Rhizoclonium, 1890, p. 582 ; Collins, Mar. Alg. Vancouver Island, 1913, p. 103. We have not seen any specimens of this species and are including it upon the authority of Collins {loc. cit.). It is decidedly more slen- der than the other four species of Rhizoclonium thus far detected on our coast. 4. Rhizoclonium lubricum S. and G. Plate 9, figs. 5a, b Filaments flaccid, lubricous, straight, cylindrical throughout, 3- 4.5 dm. long, pale green; segments 35-50/x, mostly 40/a diam., resting segments 4-6 diam. long, after division segments 1-2 diam. long ; chromatophore a coarse, parietal network ; pyrenoids small, numerous, 40-50 in resting segments; wall 2/* thick, homogeneous; rhizoids short, mere prolongations of cells, non-septate, rare; zoospores and gametes unknown. Growing attached in mud or floating on mud flats between tides. Roche Harbor, Washington, and Berkeley and Alameda on the shores of San Francisco Bay, California. Setchell and Gardner, in Gardner, New Pac. Coast Mar. Alg. IV,. 1919, p. 492, pi. 42, f. 5; Collins, Holden and Setchell, Phyc. Bor.- Amer. (Exsicc), no. 2289. This form closely resembles R. riparium f. validum Foslie, but is practically free from rhizoids, has thinner walls and larger and longer segments. From R. implexum it differs in having broader, straigliter filaments of very different consistency, as w^ll as, usually, longer seg- ments. Unlike other species of Rhizoclonium it is very lubricous, in mass, having the consistency of a Spirogyra. 5. Rhizoclonium tortuosum (Dilhv.) Kuetz. Filaments rigid, crispate and contorted, dark green, 40-70/a diam., forming woolly skeinlike or ropelike horizontal masses ; segments 1-2, up to 6 times as long as broad, wall thick, indistinctly lamellose ; rhizoids short, few or, more usually, none. 186 University of California Publications in Botany [Vol. 8 On various algae in the middle and upper littoral belts. Alaska to California. Kuetzing, Phyc. Germ., 1845, p. 205 (at least as to the plant of Dillwyn) ; Farlow, New Eng. Alg., 1881, p. 49; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 223; Collins, Green Alg. N. A., 1909, p. 328. Conferva tortuosa Dillwyn, Brit. Conf., 1805, p. 46, pi. 46 ; Harvey, Phyc. Brit., vol. 1, 1846, pi. 54 A, Chaetomorpha tortuosa Kuetzing, Spec. Alg., 1849, p. 376 ; Harvey, Ner. Bor.-Amer., part 3, 1858, p. 88, pi. 46 B. Kuetzing has described two plants, both founded, in the final analysis, upon Conferva tortuosa Dillwyn. One of these plants he bases directly upon Dillwyn 's species and refers it to Rhizoclonium (1845, p. 205; 1849, p. 384). It is credited by Kuetzing to the North Sea. Kuetzing gives ^7o'"'-%o"'' as the diameter of his Rhizoclonium tortuosum which approximates 32ja to 35fi. The Conferva tortuosa J. Ag. (1842, p. 12) which is the C. tortuosa C. Ag. (1824, p. 98) and which, in turn, is founded, as to name at least, on C. tortuosa Dillw., is referred by Kuetzing (1849, p. 376) to the genus Chaeto- morpha as Chaetomorpha tortuosa and the diameter of the filaments is given as /^s^'-zio"', or approximately 46/a to 56ju,. It is restricted by Kuetzing to the Mediterranean and Adriatic Seas, Dr. Anna Weber-van Bosse has kindly allowed us to examine the specimens in Herbarium Kuetzing under the names of Rhizoclonium tortuosum and Chaetamorpha tortuosa. There are three of the former, from the Faeroes, England and Cherbourg respectively. They all seem to be R. tortuosum in the sense in which we use the name : The specimen of Chaetomorpha tortuosa from the Kuetzing collection is from Nice and while it resembles fairly closely the Kuetzing specimens of R. tortuosum, it has much thicker walls and possibly may be found to belong to another species. "We feel convinced of the likelihood of Conferva tortuosa Dillw. being the coarse, crispate plant which has been described by Harvey (1846, pi. 54 A) as Conferva tortuosa and (1858, p. 88) as Chaeto- morpha tortuosa and finally by Farlow (1881, p. 49) as Rhizoclonium tortuosum. As we understand this species, which is not common on our coast, it forms woolly skeinlike or loose ropelike masses of a dark green color on other algae in the littoral belt of exposed coasts. The filaments are rigid, harsh to the touch and crispate or contorted. In diameter its filaments exceed those of both R. riparium and R. implexum by ^^20] Setchell-Gardner : Chlorophyceae 187 one-third or more. It varies in the length-breadth proportions of the segments, and plants with longer segments have been named forma longiariiculatum by Collins (Phye. Bor.-Amer. (Exsice.), no. 1735). 11. Hormiscia Fries Filaments simple, attached at the base by rhizoids developing from a few of the basal segments, either intramatrical, extramatrical or both ; segments multinucleate, all above the few basal ones similar and capable of division and producing zoospores or gametes ; chromato- phore covering the segment wall, entire or more or less coarsely reticu- late, with few to many pyrenoids ; multiplication by akinetes formed by breaking up of the filaments into individual segments with thick walls, either producing new filaments or zoospores ; reproduction by macrozoospores, by microzoospores and by gametes, produced many in a segment ; macrozoospores obovoid, extending posteriorly into a long "tail," provided anteriorly with 4 cilia; microzoospores smaller with less obvious tail and 4 cilia ; sexual reproduction by 2-ciliated (possibly in some species by 4-ciliated) iso- or hetero-gametes. Fries, Flora Scanica, 1835, p. 327. Urospora Areschoug, Observ. Phyc, 1866. The genus Hormiscia, as constituted hy Fries, comprised two !atTnatous but occasionally of gloeocapsoid cells, except at the base where thickening occurs by the descent of elongated rhizoidal cells forming several layers; vege- tative multiplication by 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 Monostroma comprises those members of the Ulvaceae which, at maturity, form an expanded membrane of a single layer of cells. Certain species of Monostroma develop nearly 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, with 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 (2-4 or more) after the fashion of Gloeocapsa or Chroococcus. 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, intrud- ing into warmer zones only in winter and spring when the temperature of the water is lowered. 236 University of California Puhlioations in Botany [Vol. 8 Key to the Species 1. Frond saccate until late, then rupturing 2 1. Frond expanded very early 3 2. Membrane 15-20m thick, dehcate in texture 1. M. Grevillei (p. 236) 2. Membrane 25-45m thick, tougher 2. M. arcticuin (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 40-50m thick 7. M. orbiculatum (p. 242) 4. Membrane less than 30m thick 5 5. Frond 7-10m 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. zostericolu (p. 238) 7. Cells arranged in distinct groups of 4-6, rounded 5. M. quatemarium (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 15-20ju, thick, cells quadrate with rounded angles, closely set, horizontally oval in cross section, 12-14jLt high ; sporiferous 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. Enteromorpha Grevillei Thuret, Note sur la Syn. Ulv., 1854, p. 25. Certain of the species of Monostroma retain the saccate habit until late, or rather until the sack has reached considerable size, before splitting. Two species, 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. Monostrovia Grevillei is of delicate consistency and lubricous, differing in both these characters from any of the forms of M. 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 : Chlorophy&eae 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, Monostroma Grevillei is a summer plant in the Greenland waters (Upper Boreal Zone), but invades the North Temperate Zone in spring-time. On the Pacific Coast, our only specimens are from Bering Sea but Collins (1903, p. 13) states that it descends to Monterey, California, which is much above its accustomed temperature. The reference of Collins to Monterey is based on two small speci- mens found attached to Gloiosiphonm verticillaris Farl., collected by Mrs. J. M. Weeks. Reexamination of these specimens, although not convincing, leads as to the opinion that they may be nearer Mono- stroma zostericola than to any forms of M. Grevillei. 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 him and other authorities as to their disposition. Monostroma Grevillei var. lubricum (Kjellm.) Collins Frond up to 15 cm. long, pale or whitish green, delicate, very lubricous and flaccid, of irregular outline, laciniate, plicate, margin often crisped and lacerate ; frond 18-22/a 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 quiet waters. Alaska. Collins, Green Alg. N. A., 1909, p. 209. Monostroma lulricum Kjellman, Spetsb. Thall., 1877, p. 48, pi. 4, f. 8, 9; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 207. Monostroma Grevillei var. Vahlii (J. Ag.) Rosenv. More slender in form, often cylindrical, 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 be clearly the Monostroma Vahlii of J. G. Agardh. 238 TJniversity of California PuNications in Botany [Vol. 8 2. Monostroma arcticum Wittr. Frond attached, at first saccate, later splitting into a few broad laciniae ; subradiately plicate, with crisped margin ; pale green, becom- ing yellowish in drying; membrane 25-45/a thick; cells 4-6 angled, closely set, irregularly placed ; in cross section either vertically or horizontally oval, 10-30/a 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; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 208; Collins, Holden and Setchell, Phyc. Bor.-Amer., (Exsicc), no. 910. Monostroma latissimiom Setchell and Gardner, Alg. N.W. Amer., 1903, p. 207 (in part). Rosen vinge (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 31. fuscum, M. spleiidens and M. BUjttii. 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 Rosen- vinge, however, in uniting with Monostroma arcticnm, 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/A thick, cells quadrate to vertically oblong in cross section, 5-8/a high. 1920] Setcheil-Gardner : Chlorophyceae 239 In the sublittoral belt, growing on Zostera. 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; Setehell and Gardner, Alg. N.W. Amer., 1903, p. 209 (prob- ably not of Kjellman). Monostroma zostericola is known thus far from the 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. leptodermum) ; 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 growing on Zostera. The species is very delicate and its membrane very thin. The only species of this genus on our coast with anything 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 3Ionostro'ma leptodermum, of Kjellman (1877fl, 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 case in any of the specimens from our coast. The cells in ours seem to agree fairl}^ well 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 28, 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/a thick; cells with rounded angles, 6-7/a diani., subspherical in cross section, grouped within each areole. Growing on' Zostera in quiet waters. Sitka, Alaska. Setchell and Gardner, Phyc. Cent. 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, 20-23/i, 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;Lt high. Floating in brackish and in fresh water. Washington to southern California. 1920] Seichell-Gardner : Chlorophyceae 241 Desmazieres, Plantes Crypt, 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. Pliyc, vol. 6, 1856, p. 6, pi. 13, f. 2. Monostrmiia quaternarium resembles M. latissimum in habit and habitat. Both are usually found in either brackish or fresh water and are not strictly marine. Both are usually found floating and are more or less indefinitely expanded. In M. qu-aternarium the cells are rounded, segregated in small groups of three or four in surface view, while in M. laUssimum the cells are angular and closely placed, although at times appearing somewhat grouped. It is by no means a certain matter to place some specimens definitely in one species or the other. Such a case is presented by no. 218 of Farlow, Anderson and Eaton's Algae Americae Borealis Exsiccatae, collected near Santa Cruz, California, probably in an estuary. 6. Monostroma latissimum (Kuetz.) Wittr. Frond at first attached, afterwards floating; thin and soft, glossy, of irregular shape, more or less plicate near the even or undulate margin; membrane 20-25/a thick, cells 4—6 cornered or roundish, closely set, without order or more or less distinctly in twos, threes and fours ; in cross section vertically oval or nearly circular, 14-18/a liigh. Attached to various objects in the lower littoral belt when young, but soon becoming free and floating in quiet waters, salt marshes, ditches, etc. Washington to central California. Wittrock, Monostr., 1866, p. 33, pi. 1, f. 4; Collins, Green Alg. N. A., 1909, p. 211; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 207. Viva laUssima Kuetzing, Phyc. Gen., 1843, p. 296, pi. 20, f. 4. As stated under the preceding species, Monostroma latissimum is usually to be found floating in shallow warmer waters, either brackish or fresh, seldom, if ever, in true marine localities. It is to be dis- tinguished from the last {M. quaternarium) by the appearance of the cells both in surface view and in section as indicated in the descriptions. The propriety of adopting the specific name latissimum for this species may be questioned. It seems to be the Viva latissima of Kuetz- ing, but probably not the Viva latissima of Linnaeus. We are not in a position to discuss this question, and simply follow later usage. 242 University of California Publications in Botuny [Vol. 8 7. Monostroma orbiculatum Thur. Frond membranaceous, attached by fibrils, or later free ; soft and flaccid, sub-orbicular or irregular in outline, often radially plicate, with undulate margin, 30-40/a thick; cells angular, varying much in size and arrangement, often irregularly elongate, closely set, but with chromatophore not occupying the whole cell ; in cross section vertically oval, 25-30ju. high. In brackish water attached to various objects in ditches of salt marshes. Central California. Thuret, Note sur la Syn. Ulv., 1854, p. 388; Collins, Green Alg. N. A., 1909, p. 212 ; Wittrock, Monostr., 1866, p. 39, pi. 2, f . 6. The present species resembles very closely the preceding and is, in fact, to be distinguished from it chiefly by its greater thickness. It may be a question as to whether it ought to be united with Monostroma latissimum or not. So far as our experience goes, however, the M. latissimwm plants are definitely not over 25ju, in thickness, and those of M. orbiculatum seldom less than 35/i.. This seems to indicate suf- ficient difference for keeping them distinct. 8. Monostroma fuscum (Post, and Rupr.) Wittr. Frond membranaceous, at first tubular, soon splitting, dull green, more or less lobed but not divided to the base ; membrane 20-35ju, thick ; cells 4-6 angled, very closely set, in cross section quadrate, with only slightly rounded corners, occupying nearly the entire thickness of the frond. On stones in the middle littoral belt, and floating in salt marshes. From Alaska to Puget Sound. Wittrock, Monostr., 1866, p. 53, pi. 4, f. 13; Collins, Green Alg. N. A., 1909, p. 213; Saunders, Alg. Harriman Exp., 1901, p. 409; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 208. Ulva fusca Post, and Rupr., Illust. Alg., 1840, p. 21. Ulv>a Lactuca var. rigida Setchell and Gardner, Alg. N.W. Amer., 1903, p. 209 (in part). Monostroma fuscum var. splendens (Rupr.) Rosen v. Frond deep green, glossy, 50-55ju, thick, more deeply parted than in the other forms ; cells similar to those of var. Blyttii or more rounded. From Alaska to Vancouver Island. 1920] Seichell-Gardner: Chlorophyceae 243 Collins, Ulvaceae of N. A., 1903, p. 12, Green Alg. N. A., 1909, p. 213 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 209 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsiec.), no. 911. Mono- stronia splendens Wittrock, Monostr., 1866, p. 50, pi, 3, f. 12; Setchell, Alg. Prib., 1899, p. 591. Ulva splendens Ruprecht, Tange Och., 1851, p. 410. Monostroma fuscum var. Blyttii (Aresch.) Collins Frond deep green, blackish in drying, 60-70ja thick ; cells ' ' palisade- form" in cross section. Growing in tide pools and on pebbles in the sublittoral belt. Van- couver Island and Washington, Collins, Ulvaceae of N. A., 1903, p. 12, Green Alg. N. A., 1909, p. 213. Monostroma Blyttii Wittrock, Monostr., 1866, p. 49, pi. 3, f. 11. Ulva Blyttii Aresch., in Fries, Sum. Veg. Scand., 1846, p. 129. We are puzzled, when it comes to the discussion of Monostroma fuscum, whether to treat of it as a species or as a group of species. The typical Monostroma fuscum is comparatively thin (20-25/i, accord- ing to Wittrock, 1866, p. 53), turning only a light brown on drying instead of black, and with cells quadrate or only slightly vertically elongated in cross section. The var. splendens is a thicker plant (49- 53ju, according to Wittrock, 1866, p. 51), turning black, adhering even less well to paper than the typical form and with cells vertically much elongated in cross section. The var, Blyttii differs from var. splendens chiefly in being thicker (65-72/i, according to Wittrock, 1866, p. 49), but is otherwise essentially the same. Rosenvinge (1893, p. 940, 1894, p. 146), relying upon the obser- vations of Kleen (1874, p. 42), reduces the three species of Wittrock to two varieties of one, viz., var. typica and var. splendens of Mono- stroma fuscum. The arrangement of Rosenvinge has been generally followed and we feel that we can not do better than adopt the general opinion. We have, however, followed Collins (1909, p. 213) in retain- ing the varieties (or forms?) of splendens and Blyttii as well as the typical form. The typical form is perhaps a younger or less developed form and seems more distinct from both var. splendens and var, Blyttii, than they do from one another. We may expect any, or all, of the three forms anywhere along the coast from the Bering Sea to the Puget Sound region. We have had no opportunity of observing the earlier stages of growth of any of the forms of this species, but Postels and Ruprecht 244 University of California Publications in Botany [Vol. 8 (1840, p. 21) describe the young specimens as provided with a short stipe, and Rosenvinge (1893, p. 942, f. 48, 1894, p. 148, f. 48) con- firms this and adds figures of the young plants with stipes which remain tubular. No. 387 of Tilden's American Algae is, in our copy at least, a light colored plant, provided with a distinct tubular stipe about 3 cm. long and 3-4 mm. in diameter (in pressed specimen). This specimen previously referred by us to Ulva Lactuca var. rigida (cf. Setchell and Gardner, 1903, p. 210), has the structure, although not the exact color, of Monostronia fuscum. Rosenvinge (1893, p. 942, f. 17 C, D, 1894, p. 147, f. 17 C, D) calls attention to the fact that each cell in this species contains two chro- matophores, one at each end, and Jonsson (1904, p. 631) emphasizes this as characteristic of this species in distinction from all other species of Monostronm. Collins (1909, p. 25), however, finds only one chromatophore in fresh material of 31. fiiscum from Revere Beach, Massachusetts, and also calls attention to Wittrock's figure (1866, pi. 3, f. 11) which he says "shows a perfectly uniform chromatophore quite like that of the Revere Beach plant." We have seen what appear to be two distinct chromatophores in some of our specimens of varieties splendens and Blyttii where the cells are much elongated verticall.y, but have failed to find them in plants seemingly to be more of the type of the species. 19. Enteromorpha Link Frond persistently tubular, usually slender, but often ample, simple, proliferous or branched, its wall consisting of a single layer of cells, commonly, but not always, arranged parenchymatously ; all the cells of the membrane, except the very lowest, capable of produc- ing zoospores or gametes, which are discharged through an opening in the outer cell wall. Link, Epistola, 1820, p. 5. The name Enteromorpha has been for so many years practically agreed upon among writers as the name for this genus that there is little need, perhaps, for anticipating any change. The only name which seems strictly and definitely to antedate it is that of Tuiidaria of Roussel (Flore du Calvados, ed. II, 1806) which is said to have been founded upon Ulva intestinalis (cf. Desvaux, Journ. Bot., 1813, p. 144). It is not possible for us to verify this reference at present and we follow the weight of authoritj^ in retaining Enteromorpha for the accepted generic name. 1920] Setchell-Gardncr : Chlorophyceae 245 Enteromorpha is a germs of the Ulvales characterized by its tubular frond which is usually narrow, although much dilated at times in the case of certain varieties of Enteromorpha intestinalis. The species are usually branched, although some are normally simple or, at times, proliferous. This definition or characterization leads us to exclude E. percursa and its allies, E. aureola and its allies, and E. Lima, the two former being referred each to its own genus, viz., Percursaria and Capsosiphon respectively, and the last to the genus Ulva. The par- ticular reasons for thus excluding from the genus Enteromorpha plants heretofore commonly referred to it will be given under the respective genera or species, while the general reason is that Entero- morpha thus reduced is more readily defined and apparently more natural. In addition to these changes, we have added to the genus Enteromorpha the species commonly known as Monostrom,a groen- landicum, because in detail of habit, at least, it is very much closer to Enteromorpha than to Monostroma and not so very diverse from some species of Enteromorpha even in structure. The more characteristic species of Enteromorpha have the cells arranged closely set, and parenchymatous in appearance, but certain species show, at times, the cells separated considerably from one another by an intercellular jelly and this condition is normal in E. groenlandica, which, for this reason, usually has been placed under the genus Monostroma. The cells are arranged in longitudinal rows in many species. Some species show a continuance of this arrange- ment even on into the adult condition, while others soon lose it. The chromatophore generally "fills the cell as seen in surface view, but in a few species it occupies only a small portion of the surface of the cell. Much is to be determined in Enteromorpha, as is also the case in Monostroma and Viva, from the thickness, shape and proportions of the cells, and the disposition of the enclosing intercellular substance in cross sections of the membrane. Such sections also show the degree of compression of the frond and whether the walls are completely separated from one another or not. In branching there is great variation, not only in the genus, but within many of the species. It has seemed best, nevertheless, to consider the method of branching as one of the chief characters in separating the species. The species of Enteromorpha present difficulties which have not yet been entirely overcome. The habit is of importance, but varies considerably either under environmental changes or with age in such 246 University of California Publications in Botany [Vol. 8 a fashion as to be insufficient in itself for diagnosis. The anatomical characters, on the other hand, seem to be more reliable, but, of them- selves, present difficulties and seeming abnormalities or departure from type. Very few of the older species have been carefully described anew from the type specimens, so that uncertainty holds in many cases as to the exact application of specific names. Different writers, also, differ decidedly as to their views of specific limits and groupings of forms, so that a student of this group finds much variance of opinion, and consequent resulting confusion. We have followed the accounts of Collins (1903 and 1909, p. 195 et seq.) very largely, but with due attention to the revision of J. G. Agardh (1883, p. 115 et seq.) and the critical remarks of Reinbold (1889, p. 113 et seq.), Borgesen (1902, p. 487 et seq.), Jonsson (1903, p. 343 et seq.) and Kylin (1907, p. 4 et seq.). Very considerable assistance has been obtained also from the earlier monograph of the group by Ahlner (1877) especially as interpreted by J. G. Agardh. Study has been made of the living plant so far as possible, and dried specimens have been boiled in water before examination to restore cell outlines and chromatophores. This method of preparation has given very satisfactory results, the dried specimens swelling up and assum- ing a form and structure closely approximating that of the living material. Even the chromatophores are fairly well restored to size, shape and position. The species of Enteromorpha inhabit brackish water and strictly fresh water as well as strictly salt water and that which passes for the same species may be found in all three. The amount of salinity of the water may, seemingly at least, have very different effects par- ticularly upon the branching and the thickness of the membrane. Careful cultures, however, are needed to establish this fact clearly and convincingly. It may be stated that the culture of various species and forms of the different species of Enteromorpha is very necessary before a definite basis for many of the distinctions now employed maj^ be assured. The species of Enteromiorpha are probably more nearly "cosmo- politan" than those of any other genus of marine algae, although the term cosmopolitan can not, in all probability, be used in the strictest sense, even in connection with them. The ranges of the different species along our western coast of North America are more extensive than those of the species of most other genera. This is to be explained, we think, by the fact that the species of Enteromiorpha 1920] Setchell-Gardner : Chlorophyc&ae 247 are of rapid development and early maturity, so that their effective season of growth may be short, and on the basis of their being, for the most part, essentially tropical or subtropical species. Such warm water species of rapid development may extend into zones of colder surface waters by growing in the upper littoral belt where they may take advantage of the temperatures of the air, or by inhabiting shallow pools or lagoons the temperature of which is raised by the influence of the atmosphere and sunlight. Key to the Species 1. Cells separated, often widely from one another, seldom parenchymatous, un- branched 1- E. groenlandica (p. 248) 1 . Cells usually distinctly parenchymatous, simple or more usually branched 2 2. Cells not arranged in longitudinal rows except, at times, in very youngest parts 3 2. Cells arranged in longitudinal rows in the greater portion of the frond.... 7 3. Frond with more or less plentiful branches 4 3. Frond simple or with few proliferations 5 3. Frond beset with mostly simple, stout, spinelike branchlets 6. E. acanthophora (p. 2,54) 4. Frond flattened, branching from the margins 2a. E. micrococca forma subsalsa (p. 249) 4. Frond tubular compressed, branches contracted at the base, becoming broader above 4. E. compressa (p. 251) 5. Cells 10-16m diam., fronds usually inflated and constricted, often of large size 5. E. intestinalis (p. 252) 5. Cells 4-8m diam., fronds usually short 6 6. Membrane 8-10m thick, cells 5-7^ diam 3. E. minima (p. 250) 6. Membrane 15-20^ thick, cells 4-5m diam 2. E. micrococca (p. 249) 7. Frond simple, inflated and flexuous 8. E. flexuosa (p. 255) 7. Frond simple or with occasional proliferations, not inflated 8 7. Frond regularly branched. 10 8. Frond narrowly linear, strongly compressed 10. E. marginata (p. 257) 8. Frond filiform, capillary or tubular 9 9. Frond capillary of few longitudinal rows of cells 12. E. torta (p. 258) 9. Frond coarse, plainly tubular, of numerous longitudinal rows of cells 9. E. tubulosa (p. 256) 10. Frond beset with numerous thorn-like branches 11. E. salina var. polyclados (p. 257) 10. Frond proliferous, branches similar to main axes... 7. E. prolifera (p. 254) 10. Branches of successive orders, tapering from base to apex 11 11. Chromatophores filling the cell 12 11. Chromatophores not filling the cell 13 12. Ultimate ramuli and branch tips of a single series of cells 13. E. crinita (p. 258) 12. Ultimate ramuU and branch tips of more than one series of cells 14. E. erecta (p. 259) 13. UltimateramuUandbranchtipsof a single series of cells .15. E. plumosa (p. 259) 13. Ultimate ramuli and branch tips of more than one series of cells 16. E. clathrata (p. 260) 248 University of California Publications in Botany [Vol.8 1. Enteromorpha groenlandica (J. Ag.) S. and G. Frond filiform, tubular, ejdindrical, up to 15 cm. long, from a very- slender base expanding to 1 mm. diameter; apex broken only at exit of spores ; cells in the lower part loosely arranged in twos and fours, roundish angular; cells in the upper part more evenly distributed, more or less loosely set; in cross section the membrane 25-35/;. thick; the cells radially elongate, 2-4 times as long as broad ; in the younger parts the central cavity filled with a gelatinous substance which dis- appears as the plant becomes older; spores or gametes forming first at the summit of the frond, and developing successively in lower cells. On small boulders in the middle littoral belt. Ala.ska (Bay of Unalaska and Kukak BajO- Setchell and Gardner, Phyc. Cont. I, 1920, p. 280. Monostroma groenlandicum J. Agardli, Till Alg. Syst., part III, 1883, p. 107, pi. 3, f. 80-83 ; Collins, Green Alg. N. A., 1909, p. 208 ; Saunders, Alg. Har- riman Exp., 1901, p. 410; Setchell and Gardner, Alg. N.AV. Amer., 1903, p. 208. Enteromorpha groenlandica has always been puzzling as to its proper placing. While technically it may seem to belong to the genus Monostroma, under which it was originally described, more properly than to any other genus of the Ulvaceae, yet its slender, filiform habit certainly more closely resembles that of some species of Enteromorpha. From Enteromorpha, however, it differs in not having its cells set sufficiently closely together to be parenchymatous in appearance. It is at first solid, becoming hollow only late, but never rupturing longi- tudinally and opening out into a membrane as do the characteristic species of Monostroma. Certain species of Enteromorpha show a tendency towards abundance of intercellular jelly at times, while certain species of Monostroma are parenchymatous. It seems best to us, therefore, to transfer this species to Enteromorpha. The plants of the North Pacific Ocean, as Collins (1909, p. 209) states, have decidedlj^ smaller cells than those of the North Atlantic, measuring 8-lOjit in diameter, as against 12-16/a as seen superficially. It seems, therefore, to constitute a different form. The species-is a summer plant of the Upper Boreal Zone, invading the Lower Boreal and North Temperate Zones only as a short-lived plant of the springtime when the waters are colder than in the summer. This intrusion happens, so far as we have evidence, only on the eastern 1920] Setchell-Gnrdner : Chlorophyceae 249 coasts of North America where the Massachusetts coast experiences a much colder winter and spring season than do western coasts of North America of the same zones. On the Pacific Coast, so far as our knowl- edge goes, the species is confined to the Bering Sea and adjacent por- tions of the Alaskan Peninsula where the summer temperature of the surface waters seldom, if ever, rises above 10° C. 2. Enteromorpha micrococca Kuetz. Frond 1-5 cm. long, 1-5 mm. wide, tubular or compressed, simple or slightly proliferous at times, much curled and twisted ; cells angular, 4-5|U, diam., in no definite order ; membrane 15-20/x thick, with distinct inner hyaline laj^er. Growing in the upper littoral belt, on rocks and on woodwork. From Alaska (Dutch Harbor) to Mexico {fide Collins, loc. cit.). Kuetzing, Tab. Phyc, vol. 6, 1856, p. 11, pi. 30, f . 2 ; Collins, Green Alg. N. A., 1909, p. 204 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 211 ; Saunders, Alg. Harriman Exp., 1901, p. 411. 2a. Enteromorpha micrococca forma subsalsa Kjellm. Plate 16, fig. 1 Frond compressed, much contorted, with numerous, patent or uncinate, shorter or longer branches from the margin, the latter again branched, all broad at the base and tapering to a point. Growing on stones in the littoral belt. Alaska (Skagway) to Wash- ington (Puget Sound). Kjellman, Alg. Arctic Sea, 1883, p. 292, pi. 31, f. 1-3; Collins, Green Alg. N. A., 1909, p. 204, Mar. Alg. Vancouver Is., 1913, p. 102 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 211 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1068 (fresh water). Enteranwrpha nmiinia Setchell and Gardner, Alg. N.W. Amer., 1903, p. 213 (in part) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 912. Enteromorpha micrococca is, in typical form, a low plant forming a layer on rocks and woodwork high up in the littoral belt. It is to be distinguished by its small cells, not arranged in longitudinal rows, and its thicker membrane which is reinforced by a hyaline layer on the inside. In its ordinary marine habitat, it seldom shows any 250 University of California Publications in Botany [Vol.8 tendency towards branching, but plants agreeing with it in anatomical characters, but growing in brackish or fresh waters, branch abundantly from the margins, the branches tapering at the tips and being usually curved. Such plants are referred under the forma siibsalsa. This variety occurs at times, especially in fresh water, up to 10 cm. or more long. The var. bullosa which Collins distributed under no. 1067 of the Phycotheca Boreali-Americana seems to differ decidedly from Enteromorphu micrococca in the size and shape of the cells and approaches more nearly E. intestinalis in structure. This variety is known, thus far, only from fresh water (San Leandro, California) and does not strictly come under our consideration. 3. Enteromorpha minima Naeg. Frond 1-10 cm. long, 1-5 mm. broad, simple or slightly proliferous, dilated or collapsing, soft and delicate, cells angular, 5-7;u, diam., arranged in no definite order; membrane 8-10/^ thick, equally thick- ened on both surfaces. Growing on stones and on wood in uppermost littoral belt. From Alaska (Unalaska) to Mexico. Naegeli, in Kuetzing, Sp. Alg., 1849, p. 482, Tab. Phyc, vol. 6, 1856, p. 16, pi. 43, f. i-m; Collins, Green Alg. N. A., 1909, p. 201, Mar. Alg. Vancouver Is., 1913, p. 102; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 213. Enteromorpha minima resembles E. campressa but is, in normal form, less likely to show any branching, is more commonly dilated, and of softer and more delicate texture. The cells are also slightly smaller in surface view. From E. micrococca, this species is to be distinguished by the larger cells and thinner membrane which is sel- dom noticeably thickened on the inside, although Kuetzing (1856, pi. 43, f. m) so represents it. Enteromvorpka minima resembles E. micrococca rather than E. compressa in size, but is found in typical form up to 10 cm. high. In fresh water forms attributed to this species we find plants up to 20 cm. long and sometimes with the cells decidedly separated from one another as in Monostroma. In a form from drip- ping rocks above high water mark on San Juan Island, Washington, distributed under no. 912 of the Phycotheca Boreali-Americana, the plants are large and the cells small, with the membrane thickened on the inside. This seems to approach very closely to E. micrococca. 1920] Setchell-Gardncr : Chlorophyceae 251 4. Enteromorpha compressa (L.) Grev. Plate 14, figs, 7, 8 ; plate 16, fig. 3 Frond tubular, more or less compressed, sometimes constricted, varying much in dimensions; branches usually simple, cylindrical or expanding above, in either case narrowed at the base, similar in appear- ance to the main axis ; cells in no definite order ; membrane rather thin. Growing in the middle and lower littoral belts. From Alaska (Bering Sea) to Mexico (Magdalena Bay). Greville, Alg. Brit., 1830, p. 180, pi. 18 ; Collins, Green Alg. N. A., 1909, p. 201, Mar. Alg. Vancouver Is., 1913, p. 101; Setchell and Gardner, Alg. N. W. Amer., 1903, p. 213. Enteramorpha proUfera Setchell and Gardner, Alg. N.W. Amer., 1903, p. 221 (as to no. 5687 only). Enteromorpha fascia Postels and Ruprecht, Illust. Alg., 1840, p. 21 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 211 ; Collins, Green Alg. N. A., 1909, p. 204. Viva compressa Linnaeus, Fl. Suec, Ed. II, 1755, p. 433. We have followed the opinion of J. G. Agardh (1883, p. 137) as to the nature and limits of Enteromorpha compressa. The habit of typical plants is well illustrated in our figures (plate 14, figs. 7, 8, and plate 16, fig. 3 ) . The branches may arise from the very base or at differ- ent heights along the axis. They are uniformly constricted at the base and usually expanded to a rounded tip. The broader portions of the frond are almost always flattened and the layers may be very imper- fectly separated. Sections of such imperfectly tubular fronds often bear a striking resemblance to those of Viva Lima, especially when separation is present only on the margins as may happen in spots. The differences between Enteromorpha compressa and E. minima have already been noticed under the latter species. The resemblance to narrow forms of Viva Lima is sometimes puzzling, especially in unbranched specimens (var. sulsimplex J. Ag.) or in specimens only slightly branched. We refer under Enterornorpha compressa the E. fascia of Postels and Ruprecht (1840, p. 21) since the habit (plate 16, fig. 3) is the same and the size and shape of the cells, both in surface view and in cross section, are identical. The cell contents, however, in the type specimens of E. fascia are disorganized in such a way as to seem almost as if there were groups of small cells within the larger ones. The color of the type specimens is also somewhat brownish. We ascribe this as well as the peculiar appearance of the cell contents to 252 University of California PuhUcations in Botany [Vol. 8 some abnormal state or unusual treatment of the specimens. The type specimens of E. fascia, as they were found in the Imperial Academy of St. Petersburg in 1903, were labelled as having been collected by the Luetke Expedition in Kamtschatka. Of specimens distributed from our coast we find in our copy of the American Algae that Tilden's no. 265, under the name of E. com- pressa var. complanata is E. crinita and no. 264, under the name of E. comprcssa var. suhsimplex is E. plumosa. Most of the specimens available to us for examination are close to the typical form of E. compressa but certain plants collected by one of us (Gardner) at Coos Bay, Oregon, seem referable rather to var. suhsimplex J. Ag. (1883, p. 137). 5. Enteromorpha intestinalis (L.) Link Frond simple or having at the base a few branches similar to the main frond, or occasionally a few proliferations above ; length varying from a few centimeters to several meters ; diameter from 1-10 cm. ; at first attached by a short cylindrical stipe, but often later detached and floating; cylindrical or expanding above, more or less inflated, often much crisped and contorted, and irregularly and strongly constricted ; cells 10-16/x diam., in no regular order ; thickness of membrane vary- ing from 50/x, below to 20/a above, generally thickened on the inside; cells in cross section from 12-30//,. Common in its various forms from Alaska (Kukak Bay) to Mexico (La Paz). Link, Epistola, 1820, p. 5 ; J. Agardh, Till Alg. Syst., part 3, 1883, p. 131 ; Collins, Green Alg. N. A., 1909, p. 204, Mar. Alg. Vancouver Is., 1913, p. 102 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 212 ; Saunders, Alg. Harriman Exp., 1901, p. 411. Ulva intestinalis Lin- naeus, Flo. Suec, Ed. II, 1755, p. 418. Howe (1911, p. 490) has referred doubtfully a plant from La Paz, Mexico, to this species. The following forms have been detected on our coast : Forma cylindracea J. Ag. Frond long and slender, of uniform diameter; usually floating unattached. ~ J. Agardh, Till Alg. Syst., part 3, 1883, p. 131 ; Collins, Green Alg. N. A., 1909, p. 205 ; Mar. Alg. Vancouver Is., 1913, p. 102 ; Saunders, Alg. Harriman Exp., 1901, p. 411; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 212. 1920] 8etch€ll-Gardner : Chlorophyceae 253 Forma maxima J. Ag. Frond large, up to 4 cm. diam., inflated and buUate, producing small, scattered branches. J. Agardh, Till Alg. Syst., part 3, 1883, p. 132 ; Collins, Green Alg. N. A., 1909, p. 205, Mar. Alg. Vancouver Is., 1913, p. 102 ; Saunders, Alg. Harriman Exp., 1901, p. 411 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 212 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1182. Forma clavata J. Ag. Frond always attached, filiform below, enlarging more or less abruptly upwards, open at the upper end, 1-5 cm. wide, 1-5 dm. long. J. Agardh, Till Alg. Syst., part 3, 1883, p. 131 ; Collins, Green Alg. N. A., 1909, p. 205, Mar. Alg. Vancouver Is., 1913, p. 102. Entero- morpha intestinalis f. genwina Hauck, Meeresalg., 1885, p. 426 ; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 212 ; Tilden, Amer. Alg. (Exsicc), no. 263. There appears to be no authenticated type specimen of the Ulva intestinalis of Linnaeus in existence (cf. Jackson, B. D., 1912, p. 147), so that we must follow general tradition as to the nature of this species. As generall}^ agreed upon, it possesses a tubular frond usually inflated, of varying length and diameter, often twisted or constricted, usually branched from a slender base, occasionally slightly proliferous above, and with the rather large, angular or slightly elongated cells not arranged in longitudinal rows, at least not in the adult frond. Under this conception are arranged many and seemingly diverse forms both as to shape and size. The most slender plants of f. cylin- dracea, e.g., may not be much over 1 or 2 mm. in greatest diameter, while the largest of f. maxima, on the contrary, may be 10 cm. through. In regard to amount of inflation, smoothness or rugosit^y of surface, constriction or lack of it, and even of thickness or thinness of the membrane itself, there is much difference between specimens seemingly correctly referred to Enteromorpha intestinalis. What these very diverse forms indicate needs cultural experimentation to demonstrate. At present, we assume an identical genetic constitution for all and hold the varjang environmental conditions responsible for transformations of form. This method is very unsatisfactory, but it is the best that can be done at present. Even with the wide range of characters we have given to the species, we have, nevertheless, followed the more 254 University of California PuhlicaUons in Botany [Vol. 8 restricted point of view rather than the more ample conception. The form names appended to the species, as given above, are simply for the purpose of giving some idea of the amplitude of variation of the species even as most narrowly delimited. 6. Enteromorpha acanthophora Kuetz. Frond more or less proliferously branched, the branches usually constricted at the base, beset with numerous short, spinelike ramuli, with somewhat narrowed base and acute tip ; cells 11-13;«, diam., angular, showing no longitudinal arrangement except indistinctly at the tips of the ramuli and in the spinelike branchlets. Guaymas, Mexico. Kuetzing, Sp. Alg., 1849, p. 479, Tab. Phyc, vol. 6, 1856, pi. 34, f. 1; Collins, Green Alg. N. A., 1909, p. 200 (in part). The figure and description of Kuetzing (1849, p. 479 and 1856, pi. 34, f. 1) provide our chief knowledge of this species, the type specimens of which are from New Zealand. We have not seen the type but have studied New Zealand specimens which seem to belong here. "We are encouraged to refer to this species, although doubtfully, specimens collected by T. S. Brandegee at Guaymas, Mexico, which have a general resemblance to Enteromorpha intestinalis, but which are beset with short, spinelike branches. We do not think that no. 515 of the Phycotheca Boreali-Americana, a plant of fresh water, is prop- erly to be referred to E. acanthophora. Its membrane is too thin (about 13jtt, instead of 30-45/*) and its cells (4-5/x diam., instead of 10-13/t) and cross section, as well as its branching more closely, resemble those of E. micrococca f. suhsalsa, although not strictly in agreement with them. 7. Enteromorpha prolif era (Muell.) J. Ag. Frond up to several meters long and 2 cm. diam., tubular or com- pressed, with more or less abundant proliferous branches, which are usually simple, but sometimes also proliferous ; branches varying much in length and diameter ; cells 10-12/* in diameter, in the younger parts always arranged in longitudinal series, which become somewhat less distinct in the older parts ; membrane 15-18/i, thick, not much exceed- ing the dimensions of the cells in cross section. 1920] Setchell-Gardncr : Chlorophyceue 255 Growing on sticks and stones, sometimes floating, in quiet waters and sheltered bays. From Alaska (Sitka) to central California. J. Agardh, Till Alg., Syst., part 3, 1883, p. 129, pi. 4, f. 103, 104; Collins, Green Alg. N. A., 1909, p. 202; Saunders, Alg. Harriman Exp., 1901, p. 411; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 211; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 913; Tilden, Amer. Alg. (Exsicc), no. 385. Ulva prolifera Mueller, in Fl. Dan., vol. 5, fasc. 13, 1778, pi. 763, f. 1. We must necessarily adopt the idea of J. G. Agardh as to the nature and limits of Enteromorpha prolifera, but neither he, nor any other writer, as far as we know, has examined the type. The illustra- tion in the Flora Danica {loc. cit.) simply shows the habit and might represent either this species or some form of E. intestinalis. The fronds of forms of Enteromorpha prolifera resemble those of forms of E. intestinalis in habit, but are generally more proliferous. They vary from tliose of E. intestinalis in having slightly smaller cells, but differ particularly in having the cells arranged in longitudinal rows in the lower portions, at least, and in the branches. In size and shape, as well as in extent and variety of branching, there is great variation. Enteromorpha prolifera also resembles E. compress'a at times, when the tube is collapsed, but may generally be distinguished from that species by the longitudinal arrangement of cells in the branches. It is closely related to E. tuhnlosa and E. flexuosa, but in these species the cells are more regularly and uniformly arranged in longitudinal rows than they are in E. prolifera. Enteromorpha tululosa is more or less branched and the membrane is not thickened within, while E. flexuosa is typically unbranched and with the membrane inwardly thickened. E. prolifera may be simple at first, but is usually branched later and is destitute of a thickening of the inner surface of the membrane. 8. Enteromorpha flexuosa (Wulf.) J. Ag. Frond cylindrical, tubular, simple, tapering to a filiform stipe below, inflated above, flexuous and intestine-like; cells 8-12/i. long, 6-8/A wide, roundish polj^gonal, in longitudinal series; membrane somewhat thickened on the inside; chromatophore filling the thick- walled cell. Growing on rocks and on other plants. Santa Barbara, California. 256 University of California PuUimtions in Botany [Vol. 8 J. Agardh, Till Alg. Syst., part 3, 1883, p. 126 ; Collins, Green Alg. N. A., 1909, p. 203. Conferva flexuom Wulf., in Roth, Cat. Bot., II, 1800, p. 188. J. G. Agardh {loc. cit.) is responsible for separating this species from among the forms previously referred to E. intestinalis. No recent examination of the type is reported. As taken by J. G. Agardli it seems to be a simple, more or less slender tube with the cells arranged in longitudinal rows and with the membrane somewhat thickened on the inside. It is generally regarded as being an inhab- itant of warmer waters (cf. J. G. Agardh, 1883, p. 127, and Collins, 1909, p. 203). We have not seen it on our coast, but J. G. Agardh credits to this species a specimen collected by Mrs. Bingham at Santa Barbara, California. 9. Enteromorpha tubulosa Kuetz. Plate 14, fig-s. 4, 5 Frond simple or with short proliferations, usually near the base, but with occasional longer proliferations some distance above the base, tubular and nearly cylindrical throughout, or enlarging upward from a delicate cylindrical stipe and becoming compressed above; cells squarish, 11-15/a diam., arranged in longitudinal series through- out, less distinctly so in the upper mature parts; membrane 15-24/a diam., walls equally thickened on both sides, with cells squarish or slightly elongated radially, chromatophore filling the outer end of the cell. Growing attached to rocks in the lower littoral belt, or floating in intertwined masses in pools in salt marshes. Central California. Kuetzing, Tab. Phyc, 1856, p. 11, pi. 32, f. 2; Ahlner, Entero- morpha, 1877, p. 49, f. 9a, 9b. Enteromorpha pralifera var. tuhidosa Collins, Green Alg. N. A., 1909, p. 203 ; Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 462 (Key West, Florida). Kuetzing 's figure of Enteromorpha tuhidosa represents a simple plant, but J. G. Agardh (1883, p. 128) states that it branches. The main frond is tubular and slender, of nearly uniform diameter throughout. Our specimens are all branched more or less, but usually from near the base. The membrane may be thickened on both sides or not at all. There has been some difference of opinion among writers as to the proper relationship of this plant, but it seems best to us to retain it as an independent species. 1920] 8etcheil-Gard'iier : Chlorophyceae 257 10. Enteromorpha marginata J. Ag. Frond filiform, compressed, simple or with a few proliferous branches ; cells 4-8/a diam., squarish, arranged in longitudinal series, very distinctly in the two or three rows at each side, less so in the middle portion. Vancouver Island (Departure Bay) to California. J. G. Agardh, Algae Med., 1842, p. 16 ; Collins, Green Alg. N. A., 1909, p. 202, Mar. Alg. Vancouver Is., 1913, p. 102. Enteromorpha marginata is a very slender plant, usually of salt springs or salt marshes. It is most commonly simple and of low stature. It is credited to our coast by Collins {loc. cit.), but we have had no specimens for examination. 11. Enteromorpha salina var. polyclados Kuetz. Frond small, tubular, with occasional branches similar to the main filaments, all beset with short, spinelike, patent ramuli ending in a single series of cells and varying from few in some specimens to ^ery numerous in others; cells squarish, arranged in longitudinal series. Floating in tangled masses in salt-water ponds. Central Cali- fornia. Kuetzing, Phyc. Germ., 1845, p. 248; Collins, Green Alg. N. A., 1909, p. 202. Enteromorpha polyclados Kuetzing, Tab. Phyc, vol. 6, 1856, pi. 36, II. We have encountered floating in sun-heated pools in the salt marshes or in the artificially wanned water of the Key Route Pool, but all in the neighborhoods of Oakland and Alameda, California, what seems to be the above listed variety of Enteromorpha salina. Our plants are slender, with few or no main branches, cells squarish and in distinct longitudinal rows, and beset with branchlets consisting of one or two longitudinal rows of cells throughout. The main portions of the broader fronds sometimes show as many as twenty cells across, but there are only four to eight to be seen in the more usual slender fronds. We have referred all our plants to the variety but some show details of structure exactly corresponding to those of the species (cf. Kuetzing, 1856, pi. 36, f. I). 258 University of California Piiblications in Botany [Vol. 8 12. Enteromorpha torta (Mert.) Reinb. Frond small, 1-3 cm. long, filiform, simple or with occasional proliferations consisting of two rows of cells ; cells rectangular, always in longitudinal series throughout the filaments and more or less in cross series ; chromatophore thin, covering the greater part of the cell. Growing attached to rocks, in shallow pools in the upper littoral belt. San Diego, California. December. Reinbold, Rev. Juergens' Alg. aquat., 1893, p. 201 (p. 14, Repr.). Conferv^^ OPl DO no DO OD \\ // .rv !rj sm I rt U w T ! i L \r if / {^ ^•-^ Km 10 8 PLATE 11 Pseudulvella prostrata (Gardner) S. and G. Fig. 1. Showing a small section of the margin of the thallus on the surface of Iridaea laminarioides. Fig. 2. A vertical section of fig. 1, perpendicular to the long diameter of the filaments of Vlvella: the drawing is imperfect, it should show a common enclos- ing cuticle. Endophyton ramosum 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 genicvlatum 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 re© ©^ ?Oo©cc.?, io©o c-o :oo' _ PLATE 12 Ulva Lima 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 constrieta S. and G. Fig. 5. Habit sketch of a whole plant. X 30. Fig. 6-8. ShoAving 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 Pac. Coast Mar. Alg. I, 1917, pp. 377- 416, pi. 33. [332] UNIV, CALIF. PUBL. BOT. VOL. 8 [SETCHELL-GARDNER] PLATE 12 PLATE 13 Chlorochytrium inclusum Kjellm. Fig. 1. A vertical section through the host, showing 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 1. I 334 J UNIV. CALIF. PUBL. BOT. VOL. 8 [ SETCHELL-GARDNER ] PLATE 13 PLATE 14 Bryopsis plumosa (Huds.) Ag. Fig. 1. Diagrammatic illustration of a whole jDlant showing the method of branching. X 1. Fig. 2. A sketch of a branch showing the arrangement, the relative length and the constriction of the bases of the pinnules. X 40. Halioystis ovalis (Lyngb.) Areseh. Fig. 3. A habit sketch of a whole plant except the rhizoidal base. X 2. Enteromorpha 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.) Rosenv. Fig. 6. A portion of a frond showing one row of cells at one end and two rows at the other. X 250. -. /"'^nteromorpha compressa (L.) Grev. Fig. 7. A vertical section through the frond. X 250. Fig. 8. A surface vicAv. X 250. ClMetomorpha 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 zostericoJa Tilden 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 „oo j CDCDCDCDCDCDOA OOOOOCDCppir. ngsfi^^oooooooi^ 11 OO OOD R^^o M. ^2 ^OOO ^oooo^oooooooooooooog 13 8 PLATE 15 Chlorochytrium Porphyrae S. and G. Fig. 1. A vertical section through 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. Derbesia 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 Suring. 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. BOX. VOL. 8 [SETCHELL-GARDNER 1 PLATE 15 PLATE 16 Enteromorpha micrococca var. s^hsalsa Kjellm. Fig. 1. A habit sketch of a piece of a froud showing the method of branch- ing. X 20. Cladophora trichotoma (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 (Eupr.) Collins Fig. 4. Sketch showing the characters of the hooked branches. X 10. Codium Eitteri S. and G. Fig. 5. A sketch of a group of utricles. X 25. [340] UNIV. CALIF, PUBL. BOX. VOL, [ SETCHELL-GARDNER ] PLATE 16 PLATE 17 Pseudopringslieimia apiculata S. and G. Fig. 1. A section througli the thallus of a mature plant perpendicular to the host. X 250. Fig. 2. A section through the thallus of a young plant. X 250. Frasiola delicata S. and G. Fig. 3. a-f, Series of different forms of plants. X 10. Ulva 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 Vlvae 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. Cont. I, 1920, pp. 279-324. pi. 22. [342] UNIV. CALIF, PUBL. BOT. VOL. 8 [SETCHELL-GARDNER ] PLATE 17 PLATE 18 Gomontia caudata S. and G. Fig. 1. T^\o pieces of filaments. X 400. Fig. 2. a-(l, Different stages and forms of "sporangia." X 400. Internoretia Fryeana S. and G. Fig. 3. A surface view of the liost plant, showing the method of permeation and branching of a few 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. Entocladiu cingens S. and G. Fig. 7. A plant groAviug in the membrane of Chaetomorplm californica 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 If $DOC>0 PLATE 19 Gomontia polyrhisa (Lagerli.) B. and F. Fig. 1. A group of three "sporangia," the two larger nearing maturity. X 175. Gomontia liabrorhisa S. and G. Fig. 2. A young thallus. X 375. Fig. 3. a-e, Illustrating three forms of the "sporangia." Pseudnilvella consociata S. and G. Fig. 4. 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 codicoJa 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 8 PLATE 20 Prasiola delicata S. and G. Pig. 1. A micro-photograph of a marginal segment, surface view showing the arrangement of the vegetative cells. X 442. Prasiola Tneridion-alis 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, Phyc. Cont. I, 1920, pp. 279-324, pi. 25. [348] UNIV, CALIF. PUBL. BOT, VOL, 8 [SETCHELL-GARDNER] PLATE 20 '•/;<^^"* '''^ .•:***3 ' jfi^L' ^ ■ ^ "*' -.^- i*^ *^ 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 whole dried plant, showing the extreme crisped nature of the dentate margins at the base. X 0.3. [354] UNIV. CALIF. PUBL. EOT. VOL. [SETCHELL-GARDNER J PLATE 23 PLATE 24 Viva stenopliylla S. and G. A photograph of a whole plant, the type. X 0.3. [356] UNIV. CALIF. PUBL. EOT. VOL. [ SETCHZLL-GARDNER ] PLATE 24 PLATE 25 Monostroma areoJatum S. and G. A photograph of a ^vhole dried plant, the type. X 0.5. [358 J UNIV. CALIF. PUBL, BOT. VOL. 8 [ SETCHILL-GARDNER ] PLATE 25 PLATE 26 Ulva angusta S. aud G. Fig. 1. A micro-photograph of a part of the surface. X 442. Monostromu areolatum S. and G. Fig. 2. A micro-photograph of a part of the surface. Plates 21-26 are from Setchell and Gardner, Phyc. Cont. I, 1920, pp. 279-324, pis. 26-31. [360] UNIV. CALIF. PUBL. EOT, VOL. [ SETCHZLL-GARDNER ] PLATE 26 PLATE 27 Bryopsis corticulans Setchell A photograph of a whole plant. X 1. [362] UNIV. CALIF. PUBL. BOT. VOL, 8 rSETCHELL-GARDNER ] PLATE 27 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 [ SETCHELL-GARDNER 1 PLATE 28 PLATE 29 Codium fragile (Suring.) Hariot A photograph of a dried frond, showing long, slender branches and dichotomous branching. X 0.5. [ 36(5 J UNIV, CALIF, PUBL. BOT, VOL, [ SETCHELL-GARDNER ] PLATE 29 PLATE 30 Codium Setchellii Gardner A photograph of a part of a thallus. X 1- [368] UNIV, CALIF. PUBL. BOT, VOL, [ SETCHELL-GARDNER ] PLATE 30 PLATE 31 Codium sp. A photograph of a part of a dried plant. ^ Uy 9jla , /UylthAL/_ UA^lM^ ^ ' caMAaK \J [370] UNIV. CALIF. PUBL. E.OT, VOL. 8 SETCHZLL-GARDNER I PLATE 31 PLATE 32 Spongomorplia coalita (Rupr.) Collins A photograph of a gi-oup of plants showing the method of combining into rope- like masses. X 0.5. [372] UNIV. CALIF. PUBL. BOT. VOL. [SETCHELL-GARDNER ] PLATE 32 ;:-<%i:. PLATE 33 Ulvella 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 W» ■«' '•^' i/ia ^* \2^» "'»• :'^/%te* ^ INDEX Univ. Calif. Publ. Bot., vol. 8, Parts I and II. Titles of papers and names of new species, etc., are in boldface. Acrosiphonia, 207, 221. albescens, 229. duriuscula, 225. hamulosa, 229, 231. Mertensii, 228. Aegagropila, 221. Aequales, 59, 63. Agmenellum, 8. Anabaena, 90. fragilis, 69. oscillarioides, 90. propinqua, 90; figure showing, opp. 138. variabilis, 90, 91; figure showing, opp. 138. Anacystis, 6, 12, 14. elabens, 14; figure showing, opp. 130. Anadyomene, 180. Aplonema, 198. Arthrospira, 53^ breviarticulata, 54, 55 ; figures show- ing, opp. 132 and 136. maxima, 54; figure showing, opp. 138. Attenuatae, 59, 64. Bangia calophylla, 277. Blastophysa, 154. Blennothrix elegans, 81. Boodlea, 180, 232. composita, 232. Botrydium, 154, 261. Brachytrichia, 110, 111, 112. affinis, 112; figures showing, opp. 136. Quoyi, 111, 112. rivularioides. 111. Bryopsidaceae, 154, 156. Bryopsis, 156, 157, 158. abietina, 162. arbuseula, 162. Balbisiana var. Lamourouxii, 166. corticulans, 158, 160; figures show- ing, opp. 338; plate showing, opp. 362. elegans, 160. hypnoides, 158, 159, 162. Lyngbyei, 162. pennata var. minor, 158. pennatula, 158. plumosa, 158, 161 ; figures showing, opp. 336. Bulbocoleon, 287, 288. piliferum, 288. Calothrix, 94. consociata, 94, 95. Contarenii, 95, 97. Crustacea, 99. epiphytica, 95, 99. hydnoides, 82. parasitica, 95, 98. pilosa, 95, 102 ; figure showing, opp. 138. prolifera, 95, 101. pulvinata, 82, 95, 97. rectangularis, 95, 100; figure show- ing, opp. 134. robusta, 95, 96 ; figure showing, opp. 134. scopulorum, 95, 96. semiplena, 78. vivipara, 95, 101. Capsosiphon, 233, 234, 235. aureolum, 234. fulvescens, 234. Caulerpa, 156. Ceramium pulvinatum, 98. Chaetomorpha, 207, 282. aerea, 200 ; figures showing, opp. 336. antennina, 200, 203. californica, 200. cannabina, 200, 204, 205. clavata, 205, 206. var. torta, 205. confervicola, 205. Linum, 201. litorea, 205. melagonium, 199, 200, 201, 202. f. rupincola, 202. f. typica, 202. minima, 200. moniligera, 206. Picquotiana, 199, 202. spiralis, 206. torta, 200, 205, 206. tortuosa, 186, 205. Chaetomori^hopsis pacifica, 203. Claaetophoraceae, 286, 287. Chaetophorales, 281. Chaetophoreae, 287. Chaetophoroideae, 287. Chamaesiphon, 20, 25. Chamaesiphonaceae, 5, 20. CMorochytriaceae, 143, 146. Chlorochytrium, 146, 147. inclusum, 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. Chlorophyeeae, 139-374. Chlorospermeae, 140. Chroococcaceae, 5. Chroococcus, 6, 9, 10. turgidus, 10. f. submarinus, 11 ; figure showing, opp. 124. Chroolepidaceae, 30.5. Chroolepus umbrinum, 306. Cladophora, 180, 181, 207, 208, 221. alaskana, 225. albida, 208, 218, 219. amphibia, 208, 209. arcta, 223, 229, 230. f. conglutinata, 229. var. pulvinata, 229. Bertolonii var. hamosa, 208, 218. cartilaginea, 210. Chamissonis, 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. hemisphaerica, 208, 211, 212. Hutchinsiae, 208, 213, 215. var. distans, 211, 213, 214. Hystrix, 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. triehotoma, 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. adhaerens, 169. damaecorne, 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. mamillosum, 170. mueronatum, 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. californicum, 172. var. novae-zelandiae, 172. Coleochaete, 289. Coleonema arenifera, 24. Collinsiella, 144. tuberculata, 144, 145; figures show- ing, opp. 328. Conferva aestuarii, 75. aggr^gata, 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. duriuscula, 225. flacca, 284. [376] Index Conferva (cont.) flexuosa, 217, 256. glaucescens, 219. gracilis, 216. Hutchinsiae, 213. implexa, 184. laetevirens, 216. lanosa, 221. melagonium, 201. Mertensii, 227, 228. oligoclona, 207. paradoxa, 259. penicilliformis, 187, 191. percursa, 274. riparia, 183. saxatilis, 226, 228. seopaeformis, 231. scopulorum, 97. tortuosa, 184, 186. trichotonia, 210. uncialis, 221. viminea, 227. Wormskiolclii, 197. Cryptophyceae, 3. Cyanocystis, 20, 23, 25. Cyanophyceae, 3. Derbesia, 164. Lamourouxii, 164, 165, 166. marina, 164, 165; figure showing, opp. 338. tenuissima, 165. vaucheriaeformis, 165. Derbesiaceae, 154, 163, 164. Derbesieae, 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. pacifica, 22, 27, 35 ; figures showing, opp. 128. prasina, 29, 30. protea, 22, 28, 29; figures showing, opp. 130. sphaerica, 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. percursum, 274. Ecballocystis tuberculata, 145. Willeana, 145. Ectosperma, 178, Endocladia, 289. cingens, 291. codicola, 291. Flustrae, 290. viridis, 290, 291. Endodernia viride, 289. Endophyton, 287, 292. ramosum, 292, 293 ; figures showing, opp. 330. Endosphaera, 147. Endosphaeraceae, 146. Enteromorpha, 233, 244, 245, 246, 247, 261. acanthophora, 247, 254. aureola, 234. clathrata, 247, 260. compressa, 247, 250, 251, 252, 255; figures showing, opp. 336 and 340. f. complanata, 258. f. sub-simplex, 260. crinita, 247, 258, 260. erecta, 259, 260. fascia, 251. flexuosa, 247, 255, 256. GreviUei, 236. groenlandica, 248. Hopkirkii, 260. intestinalis, 247, 252, 255, 266. f. cHavata, 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. minima, 247, 249, 250. percursa, 274. plumosa, 247, 259. polyclados, 257. prolifera, 247, 254, 255, 258. var. tubulosa, 256. 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. codicola, 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 Gayella, 275, 279. constricta, 279, 280, 281; figures shelving, opp. 332. polyrhiza, 279, 280, 281. Gloeocapsa crepidinum, 21, 37. Gloeothece, 7. Gloesipheae, 3. Gloiosiphonia verticillaris, 237. Godlewskia, 25. Gomontia, 287, 300, 301. arrhiza, 300. Bornetii, 301, 302, 303, 304. caudata, 301, 304; figures showing, opp. 344. codiolifera, 300. habrorhiza, 301, 304; figures show- ing, opp. 346. polyrhiza, 301, 302, 303, 304 ; figure sho^ving, opp. 346. Gomontieae, 287. Gomphosphaeria, 21, 49. aponina, 50 ; figures showing, opp. 124. Gonidium, 8. Halicystis, 154. ovalis, 155 ; figure shoAving, opp. 336. Halimeda, 166, 176, 177. discoidea, 177; figure showing, opp. 334. Hammatoidea, 93. Herpyxonema, 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. tetraciliata, 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. eaespitosa, 41. linearis, 41, 43 ; figure showing, opp. 126. Littorinae, 41, 42; figures shoAving, opp. 128. socialis, 44 ; figure shoAAdng, opp. 126. Ilea, 234. Fascia, 234. foeniculaceus, 234. fulvescens, 234. Internoretia, 287, 294. Fryeana, 294; figures showing, opp. 344. Isactis, 104. plana, 104. var. fissurata, 105. var. plana, 105; figures showing, opp. 124. Isokontae, 142. Lamarckia, 167. Laminaria saccharina, 261. Leibleinia, 72, 73. Corallinae, 62. Leptosireae, 287. ' ' Leptothrix lamellosa, ' ' 90. Linckia atra var. coadunata, 107. Literature cited, on, Myxophyceae, 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. confluens, 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. Jloniliformia, 68. Monostroma, 235, 236. [378] Index Monostroma (cont.) angicava, 238. arcticum, 236, 238. areolatum, 236, 240; plate showing, opp. 358 ; figure showing, opp. 360. Blyttii, 238, 243. cylindraceum, 238. fuseum, 236, 238, 242. var. Blyttii, 243, 244. var. splendens, 242, 243. Grevillei, 236, 237, 238. var. lubricum, 237. var. Vahlii, 237. groenlandicum, 248. latissimum, 236, 238, 241, 242. leptodernmm, 239. lubricum, 237. orbiculatum, 236, 242. quaternarium, 236, 240, 241. saccodeum, 238. splendens, 238, 243. Vahlii, 237. zostericola, 236, 237, 238, 239; fig- ures showing, opp. 336. Myxophyeeae, 1-138. Myxophykea, 3. Nitella, 289. Nostoc, 90, 92. Linckia, 92. Quoyi, 111. Nostocaceae, 51, 89. Nostoceae, 89. Nostochopsis, 112. Oedogonium, 163. Oscillaria margaritifera, 61. neapolitana, 66. submembranacea, 71. Oscillarideae, 52. Oscillatoria, 58. acuminata, 59, 65; figure showing, opp. 124. amphibia, 63. Bonnemaisonii, 59, 60. brevis, 59, 65. var. neapolitana, 66. chalybea, 59, 67. Corallinae, 59, 62. geminata, 59, 63. laetevirens, 59, 64. limosa, 59. margaritifera, 59, 61. nigro-viridis, 59, 62. Okeni, 59, 66. Oscillatoriaceae, 51, 52, 53. Oscillatorieae, 57. Palmella conferta, 17. Palmella? 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. Phycochromophyceae, 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 shoAving, opp. 124. Golenkinianum, 80. mirabile, 78. Pleuroeapsa, 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. Polyeystis, 13. Porphyra, 261. Prasiola, 9, 275, 276. borealis, 276, 277, 278 ; figures show- ing, opp. 328. calophylla, 276, 277. delicata, 276, 278; figures showing, opp. 342, 346, and 348. furfuracea, 278. meridionalis, 276,. 278, 279; figure showing, opp. 348. tesselata, 278. Principes, 59. Pringsheimia scutata f. Cladophorae, 16, 33. Protococcales, 142, 143. Protococcoideae, 143. Protococcus rufescens, 10. turgidus, 11. Protosiphon, 154. Protosiphonaceae, 153, 154. Pseudodictyon, 287, 293, 294. geniculatum, 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. consociata, 296, 297, 298; figures showing, opp. 346. prostrata, 296, 297 ; figures show- ing, opp. 330. Eadaisia, 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. Ehizoclonium, 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. Kivulariaceae, 51, 93. Eivularieae, 93. Schizogoniaceae, 275. Schizogoniales, 142, 275. Schizogonium, 275. laetevirens, 286. Schizophyceae, 3. Schizosiphon consociatus, 95. Schizotricheae, 83. Scotinosphaera, 147. Scytosiphon erectus, 259. Setchell, 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. arcta, 222, 223, 224. f. conglutinata, 229. var. limitanea, 228. var. pulvinata, 229. coalita, 222, 225, 230, 231; figure shoAving, opp. 340; plate show- ing, opp. 372. duriuscula, 222, 225, 226. Hystrix, 222, 224, 225. lanosa, 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. f unicularis, 81, 82 ; figure showing, opp. 136. hydnoides, 81; figures showing, opp. 124. laeteviridis, 83. Syneehococcus, 6, 7. curtus, 7 ; figure showing, opp. 124. Synechocystis, 6. aquatiUs, 6; figure showing, opp. 124. Tetranema, 273. percursum, 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. Ulotrichaceae, 281, 282. Ulotrichales, 142, 281. Ulva, 233, 260, 261, 262. angusta, 262, 264 ; plate showing, opp. 352; figure showing, opp. 360. aureola, 234. ealifornica, 262, 264, 271. compressa, 251. conglobata, 270. f. densa, 270. dactylifera, 263, 272; figure show- ing, opp. 350. decorticata, 172. [380] Iridex Ulva (cont.) expansa, 262, 267, 268, 269. fasciata f. caespitosa, 270. f. costata, 272, 273. f. expansa, 268. f. lobata, 269. f. taeniata, 268, 273. fenestrata, 262, 267. fulvescens, 234. fusca, 242. intestinalis, 252. Lactuca, 261, 262, 263, 265, 266, 270. var. latissima, 266. var. rigida, 242, 265, 270. myriotrema, 266. latissima, 241, 261, 262, 266, 267, 268. Linza, 251, 261, 262, 263; figures showing, opp. 332. lobata, 262, 268, 269. percursa, 274. plumosa, 161. reticulata, 267. rigida, 269, 270. splendens, 243. stenophylla, 262, 271; figure show- 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. araericana, 296. confluens, 299. fucicola, 299. Lens, 295, 296; plate showing, opp. 374. prostrata, 297. Ulvelleae, 287. Urospora, 187. acrogona, 190. bangioides, 190, 194. collabens, 194. claviculata, 190. elongata, 190, 196. grandis, 195. Hartzii, 193. incrassata, 191, 193. mirabilis, 187. penicilliformis, 191, 195. Wormskioldii, 195, 197. Vaginaria, 85. Vaginarieae, 83. Valonia ovalis, 155. Vaucheria, 156, 178. marina, 165. Vaueheriaceae, 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, opp. 132. Schousboei, 24, 30. Zygomitus, 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 Kootb., read Kottb. line 6. For Sirococoleum read Sirocoleum. last line. For Forti read Kirchner. line 26. For Anabaena read Anabaina. For two read 2. For cognitarium read cognitarum. Delete (meneghini). Delete (decaisne). Delete (grev) and add (emend.) after Oltmanns. Delete (boby). For Bryopsidaceae read Bryopsideae. Delete (thuret). Delete 'out.' Delete (trevis). Delete (blackmann and tansley). For antidates read antedates. For Ovoidea read ovoidea. Delete 1732, ed. 1. next to last line. For Ucluet read Ucluelet. line 2. For cells read segments. At end of line insert (sw-b. E. flexuosa). For filing read filling. Insert comma after diam. For teniata read taeniata. For Blatosporaceae read Blastosporaceae. For piliferem, read piliferum. For Stechell read Setchell. For Keil read Kiel. For Acrid-type read Acarid-type. For 1-268 read 1-168. For 269-531 read 169-531. For Jajonicae read Japonicae. For 1909 read 1809. For 1909 read 1809. For Ulrothricaceae read Ulothricaceae. 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 cribosuni, read cribrosum. Add (No. 628, Collins, Holden, and Setchell, Phyc. Bor.-Am., referred under Codium Lindbergu; cf. p. 175 of text.) line 7. line 38. line 1. line 27. line 6. line 1. line 32. line 1. line 18. line 9. line 1. line 18. line 13. line 4. line 30. line 27. line 26. line 5. line 23. line 18. line 35. line 25. line 27. line 8. line 9. line 39. line 36. line 38. line 30. [382] XTNIVEBSITT OF OALIFOBNIA PUBLICATIONS— (Continued) ▼oL 6. 1914-. 1. Parasitic Florideaa, by William Albert Setcbell. Pp. 1-34, plates 1-6. 2. Phytomorula regvlaris, a Symmetrical Protophsrte Related to Coelastrum, by Chaiiles Atwood Kofoid. Pp. 35-40, plate 7. April, 1914 .05 3. Variation in Oenothera ovata, by Eatherine Iiayne Brandegee. Pp. 41-50, plates 8-9. June, 1914 „ .10 4. Plantae Mexicanae Purpusianae. VI, by Townshend Stith Brandegee. Pp. 51-77. July, 1914 „ __ „_ .26 5. Tbe Scinaia Assemblage, by William Albert Setchell. Pp. 79-152, plates 10-12. October, 1914 _ .75 6. Notes on Pacific Coast Algae. I, Pylaiella Postelsiae, n. sp., a New Type in the Genus Pylaiella, by Carl Skottsberg. Pp. 153-164, plates 17-19. May, 1915 „ _ .16 7. New and Noteworthy Calif omian Plants. II, by Harvey Monroe Hall. Pp. 165-176, plate 20. October, 1915 „ „ „ ,16 8. Plantae Mexicanae Purpusianae. VII, by Townshend Stith Brandegee. Pp. 177-197. October, 1915 _ .25 9. Floral Belations Among the Galapagos Islands, by A. L. Eroeber. Pp. 199-220. March, 1916 „ „ „ .20 10. The Comparative Histology of Certain Callfomian 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 Gilkey. Pp. 275-356, plates 26-30. March, 1916 ^ .80 12. Species Novae vel Minus Cognitae, by T. S. Brandegee. Pp. 357-361. May, 1916 „ „ „ .06 13. Plantae Mexicanae Purpusianae. VIII, by Townshend Stith Brandegee. Pp. 363-375. March, 1917 I5 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 Califomlan 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 Califomlan 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 Califomlan Species of Trillium L. Ill, 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 Califomlan Species of Trilli^lm 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 CaUfomia, by Walter C. Blasdale. Pp. 101-157. August, 1919 50 6, 7, 8. A Rubber Plant Survey of Western North America. I. CTirysotJiamnus nauseosus and Its Varieties, by Harvey Monroe Hall. II. 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. 159-278, 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 UNIVEESITT OP OAUFOBNIA PXJBLICATIONS— (Continued) 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 _ $iJ50 2. The Marine Algae of the Pacific Coast of North America. Part n. % Chlorophyceae, by William Albert Setchell and Nathaniel Lyon Gardner. '^ Pp. 139-374, plates 9-33. July, 1920 „ 2.75 V '■; t '>■