FRESH WATEE ALGJ3. 55 



PLATE I. 



Figs. l~5.~Chlamydomonas subcaudata Wille, ordinary individuals, of. description, pp. 7, 8 ; p, pyrenoid ; 



11 = nucleus, (x 700.) 

 Figs. e-W.— Chlamydomoms subcaudata Wille, encysted individuals. In figs. C and 7 the original shape 

 of the mother-cell membrane is easily recognised ; in figs. 8-10 the cysts show the 

 processes described on p. 8 ; j? = pyrenoid ; n = nucleus. ( x 700.) 

 Figs. ll-li.—C'/damijdomonas subcaudata Wille, free cysts ; in fig. 14 the cyst contains two pyreiioids. 



(X 700.) 

 Figs. 15-18. — Ghlamydomonas intermedia Chod., ordinary individuals ; p = pyrenoid ; /* = nucleus ; c = 



contractile vacuole ; s = stigma. ( x 1350.) 

 Fig. 1%.— Ghlamydomonas ehrenbergi Gorosch., ordinary individual ; p = pyrenoid ; ii = nucleus. 



(X 700.) 

 Fig. 20.— Ghlamydomonas subcaudata Wille, cyst showing division of contents into four parts, (x 700). 

 Figs. 21-25. — Ghloromonas cdpina AV^ille ; n = nucleus ; s = cyc-si3ot. In most of the individuals the 



cilia could not be traced to their full length. ( x 1350.) 

 Fig. ii'i.—Fleurococcus antarcticus W. and G. S. A\^est, f. typica ; o = oil-globules, (x 550.) 

 Fig. 27. ,, „ „ „ f . minor. ( X 550.) 



Fig. 28. „ „ „ „ i.filamentosa. (x 550.) 



Fig. 2i). „ „ ., „ i.stellata. (x 800.) 



Figs. 30, 31, 33. ,, ,, ., i: simplex; o = oil-globules, (x 550.) 



Fig. 32. ., „ ,, „ f. typica, a group of appreciably larger cells than 



those in Fig. 26. One of these cells has two pyreuoids. (x 400.) 

 Figs. 34-35. — Pleurococcus antarcticus W. and G. S. West, f . robusta, elliptical cells. ( X 500.) These 



are relatively small cells of this form. 

 Fig. 36. — Pleurococcus Jcoettlitzi sp. n., group of cells seen at a low magnification, (x 220.) 

 Figs. 37-42. — Pleurococcus Jcoettlitzi sp. n. ; 37, 30, 41, ordinary tetrads ; 38, small part of group shown 



in fig. 36 ; 40, development of daughter-cells within mother-cell ; 42, development of 



daughter-cells within mother-cell, — some of the cells of the tetrad arc abortive. 



(S'J, 40 X 500 ; other figures x 400.) 

 Figs. 43, 44. — Pleurococcus friyidus AV. and G. S. West, (x 400.) 

 Figs. 45, iG.—Penium sp., cf. pp. 20, 21. (x 500;) 

 Figs. 47, 48. — Eucapsis minuta sp. n. 47, Surface view of an older colony to show grouping of cells 



(x 1800) ; 48, Diagram of eight cells of colony to show the cubical arrangement 



(magnified about 4000 times). 

 Figs. 49-51. — Merismopedia tenuissima Lemm. ; 49, young colony ; 50, 51, older colonies, (x 1400.) 

 Fig. 52. — Phormidium frigidum sp. n. (x 1800.) 



Figs. 53, 54. — Phormidium autumnale (Ag.) Gom., apices of two filaments. ( X 700.) 

 Figs. 55-59. — Oscillatoria Jcoettlitzi sp. n. ; 55, 57, 58 are typical tricliomes. (X 700.) 

 Figs. 60-64. — Oscillatoria simplicissima Gom., var. antarctiM var. n. ; 62, f. acuminata; 61, f. spircdis ; 



64, trichome overgrown by filaments of PJtormidium amjustissimum. (x 550.) 

 Fig. 65. — Oscillatoria producta W. and G. S. West, (x 800.) 

 Fig. 66. „ subproboscidea W. and G. S. West, (x 800.) 



Figs. 67-70. — Microcystis parasitica Kiitz. (x 700.) 

 Figs. 71-73. — PJiormidiwm antarcticum W. and G. S. West, forma. (71, 72, x 850 ; 73, X 1800.) 



