FRESHWATER ALGAl. 55) 
PLATE I. 
Fies. 1-5.—Chlumydomonas subcaudata Wille, ordinary individuals, cf. description, pp. 7, 8 ; p, pyrenoid ; 
nm = nucleus. (x 700.) 
Fras. 6-10.—Chlamydomonas subcaudata Wille, encysted individuals. In figs. 6 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; p = pyrenoid ; » = nucleus. (x 700.) 
Fires. 11-14.—Chlamydomonas subcawtata Wille, free cysts; in fig. 14 the cyst contains two pyrenoids. 
(x 700.) 
Fras. 15-18.—Chlamydomonas intermedia Chod., ordinary individuals ; p = pyrenoid ; » = nucleus ; ¢ = 
contractile vacuole ; s = stigma. (xX 1350.) 
Fie. 19.—Chlamydomonas ehrenbergi Gorosch., ordinary individual ; p = pyrenoid ; 7 = nucleus. 
(x 700.) 
Fic. 20.—Chlamydomonas subcaudata Wille, cyst showing division of contents into four parts. (x 700). 
Pies. 21-25.—Chloromonas alpina Wille; = nucleus; s = cye-spot. In most of the individuals the 
cilia could not be traced to their full length. (x 1350.) 
Fie. 26.—Pleurococcus anlarcticus W. and G.S. West, f. typica ; 0 = oil-globules. (x 550.) 
> 
[Dies PATE “5 3 5 a f. minor. ( 550.) 
Fig. 28. - =f - s f. filamentosa. (x 550.) 
Fie. 29. * re = 3 f. stellata. (x 800.) 
INES, BINS Bil, Bs}, 55 ‘ = f. simplex; 0 = oil-globules. (x 550.) 
Big. 82. ~ a s f. typica, a group of appreciably larger cells than 
” 
those in Fig, 26. One of these cells has two pyrenoids. (x 400.) 
Fires. 34-385.—Pleurococeus antarcticus W. and G. S. West, f. robusta, elliptical cells. (x 500.) These 
are relatively small cells of this form. 
Fie. 86.—Pleurococcus koettlitzi sp. n., group of cells scen at a low magnification. (x 220.) 
Frias. 87-42.—Pleurococeus koettlitzi sp. n. ; 37, 39, 41, ordinary tetrads ; 88, 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 are abortive. 
(39, 40 « 500; other figures x 400.) 
Bras. 43, 44.—Pleurococcus frigidus W. and G.S. West. (x 400.) 
Fras. 45, 46.—Penium sp., ef: pp. 20, 21. (x 500.) 
Fras. 47, 48.—Lucapsis 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). 
Fias. 49-51.—WMerismopedia tenuissina Lemm. ; 49, young colony ; 50, 51, older colonies. (Xx 1400.) 
Fie. 52.—Phormidium frigidum sp. an. (x 1800.) 
Fras. 53, 54.—Phormidium autumnale (Ag.) Gom., apices of two filaments. (x 700.) 
Fras. 55-59.—Oscillatoria koettlitzi sp. n. ; 55, 57, 58 are typical trichomes. (x 700.) 
Fras. 60-64.—Oscillatoria simplicissima Gom., var. antarctiva var. n.; 62, f. acuminata; 61, f. spiralis ; 
64, trichome overgrown by filaments of Phormidium angustissimum. (X 550.) 
Fra. 65.—Oscilla/oria producta W. and G. 8. West. (x 800.) 
Fic. 66. a subproboscidea W. and G. 8. West. (x 800.) 
Fries. 67-70.—WMicrocystis parasitica Kitz. (x 700.) 
Fias. 71-73.—Phormidium antarcticum W. and G. 8. West, forma. (71, 72, X 850; 78, x 1800.) 
VOL. VI. 0 
