334 DR. Е. E. FRITSCH ON FRESHWATER ALG. 
48. OsCILLATORIA SUBTILISSIMIA, Kite. Tub, Phyc. i. 1845-49, p. 27, tab. 38. 
fig. 7. 
Sample 10, rather rare. 
49. OSCILLATORIA TENUIS, (19.; Gomont, Oseillavices, Ann. Se. Nat. Bot. 
xvi. p. 240, pl. 7. figs. 2 & 3. 
Samples 10, 11, and 15, rather rare. 
The forma sordida, Kütz., was also present. 
50. SPIRULINA SUBTILISSIMA, Ай. Phyc. gen. 1843, р. 188; Rabenhorst, 
Fl. Europ. Alg. ii. 1865, р. 98; Gomont, loc. cit. p. 272, pl. 7. fig. 20. 
Sample 10, rather common. 
NOSTOCACE.E. 
51. Isocvsris INFUSIONUM (Kätz.), Borzi, in Nuov, Giorn. Dot. Lal. x. 1876, 
p. 468. 
Samples 8, 11, 15, 15, 17, rather common. 
52. Nosroc MINUTISSIMUM, А. Phye. gen. р. 204; Rabenhorst, Fl. Europ. 
Alg. п. 1865, р. 162. 
Samples 10 and 11, rather common; 1 and 2B (yellow snow |), rare. 
RIVULARIACEZE. 
53. UALOTHRIX JERUGINEA, Thuret; Bornet et Flahault, .Nostocacées hétéro- 
cystées, 1886-88, p. 358. 
"ample 14, isolated. 
Diam. of cells =9-11 и. Only one group of filaments was seen, and the 
determination is therefore somewhat doubtful. C. @ruyinea is а marine 
form, but the habitat from which sample 14 eame would be likely to harbour 
marine forms. 
ОТАТОМАСЕ Л. 
94. MELOSIRA VARIANS, Ag. Consp. 1880, p. 64 ; Rabenhorst, FL Europ. 
Alg. 1. 1864, p. 40. 
Sample 9, rather rare. 
55. MELositA Bor, Avitz.; Van Heurck, Atlas, pl. 91. figs. 7-9. 
Sample 4 (red snow!); one short chain seen (living !). Previously 
recorded from the Antarctice (Hooker у Harvey). 
