FRESHWATER ALG.4S 287 



COCCONEMACE.E 

 Genus COCCONEMA Ehrenb. 



41 Cocconema pusilla (Grun.) nob. 



Cymbella pusilla Grun., 1875 ; Cleve, Synops. Name. Dial. I, 1894, p. 162. 

 Long. valv. 31 M; lat. 5.2 ^; striis 17 in 10 n, 

 Hob. In ponds, Mt. Erebus. 



NITZSCHIACE.& 



Genus NITZSCHIA H assail 

 42 Nitzschia subtilis (Kiitz.) Grun. var. 



Long. 39.2 /u; lat. 3.1 M; punctis 16 vel 17 in 10 ^ 



Hub. Clear Lake. 



This Nitzschia seems undoubtedly to belong to N. subtilis, and resembles very much 

 the var. glacialis Grun. (" Diat. Franz Josefs- land," Denk. Akad. Wiss. Wien. xlviii, 1884, 

 p. 107, t. 1, f. 64). It is, however, very slightly more attenuated and the carinal 

 puncta are further apart. It should also be compared with N. subtilis var. paleacea 

 Grun. (cf. V. Heurck, Synops. Diat. Belg. t. 68, f. 9, the right-hand figure). 



Genus HANTZSCHIA Grun. 



43 Hantzschia amphioxys (Ehrenb.) Grun. 



Long. 56 fj. ; lat. 8.6 //. 

 Hah. Lake on west side of McMurdo Sound. 



Var. capitellata Grun. in Cleve et Grun. " Arctisch. Diat.," K. Sv. Vet. -Akad. 

 Handl. Bd. 17, No. 2, 1880, p. 103. 

 Long. 72 M ; lat, 13 n. 

 Hal>. In pond, Cape Royds. 



44 Hantzschia elongata (Hantzsch) Grunow 



H. Amphioxys var. elongata Grun. in V. Heurck, Synops. Diat. Belg. t. 26, f. 21-24. 



Long. 168-190 /* ; lat. 9.5-11 M; carin. punct. 7-8 in 10 /u. 



Hob. Clear Lake. Lake on west side of McMurdo Sound, very common. 



SURIRELLACE.E 



Genus SURIRELLA Turpin. 



45 Surirella angusta Kiitz. 



Long. 29 M ; lat. 9.3 /x ; costaa 6 in 10 M. 

 Hub. In pond, Cape Royds. 



BEIT. ANTAECT. EXPED. 1907-9. VOL. I. il 



