132 BOTANICAL RESULTS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 



55. MELOSIRA SOL, Kiltz. ; Van Heurck, Atlas, pi. xci., figs. 7-9. 



Sample 4 (red snow !) ; one short chain seen (living) ; previously recorded from the 

 Antarctic (Hooker and Harvey). 



56. COSCINODISCUS RADIATUS, Ehrb. (1838); Rabenh., Fl. Europ. Alg., i., 1864, 

 p. 34. 



Samples 4 and 6 (red snow !), isolated ; previously recorded from Kergueleii (Hooker 

 and Harvey). A small form (diam. valve = 40-60 M), otherwise agreeing with the 

 existing descriptions. 



57. TRICERATIUM, sp. 



Sample 4 (red snow !) ; only a single dead individual seen, but fragments of the 

 valves common. 



The single individual seen closely resembled Van Heurck's (Atlas, pi cxii., fig. 1) 

 and Wolle's (Diatomacese of North America, pi. cv., fig. 8) figures of T. arcticum, 

 Bright, in the character of the areolse (small at the three corners !) ; the general shape 

 was more that of T. repletum, Grev., var. balearica, Grun. (Van Heurck, Atlas, 

 pi. ex., fig. 7). 



58. SYNREDRA, sp. 

 Sample 11, rare. 



59. EUNOTIA GRACILIS, W. Smith, Brit. Diat., i., 1853, p. 16, and pi. xxx., 

 fig. 249. 



Sample 9, rather common. 



A form with but very slightly recurved ends ; length of valve = 22 M ; breadth = 2 M. 



60. COCCONEIS COSTATA, Greg., Trans. Micr. Journ., v., p. 68, pi. i., fig. 27. 

 Samples 9 and 10, rare. 



61. NAVICDLA BOREALIS (Ehrb.}, Kiltz. ; Van Heurck, Synopsis Diat., 1885, 

 p. 76, pi. vi., fig. 3. 



Samples 4 (rare), 9, 13, and 17, rather common ; previously recorded from Cockburn 

 Island (Hooker and Harvey). 



Length of valve 35-58 M; breadth 8-11 M. 



62. NAVICULA BRAUNII, Grun. ; Van Heurck, Synopsis Diat., 1885, p. 79, pi. vi., 



fig- 21. 



Sample 10, very rare. 



Length of valve = 37 M ; breadth = 12 /u. 



63. NAVICULA BREBISSONII, Kiitz., var. DIMINUTA, Van Heurck, Synopsis Diat., 

 1885, p. 77, pi. v., fig. 8. 



Samples 9, 10, 13, and 15, rather common. 



Length of valve = 20-34 M (rarely 45-47 M) ; breadth = 5-7 M. 



