FEB8HWATER ALGiE. 11 



" Eondane " in Norway, where it was found on snow. The Antarctic individuals, like 

 those described by Wille, lacked all traces of a pyrenoid. The nucleus (figs. 21-25) 

 was prominent and situated in the centre of the cell, in which respect the specimens 

 differed from those described by Wille {cf. however, his fig. 25, where the nucleus 

 appears to be quite central). Numerous discoid chloroplasts were frequently 

 recognisable in the cells, and in some cases a slightly elongated stigma could be made 

 out, not far from the bases of the cilia (figs. 21, 25). Some of the individuals were 

 practically devoid of starch, while others contained a considerable amount. The cilia 

 were so delicate that in some of the individuals it was only possible to trace them a 

 very short way, but they appeared in general to be a little longer than the body of the 

 cell (fig. 21). 



Some of the individuals were _^of a more elongated form than those described and 

 figured by Wille (long. cell. = 13 ju. ; lat. cell. = 6 )u,, figs. 23, 24), but in view of their 

 resemblance to the type in other respects, I do not think that they belong to a different 

 species. 



PROTOCOCCACE^. 



Genus Troohisoia Kiitz. 



5. Trochiscia crass a. 



Trochiscia crassa Hansg., Physiol, und Algol. Mitteil. (1890), Tab. I. ; Prodr. d. Algenfl. v. 

 Bohmen, ii. (1892), pp. 240-241. 



Diam. cell. = 50-55 /a. Cell-wall deep brownish-red, opaque. 

 Hah. — (jrranite 'Harbour, freshwater pond, January 20th, 1902. 



ULOTRICHACE^. 

 Genus Ulothrix Kiitz. 



6. Ulothrix subtilis var. variabilis. 



Ulofhrix subtilis Kutz., Phycol. Germ. (1845), p. 197 ; Tab. Phycol. ii. (1852), Tab. 85, fig. 1. 

 Var. varialilis (Kiitz.) Kirchner, Alg. Schlesien (1878), p. 77. 



Crass, fil. = Q-7 ju. ; cells one and a half times or twice as long as broad. 



Hob. — Freshwater pond in ice off " Black Island," McMurdo Strait, December 31st, 

 1902 ; Gap pond, Winter Harbour, December 15th, 1903 (in both cases on surface 

 of Phormidium). 



This form was not common. 



