COLLECTED IN THE SOUTH ORKNEYS. 323 
with or without cilia) containing a considerable number (eight or more) of 
protoplasmie units, each with a pyrenoid (fig. 36); such individuals may 
possibly have been forming gametes. The prominent beak at the point of 
origin of the cilia, described and figured by Wille, was often difficult to 
recognize, On the other hand, in a few cases there was a very pronounced 
A. Chiamydomonas nivalis (Sommerfelt), Wille, resting-cells from the red snow (х 900). 
B. Navicula muticops's, Van Heurck, outline of an individual from sample 11 to 
show shape (X860). С. Chlamydomonas sp., resting-cells from the red snow (cf. pp. 921, 
324) (х900). D. Resting-cells from the yellow snow (cf. p. 318) (x 700), Е. Micro- 
cystis merismopedioides, F. Е. Fritsch (cf. p. 332) : upper figure, surface-view of colony 
( x 900) ; lower figure, typical colony of the same (x450). Е. Spherocystis ера бет, 
Chod., Ё nivalis, п. f., from the yellow snow (X450). G. The same, showing division 
of cells of colony (X700). H. Cælastrum microporum, Nüg., f. irregulare, F. E. Fritsch 
(cf. р. 328) (x 900). | 
development of this beak (fig. 40) in the form of а rounded. protrusion, from 
the base of which the cilia arose. Apart from these peculiarities the 
Antarctic form showed all the features described by Wille, viz. ribbing of 
the basin-shaped choroplast, an elongated stigma (rarely visible), contractile 
vacuoles, ete. 
2. CHLAMYDOMONAS EnnENBERGIL, Gorosch. in Bull. Soc. imp. d. Nat. de 
Moscou, 1890, no. 3, pp. 128-131, pl. 3. figs. 10-25. 
Samples 10 and 11, common. 
Probable zvgospores observed in sample 11. 
