16 F. E. FRITSCH. 
In view of the method of reproduction above described, this species should 
perhaps be referred to the genus Chlorella; it shows some resemblance to species like 
Chlorella conglomerata (Artari) Oltmanns (= Pleurococcus conglomeratus Artari) and 
C. regularis (Artari) Oltmanns (=P. regularis Artari). 
10. PLEUROCOCCUS DISSECTUS. 
Pleurococcus dissectus (Kiitz.) Niigeli, Gatt. eimzell. Algen (1849), p. 65, Tab. IV., E, fig. 8. 
Hab.—Freshwater pond upon ice among eskers, four miles north of Black 
Island, McMurdo Strait, September 12th, 1902; Gap pond, Winter Harbour, 
December 15th, 1903. 
Isolated cells or flat strata on the surface of Phormidiuin, as recorded by 
(iy Ay A 
Messrs. West (op. cit., p. 277).* 
PRASIOLACEA. 
Genus PRastoLa Ag. 
11. PRASIOLA CRISPA. 
(Text-figures A—D.) 
Prasiola crispa (Lightf.) Menegh.; Kiitzing, Phycol. gener. (1843), p. 295; Rabenhorst, Flor. europ. 
algarum, 11. (1868), p. 308. 
Hab.—Damp spot, summit of Cape Adare (1000 feet), January 9th, 1902; 
under boulder, fifty feet above sea, Cape Adare, January 9th, 1902; probable 
developmental stages common among the Cyanophyceous sheets from the Gap pond, 
Winter Harbour, ete. 
There can be no doubt that this is a common form in Antarctic regions (previously 
recorded by Hooker and Harvey, Wille, Fritsch, W. and G. 8. West, ete.), as the 
frequency of the characteristic packets of cells throughout the material demonstrates. 
The only mature thalli were obtained from the summit of Cape Adare, while the 
material from beneath a boulder fifty feet above sea-level at the same locality 
consisted almost entirely of the //ormidium-stage. 
The expanded thalli were irregularly folded and bullate, the cells showing 
ordinarily a very regular arrangement in groups of 16 or 32, separated by slightly 
wider interspaces (text-figure B). The dimensions of the cell-contents were 
6-7°5 xX 4-5 p in surface view and 11 yw deep in section. At other points in the thalli, 
where a formation of the cell-packets serving for reproduction was taking place, the 
arrangement becomes far more irregular, the characteristic grouping being sometimes 
almost completely lost. As stated in an earlier paper (Fritsch, op. cit., p. 331), this 
* A form resembling Protoderma was observed on the Phormidium-sheets in one of the samples from the 
Gap pond, Winter Harbour, but too little of it was seen to admit of determination. 
