138 KAARE MÜNSTER STRØM; 



• Order Protococcales. 



Family Protococcaceæ {= Pleurococcaceæ Wille). 



Genus Protococcus Ag. 



53. Protococcus viridis Ag. (= Pleurococcus vulgaris auet.) 

 Wiadikaokas — Kasbek. 



54. Protococcus sp. Pl. II, Figs. I— 10. 



This peculiar Protococcus occurred in abundance in a sample 

 from Pjatigorsk, associated with Ulothrix variabilis and 

 Stichococcus bacillaris. The cells are brick-red in colour, the 

 chlorophyll being covered with hæmalochrom. The chromoplast 

 is cup-shaped and without pyrenoid. The cells are of very 

 variable form and size, they may be solitary, and then often 

 forming thick-walled resting cells, but offener they form 

 groups with up to six cells in each. 



Family Scenedesmaceæ. 

 Genus Scenedesmus Meyen. 



55. Scenedesmus acutus Meyen. 

 Wiadikaokas — Kasbek. Abundant. 



Family Oocystaceæ. 

 Genus Chlorella Beyerinck. 



56. Chlorella vulgaris Beyerinck. 

 Kasbek — Mleti; diam. cell. Ç> ß. 



Family Palmellaceæ 

 Genus Coccomyxa Schmidle. 



57. Coccomyxa dispar Schmidle. 

 Askabad; Kasbek — Mleti. 



