Protococcacece 



233 



outer surface of the cell. There is a parietal chloroplast con- 

 taining one pyrenoid. Multiplication normally takes place by 

 autospores, but also by simple vegetative division, and reproduction 

 by quadriciliate zoogonidia has been observed by Chodat. 



G. radiata Chodat 1 is known from Surrey ; diarn. of cells 10 15 //. ; length 

 of bristles 2545 /z ; fig. 102 I) and E. G. paucispinosa West & G. S. West 2 

 is known from the plankton of Lough Neagh, Ireland ; diam. of cells 15 16 p. ; 

 length of bristles 16 /*; fig. 102 F. 



Fig. 102. A, Ricliti'i-iella botryoidcs (Schm.) Lemm., after Lemmermann, x 520. 

 B and C, R. botryoides forma quail risetti (Lemm.) Chod. ; B, from the plankton 

 of Lough Beg, Ireland (x450); C, after Lemmermann ( x 520). D and E, 

 Golenkinia radiata Chod., after Chodat ( x about 800). F, Golenkinia pauci- 

 W. & G. S. West, from the plankton of Lough Neagh, Ireland ( x 450). 



Genus Richteriella Lemmermann, 1896. The cells are spherical 

 and generally aggregated to form loose ccenobia of 8, 16, 32, or 64 

 cells. The cell-wall is thin and firm, and is furnished with long, 

 radiating bristles attached only to those surfaces of the cells which 

 face outwards. There is a single parietal chloroplast with one 

 pyrenoid. Multiplication has only been observed to take place by 

 vegetative division. This genus only differs from Golenkinia in 

 the aggregation of the cells and the fact that the bristles are more 

 or less confined to the exposed surface of each cell. 



1 Chodat in Morot, Journ. de Bot., Paris, 1894, p. 305, t. iii. 



2 West & G. S. West in Trans. Koy. Irish Acad. xxxii, sect. B, part i, 1902, 

 p. 68, t. i, f. 18. 



