154 



FRESH-WATER BIOLOGY 



145 (144, 146) 



143 (147) Cells spherical 144 



144 (145, 146) Cells solitary, membrane with short spines or network. 



Trochiscia Kiitz. 



Cells perfectly spherical, the spines or reticulate markings project- 

 ing but little. 



Chromatophores usually several. Reproduction by internal division. 

 West also reports reproduction rarely by fission and by zoospores. The 

 genus needs further investigation. 



FIG. 180. Trochiscia vestitus Reinsch. X about 260. (After Reinsch.) 



Cells solitary, bristles long, rigid, scattered over the entire 

 surface Golenkinia Chodat. 



Reproduction occurs by division in one or two directions and 

 by autospores. Chodat also reports the formation of zoogonidia 

 with four cilia. 



Golenkinia has been known to occur in great quantities almost 

 pure in large tanks of water; it also occurs in the plankton, 

 though not very abundantly. Chromatophore parietal, with one 

 pyrenoid. 



Sir Ray Lancaster believes that his Archerinia bolloni de- 

 scribed in 1885 and referred to the Protozoa is identical with 

 Golenkinia radiata described by Chodat in 1894, and with 

 Richteriella bo try aides described by Lemmermann in 1898. If 

 this be true the name Archerinia claims precedence over the 

 other two generic names. 



FIG. 181. Golenkinia radiata Chodat. X 625. (Original.) 



Cells in colonies of eight, sixteen, thirty-two, sixty-four, or 

 more cells; bristles long, only on the outer surface of a col- 

 ony Richteriella Lemmermann. 



Bristles comparatively coarse and in length many 

 times the diameter of the cells. Chromatophore single, 

 parietal, with a single pyrenoid. 



The cells are usually clustered in groups of four which 

 are aggregated into larger colonies. But little is known 

 of its reproduction except that vegetative division has 

 been known to occur. 



It is found in the plankton of large lakes. 



146 (144, 145) 



FIG. 182. Richteriella globosa Lemmermann. X 556. 

 Lemmermann.) 



(After 



147 ( J 43) Cells somewhat elongated 148 



148 (149, 150) Bristles four, two at each end or one at each end and two at 



the center, each with a basal swelling. . Lagerheimia Chodat. 



Cells ellipsoidal, with four spines on short pedicels. Chromatophore 

 single, parietal, with a single pyrenoid. Reproduction by internal 

 division. 



Chodat and West recognize the genus Lagerheimia but it is very doubtful 

 whether the presence of only four spines with basal swellings is sufficient to 

 remove it from the genus Chodatella where the spines are more numerous 

 and have not the basal swellings. 



FIG. 183. Lagerheimia genevensis Chodat. X 275. (After Chodat.) 



