PROrOCOCCOIDE^ 



413 



ovate or pear-shaped, o'02-o 025 mm. in diameter in the larger species, 

 often apiculate or spinous at the apex. The cell-contents divide, by 

 successive bipartitions, into zoospores, which commence swarming while 

 still within the mother-cell, indicating 'an approach 

 to Hydrodictyon. They escape through a lateral or 

 terminal fissure. Nearly allied to Characium are 

 Hydrocytium A. Br., also met with in fresh water, 

 and Hydriamim Rabh., found in similar localities. 

 In the last genus the zoospores also escape at the 

 apex. In Apiocystis Nag. a large number of gonids 

 are sparsely scattered through a stalked pear-shaped 

 gelatinous envelope attached to fresh-water algse. 

 They occur chiefly in the periphery, and are ulti- 

 mately converted into zoospores. 



Codiolum A. Br. is a club-shaped marine organism, about 0-04 mm. 

 in diameter, and four to six times the length, attached to rocks or sea- 

 weeds. It is propagated by zoospores, or, according to some observers, 

 also by resting hypnospores. Hauckia Bzi. (Nuov. Giorn. Bot. Ital., 



Fig. 340. — Characimji 

 ornitkocephalum A. 

 Br. (x 600). (After 

 A. Braun.) 



Fig. 341. — Apiocystis Brauniana 

 ( X 100). (From nature.) 



Fig. 342. — Codiolum gregarimjt A. Br. (magnified). 

 (After Hauck.) 



1880, p. 290) grows on rocks exposed to the sea. The gonids are placed 

 in pairs on a long hyaline stalk ; it produces zoospores of two different 

 sizes, but no process • of conjugation has at present been observed- 



