FLAGELLATE PROTOZOA (MASTIGOPHORA) 



269 



198 (19s) Protoplasmic processes connecting cells usually distinct. Poles 



of colony not differentiated by arrangement of vegetative 

 and gonidial cells. . Volvox Leeuwenhoek . . 199 



199 (204) Colonies with distinct protoplasmic processes connecting the 



cells 200 



200 (203) Protoplasmic processes very stout. 



201 (202) Colonies dioecious. 



Volvox perglobator Powers 1908. 



Colonies often exceeding i mm. in diameter. Ova or 

 oosperms not infrequently numbering several hundred in a 

 colony. Very common in the United States. 



Fig. 452. Volvox perglobator. Colony with eight daughter coenobia. 

 Cilia and protoplasmic processes not shown. X so. (From a 

 prepared mount). 



202(201) Colonies monoecious. . . . Fo/iiox gfoJator Leeuwenhoek 1788. 



The common European species. About one-half the size of the preceding species, and con- 

 taining fewer reproductive cells. This species probably occurs in the United States but, if so, 

 in much less abundance than Vohox perglobator. 



203 (200) Protoplasmic processes slender. . Volvox aureus Ehrenberg 1838. 

 A typical European species but probably occurring in the United States also. Diameter 



about 850 li. 



204 (199) Colonies apparently without protoplasmic processes connecting 



the cells Volvox spermatosphara Powers 1908, 



Monoecious forms with ripe sperms arranged in bundles 

 of 32, grouped in sperm spheres in the colonies Mature 

 colonies often exceed 600 ix in diameter. Widely dis- 

 tributed in the United States. 



Fig. 453. Volvox spermatosphara. Colony with two daughter 

 coenobia, five egg cells, and one sphere of sperm bundles, 

 X 80, (From a specimen.) 



205 (132) Usually with an outer membrane or shell in the form of plates; 



body usually furrowed; fliagella two. Usually colored. 



Subclass Dinoflagellida . . 206 



206 (209) Without a membrane around the body 207 



207 (208) Cross furrow extending only around the left side; a longitudinal 



furrow extending from the central end of the cross furrow to 

 the under part of the body Hemidinium Stein. 



