CXVIU DIV. IV. — RyvDIATA. 



CLASS v.— INFUSORIA. 



Microscopic animals, in general of extreme simplicity of organ- 

 ization. Some of the genera, however, appear to be more compli- 

 cated, thongh the details of their organization escape the deepest 

 powers of tlie microscope. 



The class is divided into two orders. 



Class. Order. 



Rotifera. 



Infusori 



^'•\± 



Homoffenea. 



ORDER I.— Rotifera. 



Body oval and gelatinous ; a mouth, stomach, intestines, and 

 arms have been observed. The mouth or head is surrounded by 

 denticulated lobes, which vibrate with great rapidity, and present 

 the appearance under the glass of a revolving wheel. 



Genus. Subgenus. Example of Species, 



Furcularia < 2. Trichocerca, Lam. . . Tri. paxillum, Miill. 



V. 3. Vaginicola, Lcim. ..Tri. innata, Miill. 



Tubicolaria, Lam. Vorticella tetrapetala 



Brachionus, Miill. 



