432 



ROTIFERA. 



Fig. 224. 



CHAPTER XV. 



ROTIFERA* (Ehrenberg). 



(1117.) THE class of animals that next presents itself for our con- 

 sideration was, until very recently, confounded with the chaotic assem- 

 blage of minute creatures to which the name of Infusorial Animalcules 

 was indiscriminately applied ; but the information at present in our pos- 

 session concerning their internal structure and general economy, while 

 it exhibits in a striking manner the assiduity of modern observers and 

 the perfection of our means of exploring microscopic subjects, enables 

 us satisfactorily to define the limits of this interesting group of beings, 

 and assign to them the 

 elevated rank in the scale 

 of zoological classification 

 to which, from their supe- 

 rior organization, they are 

 entitled. 



(1118.) The character 

 whence the class obtains 

 its name is derived from 

 the peculiar organs placed 

 upon the anterior part of 

 the body, which are sub- 

 servient to locomotion, and 

 assist in the prehension 

 of food. These consist of 

 circlets of cilia variously 

 disposed in the neighbour- 

 hood of the mouth, and 

 having, when in action, the 

 appearance of wheels spin- 

 ning round with great ra- 

 pidity, so as to produce 

 strong currents in the 

 surrounding water. 



(1119.) The annexed 

 engraving of the Stephano- 

 ceros Eichhornii-t (fig. 224) 

 exhibits an animal that would seem to be one of the connecting links by 



Stephanoceros Eichhornii (after Ehrenberg) : a, pharynx ; 

 b, stomachal cavity ; c, ova contained in the ovary ; d, re- 

 tractile muscle; e, gizzard, containing the masticatory 

 apparatus; /, rotatory organs, resembling those of a 

 Bryozoon. 



Rota, a wheel ; fero, I bear. 



Ehrenberg. 



