56 



THOUGHTS ON ANIMALCULES. 



jaws of the Rotifer (ligns. 1 and 6) and of the Floscu- 

 laria, (hgn. 5, fig. 1). 



LiGN'. 6. — Jaws and Teeth of the Rotifer, highly magnified. 



In other species, with the same type of masticatory 

 apparatus, the jaws are furnished with several teeth; 

 as in the Stephanoceros, or Crowned Animalcule, in 

 w^hich there are two distinct sets of teeth on each side. 



as shewn in the annexed figures. 



J 2 



LiGN. 7. — Jaws and Teeth of the Stephanoceros, highly magnified. 



Fig. 1. The Upper Set of Teeth, marked a, in fig. 2. 



Fig. 2. Tlie Double Set of Dental Organs, iu their natural position. 



Fig. 3, The Lower Set of Teeth, marked h, in fig. 2. 



Respiration, or, more properly, the aeration of the 

 fluids, is effected in the Rotifei'u by the constant in- 

 troduction of fresh water tlirough one or more aper- 



