152 FAUNA AMERICANA. 



The molars, to the number of eight in each jaw. 

 penetrate to the base of their respective alveoles 

 without any division into roots ; their crowns are 

 simply discoidal, transversely oblong-oval, mar- 

 gined by enamel, but which is not elevated into 

 crests or dividing ridges; the anterior tooth is 

 double, in consequence of a profound duplicature 

 in its side, so that its crown presents two oval 

 disks, of which the anterior one is smallest. The 

 molars of the upper jaw incline obliquely back- 

 wards ; those of the lower jaw obliquely forwards. 



Head and body large, so as to produce a clumsy 

 aspect; cheek pouches voluminous, exterior to the 

 mouth, from which they are separated by the com- 

 mon integuments ; they are profoundly concave, 

 opening downwards and towards the mouth. 



Legs short ; fore feet large ; hind feet small ; 



(Say.) 



This animal is, with great propriety, separated 



from the genus Cricetiis, (hamster,) Lacep. Cuv. 

 Geoff. Illig. from which it differs in the following 

 particulars. 



1. In having four molar teeth on both sides of 

 each jaw. 2. In having five toes to the anterior 

 feet. 3. In the form of the crowns of the molar 

 teeth, which are tuberculous in the Cricetus^ and 

 plane in the Pseudostoma. 4. In the length of the 

 elongated nails on the fore feet. ,5. In its enor- 

 mous cheek pouches, and in other particulars to 

 be observed in the description. 



