ORDER RODENTIA. 139 



dentition ; and the allocation of the animal among the Ham- 

 sters, must, therefore, still be considered conditional. We 

 have engraved a figure of it from our collection of drawings, 

 but are not able to add anything, either on the subject of 

 its physicalities or habits. Its superficial specific characters 

 are detailed in the Table, as are those of the Chinchilla, a 

 beautiful little animal, presumed to belong to the division 

 of Hamsters. 



The Anomalous Hamster (Mus Anomalies, Thompson) 

 must be considered also as placed conditionally only among 

 the Hamsters by the character of the cheek-pouches ; but 

 another peculiarity equally, or still more observable, con- 

 nects this species with the Echimys, or Spiny Rats, which is 

 the flattened spines or prickles, particularly on the back. 



We are indebted to Mr. Thompson for a first notice of 

 this animal, which was found in the Isle of Trinity, where, 

 however, it is very scarce. It is about the size of the com- 

 mon Rat, but the nose is more pointed ; the ears are naked, 

 round, and of moderate size : the pouches are formed by a 

 duplicature of the common tegument, like the pouch of the 

 Opossum, and are of considerable size. The body is co- 

 vered with fine lance-shaped spines, stronger on the back 

 than elsewhere, intermixed with hair. The Table will sup- 

 ply its other known characters. 



It is obvious that this species differs perhaps generically 

 from the other Hamsters, with which, indeed, it seems to 

 have no other relationship than by the cheek-pouches. Ex- 

 teriorly it has the appearance of the Echimys ; nor does it 

 seem to be quite satisfactorily shown that these latter ani- 

 mals are destitute of a similar pouch; the Mus Anoma- 

 lus may, therefore, in fact, be an Echimys proper, or a 

 pouched modification of that subgenus of Rodentia. In 

 the absence of more certain premises, it seems premature 

 to separate it otherwise than specifically ; we have, there- 

 fore, in this, as in numberless other instances, followed the 

 stream, and placed it conditionally with the Hamsters. 

 III. * 



