1294 THE RODENTS 



THE PHILIPPINE RAT 

 Genus Phl&omys 



The Philippine islands are the habitat of a peculiar species of rat (Phl&omys 

 cumingt), which differs so markedly from all others that it must be regarded as con- 

 stituting a subfamily by itself. While having the ordinary murine form, these rats re- 

 semble the gerbils in having their molar teeth divided into transverse laminae, of which 

 there are three in the first tooth of the series, and two in each of the others. The 

 incisor teeth are very broad, with smooth front surfaces. The muzzle is unusu- 

 ally short, the profile convex, and the ears rather small; while the feet are char- 

 acterized by their great breadth, and the large size of their claws. The tail is 

 shorter than the head and body, and sparsely haired. The hair is rather long and 

 coarse, and darker on the muzzle, the sides of the face, the back of the head, the 

 shoulders, and the fore-part of the back than elsewhere. 



THE HAMSTERS AND WHITE-FOOTED MICE 

 Genus Cricetus 



The well-known hamsters of the Old World, together with the American 

 white-footed mice, constitute an extensive genus of murine Rodents, which, with 

 others, represents a distinct subfamily. These Cricetines, as all the members of the 

 subfamily may be called, are characterized by the crowns of their molar teeth carry- 

 ing a number of distinct tubercles or cusps, which in the upper jaw are arranged in 

 two longitudinal rows separated by a median groove; these teeth being always im- 

 planted in the jaw by distinct roots. The whole of the Old -World Cricetines are 

 characterized by the shortness of their tails, but in some of the American forms 

 these appendages are considerably longer. The Cricetines are distributed nearly all 

 over the world, with the exception of Australia, and include the only representa- 

 tives of the Rodent order found in Madagascar. In structure they appear to be the 

 most generalized group of the entire Murine family, and it is accordingly believed 

 that they represent the ancestral stock from which came the more specialized 

 rats and mice constituting the Murine subfamily. This hypothesis is supported by 

 the circumstance that the hamsters are some of the oldest types of the family with 

 which we are acquainted, their remains being comparatively common in the Miocene 

 strata both of Europe and North America. 



The common hamster {Cricetus frumentarius) , of Europe and 

 '"p? 10 n t Northern Asia, is the typical representative of the genus under consid- 

 eration; the leading characteristics of the genus being that the incisor 

 teeth are not marked by grooves, while the first upper molar tooth generally has 

 six tubercles on its crown. Cheek pouches, which may be of large size, are 

 frequently present, and the tail is often very short. 



The hamster itself is a decidedly handsomely-colored Rodent, and is by far the 

 largest member of the group, measuring about a foot in length, of which some two 



