THE MALABAR SPINY MOUSE THE GERBILS 1291 



cept for its terminal fifth, which is flaxen colored, the tail is black. The tip of the 

 muzzle is thickly covered with hair, by means of which the nostrils can be closed. 

 The length of the head and body is about two feet, and that of the tail half as 

 much. The skull differs in the form of the front portion of the cheek arch from 

 the ordinary murine type. This species is confined to Australia and Tasmania, 

 where it is known to the colonists as the beaver rat. It is thoroughly aquatic 

 in its habits, and is not uncommon on the banks of the rivers; while it is at times 

 seen on the seashore. It is an inhabitant of Australia, Tasmania, and New Guinea. 

 The Queensland rat (Xeromys myoides] is a terrestrial species of about double 

 the size of an ordinary mouse, which, while possessing teeth like those of the Aus- 

 tralian water rat, has unwebbed toes and the external form and skull of a mouse. It is, 

 therefore, of interest as serving to connect its aquatic cousin with the more typical 

 members of the family. 



THE MALABAR SPINY MOUSE 

 Genus Platacanthomys 



The pretty little murine known as the Malabar spiny mouse {Platacanthomys 

 .lasiurus) , from elevations of about two thousand feet in the hills of Southern India, 

 is interesting as being one of the few members of the family which assume a 

 dormouse-like appearance and have arboreal habits. It represents a subfamily by 

 itself, characterized by the crowns of the molar teeth when worn showing oblique 

 and nearly parallel bands of enamel, and by the long tail being thickly haired. 

 This little mouse has long, pointed ears, and a number of broad flat spines mingled 

 \vith the hair of the upper parts. In color it is reddish brown above, and white 

 beneath; the length of the head and body being four and one-half inches, and that 

 of the tail, with the hair at the end, half an inch more. This mouse lives in large 

 trees, in which it hollows out small cavities that it fills with leaves and moss. It is 

 stated to feed on jack fruit and the pods of the pepper tree. 



THE GERBILS 

 Genus Gerbillus 



The elegant little Rodents commonly known as gerbils constitute the typical 

 representatives of a third subfamily, and are easily recognized by their elongated 

 hind-limbs, long and hairy tails, and their general jerboa-like appearance and 

 habits. Indeed, they might be mistaken at first sight for mem- 

 bers of the latter group; but a close examination will show that 

 they differ externally by their longer muzzles, smaller eyes, and 

 the presence of five functional toes to the hind-feet. They are 

 further distinguished by their molar teeth being divided into 

 transverse laminae, of which there are three in the first, two in 

 the second, and one in the third tooth of each side. The upper 

 incisor teeth are narrow and grooved, and the bullse of the I.OWER JAW AND 

 auditory region of the skull are generally very large. The true TEETH OF GERBII,. 



