118 MAMMALS OF THE PACIFIC WORLD 



to thirteen inches long. They are found only in the north of 

 Australia. The only other large rats of northern Australia are 

 the mosaic-tailed rats (Uromys), already mentioned as having 

 headquarters in New Guinea. 



Lesser Rabbit Rats (Conilurus) are easily separated from 

 the preceding. The color above is blackish brown or dark gray 

 instead of reddish brown with touches of creamy buff. The 

 underparts are white. In total length they are about fifteen 

 inches, with a tail about eight inches. They are found in north- 

 ern Australia ; one race has been recorded in the extreme south 

 of New Guinea. 



Nest-building Rabbit Rats (Leporillus) are soft-haired, gray 

 rats with large ears and white feet, marked with darker gray 

 in one species. They are noted for making large nests, which 

 may reach a height of three feet and a diameter of four, by 

 weaving twigs together, using a growing bush for the frame- 

 work. Several entrances are provided. In the center is the 

 brood chamber, lined with soft materials. These rats are lim- 

 ited to the southern parts of Australia. 



Australian Kangaroo Rats {Notomys) superficially resemble 

 the kangaroo rats of the western United States, although they 

 belong to a wholly different family of rodents. The hind legs 

 are similarly elongated and kangaroo-like, and the long tail 

 bears a tuft of hair at the end. In one species a throat pouch 

 is present. The size is small: the total length is from eleven to 

 fourteen inches, with the tail occupying from six to nine inches. 

 The distribution includes most of Australia. 



Water Rats. Subfamily Hydromyin^ 



The Australo-New Guinean Water Rats {Hydromys, Lep- 

 tomys, Pseudohydromys, and others) have basined cheek-teeth, 

 with few cross-ridges, and the infraorbital canal of the skull is 

 wide, not slit-like as in the other rats. With the exception of 

 Leptomys and the newly discovered Baiyankamys of New 

 Guinea, these rats have only two molars in each jaw. As the 



