166 



Order RODENTIA 



ORYZOMYS PALUSTRIS (Harlan) 



Rice Rat 



Description. — The rice rat, fig. 92, is a third to half the size 

 of the Norway rat and has a tail slightly shorter than the body. 

 It is grayish brown on the upper parts and silvery gray on the 



Fig. 92. — Rice rat. 



under parts. The upper side of the tail is the same color as the 

 back of the animal and the lower side is only slightly lighter. 

 The fur of the under parts oi the animal is soft and woolly. In 

 general, the rice rat closely resembles the Norway rat, but the 

 light color of the under parts, including the under side of the 

 tail, is distinctive. 



Length measurements: head and body 4- ; 4-5 1 > _> inches (120- 

 140 mm.); tail 4]4~5y 2 inches (110-140 mm.); over-all 9-11 

 inches (230-280 mm.); hind foot II4 inches (30-33 mm.). 



The skull of the rice rat is 30-33 mm. (about II4 inches) long 

 and has supraorbital ridges along the lateral margins of the 

 braincase. In this rat, the cusps on the upper cheek teeth are 



