452 



BULLETIN 5(5, UNITED STATES NATIONAL MUSEUM. 



scantily haired, not distinctly dusky above. Iris hazel. Length. 275 

 mm.; tail vertebrae, 130; ear from crown, 15; hind foot, 33. Skull, 

 20 by 35 mm. in greatest dimensions. Nasal bones slightly expanded 

 apically so as to produce a somewhat spatulate extremity. (Fig. 113.) 



Fig. 113.— Sigmodon hispidus eremicus. Skull of type, a, dorsal view; b. ventral view; 



C, LATERAL VIEW. 



Habits and local distribution. — The Western Desert cotton-rat was 

 found in abundance on both sides of the Colorado River from Yuma 

 to the Gulf of California. It was most numerous about beds of wild 

 hem]) which grow luxuriantly upon the broad savannas bordering the 

 Colorado about the mouth of the tributary called the Hardy River 

 or Hardys Colorado. On the Colorado Desert, where it lives in dense 

 growths of arrowwood, this species extends along the Salton River 

 as far as Seven Wells, in Lower California, becoming gradually scarce 

 as the stream recedes from the Colorado River. Four females, taken 

 March 24 and 25, 1894, would have given birth to four young each. 



Measurements of 48 specimens of the genus Sigmodon. 



a See also p. 453. 



b'Type. 



■ American Museum of Natural History. 



