604 



U. S. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



List of specimens. 



1 13 specimens. 



9 specimens. 



SIGMODON BERLANDIERI, Baird. 



Sigmadan Berlandieri, BAIRD, Pr. A. N. Sc. Phila. VII, April, 1855, 333. 

 ??Arvicola teziana, AUD. & BACH. N. Am. Quad. Ill, 1853, 229; pi. cxlvii, f. 2. 



SP. CH. Tail equal to or longer than the trunk. Color above, grayish yellow brown, lined with black, 

 than in S. hispidtu. 



Claws weak* r 



This species is about the size of S. hispidus, though perhaps more slender, and with a longer 

 tail. The ears are large and rounded, projecting beyond the long hairs of the head ; the ant - 

 tragus well developed ; the surface of the ear vifch short close hairs. The whiskers are about 

 the length of the head. The tail is nearly equal to the trunk in length; it is covered \vi<h 

 narrow annuli not concealed by the few hairs which spring from between them at regular 

 distances ; they are narrower and more numerous in a given space than in S. hispidus, and less 

 concealed by the hairs. The third finger is longest, the fourth scarcely shorter ; the claw of tlie 

 second extends to the" end of the bulb of the third, that of the fifth barely to the base of theclaw of 



