504 
U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY-GENERAL REPORT. 
List of specimens . 
SIGMODON BERLANDIERI, Baird. 
Sigmodon Berlandieri, Baird, Pr. A. N. Sc. Phila. VII, April, 1855, 333. 
? ? Arvicola texiana, 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. Claws weaker 
than in S. hispidus. 
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 anti¬ 
tragus well developed ; the surface of the ear with 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 with 
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 the 
second extends to the end of the bulb of the third, that of the fifth barely to the base of the claw of 
