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



List of specimens. 



> Measured before skinning. 



* Collected by W. Stimpson. 



There is a small mouse, described by Audubon and Bachman, under the name of Mus caroli- 

 nensis, which appears different from Reithrodon humilis, but in the grooved incisors seems to 

 belong to the same genus. They mention it as existing very sparingly in the maritime districts 

 of South Carolina, and found usually in low grounds, partially inundated. The description is 

 as follows : 

 REITHRODON CAROLINENSIS. 



Mus carolinensis, AVD. & BACH. J. A. N. Sc. Phil. VIII, n, 1842, 306. IB. N. Am. Quad. Ill, 1854, 332. 

 Hesperomys earolinensis, WAGNEB, Wiegm. Archiv, 1843, n, 61. 



Sf. CH. Upper fore teeth slightly grooved ; tail, half an inch longer than the body ; ears long ; color, light plumbeous; 

 under parts and hind feet scarely lighter 



Point of nose, lips, chin, fore feet, and nails, white ; whiskers, dark brown. A narrow fawn- 

 colored ring round, the eye. Ears, legs, and tail, light ashy brown. Fur on the back and sides 

 uniform light plumbeous ; the under surface scarcely a shade lighter. 



The grooved incisors distinguish this species from the common mouse, and the Hesperomys 

 leucopus; from the other North American Reithrodons the dark color of the belly and hind feet 

 constitute a decided characteristic. 



