4-22 



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



List of specimens. 



i The second line of measurements contains such as were made before the animal was skinned. Width of head, .75 ; length of cheek pouches, 

 .80; fore claw, .17; hind claw, .11; length of opening of cheek pouches, .55; depth of do., .67. 



The second line of measurements contains such as were made before the animal was skinned. Width of head, .75; length of cheek pouches, 

 .80; fore claw, .17; hind claw, .11. 



PEROGNATHUS MONTICOLA, Baird. 



SP. Cu. Antitragus lobccl ; soles naked. About as large as the domestic mouse. Tail rather shorter than the head and 

 body, fully coated with hair. Hind feet rather short. Color above mixed cinnamon and dusky ; flanks scarcely clearer, 

 beneath white ; tail colored to correspond with these regions. Hairs below as well as above, plumbeous at base, those above 

 exhibiting this color for nearly two-thirds their length. Outside of fore leg dusky to the wrist. 



The specimen of this species, collected by Dr. Suckley, is about the size of a common mouse 

 Mus musculus, to which it bears no inconsiderable resemblance, though readily distinguished 

 by the grooved incisors, external cheek pouches, and small ears. The snout is acute and entirely 

 hairy, except the septum and the inner margin of the nostrils. The whiskers are longer than 

 the head, and principally white, though the longest are black at the base. The ears are 

 moderate, not much larger than the orbit , subtriangular ; the exterior face naked except on 

 the posterior half ; the margins and inner surfaces coated with short stiff hairs. The tail is 

 about as long as the body, everywhere densely hairy without showing the murine scaly rings ; 

 there is a slight elongation of the hairs towards the tip. The claws of the fifth or outer fingers 

 and toe reach to the bases of those of the fourth, respectively, next them. 



The upper parts of body and sides with the outside of the arm and leg are of a mixed 

 cinnamon and black, the individual hairs being clear plumbeous for nearly the basal two-thirds, 

 then cinnamon with a slight tip of black ; the belly is dull whitish, the boundary between the 

 two constituted by a tint of clear whitish cinnamon. There is a considerable mixture of black 

 hairs on the cheek and top of the head ; though the orbital region and lower part of the cheeks 

 are yellowish brown. The inner surface and margin of the ears are cinnamon ; the hairy 

 portion of the exterior with the inflexed portion dusky ; the lighter margin showing very 

 distinctly behind this. The feet are dull whitish, the lower part of the legs suffused with 

 cinnamon. The upper part of the tail is like the back, the lower like the belly, and the sides 

 have the same cinnamon tint of the flanks. 



