48 



MAMMALOGY. 



" Total length, six and one-eighth inches, including the tail, which 

 is one and a half inches long. 



" Our specimen was obtained on the 4th of October, near the 

 head waters of the Sacramento River, in California." 



5. Genus PEROGNATHUS, De Wied. 

 Crlcetodipus, Peale, Zool. Exp. Exp. Mamm. p. 52* (1st ed. 1848). 



1. Perognathus parvus (Peak). 



Cn'cetodipus parvus, Peale, Zool. Exp. Exp. Mamm. p. 53 (1st ed. 1848). 



A single specimen of this species is in the collection, which, having 

 remained in spirits for a length of time, very probably sufficient to 

 affect its colors, we deem it most proper to transcribe the description 

 by Mr. Peale : 



" Head ovate ; the snout elongate, pointed, and covered with hair, 

 excepting the nostrils, which are small and convolute ; lips large, 

 tumid, and covered with short hairs ; whiskers numerous, wdiite ; a 

 tuft of white hairs or bristles on the chin ; cheek-pouches spacious, 

 opening outside of the mouth, and reaching from the upper lip to the 

 throat, the cavity extending backwards to the ears, and lined with 

 hair ; eyes medium-sized ; ears small, round, and fringed with hairs ; 

 fore legs small; the feet moderate, margined with bristly hairs; the 

 nails short, curved, excepting that of the thumb, which is orbicular, or 

 resembling the human thumb nail; hind legs long; the feet larger and 

 strong, tive-toed, the middle one slightly longer than the rest, inner 

 toe shortest, reaching only to the end of the metatarsal bones of the 



* " Head and body nearly equal in size ; spacious cheek-pouches outside of the mouth ; 

 upper cutting teeth small, narrow, incurved and channelled longitudinally on the ex- 

 terior; lower cutting teeth narrow, rounded, and approximating at the points; molars 

 with six rounded tubercles on each; ears small, rounded; eyes medium sized; fore legs 

 small, feet with four toes and a thumb, the latter having a flattened nail ; hind legs 

 large, strong, the feet having five long toes, each with a distinct metatarsus, tail longer 

 than the head and body. 



"Dental formula: incisors, |; canines, g J] ; molars, | |=16." (Peale, as above.) 



