PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 475 

 Actual measurements in inches of six specimens of Cricefodipus parvus (Baird) Coues. 



If this table be examiiied, it will be perceived that in C- parvus (1) 

 the head is longer by one-tenth inch than in G. flavus^ and that (2) the 

 eye is decidedly nearer the ear in the former species than in the latter. 

 Fnrthermore, it appears that in G. jjarvus (3) the tail is always longer 

 than the head and body, averaging about half an inch more ; and that 

 (4) the length of the hind-foot approximates closely to one- third that 

 of the head and body, sometimes exceeding one-third. The hind-foot 

 of G. parvus it will be observed does not average quite as much as Dr. 

 Coues was led to suppose; nevertheless, it is longer than in G. flavus. 



There is another character, which, unless I am very much deceived, 

 will make it an easy matter to distinguish the two species from each 

 other; 1 refer to the colors of the hair. In parting the hair of a specimen 

 of G. flavus^ along the center of the dorsal surface, from near the tip of 

 the nose to the base of the tail, it will be seen, as Professor Baird has 

 already observed,* that the basal portion of the hair, nearly two-thirds, 

 is everywhere of a clear lead-color, a portion above, not as wide, buff, 

 and the tip dusky. In G. parvus a decidedly different distribution 

 obtains. The majority of the hairs of the top of the head are light 

 buff from immediately below the tip almost or quite to the base; a 

 smaller proportion are dusky throughout, darkest at the tip. On the 

 neck the plumbeous color is discernible at the base of the hairs, but 

 does not occupy more than about one-half of the total length. Pos- 

 teriorly the proi)ortion of lead-color diminishes rapidly, so that about 

 Ihe base of the tail it is barely perceptible, or may be said to have dis- 

 a])peared entirely. The tail is distinctly bicolor. The hair of G. parvus 

 is coarser than that of the Yellow Pocketmouse, more inclined to be 

 hispid, and shorter, measuring scarcely more than one-quarter of an 

 inch at the middle of the back. In general color but little tliff'erence is 

 observable between the two species, but when the hair is disarranged 

 the former species appears more strongly fulvous than G. flavus, on 

 account of the lack of lead-color at the base of the hairs. 



* Baird. Mammals, Pacific R. R. Survey, viii, 1857, j). 424. 



