;:•;■: 



niC) 



MONOc.RAPna OP north American rodentia. 





iiiui: 





iilliiliii 



As noticed i'liitlRT dii, tlio Cricetodipus parvus ^A' Pealo iti nn uiicertnin 



animal. In erecting Cricetodipus into a genug, I take C. Jlavus of Bainl ns 



the type, and follow tiiis author in distinguishing a second species, whicii latter 



is prol)al)ly, hut not certainly, the C. parvus of Peale. The two appear to 



(.onstantly differ in the* following characters: — 



Tuil Dcarcely or not longer tlian tbe hcwl and body ; bind f(.ot Bcstoely or iiot one-third as long as head 

 nnd UHly. flavus. 



Tail ducidcxlly longer than hood and body ; bind foot more than one-third oa long ns Ueati ond body, 



PAUV'is (of Oaird). 



CRICETODIPUS FLAVUS. Baird. 



•' 

 •■ 



Tellow Fooket-monse. 



Ptrognathtit flavui, Biikd, Proc. Aoad. Nat. 8ri. Phila. 1855, ."m.— Baihd, M. M. A. 1857, ii3, pi. 8, f. 3, pi. 2\ 

 t.Sa-f (assigned to Ci'ioefo({i>«ii).— Baiiid,P. K. R. Rup. x, 1859, 'iunnison's and Beckwith'a 

 Rout«, Maniiu.p.8.— BAriiD,U.8. Mex. B. 8urv. ii, pt. ii, 1859, Mamm. 42.— SuCKL., P. U. B. 

 Rep. xii, pt. ii, 1860, 101 (Montana).— Hayd., Trans. Am. Phil. 8oc. zii, 1863, 147 (Lonp Fork of 

 Platte).— Allkn, Pioc. Bast. 8oc. N. H. xxii, 1874, 42 (Yellowstone River). 



Crieeodiput flavut, Giiay, P. Z. 8. 1868, 203 (compiled ).—CouE8, Proo. Phila. Aoad. 1875, 300 (mouo- 

 gniphic).— CouES & Yar;iow, ZoOI. Expl. W. 100 Merid. 1875, 109. 



Oloijiiotit JIaea, CoiiRs, Proc. Fill's. Acad. 1875, 305 (provisional name). 



Diagnosis. — Much snialler than Mus musculm; head and body two 

 inches ; taU the same ; hind foot 0.65 ; ear small, not overti '^g the fur, 

 simple, without lobe of antitnigus or tragus. Soles entirely hairy on the pos- 

 terior half. Tail not decidedly longer than the head and body. Hind foot 

 scarcely or not one-third as long as head and. body. Above, pale buff, inti- 

 mately blended with blackish ; below, including whole fore leg, snowy white; 

 sides with a clear buff stripe; tail obscurely bicolor; white touches often 

 found about the ears. ' 



Habitat. — Rocky Mountain region of the United Staves and eastward in 

 the Middle Faunal Province, from the British Possessions (lat. 49°, Coues) to 

 Chihuahua, Mexico. (In the Pacific region replaced by C. parvus.) 



(Dcscripiion from numerous alcoholic nnd dry specimens, including 

 Baird's types) — In general points of exterior conformation, this animal is so 

 similar to species of Perognathus already fully treated that the account of 

 theF-<; fentures may be abridged, ^he generic character of structuie of the 

 oar and hairiness of the sole, with the diminutive size, are the chief iwinls. 

 The ear is very small and simple, not overtopping the fur of the parts. It 

 is evenly rounded; there is no lobation whatever of either ant'tragus or 

 tragus, the slight notch w hich exists being formed in '"ront by the fol»L -over 

 edge of the ear itself, and behind by the antitrngal ridge. The head is full, 



