2 < i S BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



Measurements of ...' specimens of Sdvrus griseus anthonyi. 



'American Museum of Natural History. ''Type. 



Subgenus AK.EOSCIURUS Nelson (1899). 



SLENDER SQUIRRELS. 



Armosciurus Xet.son, Proc. Washington Acad. ScL, I. p. 29, pi. i, fig. 3, May 

 !>, 1899 ( Revision of the Squirrels of Mexico and Central America). 



Dentition.— 1. g; P. ~; M. g = 20. 

 The following is the original description: 



Type Scwrus oculatus Peters, from eastern Mexico. 



Distribution. — Mountains bordering the tableland of Mexico from the vol 

 canoes of Orizaba and Tolnca north to central Arizona and west-central New 

 Mexico. Transition zone. 



External characters. Size large; body rather slender; tail usually long, 

 sometimes exceeding length of head and body: upper parts gray or yellowish; 

 nnderparts white or yellowish. 



Cranial characters. — Premolars |. Sknll rather short, depressed: brain case 

 broadened ;it parietals; occiput low and broad: front of sknll depressed at base 

 of rostrum (more arched in Parasciurus) ; rostrum light; nasals narrow, 

 slightly tapering posteriorly; upper end id* preruaxillae narrow. 



