278 



BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



in northeastern Sonora, Mexico, and the Huachuca Mountains, 

 southern Arizona. 



Characters. — Similar to typical Scivrus arizonensis., but slightly 

 smaller, with a broad band of gray over back of neck and shoulders, 

 separating the median grizzled yellowish or pale rusty area into a 

 narrow patch on crown and ears, and a larger one on lumbar region 

 and rump. Mammiv : P. |, A. | 



1 



Color. — Mr. Nelson describes May specimens from the Huachuca 



Mountains, Arizona, as 

 follows : 



ITpper parts, iuelnding top of 

 nose and base of tail, pale 

 grizzled gi'ay with rnsty yellow 

 AA'ash on back of crown, Inm- 

 bar region, and rump ; sides of 

 neck, flanks, and outside of 

 hind legs somewhat paler than 

 top of shoulders ; fore feet and 

 outside of legs grizzled gray- 

 ish white, sometimes pale 

 gray ; hind feet pale grizzled 

 gray ; ring around eye whitish, 

 or slightly buffy ; sides of 

 head whitish gray, often with 

 postocular yellowish brown 

 suffusion ; ears dingy grayish 

 or dull yellowish, sometimes 

 with small patch of dull gray 

 or rusty yellow behind base ; 

 under parts white : tail above 

 black washed with white, 

 heaviest along border ; below, 

 broad median area grizzled 

 rusty, dull orange yellow or 

 yellowish brown, with heavy 

 black border and broad white 

 edge. Hairs on back black, 

 with white tips and broad yel- 

 low subbasal or basal rings, or 

 with subterminal buffy yellow 

 rings, mixed with other hairs wholly black. Winter pelage similar to that of 

 summer, but a little grayer on sides of l)ody and outside of legs and feet; ears 

 more thickly haired and dull rusty, with basal patches of same color; white 

 on tail more distinct. (Proc. Washington Acad. Sci., I. 1899. p. 96.) 



jSkvII. — Larger than typical Sciurus arizonensis^ otherwise simi- 

 lar; differs from S. oculatus in having much smaller audital bulla, 

 larger rostrum, more inflated j^arietals, with occiput higher and 

 narrower. Greatest length of skull (fig. 44), 63 mm.; greatest 

 breadth, 37 ; palatal length, 27.5 ; interorbital breath, 20. 



Fig. 44.— Sciurus arizonknsis huachuca. Huachuca 

 Mountains, Arizona. (Cat. No. 58966,U.S.N.M.) o, Dor- 

 sal view; 6, ventral view; c, lateral view. 



