94 



NELSON 



distinct. This is probably the summer pelage but may possibly rep- 

 resent a local form. Two specimens from Santa Teresa have the 

 entire underparts dark rusty buffy and are the only ones showing this 

 color below. 



Measure7ne7its. — Average of five adults from type locality : total 

 length 565.8; tail vertebrae 272 ; hind foot 77.5. 



Cranial characters. — Premolar \. Upper molars broader and 

 heavier than in 6". oculatus, but otherwise the skulls are scarcely dis- 

 tinguishable. Five adult skulls from the type locality average : basi- 

 lar length 55.5 ; palatal length 28.4; interorbital breadth 20.7 ; zygo- 

 matic breadth 37.1 ; length of upper molar series 11.7. 



General notes. — The type of 6". alstoni Allen came from the Sierra 

 Valparaiso, but in renaming the species Dr. Allen called it S. 

 nayaritensis from the Nayarit Mts., a part of the Sierra Madre about 

 100 miles southwest of the type locality. 



Specimens examined. — Forty-one : from Sierra Valparaiso, Sierra 

 Madre, and Plateado, Zacatecas; Sierra Madre, northern Tepic; 

 Sierra de Juanacatlan and Barranca Beltran (east base Sierra Nevada 

 de Colima), Jalisco. 



SCIURUS APACHE Allen. Apache Squirrel. 



Sciurus griseoflaviis Thomas, Proc. Zool, Soc. London, 1882, p. 372 (not 



S. griseofiavits Gray, 1867). 

 Sciurus niger ludoviciatius Thomas, Proc. Zool. Soc. London, 1890, p. 73, 



footnote. 

 Sciurus apache Allen, Bull. Am. Mus. Nat. Hist., N. Y., v, p. 29, March 



16, 1893. 



Type locality. — Mountains of northwestern Chihuahua (near Ba- 

 vispe River .?) , Mexico. Type no. ff^f , American Museum of Natural 

 Histoi"y, New York. 



Distribution. — Mixed oak and pine forests of Transition zone in 

 the Sierra Madre of western Durango and Chihuahua, eastern Sonora 

 and northeastern Sinaloa, Mexico, and the Chiricahua Mountains of 

 southern Arizona. 



Characters. — Size large, about equalling S. ludoviciamis to which 

 it bears a strong general resemblance in color, but is readily distinguish- 

 able by its gray ears, darker, more iron gray upperparts, dull rusty 

 ferruginous hind legs and black upper surface of the tail which is 

 thinly washed with pale yellowish white, or rusty buff. Pelage thick 

 and soft; ears thinly haired. Teats: ^- \^-\ i- y- 



Color. — Summer pelage : Upperparts including top of nose and 

 base of tail dark, sometimes almost iron gray, often washed but never 



