88 NELSON 



AR^OSCIURUS subgen. nov. (p1. I, fig. 3.) 

 SCIURUS OCULATUS Peters. Black-backed Squirrel. 



Sciurus r«//5/r«/z^J LiCHTENSTEiN, Abhandl. K. Akad. Wiss., Berlin (1827), 



p. 116, 1830. (Not S. capistratus Bosc, 1802.) 

 Sciurus carolinensisSxvssv^-E., Rev. et Mag. de Zool., 2e ser., xiii, p. 4, 1861. 



(Not S. carolincnsis Gmelin, 1788.) 

 Sciurus oculatus Peters, Monatsber. K. Akad. Wiss., Berlin 1863, p. 63. 

 Sciurus hypopyrrhus Allen, Bull. U. S. Geol. Survey Terr., iv, pp. 881- 



882, 1878 (part). 

 Sciurus niger melanonotus Thomas, Proc. Zool. Soc. London, pp. 73-74, pi. 



VI, 1890; Allen, Bull. Am. Mus. Nat. Hist., v, p. 30, 1893 ; Ibid., ix, 



p. 198, 1897. 



Type locality. — Mexico, probably near Las Vigas, Vera Cruz. Type 

 no. 1434 Berlin Museum. 



Distribution. — Pine and oak forests of Transition and Boreal zones 

 in northern Puebla, western Vera Cruz (Cofre de Perote — Mt. Ori- 

 zaba), Hidalgo, eastern Queretaro, and southeastern San Luis Potosi, 

 Mexico (alt. 6000-13,000 feet). 



Characters. — Size large ; upperparts gray with large black or 

 blackish area along middle of back ; belly buffy. Pelage rather soft 

 and dense; under fur long; tail long and full. Teats: p. ^ a. f i. \. 



Color. — Crown between ears, and broad band along middle of back 

 from shoulders to base of tail, black or blackish, shading on edges to 

 dark gray like remainder of upperparts ; ring around eye well marked, 

 buffy whitish or buffy ; cheeks usually grizzled gray like sides of neck 

 but sometimes washed with buff ; ears dingy gray frequently washed 

 with dull buff of variable intensity; basal ear patch varying from 

 dingy white to dark buffy (sometimes absent in summer) ; feet varying 

 from grizzled gray washed with buffy to rich buff shading to gray on 

 outside of fore legs ; outside of lower hind legs varying from gray like 

 rest of thigh to dark rusty brownish. Underparts varying from white 

 with pale dull buffy suffusion to rich ochraceous buff ; tail above black, 

 heavily washed with white ; below, with broad median area of grizzled 

 yellowish gray, bordered with black and heavily edged with white. 

 Hairs of back black, with one or two rings of gray, yellowish gray or 

 brownish gray, mixed with other hairs wholly black. 



Variation. — The black dorsal band is usually present, sometimes 

 continuous from crown to tail (as in a specimen from Tulancingo), 

 and varies from 25 to 50 mm. in width ; but in two specimens from 

 the Cofre de Perote, Vera Cruz, and in nearly all from Pinal de 

 Amoles, Qiieretaro, it is i^epresented only by a black wash. The buff 

 on underparts of the latter specimens is decidedly richer than on ordi- 



