164 Baii(j!i — The Sqidrirl.'^ of Eastern Xorfh America. 



Geographic dlslrihulion. — Limits of range unknown, probably the higher 

 soutliern Alleghanies. 



General characters. — Size smallest of the eastern flying squirrels ; similar 

 in general appearance to .S'. sahrimts, but darker in color; soles naked in 

 summer. 



Color. — The tj'pe (in summer, beginning to change to winter pelage) : 

 upper parts hair brown, shading in places toward isabella color ; ears and 

 upper surface of tail, feet, and hands sooty ; cheeks dark gray; a black 

 orbital ring; under parts grayish white, the hairs somewhat darker at 

 base ; under surface of tail drab, shading to sooty ; soles and palms naked ; 

 the skin black. 



Cranial cliaructers. — Skull very small, similar to that 

 of S. sahrinna in respect to the flat audital bulite and 

 large teeth, but differing in having the foramen ovale 

 transversely oval instead of round. The peculiar 

 pug-nosed eff"ect given by the turned-up ends of the 

 Fig. 29.— Rostrum of nasals is even more exaggerated than in sabrinus. 

 Sciuropterus siius. gjgg ^f ^j^g type skull : basilar length, 25.8 ; occipito- 

 nasal length, 31; zygomatic breadth, 19; greatest 

 height of cranium above palate, 12.2 ; greatest length 

 of single half of mandible, 18.6. 



Size. — The type: total length, 214; tail vertebrte, 

 92; hind foot, 28. 



General remarks. — Sciuropterus silus is known at 

 present only by the type, all my efforts to get ad- 

 ditional specimens having so far failed. Lieut. Wirt Robinson spent 

 part of the summer of 1896 at White Sulphur Springs, W. Ya., and 

 kindlj' offered to get me flying squirrels. He succeeded in taking but 

 one, a jierfectly typical example of «.S'. volans. It was taken at an altitude 

 of about 1,200 feet lower than the type of S. silas. It is probable that 

 the ranges of the two species overlap. 



Sciuropterus silus hears no very close relationship to S. rolanx, although 

 it is even smaller than that species. Its affinities lie with 6'. sabrinus, of 

 which it is probably the Alleghany Mountain rej)resentative. It is, how- 

 ever, so very much smaller than that species and differs from it so much 

 in other respects that I have accorded it specific rank. 

 Specimen examined. — The type. 



Fig. 30.— Rostrum of 

 Sciiii'Opieriii volans. 



Sciuropterus volans volans (Linn.). Southern Flying Squirrel. 



1758. Mas volans Linn., Syst. Nat., ed. 10, I, 1758, p. 63. 



1758. Sciurus rolans Linn., Syst. Nat., ed. 10, I, 1758, p. 64 (in part). 



1788. Sciurus volucella Pallas, Nov. Spec. Glires, 1788, p. 351. 



1818. Pteromys volucella Desmarest, Nouv. Diet. d'Hist. Nat., XXVII, 

 1818, p. 406; And. and Bach., Quad. N. Am., I, 1849, p. 216, pi. 

 XXVIII ; Baird, ]Mamm. N. Am., 1857, p. 286. 



1828. Sciuropterus volucella Cjeoffrov, Diet. Class. d'Hist. Nat., XIV, 1828, 

 p. 132. 



1874. Sciuropterus vohicella. \&r . volucella Allen, Proc. Boston Soc. Nat. 

 Hist., XVI, 1874, p. 189 ; Monog. N. Am. Sciurid^e, 1877, p. 6.55. 



1890. Sciuropterus volans Jordan, Man. Vertebrates, 1890, p. 324, foot- 

 note. 



