SQUIRRELS OF MEXICO AND CENTRAL AMERICA lOI 



to dingy ferruginous; tail above black, thinly washed with dull yel- 

 lowish ; below, with broad median area grizzled yellowish brown, in- 

 distinctly and narrowly bordered with black and thinly edged with 

 dull yellow. Hairs on back, black with narrow subterminal (some- 

 times median) ring of rusty yellow. 



Variation. — The series at hand shows comparatively little variation. 

 Four specimens representing the summer pelage (Ma}' lo to Sept. 27) 

 are rather darker above and dingy ferruginous below. Specimens 

 in winter pelage (October to May) have more ochraceous backs and 

 yellower bellies. Apparently there is no seasonal difference in the tail. 



Measiirei7ients. — Average of five adults from type locality : total 

 length 361.4; total vertebrce 169.4; hind foot 51.6. 



Cranial characters. — Premolars \. Skull averaging a little smaller 

 than that of S. hoffmaiini but otherwise very similar. Five adult 

 skulls from the type locality average: basal length 42.1; palatal 

 length 22.1 ; interorbital breadth 16.3; zygomatic breadth 30.4 ; length 

 of upper molar series 8.3. 



General remarks. — Sciuriis richmondi bears a general resem- 

 blance to 6". deppei but is readily recognized by its yellow washed 

 tail and single premolar. It differs from the still nearer S. cestuans 

 ho^nianni of Costa Rica by the yellower back and underparts and the 

 slender, yellow washed tail. 



Specimens examined. — Eighteen : all from the type locality. 



BAIOSCIURUS subgen. nov. (p1. I, fig. 4.) 



SCIURUS DEPPEI Peters. Deppe's Squirrel. 



Sciurus deppei Peters, Monatsber. K. Akad. Wiss. Berlin, 1863, p. 654; 

 Alston, Proc. Zool. Soc. London, 1878, pp. 668-669, (P^rt ; Mexico, 

 Guatemala, and Honduras); Allen, Bull. U. S. Geol. Survey Terr., 

 IV, p. 885, J878 ; Alston, Biol. Cent. -Am., Mamm. p. 133, 1880 

 (part; Mexico, Guatemala, and Honduras); Sumichrast, La Natu- 

 raleza, V, p. 324, 1882 ; Thomas, Proc. Zool. Soc. London, 1890, p. 74; 

 Allen, Bull. Am. Mus. Nat. Hist., N. Y., ix, p. 190, 1897. 



Macroxus tephrogastcr Gray, Ann. & Mag. Nat. Hist., 3d ser., xx, p. 431, 

 1867 (part-^ Mexico, Guatemala, and Honduras) ; Ann. & Mag. Nat. 

 Hist., 4th ser., x, p. 408, 1872. 



Macroxus ta^m'urus Gray, Ann. &: Mag. Nat. Hist., 3d ser., xx, p. 431, 

 1867. 



Macroxus griscogaia Gray, Ann. & Mag. Nat. Hist., 3d ser., xx, p. 429, 

 1867 (part: Mexico [and Honduras?]). 



Type locality. — Papantla, Vera Cruz, Mexico. Type in Berlin 

 Museum. 



Distribution. — Humid Tropical and Austral zones from Truxillo, 



