SQIJIRRELS OF MEXICO AND CENTRAL AMERICA IO5 



Variation. — The main variation is in the amount of rusty on the 

 ears, and in the color of the underparts, which ranges from white to 

 deep buffy yellow. Some specimens are considerably grayer above — 

 less shaded with yellow — than others. No melanistic specimens seen. 

 Spring and autumn specimens show no seasonal differences. 



Measurements, — Average of five adults from type locality : total 

 length 3S7.4,; tail vertebras 188.3 ; hind foot 54. 



Cranial characters. — Premolars f . Skull indistinguishable from 

 that of typical 5". deppei. Four adult skulls from type locality aver- 

 age : basal length 41.7; palatal length 21.4; interorbital breadth 15.3; 

 zygomatic breadth 28.4; length of upper molar series 9.1. 



General notes. — Sciurus negligens closely resembles S. deppei in 

 size and general appearance, and inhabits the more arid country lying 

 north of the region occupied by the latter species. It is readily dis- 

 tinguished from S. deppei by the much grayer color of the upperparts. 



Habits. — These squirrels are most numerous in the stunted forests 

 of ebony, 15 to 25 feet high, which cover great areas in their range 

 and furnish their main food supply. We found them in the greatest 

 abundance at Velasco, San Luis Potosi, where the ground under the 

 trees was strewn with gnawed seed pods. 



Speci?nens examined. — Twenty-three : from Alta Mira and Victoria, 

 Tamaulipas ; and Velasco and Jilitla, San Luis Potosi. 



Subgenus MICROSCIURUS Allen (p1. I, fig. 6; p1. II, fig. 2.) 

 SCIURUS ALFARI Allen. Alfaro's Pigmy Squirrel. 



Sciurus {Microsciurus) al/ari AiAJK^i, Bull. Am. Mus. Nat. Hist., N. Y., 



vii, p. 333, Nov. 8, 1895 ; Ibid., ix, p. 35, 1897. 

 Sciurus alfari Alfaro, Mamiferos de Costa Rica, pp. 31-32, 1897. 



Type locality. — Jimenez, Costa Rica. Type no. VA"» Ameri- 

 can Museum of Natural History, New York. 



Distributiojt. — Dense humid forests of northern, eastern and south- 

 western Costa Rica. 



Characters. — Size very small ; ears short and rounded, upperparts 

 dark, minutely grizzled reddish brown, the reddish most intense on 

 nose and sides of head ; ring about eye reddish buffy. Pelage soft and 

 dense; tail slender. Teats: p. y a. i i. \. 



Color. — (Of type) : Entire upperparts including ears and outside 

 of legs, minutely grizzled dark brown, suffused with dull rufous ; rufous 

 most intense on head and brightest on narrow ring about eye ; feet 

 and toes grizzled rusty brown slightly paler than back ; chin, throat, 



