SQUIRRELS OF MEXICO AND CENTRAL AMERICA 47 



back; tail above black, washed with white; below, with well defined 

 broad median area varying from grizzled yellowish or rusty brown to 

 clear ferruginous, narrowly bordered with black and edged with 

 white. Hairs of back black with white tips and basal, median or 

 subterminal rings of rufous. 



Variation. — Most of the series from Cerro San Felipe, Reyes, and 

 Mt. Zempoaltepec agree in having the feet white. When the nape 

 patch is well defined the area between the eye and base of ear is usually 

 yellowish brown. 



A Zempoaltepec specimen is brighter rufous below, and the reddish 

 buffy rings of the dorsal hairs are brighter and more conspicuous than 

 usual. The three specimens from the vicinity of Ozolotepec, at the 

 southeast end of the Valley of Oaxaca, are in winter pelage and differ 

 from summer specimens from the Cerro San Felipe in having the sides 

 of the head and ring around eye shaded with dark buffy, and the feet 

 grizzled gray. The squirrels from near Ozolotepec live in an isolated 

 group of mountains, though not distant from the range of which the 

 Cerro San Felipe forms a part, and probably represent a local form 

 not sufficiently differentiated to warrant subspecific recognition. A 

 single specimen from Cerro San Felipe, with feet grizzled gray, repre- 

 sents Wagner's var. ^ {=. S. variegatus foliopus Fitzinger) ; and an- 

 other with feet white suffused with rufous represents Wagner's var. 

 f (^=. S. variegatiis rujipe'!^ Fitzinger) showing that these forms were 

 based upon individual variation. Apparently there is no striking differ- 

 ence between summer and winter pelages. No melanistic specimens 

 seen. 



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

 length 527.6; tail vertebra 257.6; hind foot 70.2. 



Cranial characters. — Premolars \. Skull (pi. II., fig. 3) more 

 slender and rostrum longer than in typical S. aureogaster. Five adult 

 skulls from the type locality average : basal length 52.2 ; palatal length 

 27.3; interorbital breadth 18.6; zygomatic breadth 34.5; length of 

 upper molar series 10.7. 



General notes. — In 1S37 Wagner named this squirrel Sciuriis 

 albipes.1 and in 1843 replaced this name by S. varitcs, mentioning two 

 varieties, var. /5("pedibus nigro-cinereis ") and var. ^ ("pedibus fer- 

 rugineis"). In March, 1867, Fitzinger named these varieties respec- 

 tively Sciurus variegatus polioptis and Sciurus variegatus rufipes., 

 and in the following December Gray named the species Macroxus leu- 

 cops. Recently Dr. J. A. Allen has shown that both of Wagner's 



Proc. Wash. Acad. Sci., April, 1899. (4?) 



