sql:irrels of Mexico and central America 53 



Type locality. — Hacienda Magdalena, Colima, Mexico, Type no. 

 |4-i-|^J. U. S. National Museum, Biological Survey Collection. 



Distribution. — Arid tropical coast region in State of Colima, 

 western ISIexico (below 2000 ft.). 



Characters. — Pelage thinner and tail more slender than in other 

 subspecies of 6". poliopus ; nape and rump patches well marked, rusty 

 or yellowish brown ; back gray mixed with considerable rusty; feet 

 dark iron gray or blackish. Teats : p. i a. -| i. \. 



Color. — Nape and rump patches distinct, varying from yellowish 

 brown to dark rusty shaded with black ; nose and forecrown grizzled 

 iron gray, sometimes suffused with yellowish brown extending forward 

 from nape patch ; rest of back rather pale grizzled gr^iy, abundantly 

 intermixed with rusty ringed hairs ; outside of legs iron gray ; fore feet 

 dark iron gray ; hind feet darker iron gray varying to black and thinly 

 grizzled with gray ; sides of head dingy grizzled gray, sometimes suf- 

 fused with yellowish brown ; ring around eye dingy white or dull buff ; 

 ears like nape, with small basal patch of dull whitish or dingy rusty; 

 underparts white; tail at base like back; rest of tail above black 

 thinly washed with -white; below, with broad median area dark 

 grizzled iron gray (sometimes faintly washed with yellowish) bor- 

 dered by black and thinly edged with white. Hairs of back black with 

 white tips and basal, sub-basal or subterminal rings of buffy or rusty. 



Variation. — The upperparts vary from pale gray to iron gray ; the 

 feet are usually darker than the back, but sometimes paler. An imma- 

 ture specimen from the type locality is pale gray with the rusty rump 

 patch nearly obsolete. A female taken in February at Armeria has the 

 inside of fore limbs, thighs, and sides of belly washed with buffy, and 

 median area on under side of tail dark grizzled fulvous. The black 

 border on lower surface of tail varies from a narrow line to a band 

 half an inch wide. 



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

 length 526; tail vertebrae 267; hind foot 67.6. 



Cranial characters. — Premolars \. Skull somewhat smaller but 

 not otherwise separable from that of typical .5". poliopus. Five adult 

 skulls from near type locality average : basal length 502 ; palatal 

 length 26.7; interorbital breadth 19. i ; zygomatic breadth 33.8 ; length 

 of molar series 11.2. 



General notes. — Sciurtis p. colimensis is most closely related to 

 S. p. cervicalis^ but typical specimens are readily distinguished by 

 paler backs and strongly marked reddish or fulvous nape and rump 

 patches. The feet are darker than in any of the other subspecies of 



