Nelson — Desrriptionti of New Squirrels from Mexico. 14!) 



Zonal (listrilnttioii. — Arid tropical. 



Suhsperijir characters. — Most like Sciunis p. ncmoralis, but upperparts 

 paler or lighter gray, nuchal patcli more clearly defined yellowish ; rump 

 patch more obsolescent. 



De.scriplioii of ti/pe. — Toj) of head iron-gray ; nape patch ochraceous 

 mixed with black ; rest of bacik pale grizzled gray with slight mixture of 

 ochraceous grizzling posteriorly, but not sufficient to form a rump patch ; 

 sides of body paler than back ; top of tail black with heavy wash of wdiite ; 

 tops of feet white; underparts of body white; median area on underside 

 of tail dull gray bordered with blackish ; outer edge of tail white. 



Measurements of type. — Total length, 543 ; tail vertebrae, 275 ; hind foot, 69. 



Skull characters. — Rostrum lieavier and braincase narrower than in S. p. 

 nemoralis, with braincase more abruptly constricted posteriorly and occipi- 

 tal diameter shorter. 



General notes. — Compared with a similar series of typical >S'. p. nemoralis 

 (the most closely allied form) the i)resent subspecies is distinctly lighter 

 colored, the yellowish nape patch averages decidedly better defined, and 

 the rump patch is scarcely or not at all appreciable in most specimens and 

 poorly defined when present. In all except melanistic specimens the pale 

 grayish wash on the back and sides is underlaid with buffy or yellowish 

 similar in shade to the na^ie patch and varying in amount so that in some 

 specimens it is scarcely distinguishable, but it usually shows through the 

 overlying gray sufficiently to give a pale yellowish suffiision. As might be 

 supposed from the climatic differences the tail is decidedly slenderer or 

 less bushy than in nemoralis and the pelage much thinner and shorter 

 haired. Melanism sometimes occurs in this form, as attested Ijy one 

 specimen taken. 



Sciurus poliopus perigrinator subsp. nov. 



PUKBLA SQUIKREL. 



Type No. 70,279, adult female, U. S. National Museum, Biological Survey 

 Collection. From Piaxtla, Puebla, Mexico. Collected November 25, 1894, 

 by E. W. Nelson and E. A. Goldman. Original No. 7104. 



Geographic distribution. — Southern Puebla, northwestern Oaxacaand ad- 

 jacent parts of Guerrero. 



Zonal distribution. — From upper Sonoran to arid tropical. 



Subspjecific characters. — Most like Sciurus p. hernandezi but more brightly 

 colored ; rump and nape patches well marked ; underside of tail rusty red 

 almost as in typical poliopus. 



DescrijAlon of type. — Top of nose and fore jaart of crown iron-gray ; back 

 part of crown and nape marked with a dark ochraceous buffy j)atch 

 mixed with black; rest of upperparts to rump light iron-gray, underlaid and 

 mixed with ochraceous; sides of body paler than back; rump with a 

 distinct ochraceous patch mixed w^ith black ; tops of feet white ; upper- 

 side of tail black with a strong wash of white and underlaid basal ly with 

 rusty ochraceous; underparts of body rich cream-buflF; underside of tail 



