MAMMALS OF THE MEXICAN BOUNDARY. 151 



the valley, at least, as Del Rio, Val Verde County. Sporadically 

 northward to San Antonio, at which point 1>. ui. tcxeiisi.s occurs Avith 

 D. ri)'(jhu(ni((, the latter greatly predominating. It doubtless ranges 

 somewhat to the southward of the Rio Grande, but there are no 

 specimens available for examination from between Brownsville and 

 Tampico. 



Dichromatic, the black phase, in the material examined, prevailing 

 in the ratio of five to one of the grap phase, as shown by the follow'- 

 ing record of specimens examined : 



Texas: San Antonio, 2, black phase; Rockport, 3 — 2 in black 

 phase, 1 in gray phase; Corpus Christi, 4 black phase; Nueces 

 Bay, 2, black phase; Alice, 1, black phase; Sycamore Creek, 1, 

 black phase; Del Rio, 2 — 1 in black phase, 1 in gray phase; Eagle 

 Pass, 1, black phase; Fort Clark, Kinney County, 8 — \r black and 4 

 gray; Brownsville, 6 — 3 in black phase and 3 in gray phase. Also 

 additional skulls. 



Mexico: Matamoros, 1. 



Total, 31, and 7 additional skulls. (-/. .1. Allen.) 



Description. — Pouch complete. Size large (see tabulated measure- 

 ments, p. 152) ; tail long, scaly, prehensile, with basal half black, and 

 apical portion flesh color; ears entirely black; coat consisting of 

 crinkled, ^vooly underf ur mingled with long bristle-like hairs ; color 

 dichromatic. 



Gray phase. — An outer long coat of white bristly overhair, fiO to 

 80 mm. long over the middle of the back and on the rump ; beneath 

 this is a coat of soft long underfur, white for about two-thirds of its 

 length, the apical portion black, the long white overhair and the 

 black outer zone of the underfur giving a dark grizzled general effect. 

 Cheeks pure white, wdth generally a whitish spot over each eye, and 

 a whitish area surrounding the base of the ears; whole top of the 

 head and nose dusky brown, varying in intensity in different indi- 

 A'iduals, with a blackish stripe running from the ear through the 

 eye to the nose. Fore and hind limbs black, including the feet except 

 the nails, which are yellowish white; upper part of the limbs more 

 or less grizzled with long white overhair. Beneath, the pelage con- 

 sists mainly of the soft underfur, which is much shorter and thinner 

 than on the upper surface, with the tips of the fur more or less tinged 

 with dusky and with a few long bristly overhairs. 



Blael' phase. — Long, bristly overhair black instead of white, be- 

 neath which is the usual soft, long underfur, white for its basal two- 

 thirds and tipped with black. In other respects as in the gray phase. 



During the breeding season the pouch of the female is lined with 

 fine, crinkled, woolly hairs of a rusty chestnut-brown color. During 

 the nonbreeding period the pouch hairs are often gray or even 

 whitish. (/. .1. AVeu.) 



