NATURAL SCIENCES OF PHILADELPHIA. 291 



Since the introduction of this species, as above, no additional 

 specimens have come to hand ; and as we have no further ma- 

 terial for amplification or verification of the original descrip- 

 tion, there is little more to be said about it at present. The 

 animal appears to be perfectly distinct from any other described 

 in this paper. With much the same size and proportion as those 

 of P. monticola, it is immediately distinguished by the radical dif- 

 ference in the conformation of the ear, the stouter as well as 

 rather longer feet, and the whiteness of the whole fore leg. From 

 penicillatus it differs in the much shorter and not penicillate tail, 

 less extensively denuded soles, and presence of a strong lateral 

 fulvous stripe. It is decidedly smaller than P. fascialus, with 

 which it shares the fulvous stripe, with a tail longer instead of 

 shorter than the body. Ears scarcely half as large, etc. From 

 all these species finally, it differs in the extraordinary harsh, 

 stiff, coarse hair; this is of great length, and devoid of under 

 fur, as in other species, but represents, in an exaggerated degree, 

 the pelage which is characteristic of the genus, in distinction 

 both from Dipodomys and Cricetodipus. 



The coloration of the species cannot be given with sufficient 

 accuracy. Both the specimens have been skinned out of alcohol, 

 and the tints are probably somewhat modified. One of them has 

 been so discolored by long immersion in a dirty fluid, as to be of a 

 uniform dingy greenish-brown in which the original colors cannot 

 be in the least discovered. The other, in better state, shows the 

 characters pretty well. There is a strong fulvous or salmon-colored 

 stripe along the whole body, just as in P. fascialus. The light 

 color of the upper parts is rather a pale cinnamon than the sandy 

 yellowish of P. fascialus. The hairs are light plumbeous at base, 

 and man} 7 of them are tipped with black, giving the dark surface 

 lining. The tail is sharply bicolor to correspond with the body. 

 The under parts, including the whole fore leg and the foot and in- 

 side of the hind leg, are white. 



As in the case of P. monticola, further information respecting 

 this species is much to be desired, particularly as there appear to 

 be some Mexican animals of this genus, with which we are at 

 present not well acquainted. The following measurements are 

 those given by Baird in his original notice : 



20 



