RODENTIA SACCOMYINAE DIPODOMYS PHILLIP1I. 



41 



The general distribution of color is much as in D. ordii and other species of the genus ; upper 

 parts yellowish brown, with a little dusky intermixed ; lighter on the sides. Sides of snout, 

 spot above the eye behind the ear, a stripe crossing the groin from the belly to the base of the 

 tail, fore legs, tarsi and feet, with the under parts generally, pure white. Tail white, with a 

 smoke-brown stripe on the upper side from near the white base to the tip of the tail, and another 

 on the lower side nearly to the tip, where it becomes obsolete. On the terminal third of the tail, 

 however, the dark marking is confined more and more to the tips of the hairs, and at its 

 extremity the general impression is that of a white tuft. 



A specimen from Los Angeles, No. 41, is in more mature condition. In this the head is 

 narrower than in D. ordii, and with somewhat the same ground color, has this more relieved 

 by dusky tips to the hairs on the head and back. It agrees in locality with the D. agilis of 

 Gambel. 



I am very far from satisfied that this species, as described above, is really distinct from what 

 I call D. agilis, as the characters seem to me too intangible to distinguish them. There are 

 various shades of gradation in the colors of the terminal portion of the tails. Generally the 

 dusky inferior stripe -runs out about an inch from the end of the vertebrae, leaving the end of 

 the tail white, with only a tinge of plumbeous on the upper surface and tip, the basal and 

 larger portion being white. Sometimes, however, the prevailing impression is plumbeous 

 instead of white. 



Two specimens one from California, precise locality unknown, the other from Fort Reading- 

 have the entire tip of the tail, all round, for about half an inch before the end of the vertebrae, 

 well defined white, without any plumbeous. Just before the white tip the tail appears to be 

 plumbeous all round. In the Fort Reading specimen the tail is unusually long ; in the other 

 it is only moderately so. The colors of these specimens are quite dark, more like the D. agilis, 

 as described. 



List of specimens. 



' Hairs at tip of tail pure white. 



" Hairs at tip of tail white at base, with dusky tips. 



9 Terminal brush pulled off. 



4 Very similar to 472 and 473. 



