298 Univi rsity of California Publications in Zoology (Vol. 12 



ends, contrary to the condition in pliant; nasals uniformly broader 

 than in phaea; interpterygoid fossa broader. Coloration dorsally 

 shiny black instead of oehraeeous-buff ; ventrally warm buff instead 

 of ochraceous-buff or light ochraceous-buff (Ridgway's Color 

 Standards and Nomenclature, 1912. used as color guide). 



Material : Twenty specimens of Aplodontia phaea; four speci- 

 mens of Aplodontia nigra. Tt should be noted that both series, with 

 the exception of two specimens of .1. phaea (nos. 8973, 8974). were 

 taken during the summer season, so are strictly comparable as to 

 pelage. 



Descriptive Remarks: Coloration. — The blaek-and-gray dorsal 

 appearance of Aplodontia nigra is unique among known California 

 aplodonts. This character marks the new species off sharply from A. 

 phaea, to which its size and cranial characters show it to be most 

 closely related. The prevailing color tone seen in a dorsal view is. in 

 nigra, shiny black: in phaea, ochraceous-buff. The dorsal coloration 

 is modified somewhat in nigra by the dark plumbeous bases of the 

 hairs showing through. Some of the dorsal hairs are tipped with 

 buffy. These are so few. however, that the general dorsal aspect is 

 shiny black only faintly sprinkled with grayish. In pliara. the 

 ochraceous-buff of the dorsal surface varies toward light ochraceous- 

 buff. The general coloration is modified by the showing through of the 

 dark plumbeous bases of the hairs and also by the admixture of 

 numerous black hairs. There is also a sprinkling of hairs tipped with 

 light buff. The result of the mixture of these variously marked hairs 

 is a grizzled ochraceous-buff appearance. 



Face in A. nigra is dark quaker drab; near pale quaker drab in 

 A. phaea. 



Sides paler than back in .1. nigra, there being fewer black hairs, 

 and more buffy-tipped ones. In .-1. phaea the sides are nearly the 

 same as the back, grading into the coloration of the underparts. 



There is much more blackish externally on both fore and hind feet 

 in A. nigra, as well as on the rump and tail. In A. phaea these parts 

 tend to be browner. The feet in A. nigra are blackish, in pinna 

 brownish. 



A. nigra has basal portions of hairs ventrally varying between 

 plumbeous, deep plumbeous, and dark plumbeous, and upper portions 

 of the same hairs warm buff. Phaea has hairs ventrally a paler shade 

 on their basal portions, varying between plumbeous and cinereous, 

 and their outer portions ochraceous-buff or light ochraceous-buff. 



