12 



Annals of the Carnegie Museum. 



Pelage. — Upper parts dark cinnamon-brown^ in tone, sides lighter, 



demarcation between same and drab-gray under parts better defined 



than in the larger O.j. helleri. Tips of hair over 



upper parts ochraceous to light buff; on lower 



parts gray washed with light bufT; anterior 



and ocular portions of face without the light 



markings of the larger species; ears well clad, 



contrasting with the poorly clad, to much worn 



ears of 0. j. helleri; light posterior orbital 



patches same in both subspecies; tail dark 



above, light below (annulations 14 to 10 mm. 



Fig. I. Lower inci- against II to lo nmi. in the larger form); cov- 



sorsof type (No. 29). i- pred with dark light-tipped hair, claws light to 

 viewed from in front; 2, , 



translucent. 

 2 

 from above. X - 

 I 



Genus Gerbillus Desmarest. 



4. Gerbillus bilensis sp. nov. 



Type from dry plain near Bilen, Abyssinia. (Original field-number 

 7519, Dec. 19, 1911.) 



General Characters. — In markirgs and coloration closely agrees 

 with the description of the much larger G. pyranriduni Geoffroy of 

 Egypt (see J. Anderson, "Zoology of kgypt," 1902, p. 255) and differs 

 from G. pygargiis Cuvier from Suakin (/. c, p. 256) and G. pulvinatiis 

 Rhoads from southern Abyssinia, which it more nearly resembles in 

 size, by its pronouncedly dark median dorsal area, black eye-lids, dark 

 postocular stripes, and strongly buif coloration of the under surface of 

 the tail. 



Skull. — The hinder portion of the skull of the type is gone; the 

 molars are somewhat worn. Compa.-ed with the type of G. pulvinatiis 

 Rhoads,'' the general proportions arc the same, but the interorbital 

 region is slightly broader. 



Pelage. — Median portion of back and rump heavily marked with 

 black, anterior and lateral portions bright ochraceous buff (cf. Ridg- 

 way), under parts pure white. Indi\idual hairs of upper fianks and 

 back light slate-gray at base and light ochraceous buff at tips, which 



« Ridgway, I. c. (cf. footnote 4). 



' Proc. Acad. Nat. Sciences of Philada., Vol. 48, 1896, p. 537. The writer has 

 had access to the specimens through the kindness of Mr. Witmer Stone, the Curator 

 in charge. 



