1896.] NATURAL SCIENCES OF PHILADELPHIA. 537 



46. Gerbillus sp. ? 



Three young specimens (Nos. 3,854, 3,855, 3,928), two in skins and 

 one in alcohol, all taken at Sheikh Husein, October 12, 1894. I am 

 unable to even conjecture about, except to say they differ specifically 

 from any others in the collection. 



They are about two-thirds grown ; the tail is just equal to head 

 and body in length, and the size of skull and hind foot Avould indi- 

 cate a species smaller than leiicogaste?: This species is remarkable 

 for the blackness of the ears, back, rump, upper tail and soles of the 

 feet. The upper ground color is brownish-fawn fading to purer 

 fawn on the sides. The underside and feet are clear white. 



No. 3,855 measures 180 mm. in length; tail, 90; hind foot, 30. 

 The skull is 27 mm. long, 



47. Gerbillus pulvinatus sj). nov. Cushioned Gerbillus. 



Type, No, 3,930, ad, S ; collection of the Academy of Natural Sci- 

 ences of Philadelphia, Collected by Dr. A. Donaldson Smith at 

 Rusia, Lake Rudolf, Africa, August 5, 1895. 



Description — Size medium, tail with pencil nearly li times 

 length of head and body. Soles and toes of fore and hind feet cush- 

 ioned throughout with hairs like those of the upper surfaces of the 

 feet. 



Color (from type alcoholic specimen) above, from hind nose to 

 tail, fawn, sparingly lined with black tipped hairs, much blacker 

 across hind rump and thighs. Upper tail fawn, becoming blackish- 

 brown toward penicillate tip, the underside white almost to tip. 

 Hind feet, including lower portion of hind leg, white; forelegs and 

 feet, lower parts, including sides, lower cheeks, upper lips, to eyes, 

 nose, hinder bases of ears, superciliary stripes and spots between eyes ' 

 and ears, white, the white greatly encroaching on the paler fawn of 

 upper sides and lower outer half of hams. Ears fully and coarsely 

 haired on outer surface with golden fawn anteriorly, becoming 

 darker on the hinder parts. 



Skull (teeth worn, 3 anterior cusps of m. 1 yet distinct) ; first sec- 

 tion of m- 1 consisting of a single rounded oval cusp, without fold or 

 division and distinct from its neighbor ; second (median) transverse 

 section of same tooth consisting of two distinct circular cusps of equal 

 size; third (posterior) section of same is a single elliptic transverse 

 cusp forming the widest portion of the tooth. Audital bullae large, 

 tumid, widely separated from the slender basi-occipital. Incisive 

 foramina not reaching anterior plane of molars. 



