A NEW RODENT OF THE GENUS GEORYCHUS 



By EDMUND HELLER 

 Field Naturalist, Smithsonian African Expedition 



With One Plate 



It has seemed desirable that the more conspicuous new mammals 

 discovered by the Smithsonian African Expedition should be de- 

 scribed at once, without waiting for the general account of the col- 

 lections. This paper contains the first of these descriptions. 



GEORYCHUS KAPITI, new species 



Types from Potha, Kapiti Plains, British East Africa; adult 

 female, No. 161708, U. S. Nat. Museum; collected by J. A. Loring, 

 May 3, 1909; original No. 6027. 



General characters. — Size small, about that of G. nimrodi, but 

 skull relatively much larger, the nasals extending posteriorly con- 

 siderably beyond the premaxillaries ; coloration uniform drab-gray 

 with a strong cinnamon-brown wash and without any white occipital 

 patch. 



Coloration. — Uniform drab-gray everywhere, the back with a 

 strong cinnamon-brown wash ; ears, a spot on each side of snout at 

 base of whiskers, and the long hairs covering the tail, whitish, but not 

 forming any noticeable contrast with adjacent parts ; hair everywhere 

 plumbeous gray (about Ridgway's No. 6) at base. 



Skull. — Relatively large and wide zygomatically. Nasals extend- 

 ing well beyond premaxillaries. Functional cheekteeth four, the 

 crowns, when worn, subcircular in outline except the last, which has 

 a large posterior prism ; fourth cheektooth (m^) largest, the first func- 

 tional tooth (pm-) considerably smaller than the last (m^). Incisors 

 long and slender, uniformly chalky-white in coloration. 



Measurements. — Type: Head and body, 165; tail, 19; hind foot, 

 33 (29.6) ; skull, condylobasal length, 42.8; zygomatic breadth, 32.8; 

 interorbital constriction, 8.8; postorbital constriction, 9.0; mastoid 

 breadth, 20.2; nasal, 16.8; diastema, 14.6; depth at middle palate, 

 15.6; mandible, 33.6; maxillary toothrow (functional teeth, alveoH), 

 8.0; mandibular toothrow (functional teeth, alveoli), 7.0. 



This species is apparently most closely related to nimrodi of Mata- 

 bele Land, with which form it agrees in size, in the absence of a 



469 



