I. A NEW GENUS AND SOME NEW SPECIES AND 

 SUBSPECIES OF ABYSSINIAN RODENTS. 



By Childs Frick. 



(Plates I-V.) 

 The forms herein described were collected by members of the party 

 during a ten months' journey, which was made by the author from 

 Dirre Doua, Abyssinia, to Nairobi, British East Africa (1911-1912). 



Stenocephalemys^ gen. nov. 



A large soft-furred, big-eared rat with white feet and tail, occurring 

 in the Chilalo mountains at an elevation of ten thousand feet above 

 sea-level. It shows resemblances to Epimys, but differs so essentially 

 in certain features of the skull, that it seems best to place it in a 

 separate genus, for which I propose the name Stenocephalemys, with 

 reference to the characteristic narrowness of the frontals. 



Characters. Skull. — Remarkable constriction of the interorbital 

 region, and posterior position of the narrowest point; anterior portion 

 of frontal broader than the posterior, which results in a peculiar 

 pinching in of the shortened frontal portion of the brain-case, accom- 

 panied by a stretching of the squamosals, which here form an unusually 

 large portion of the anterior lateral roof of the cranium; width and 

 strength of malar portion of zygomatic arch together with narrowness 

 of antorbital plates and open oval shape of suborbital foramina; 

 elongation and marked slenderness of maxillary-premaxillary region; 

 strongly arched postero-anterior profile of upper surface of skull; 

 smallness of bullae. 



The form most nearly approaching the new genus in its peculiar 

 orbital constriction is Dasymys, but Dasymys differs in the arrange- 

 ment of its molar pattern and in entirely lacking the posterior narrow- 

 ness of the frontals and other important characters of the skull (see 

 Plate I, figs. 6-10 and Table of Ratios.) In the development of the 

 maxillary-nasal region the small forest-mouse, Epimys tulhergiendorobce 

 Heller, is very similar to the new genus, the nasals of this Epimys 

 being almost proportionately as long as, and the width of the anterior 



1 <TT€vb% = narrow, K€(t>a\ri = head, and fj,vs = mouse. 



