RODENTS OF LIBYA 217 



mystacial, subauricular, and scapular areas nearly pure white and 

 sharply contrasting with black areas around eyes and base of ear; 

 postauricular patches inconspicuous and Pale Pinkish Cinnamon 

 strongly suffused with gray; pinna of ear moderate in size, sparsely 

 haired, approaching color of the dorsum, and with a conspicuous tuft 

 of buffy hairs on the anteroventral margin; vibrissae relatively long 

 with white and black individual hairs; fore and hind feet relatively 

 small with four and five functional digits respectively, white above 

 and naked below with prominent palmar and plantar pads, tail relative- 

 ly long with three distinct zones of color on both surfaces; a proximal 

 region of grayish-brown, a more extensive middle region of black, and 

 a terminal tuft of white. Skull: Small and gracile; rostrum narrow 

 and attenuated; interorbital region markedly constricted; parietals 

 prominently domed; zygomata bowing slightly laterally; auditory 

 bullae conspicuously inflated ventrally; basioccipital broad and tri- 

 angular; pterygiod region with numerous large foramina; molariform 

 teeth small, with two prominent cusps on the labial surfaces; anterior 

 palatine foramina large and laterally expanded posteriorly; mandible 

 with large oval foramen in the angular process. 



Comparisons. From representatives of Eliomys quercinus melanurus 

 Wagner from the Gebel Musa and near St. Catherine's Monastery, 

 Sinai, the type specimen of Eliomys quercinus denticulatus from El 

 Gatrun, Fezzan, differs in markedly smaller size, particularly the ears 

 which are strikingly smaller; more domed braincase; much shorter 

 molariform too throw and smaller individual teeth; longer inter- 

 parietal and a more truncated dorsal margin of the foramen magnum; 

 dorsum slightly darker with greater suffusion of light brownish hairs, 

 especially in the interauricular and rostral regions; postauricular 

 patches more conspicuous; tail white terminally, rather than black, 

 and darker proximally owing to a greater duffusion of brown. In E. q. 

 denticulatus, there is a more gradual transition from the brownish- 

 gray color of the base of the tail to the solid black of the middle and 

 distal portions, whereas in E. q. melanurus the grayish color of the 

 base of the tail transforms abruptly into black. 



Compared to a representative of Eliomys quercinus cyrenaicus Festa 

 from five kilometers southeast of Derna, Cyrenaica, the type specimen 

 of Eliomys quercinus denticulatus from El Gatrun differs in having 

 skull smaller, interparietal longer, braincase more domed, rostrum 

 narrower and more attenuated, anterior palatine foramina slightly 

 wider, foramen in the angular process of the mandible larger, molar- 

 iform too throws markedly shorter, and with smaller individual teeth. 

 These two subspecies are comparable in external dimensions except 

 for the longer tail of E. q. denticulatus, which is white terminally, 

 rather than black as in E. q. cyrenaicus. They are also similar in dorsal 



285-134 O— 68 15 



