RODENTS OF LIBYA 239 



[17.8]; greatest breadth across antorbital processes 22.3 (22-23.5), 

 22.1 (21-22.8), [22.7]. 



Diagnosis. Upperparts Cinnamon-Buff, more uniform anteriorly 

 and becoming darker posteriorly owing to a slight admixture of 

 brownish-tipped hairs; entire underparts, postauricular regions, and 

 flanks whitish, the latter with infusions of brownish hairs imparting 

 a streaked appearance; cheeks, mystacial areas, circumorbital regions, 

 and pectoral areas Pale Pinkish Buff; anterior margins of pinna of ear 

 with row of Pinkish-Buff hairs; remainder of pinna sparsely haired 

 and Clay Color; tail and hind feet Pale Pinkish Buff dorsally; hind 

 feet heavily furred, frequently Ochraceous-Salmon resulting from 

 artificial staining by the substratum; tail, dorsally, approximating 

 color of back but becoming lighter, more Pinkish-Buff, posteriorly 

 and terminating in a distinct tuft or pinna of Bister Brown proximally 

 and white distally; brown portion of the pinna becoming indistinct 

 ventrally; tail, ventrally, Light Pinkish Cinnamon becoming lighter 

 distally. In some specimens, the pinnate tail is stained a deep Ochra- 

 ceous-Orange owing to prolonged contact with the reddish-orange 

 substratum. Skull: Small; molariform teeth relatively small; auditory 

 bullae moderately inflated; rostrum moderately narrow; zygomata 

 convergent anteriorly; malar bone expanded laterally forming a wing- 

 like antorbital process; lachrymals distinct and appearing as posterior 

 appendages of the maxillary; infraorbital foramina large; braincase 

 moderately vaulted; upper and lower incisors relatively short and 

 narrow; angular process of mandible with posterolaterally directed 

 process and possessing a well-defined foramen on its anterior margin, 

 coronoid process small and reduced to a secondary process. 



Comparisons. From topotypes of Jaculus jaculus jaculus, J. j. 

 cufrensis differs in markedly smaller cranial measurements and gen- 

 erally smaller body size. The auditory bullae are less inflated in 

 J. j. cufrensis, and the skull appears less massive in all general aspects. 

 In color, J. j. cufrensis is lighter and more uniform in dorsal coloration 

 (Cinnamon-Buff as opposed to Tawny-Olive), has paler colored 

 vibrissae, less suffusion of dark hairs on lateral body surface, flanks 

 white or creamy as opposed to buffy or tan, and much less admixture 

 of dark hairs on the dorsum. 



When compared with Jaculus jaculus butleri Thomas from the 

 Sudan, J. j. cufrensis is similar in greatest length of skull, condy- 

 loincisive length and least interorbital breadth but is significantly 

 smaller in zygomatic breadth, length of nasals, size of infraorbital 

 foramina and breadtli of rostrum. Jaculus jaculus cufrensis has a 

 slightly more vaulted skull, greater flaring of the nasals anteriorly 

 and more ventrally inflated auditory bullae. In color, J. j. cufrensis 

 differs from J. j. butleri in having less admixture of dark hairs on the 



