230 U.S. NATIONAL MUSEUM BULLETIN 275 



Jaculus deserti vastus, new subspecies 



Holotype. Adult male, skin and skull, USNM 325837, from 

 Wadi er Rueis, Gebel el Harug el Asued, 340 km WNW Tazerbo 

 Oasis, Cyrenaica Province, Libya; obtained Apr. 29, 1962, by G. L. 

 Ranck, original no. 2116. 



Specimens examined. The type only. 



Measurements. Measurements of the type specimen are as follows: 

 Total length 311, length of tail 203; length of hind foot 67; length 

 of ear 24; greatest length of skull 34.3; condyloincisive length of 

 skull 30.3; crown length of upper molariform toothrow 5.3; greatest 

 breadth across zygomatic processes 23.6; least interorbital breadth 

 12.6; length of nasals 12.3; breadth of rostrum at level of antorbital 

 foramina 5.2; greatest breadth of braincase 18.2; greatest breadth 

 across antorbital processes 23.2. 



Diagnosis. Upperparts Light Pinkish Cinnamon grading to Pale 

 Pinkish Cinnamon on sides, flanks, pectoral regions, and rostral 

 areas; all upperparts with strong suffusion of brownish-tipped hairs 

 more concentrated on rump; mystacial, circumorbital, subauricular 

 areas, forearms and entire venter, Pale Pinkish Buff; vibrissae long 

 and darkly colored basally; pinnae of ears sparsely haired and white 

 dorsally; forefeet naked ventrally and bearing five claws; hind feet 

 heavily furred ventrally, bearing three claws, and sole with strong 

 suffusion of Mummy Brown hairs. Tail indistinctly bicolored Pinkish 

 Buff dorsally and Light Buff ventrally and with terminal pinna which 

 is Clove Brown proximally and white distally. Skull: Large, auditory 

 bullae large and markedly inflated; zygomata robust; incisors large 

 and heavy; braincase slightly vaulted; ramus of mandible heavily 

 fenestrated and angular process with two distinct oval foramina of 

 unequal size. 



Comparisons. From representatives of J. d. deserti of Algeria, 

 this specimen from the Wadi er Rueis differs in its much larger size, 

 particularly in the length of the hind feet and tail. 



Jaculus deserti vastus differs from representatives of Jaculus deserti 

 favillus from 20 miles west of Sidi Barrani, Western Desert Gover- 

 norate, Egypt, in slightly longer tail, much larger hind feet, shorter 

 ears, longer molariform toothrow, larger and more uniform foramina 

 on angular process, paler, less variegated dorsal pelage, and more 

 buffy venter. 



This specimen closely resembles representatives of Jaculus deserti 

 schliiteri from Feiran Oasis, Sinai Governorate, and Wadi Ghuweibba, 

 Eastern Desert Governorate, Egypt, but differs in smaller body size, 

 slightly shorter length of tail, hind feet, and ears, longer molariform 

 toothrow, wider interorbital breadth, shorter nasals, slightly paler, 

 less variegated color of dorsum and more buffy venter. 



