RODENTS OF LIBYA 185 



the noticeably larger and more inflated auditory bullae and complete 

 closure of the suprameatal triangles of M. caudatus. 



Ecological observations. These jirds apparently prefer areas of 

 low elevation on the coastal plain and are unknown from the higher 

 Saharan interior where they are supplanted by the bushy-tailed 

 Meriones caudatus. 



At Nalut, two specimens, 321835 and 321836, were obtained from 

 some large dunes near the coastal escarpment. These dunes supported 

 a sparse vegetative cover of Calligonum and thorny perennials. Two 

 specimens of M. caudatus and a large series of Gerbillus aureus were 

 taken from the same trapline. According to Setzer (1957), the habitat 

 at Gheminez and Zliten consisted of poorly vegetated rocky-clay type 

 of soil and fallow barley fields. 



Although this subspecies is known from comparatively few speci- 

 mens and has been collected from only four localities, it doubtless 

 has a wide distribution and is probably sympatric with practically 

 all other species of coastal rodents throughout the Mediterranean 

 littoral of Libya. From the vicinity of El Agheila, it has been taken 

 with Gerbillus eatoni, G. gerbillus, G. pyramidum, G. amoenus, G. 

 henleyi, Pachyuromys duprasi, Meriones caudatus, and Psammomys 

 obesus. At Gheminez, Jaculus orientalis, Allactaga, tetradactyla, and 

 Gerbillus aureus occur with M. I. auratus. 



The subspecific name auratus is derived from the Latin "aurum," 

 meaning gold or of gold, and has reference to the golden cast of the 

 dorsal pelage in members of this subspecies. 



Meriones libycus azizi Setzer 



Meriones shawi azizi Setzer, Proc. Biol. Soc. Wash., vol. 69, pp. 205-206, Dec. 

 31, 1956 (5 km SE Derna, Cyrenaica, Libya). 



Specimens examined. Twenty, from Cyrenaica: 3 km E. Derna, 

 1; 5 km SE Derna, 2; 7 km E Maraua, 1 ; 2 km N Coefia, 5; 8 km 

 N Benghazi, 2; 20 km E Tobruch, 9. 



Measurements. Measurements of two adult females, 302243 and 

 325604, from 5 km SE Derna and 20 kilometers east of Tobruch 

 are, respectively: Total length 259, 252; length of tail 131, 123, 

 length of hind foot 32, 31; length of ear 17, 19; greatest length of 

 skull 36.8, 36.4; length of palate 16.4, 16.5; length of audital portion 

 of auditory bulla 12.3, 12.8; alveolar length of upper molariform 

 toothrow 5.6, 5.7; least interorbital breadth 6.1, 5.7; length of nasals ?, 

 13.7; breadth of rostrum at level of antorbital foramina 3.2, 3.7; 

 greatest breadth across zygomatic arches 20.4, 20.6. 



Diagnosis. Upperparts ranging from Snuff Brown to Buffy Brown 

 becoming paler on sides and flanks and approaching Tawny-Olive; 

 all of dorsum strongly suffused with blackish-brown hairs resulting 



285-134 O — 68 13 



