RODENTS OF LIBYA 139 



of these gerbils in eastern Tunisia and Algeria. Members of this 

 subspecies have no physical contact with those of G. c. wassiji of 

 the Mediterranean littoral, and it is doubtful if gene flow is a com- 

 mon occurrence between animals of G. c. dodsoni and G. c. haymani, 

 whose range includes the isolated depressions and the oases of Giara- 

 bub and Siwa far to the east. 



Ecological observations. In the Gebel Nefusa, these gerbils 

 inhabit the crevices and fissures of the rocky outcroppings along 

 canyons that descend onto the coastal plain. Those from the Gebel 

 es Soda were taken among the coarse extrusions of volcanic material 

 near the highest point of the gebel. The large series from Brach was 

 obtained from moist areas supporting dense growths of sedges and 

 grasses associated with agriculture. At Temenhint Oasis, two speci- 

 mens were obtained from the sand surrounding date palms. Near 

 Ubari, two additional specimens were obtained from the practically 

 denuded margins of a shallow wadi which supported sparse growths 

 of acacia and occasional dried grasses. Near Ghat the habitat was 

 typical "hamada" desert without any visible plant cover. 



At the oases of Bzema and Tazerbo, these gerbils occur abundantly 

 in the dense pockets of sedges that occupy the low-lying interior 

 portions of the palm groves. In fact, at Tazerbo, trap yields exceeded 

 85 percent and were the highest recorded for Libya. 



A specimen from Tazerbo Oasis, an adult male, 325387, is strikingly 

 different in color from other specimens from this locality. It is uni- 

 formly gray throughout except for the tail, which is strongly suffused 

 with brown. 



One specimen, an adult female, 325403, from Bzema Oasis is heavily 

 suffused with white on the dorsum, the tail has uniform admixtures 

 of white hairs throughout, and the ears and feet are extremely pale. 

 This specimen is the only example of albinism or partial albinism 

 observed in this species. 



(Jerbillus campestris haymani Setzer 



Gerbilius campestris haymani Setzer, Journ. Egypt. Publ. Health Assoc, vol. 33, 

 no. 6, pp. 208-209, 1958 (Siwa Oasis, Western Desert Governonite, Egypt). 



Specimens examined. Four, from Bahr el Tubat, Cyrenaica 

 Province, Libya. 



Measurements. Measurements of two adult males, 325501 and 

 325502, and two adult females, 325503 and 325504, from the above 

 locality are, respectively: Total length 268, 240, 239, 241; length of 

 tail 160, 141, 136, 140; length of hind foot 29, 30, 27, 28; length of 

 ear 17, 17, 17, 17; occipitonasal length of skull 32, 31.2, 31.5, 31.5; 

 length of auditory bulla 10.3, 9.8, 10, 10.1; length of upper molari- 

 form toothrow 3.9, 3.8, 4.2, 4.2; greatest breadth across zygomatic 



