RODENTS OF LIBYA 141 



a portion of western Egypt. Later, Wassif (1956) recognized that these 

 gerbils from Siwa Oasis were distinct from those of the Mediterranean 

 littoral and assigned the coastal population to G. c. campestris and 

 those of the interior to G. c. dodsoni. Setzer (1958) concluded that the 

 gerbils from Siwa Oasis and those from the coastal areas were distinct 

 from each other and from both G. c. dodsoni and G. c. campestris; 

 accordingly, as new subspecies, he described the interior population as 

 G. c. haymani and the coastal population as G. c. wassifi. 



It is now known that G. c. haymani represents a subspecies which 

 can be distinguished from all other subspecies of Gerbillus campestris 

 by its larger size, and its range is limited to the low-lying, sandy 

 depressions surrounding Bahr el Tubat and Siwa Oasis. When speci- 

 mens become available from Giarabub Oasis in Cyrenaica Province, 

 Libya, and the Qattara Depression of Egypt, they probably also will 

 be referable to G. c. haymani. 



This small series was taken in the midst of an extensive growth of 

 Phragmites adjacent to the large saline lake of Bahr el Tubat. The 

 substrate in this habitat was hard, impervious, sandy clay which was 

 furrowed with cracks and crevices and covered with encrustations of 

 whitish salts. 



Gerbillus campestris patrizii (de Beaux) 



Dipodillus dodsoni patrizii de Beaux, Ann. Mus. Civ. Stor. Nat. Genova, vol. 55, 

 pp. 379-381, 1932 (El Giof, Cufra Oasis, Cyrenaica Province, Libya). 



Specimens examined. Thirty-two, from Cyrenaica: El Hauuari, 

 Cufra Oasis, 15; El Giof, Cufra Oasis, 17. 



Measurements. Averages and extremes of 10 adult males and 7 

 adult females from the type locality are, respectively: Total length 

 211.8 (183-233), 213 (192-225); length of tail 118.4 (97-131), 121.7 

 (110-127); length of hind foot 26 (23-28), 26.1 (24-27) ; length of ear 

 15.9 (15-18), 15.7 (14-17) ; occipitonasal length of skull 29 (27.6-30.3), 

 28.6 (26.1-28.8); length of auditory bulla 9.3 (8.5-10), 9.3 (8.4-9.5); 

 crown length of upper molariform toothrow 3.8 (3.4-4), 3.8 (3.3-4); 

 greatest breadth across zygomatic arches 15.2 (14.3-15.8), 15.2 

 (14-16.2) ; least interorbital breadth 5.2 (4.8-5.4), 5.2 (5-5.6) ; breadth 

 of rostrum at level of antorbital foramina 3.1 (2.8-3.3), 3.1 (2.8-3.3); 

 length of nasals 11.2 (10.5-11.7), 10.9 (9.7-11.4). 



Diagnosis. Representatives of this subspecies are extremely 

 variable in dorsal coloration ranging from Ochraceous-Tawny through 

 Avellaneous, Cinnamon, and Tawny-Olive. Nearly all specimens have 

 strong suffusions of dark colors on the middorsal region and rump, 

 which impart a streaked appearance to the entire dorsum. This 

 variegated dorsal color is perhaps the most diagnostic and unifying 

 character of this subspecies. Other characteristics of this subspecies 

 are as follows: Postauricular patches indistinct and suffused with buff; 



