90 U.S. NATIONAL MUSEUM BULLETIN 2 75 



patches conspicuous and white; supraorbital patch white; mystacial, 

 circumoral and pectoral areas, forelegs, hindlegs, feet, and entire 

 underparts pure white; pinna of ear sparsely haired, darker colored 

 distally, Cinnamon-Buff on anteromedial surface, and bearing a row 

 of fine buffy hairs on anterior margin; vibrissae short and composed 

 almost entirely of white hairs; fore and hind feet bearing five digits 

 with claws; tail relatively short, distinctly bicolored Cinnamon-Buff 

 dorsally, Pale Pinkish Buff ventrally, and with faint terminal Avella- 

 neous pencil. Skull: Relatively small, gracile, and flattened in profile; 

 anterior palatine foramina relatively wide; upper molariform tooth- 

 rows bowed slightly laterally, relatively short, and individual teeth 

 small; auditory bullae relatively small; zygomatic arches bowed 

 slightly medially. 



For comparisons with G. a. aureus and G. a. nalutensis, see accounts 

 of those subspecies. 



Remarks. This subspecies is known only from the coastal plain in 

 the vicinity of Sirte on the western shores of the Gulf of Sirte, but 

 its range probably includes a much greater area to the east. I was 

 unable to obtain additional specimens of this subspecies and, conse- 

 quently, obtained no firsthand data regarding their habitat preferences. 

 Setzer (1956, p. 181) describes the habitat at the type locality as 

 consisting of "loose coastal dunes where the vegetation had been 

 heavily eaten by domestic animals." The pale dorsal color of these 

 gerbils may result from a genetic response to the color of these sandy 

 areas. 



One specimen, no. 302096, from 5 kilometers east of Sirte has large 

 molariform teeth and anterior palatine foramina, a flattened brain- 

 case, and is pallid in dorsal color. These characters are typical of 

 G. a. faviUus, and this specimen is referred to that subspecies. This 

 same specimen, however, in size of body, external measurements, 

 and the small size of the skull closely resembles animals belonging to 

 GerbiUus (jerbiUus. This parallelism probably does not indicate a direct 

 relationship with G. gerbillus but more likely is the result of a response 

 to similar environmental conditions or represents an extreme in the 

 range of variation for the subspecies G. a.faviUus. 



(lerbillus aureus nalutensis, new subspecies 



Holotype. Adult male, skin and skull, USNM 321816, from 40 km 

 ENE Nalut, Tripolitania Province, Libya: obtained Nov. 12, 1961, 

 by H. W. Setzer, original no. 3113. 



Specimens examined. Forty, all from the type locality. 



Diagnosis. Upperparts Tawny-Olive with strong suffusion of 

 blackish hairs in interauricular and subanricular regions and on rum]); 

 sides and flanks paler than dorsum; eye ring black; postauricular and 



