190 U.S. NATIONAL MUSEUM BULLETIN 2 75 



Other species of rodents occurring in these more lush habitats of 

 the Libyan coastal plain include Gerbillus henleyi, Gerbillus campestris, 

 Gerbillus eatoni, Jaculus orientalis, Spalax ehrenbergi, and Gerbillus 

 kaiseri. 



Psammomys obesus obesus Cretzschmar 



Psammomys obesus Cretzschmar, Riippell Atlas, 58, pi. 22, 1828 (near Alexan- 

 dria, Egypt). 



Specimens examined. Sixteen, from Cyrenaica: 20 km E To- 

 bruch, 13 (1 skin only) ; 5 km W Bardia, 3. 



Measurements. Averages and extremes of six adult females and 

 the measurements of one adult male, 325646, from 20 kilometers east 

 of Tobruch, are, respectively: Total length 285.8 (271-300), 288; 

 length of tail 122.5 (110-128), 110; length of hind foot 35.2 (35-36), 

 38; length of ear 14.8 (14-17), 15; greatest length of skull 42.2 (40.4- 

 43.5), 40.5; length of auditory bulla 14.3 (13.5-14.6), 13.6; alveolar 

 length of upper molariform toothrow 7 (6.5-7.6), 6.7; least inter- 

 orbital breadth 6.7 (6.3-7), 6.8; length of nasals 16.3 (15.3-17.6), 

 16.3; breadth of rostrum at level of antorbital foramina 4.3 (4-4.6), 

 4.5; greatest breadth across zygomatic arches 24.9 (23.8-25.5), 23.6; 

 least breadth between parietal ridges 10.9 (10.5-11.2), 10.5. 



Diagnosis. Pelage of dorsum dense and long but in old specimens 

 heavily worn, particularly in middorsal region where denuded patches 

 often disclose plumbeous-colored basal portions of hairs; sides 

 varying from Pale Orange- Yellow to Light Orange- Yellow and 

 flanks becoming darker in middorsal region approaching Ochraceous- 

 Tawny; all parts of dorsum interspersed with brownish hairs; thus 

 entire upperparts formed from a variety of colors and color patterns 

 resulting in a pronounced variegated appearance; area between the 

 ears and above the eyes, however, more uniformly colored Cinnamon 

 or Ochraceous-Tawny ; circumorbital areas Light Ochraceous-Buff 

 heavily suffused with black; this color pattern extending anteriorly 

 along the rostrum and posteriorly to the level of the ears ; circumoral 

 and mystacial areas and dorsal surfaces of fore and hind feet and 

 legs ranging from Warm Buff to Antimony Yellow, the latter being 

 more concentrated in the scapular regions, which appear more brightly 

 colored than the surrounding pelage; ears relatively short, medial 

 surface of pinna with uniform covering of buffy hairs; anterior margin 

 of pinna with prominent row of rather stiff hairs, which project 

 backward into inner surface of the pinna; vibrissae stiff and relatively 

 short, formed of about equal numbers of black and buff-colored hairs ; 

 palmar surfaces of front feet naked and bearing distinct metacarpal 

 tubercles; four primary digits (2-5) with evenly spaced transverse 

 ridges and terminating in well-developed claws; first digit rudimentary 

 without functional claw; plantar surfaces of hind feet with irregular 



