RODENTS OF LIBYA 99 



(10-10.8), 10.3 (10-10.6), [10.8]; crown length of upper molariform 

 toothrow 3.9 (3.8-3.9), 3.9 (3.8-4), [3.8]; greatest breadth across 

 zygomatic arches 15.9 (15.4-16.8), 15.8 (15.4-16.5), [16.8]; least 

 interorbital breadth 5.8 (5.5-6.3), 5.8 (5.4-6), [6.3]; breadth of 

 rostrum at level of antorbital foramina 3.2 (3.1-3.4), 3.3 (3-3.4), [3.4]; 

 greatest length of nasals 11.5 (11.4-11.8), 11.4 (11.3-11.6), [11.8]. 



Diagnosis. Sides and dorsum variegated or particolored ranging 

 from Pinkish-Cinnamon to Cinnamon; all areas, particularly the 

 sides, with admixture of lighter colored hairs; postauricular patch 

 prominent and Light Buff; mystacial, cir cum orbital, and pectoral 

 areas Pinkish Buff; eye ring black; underparts generally white, but, 

 in some specimens, with a ventromedian line suffused with Light 

 Pinkish Cinnamon; dorsal surface of forelegs, hindlegs, and feet Pale 

 Pinkish Buff; fore and hind feet sparsely haired ventrally and bearing 

 five digits with claws; pinna of ear relatively long and almost naked, 

 Cinnamon-Buff basally and Deep Grayish Olive distally, and with 

 row of delicate buff-colored hairs on anterior margin; vibrissae 

 relatively short and composed of about equal numbers of white and 

 brown hairs; tail faintly bicolored Cinnamon-Buff dorsally and 

 Pinkish Buff ventrally and bearing an indistinct Drab terminal tuft 

 or pencil. Skull: Relatively large and compact; braincase moderately 

 inflated; interorbital region with distinct longitudinal, median fossa; 

 zygomata relatively heavy; upper molariform toothrow relatively 

 short, straight, yet divergent anteriorly; anterior palatine foramina 

 large and widely open; posterior palatine canals markedly wide and 

 bowed slightly laterad; auditory bullae relatively short and moder- 

 ately inflated ; nasals relatively long. 



Comparisons. This new subspecies differs markedly from specimens 

 representing Gerbillus eatoni eatoni from 15 kilometers west-northwest 

 of Marble Arch, Tripolitania Province, and those from 10 kilometers 

 south of Agedabia, Cyrenaica Province, in darker, more variegated or 

 particolored dorsal pelage (Cinnamon as opposed to Clay Color), more 

 anteriorly divergent and shorter upper molariform toothrows, shorter, 

 narrower, and less inflated auditory bullae, greater length of skull, 

 shorter and wider posterior palatine canals, longer nasals, and less 

 doming of the braincase. 



From a subadult, topotypical specimen of G. e. eatoni from El 

 Cusher, Tripolitania Province, specimens of comparable age from 

 Coefia are paler in dorsal color, have less distinctly bicolored tails, 

 lack the strong suffusions of brownish hairs on the middorsum, have 

 relatively and absolutely markedly smaller arid less inflated auditory 

 bullae, much less inflated braincases, and longer posterior palatine 

 canals. 



From specimens representing Gerbillus eatoni inHatus from 10 kilo- 

 meters southwest of Fort Capuzzo, Cyrenaica Province, G. e. versicolor 



