referred to the Genus Meriones. 271 
backwards as the occipitals, and their postmeatal portion is 
but little swollen, with a straight posterior margin. 
Dimensions of the type: 
Head and body 161 mm.; tail 183; hind foot 41 ; 
ear 28. 
Skull: greatest length (median) 43; condylo-incisive 
length 38°5; zygomatic breadth 22°5; nasals 16°6; inter- 
orbital breadth 7; least breadth across brain-case 1772 ; 
meatal breadth 21:3; palatine foramina 8-3 ; upper molar 
series 6°2. Bulle: greatest diagonal horizontal diameter 13 ; 
distance from back of bulla to front of meatus 9; supra- 
meatal triangle, length 3°5, height 2. 
_ Hab. (of type). Dopulan, Bachtiari Mountains, 120 miles 
N.E. of Ahwaz, Persia. Alt. 6000'. 
Type. Adult male. B.M. no, 5. 10. 4. 35. Original 
number 36. Collected 18th April, 1905, by R. B. Woosnam ; 
presented by Col. A. C. Bailward. 
In my account of the Bailward collection * I referred this 
exceedingly handsome gerbil to M. persicus ; but now that I 
realize the systematic value of the difference in size of the 
bulla, I consider it should be distinguished specifically from 
that animal. 
Meriones isis, sp. n. 
The Lower Egypt representative of the c group, that of 
which M. shawi is typical. 
Size rather less than in true shawi. General colour rather 
greyish or drabby buff, but of the only two available skins 
one has been exhibited for many years and the other skinned 
out of spirit. Underside white, the hairs slaty at base. 
Light ear-patches little developed. Tail rather shorter than 
head and body, dull whitish or buffy whitish on the sides and 
for its whole length below, slightly darkened above by 
blackish hairs, but very little tufted at the end, the longest 
hairs barely 10 mm. in length. 
Skull, as compared with that of MM. guyonz, the South- 
Algerian and Tripolitan representative of A. shawi?, of similar 
general form, with comparatively small bull and small 
suprameatal triangles. Bulle, however, slightly smaller, and 
interorbital breadth distinctly greater, this latter being the 
chief difference between the Egyptian and Algerian animals. 
Palatine foramina reaching to the level of the anterior root 
of m’, 
* P. ZS. 1905, ii. p. 523. 
