266 Mr. O. Thomas on Gerbils 
Dimensions of the type :— 
Head and body 129 mm. ; tail 125; hind foot 30; ear 16. 
Skull: median length 38°5; diagonal length 41; zygo- 
matic breadth 21 ; interorbital breadth 5°9; bimeatal breadth 
23-5; palatine foramina 7°1 ; upper molar series 5°3. Bulle : 
diagonal length 16°38; meatal length 14°55; suprameatal 
triangle, lenyth 6°4, height 5°7. 
Hab. Vripoli. ‘Type from Gebel Limhersuk, in the north- 
west part of the country. 
Type. Adult male. B.M. no. 2.11.4. 64. Collected 
19th July, 1901, by E. Dodson. Presented by J. I. 8. 
Whitaker, Esq. Fourteen specimens examined. 
This ‘Tripoli gerbil is very closely allied to pallidus, but 
seems to differ fairly constantly in the characters above 
noted. The Sudan animal is itself very near to true 
M. crassus of Sinai, but has rather less enormous bulle. 
The specimens representing both this and -M/. libyeus 
caudatus were included under Meriones schousboei in my 
account of the Tripolitan mammals presented by Mr. Whitaker 
in 1902 *. 
M. crassus, pelerinus, and pallidus are the species with 
the largest bulle and suprameatal triangles in the genus, 
and together form group a. 
Meriones pelerinus, sp. n. 
A species of group a allied to A/. crassus, but with larger 
teeth and longer palatine foramina. 
Size about as in JM, crassus or a little larger. General 
colour paler and greyer than in that species, a little darker 
than “ pinkish buff,’ the tips of the hairs blackened on the 
back, clearer on the sides. Belly quite white, not very 
sharply defined laterally. Lighter eye and ear-markings not 
strongly marked. Proectote of ears dark pinkish buff. 
Hands and feet white; soles with their posterior halves 
naked except just along the edges. Tail not very long, 
whitish buff, the terminal crest black, not heavily developed, 
extending along about 35 mm. at its end, its longest hairs 
12 mm. 
Skull, like crassus, with enormous bull, which project 
backwards about 3 mm. behind the level of the occiput, and 
have their premeatal swelling close against, and surpassing 
below, the posterior corner of the zygomata. Suprameatal 
triangle very large, with rounded angles. Palatal foramina 
projecting backwards between the roots of m. 
* P. ZS. 1902, p. 9. 
