2G6 Mr. 0. Thomas 07i Qerhih 



Dimensions of the type : — 



Head and body 129 mm. ; tail 125 ; hind foot 30; ear IC. 



Skull : median length 38'5 ; diagonal length 41 ; zygo- 

 matic breadth 21 ; interorbital breadtli 5*9; bimeatal breadth 

 23'5 ; palatine foramina 7*1 ; upper molar series 5'3. Bull;e : 

 diagonal lengtii 16*8 ; meatal length 14'5 ; suprameatal 

 triangle, length 6*4, height 5*7. 



Ilab. Tripoli. 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. S. 

 Whitiiker, Esq. Fourteen sj)ecimens examined. 



This Tripoli gerbil is very closely allied to palUdiis, but 

 seems to differ fairly constantly in the cliaiacters above 

 noted. Tlie Sudan animal is itself very near to true 

 M. crassus of Sinai, but has rather less enormous bull*. 



Tiie specimens representing both this and M. lihycus 

 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 bullae and suprameatal triangles in the genu.«, 

 and together form group a. 



Jileriones pelerinus, sp. n. 



A species of group a allied to M. crassus, but with larger 

 teetli and longer palatine foramina. 



Size about as in M. crassus or a little larger. General 

 colour paler and greyer than in that species, a little darker 

 than " pinkish bufty the tips of tiie hairs blackened on tlie 

 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, 

 wdiitish buff, the terminal crest black, not heavily developed, 

 extending along about 35 mm. at its end, its longest hairs 

 12 mm. 



Skull, like C7Xissiis, with enormous bullae, which project 

 backwards about 3 mm. behind the level of the occiput, and 

 liave their ])remeatal swelling close against, and surpassing 

 below, the posterior corner of the zj-gomata. Suprameatal 

 triangle very large, with rounded angles. Palatal foramina 

 projecting backwards between the roots of ni^. 



* P. Z. S. 1902, p. 9. 



