150 On new Species of Gerbillus and Taterillus. 



Taterillus gyas ) sp. n. 



A Taterillus with decidedly larger skull than any other. 



Size rather, but not conspicuously, larger than in T. emini. 

 General colour above strong and dark, near "'cinnamon," or 

 even approaching tl tawny " ; sides cinnamon-buff. Ears 

 rather large. Hands and feet white ; soles quite without 

 any trace of the usual transverse band of fur. Tail long, its 

 basal half brownish above, dull buffy below; terminal tuft 

 well developed. 



Skull conspicuously larger and more heavily built than in 

 any known Taterillus. Interorbital region rather more 

 parallel-sided than usual, the supraorbital ridges strongly 

 developed. Posterior palatal foramina extending from the 

 level of the front root of m l to the middle of m 8 . Bullae of 

 average proportional size. 



Dimensions of type (measured in flesh) : — 



Head and body 127 mm. ; tail (damaged in type, 175 mm. 

 in another specimen of about the same size) ; hind foot 34; 

 ear 21. 



Skull : greatest length 39 ; condylo-incisive length 35 ; 

 zygomatic breadth 1.9'5; nasals 15*6; interorbital breadth 7*3; 

 breadth of brain-case 15 8 ; zygomatic plate 7*3 ; palatal 

 foramina, anterior 7"2, posterior 4*6 ; horizontal diagonal 

 diameter of bulla 102 ; upper molar series 5*5. 



Hob. Kamisa, Dinder R., Sudan. 



Type. Adult female. B.M. no. 14. 3. 8. 24. Original 

 number 55. Collected 26th December, 1913, by Willoughby 

 P. Lowe, and presented by Abel Chapman. Two adult and 

 six young specimens examined. 



This Taterillus is remarkable for its large size and the 

 complete absence of the hairy band across the soles. It thus 

 considerably resembles the members of the genus Taterona. 

 But its elongate posterior palatine foramina show that its 

 place really is in this genus, all the more that T. gracilis 

 proves to be variable in the development of the same hairy 

 band. In that species the band is commonly absent, fairly 

 often slightly or partially developed, and occasionally fully 

 developed, all extremes occurring in any one locality. 

 This species ranges eastwards from the Gambia to Upper 

 Nigeria, where it occurs side by side with T. nigerice on the 

 Bauchi Plateau. The latter was first described from a 

 single specimen, but about a score of gerbils have been more 

 recently sent by Mr. Fox, and were all supposed to be of 

 the same species as the first. I now find, however, that they 



