Pigmy Gerhils from British East Africa. 489 



This Voi Dipodillus is evidontly more noailv related to 

 the northern form D. diminutus, iVom tlie Northern Guaso 

 Nyiro than to the Naivaslia species, D. harwoodi. In 

 general dimensions it is intermediate between these two 

 species and in colour rather riclier and brighter than 

 diiuhiutus. 



This handsome little Gerbil I have named after tlie col- 

 lector, Mr. Bhiyney Percival, the value of whose iield-work 

 in British East Africa it wouUl be ditlicult to exaggerate. 



Dipodillus luteuSj sp. n. 



Allied to D. hariooodi, Thos., but distinguished by its very 

 much duller and paler colour. 



Size of body as in harwoodi, tail rather shorter. 



General colour of dorsal surface dirty drab-buff, near 

 " tawny-olive ^' (Ridgway, l'.'12j, washed over with greyish 

 brown, the resulting efi'ect very nuicli paler and more sub- 

 dued than in hariooodi. Backs of hands and feet and under 

 surface of body white. 



Skull sligiitly larger, with broader nasals and wider brain- 

 case. 



Dimensions of the type (measured in the flesh) : — 



Head and body 74 mm. ; tail 94 ; hind foot 21 ; ear 10. 



Skull: greatest length 26'y ; basilar length 19"3 ; zygo- 

 matic breadth 13'5 * ; interorbital constriction 5*4 ; breadth 

 of brain-case 12'8; length of anterior palatal foramina 5; 

 length of upper cheek-teeth (from front alveolar border to 

 back of last molar) 4. 



Hah. Southern Guaso Xyiro, Nyanza Province, British 

 East Afiica. Altitude G500 feet. 



Tijpe. Adult male. B.M. no. 13. 10. 18. Q5. Original 

 number 118. Collected by W. P. Lowe, Esq., on November 

 29th, 1912, and presented to the British Museum by G. P. 

 Cosens, Esq. 



The j)ale drab colour of this form immediately separates it 

 from haricoodi, diminutus, and percivali. 



We thus have four species of the genus THpodillus in 

 British East Africa : — (i.) D. diminutus, ivova. the Northern 

 Guaso Nyiro (altitude 3200 feet) ; (ii.) />. percivali, from 

 Yoi (altitude 2500 feet) ; (iii.) D. harwoodi, from Naivaslia 

 (altitude 6300 feet) ; and (iv.) 1). luteus, from the Southern 

 Guaso Nyiro (altitude 6500 feet). 



♦ Approximate 



