256 MESSRS. OLDFIELD THOMAS AND M. A. C. H.TNTON OJST 



Lai-ger than chadensis and leti-couonlrinus. Colour about as in 

 the latter. 



Upper surface of body very much as in leucoicvibrinus, that is 

 to say near " sayal-brov/n," decidedly darker than in chadensis. 

 Light lateral line sharply defined white. Dull lateral line darker 

 than the back. 



Skull decidedly larger than in chadensis and leiijcoumbrinus, the 

 total length of the skull about 61-63 mm. 



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



Head and body 270 mm. ; tail 246 ; hind foot 65 ; ear 17. 



Skull : greatest length 62 ; eondylo-incisive length 58*5 ; 

 zygomatic breadth 33 '5 ; nasals 19 ; palatilar length 31°7 ; cheek- 

 teeth exclusive of ^^^ 12 ; lower cheek-teeth 13. 



Hah. Region of Wadi Aribo, extending eastward to Jebel 

 Marra. Type from Zalingei. 



Type. Adult female. B.M. No. 23.1.1.99. Original 

 number 722. Collected 20 May, 1921. 



Distinguished both from leucoumbrinus * and chadensis by its 

 larger size, and from chadensis by its darker colour, though the 

 Jebel Mari-a specimens are a little paler than those from the 

 Wadi Aribo. 



28. Heliosciurus bongensis canaster, subsp. n. 



6. 671, 705. $. 663, 706. Foot-hills of Jebel Marra. 

 4000'. 



A paler and greyer form of the II. bongensis of the Bahr-el- 

 ' Ghazal. 



Size a,s in bongensis, Dorsal colour as in that animal or incon- 

 spicuously paler. But sides, forearms, hips, and backs of legs 

 far paler, whitish or greyish white. Under surface quite white 

 to the bases of the hairs, a patch of buffy on each side of tarsus. 

 Top of muzzle greyish white, much paler than the crown. White 

 supra- and infra-orbital lines well marked ; ears prominently 

 whitish. Upper surface of hands ixnd, feet greyish white. Tail 

 similarly ringed to that of bongensis, but paler throughout. 



Skull about as in bongensis, equally smaller than that of multi- 

 color. Nasals rather longer. 



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



Head and body 178 mm. ; tail 217; hind foot 44; ear 15. 



Skull : greatest length 44 ; eondylo-incisive length 38-7 ; 

 zygomatic breadth 26; nasals 14x6'8; interorbital breadth 13; 

 maxillary tooth-row 8"8. 



* With regard to leucownhrinws, that species was founded by Riippell in so vague 

 and general a manner that it needs pinning down to some particular form, as it may 

 have included quite a number of distinct races. There is in the British Museum one 

 of his original specimens, purchased of the Seuckenburg Museum (B.M. No. 79 h), and 

 this we propose to select as a lectotype. It is of a pale cinnamon-brown colour, and 

 corresponds in size with specimens having a skull-length of about 58 mm., its lower 

 cheek-teeth 12 mm. It was received as from " Abyssinia," but how far this is 

 trustworthy we are not in a position to state. 



