472 Mr. O. Thomas on the 



ridges, but these are irregular in development and shape, 

 and are considerably surpassed in height by the lateral 

 cusps, especially that at the antero-internal corner of each 

 tooth. 



Range. Ethiopian Region, most numerous in the east and 

 south. 



6. Protoxerus. m 



Type. 

 Xerus, subg. Protoxerus, Major, P. Z. S. 1893, p. 189 . . P. stangeri. 



Size very large. Skull heavily built, of normal shape ; 

 upper part of anterior zygoma-root bowed over as in the 

 Spiny Squirrels {Xerus, &c.), its ridge carried forward beyond 

 the maxillo-premaxillary suture; anteorbital foramen rounded, 

 often very large. 



Cheek-teeth r, in structure somewhat intermediate between 



those of Xerus and the true Squirrels. {Cf. figures by 

 Major, I. c.) 



Range. West African Forest region, eastvirards into 

 Uganda. 



The six known forms of Protoxerus were worked out by 

 me in 1906 *, and considered all to be subspecies of 

 P. stangeri. 



7. Epixerus. ^ypg 



Genus novum J^- wilsoni 



{Sciurm loilsoni, du Ch.). 



General characters as in Protoxerus^ but the skull elongated, 

 with a long muzzle, as in Funisciurus. Anteorbital foramen 

 narrow, compressed, slit-like. Bullae comparatively very 

 small. Palate produced behind molars further than in any 

 of the previous genera, more approaching the Xerus group. 



Ciieek-teeth ■^. Lower molars simple, basin- shaped, each 



with four well-marked cusps at the corners. 



Range. West Africa. 



The two Giant Squirrels that I refer to this genus, 

 E. wilsoni and ehii^ were transferred by de Winton from 

 Major's Protoxerus to Funisciurus, a transference which I 

 accepted in my paper on African Giant Squirrels, but I now 

 think that, judging by the characters of the zygomatic ridge 

 and molar structure, their resemblance to Funisciurus is 

 merely accidental, and that they ought to constitute a group 

 by themselves. 



* Ann. Mag. N. H. (7) xviii. p. 29-5 (1906). 



