•i(J XF.RUS. 



JLei'us. 



The harshness of the fur , the shortness of the ears , the 

 long claws and the elongated middle toe characterise this 

 genus. Palate extending a rather considerable distance behind 

 the molars. Jugalia depressed. The hairs are short and very 

 sparingly spread , especially on the under parts of the body : 

 they are attenuated at both ends, acutely pointed and flat- 

 tened. Each hair is provided with a longitudinal channel 

 or groove , and so the hairs are not circular in a transverse 

 section; they are very rigid and but little flexible. The 

 hairs of the depressed tail are always less rigid. 



The ear is less developed than in any other Squirrel 

 and is^ either quite absent or is shaped nearly as the human 

 earconch. 



The middle toe of fore and hind legs is longer than the 

 other toes. All the claws are more developed than in other 

 Squirrels and are nearly straight. 



The characters cited clearly indicate a peculiar manner 

 of living and indeed the species of this group have with- 

 out exception burrowing habits; contrary to the species 

 of the genus Sciurus which are Tree-Squirrels , they are 

 Ground- Squin^els . 



The several authors and compilers have described or cited 

 a large number of species as belonging to this genus, for 

 instance: Wagner six, Temminck six , Giebel five, Fitzin- 

 ger eleven. Gray three with one variety, Huet eight and 

 Trouessart nine species. — After a very careful examination 

 and after having seen nearly all the specimens of this group 

 contained in the different Musea, I cannot distinguish more 

 than three well defined species. One of these, Xerus capen- 

 ais , is only found in South Africa , the two others Xerus 

 erythopus and Xerus ratilus inhabit both East and West 

 Africa and apparently do not occur in those districts , where 

 the South African species is living. 



According to the presence or absence of the external ear 

 and to the form of the skull I distinguish the following groups: 



Notes from tlie Leyclen IVIuseum, "Vol. IV. 



