MAjSOIALS of AXGLO-EGYPTIAX SUDAX — SETZER 495 



short and narrow; the braincase is much flattened; the nasals are 

 narrow but relatively long; and the lachrymal bone is small. 



The type is an old adult with much-worn teeth. Hinton and 

 Kershaw (1920, p. 99) considered soror to be a member of the hen- 

 vevuta complex, which seems to be correct. The tail in both soror 

 and flavipes is untufted, but whether this is of significance in allocatirg 

 species to groups is quite questionable. 



Genus Taterillus Thomas 



So far as can be determined at this time, there is no character by 

 which emini, anthonyi, butleri, rufus, perluteus, and clivosus can be 

 distinguished as species. 



Hatt (1934, p. 3) mentions integradation of anthonyi with butleri, 

 and in certain specimens from Delami, Nuba Mountains, there is 

 what appears to be integradation with rufus. 



While no actual intergradation can be demonstrated between 

 gyas and any of the contiguous kinds, there are certainly no morpho- 

 logical differences to warrant retention of this form as a full species. 



The peripheral kinds, gyas, emini, and clivosus, are all dark in color, 

 while those in the center of the area under consideration are paler 

 and ending in the palest of the group in perluteits. 



Hatt (1934, p. 3) when describing anthonyi, referred to the species 

 congicus as a subspecies of T. eraini. From the degree of morpholog- 

 ical difference, and o%vuig to the fact that specimens from Wau are 

 immediately separable as T. e. butleri and as T. congicus, I feel that 

 congicus should stand as a full species untU its relationship with an 

 allied species, T. nigeriae, has been clarified. It is certainly not a 

 part of the complex known as the emini group. 



Since T. rufus and T. butleri are shown to be only subspecies of one 

 species, the name Gerbillus {Taterina) lorenzi Wettstein, which has 

 been considered synonymous with T. butleri, should be transferred to 

 the synonymj^ of T. e. rufus which shares its type locality but has 

 page preference. 



Color, as such, in these gerbils is relativelj^ constant but there is 

 some divergence in one given population such as may be seen in 

 specimens from the vicinity of El Fasher and from Torit. In com- 

 parison with the degree of variation found in the crania (in regard 

 to the auditory bullae, the lateral bowing of the anterior palatal 

 foramina, and other characters) color varies not at aU. It is only 

 by comparing the skin and the skull with kno^^Tl specimens that one 

 can arrive at anv satisfactorv determination. 



386559 — 56- 



