MAMMALS OF ANGLO-EGYPTIAN SUDAN — SETZER 515 



In striatus, the anterior palatine foramina are nearly parallel-sided 

 as opposed to constricted anteriorly in macculus. The upper tooth- 

 row, the least interorbital breadth, the breadth of the rostrum, and 

 the coudyloincisive length are all noticeably larger in striatus than 

 in macculus. 



Remarks on Rattus-Mke genera 



In attempting to identify the various species of rattoid animals 

 found in the Sudan, extreme confusion was apparent. Without a 

 complete revision of the "genera" entailed in this group, the follow- 

 ing remarks are of necessity limited in their application. It is ap- 

 parent, however, that so far as the kinds found in the Sudan are con- 

 cerned these differences and similarities do apply. 



It is apparent to me that EUerman and his co-authors have gone 

 to an extreme in what they classify under the genus Rattus. Cer- 

 tainly there appears to be a superfluity of generic names applied to 

 the i?a/^ws-hke rats in central Africa. Among these I am primarily 

 concerned with Aethomys, Mastomys, Praomys, Hylomyscus, and 

 Myomys. Ellerman, Morrison-Scott, and Hayman (1953) consider 

 these genera to be, at best, subgenera of the genus Rattus, and they 

 consider the name Myomys to have no status since the type species 

 is not certainly identifiable. For the Anglo-Egyptian Sudan, Aeth- 

 omys, Mastomys, and Praomys are distinguishable from typical Rattus 

 rattus at both the generic and specific levels. The genus Praomys as 

 here understood contains the names previously referred to Myomys 

 and Hylomyscus. I can find no means by which either of the above 

 genera can be distinguished from Praomys even at the subgeneric 

 level, but the species can be distinguished without question. It is 

 true that this particular complex is in dire need of a revision which 

 is not based on a single character only. 



The significance of the mammary formula is at the present of no 

 importance in determining generic rank among these animals since 

 males, and females taken other than in the breeding season, do not 

 show the mammae at all. Table 1 is based on cranial characters that 

 are consistent in the specimens and species examined from the Sudan 

 and which I feel are of sufficient importance to warrant retaining these 

 names as full genera. This has been an extremely difficult assemblage 

 to classify, but the characters of the table do separate the genera oc- 

 curring together. It is apparent that Ellerman and his co-authors, 

 in lumping so many genera and species, are either unaware of or have 

 ignored the matter of convergence in these particular animals. 



