EAST AFKICAN MAMMALS IN NATIONAL MUSEUM. 67 



1915. Masfomys Thomas, Ann. and Mag. Nat. Hist., eer. 8, vol. IG, p. 477. 



December. (R. coucha.) 



1916. liatlus UoLLiSTEU, Proc. Biol. Soc. Washington, vol. 29, p. 126. June 6. 



The typical rats (Genus Rattus) of the African continent have been 

 separated into five subgenera by Thomas in a recent paper.^ As 

 stated by Thomas, the detailed characters of these groups will need 

 much further study, but he has presented a key based entirely on 

 mammary formulae by which his named subgenera may be distin- 

 guished if one possesses breeding female examples. From a study 

 of the skulls and teeth of the rats of eastern Africa it is evident that 

 these groups are of unequal value, though all will doubtless prove 

 valid superspecific groups in the final revision. It is indeed probable 

 that the number of subgenera should be increased rather than 

 reduced. According to the arrangement of Thomas, the species 

 listed in this paper apparently fall into the following subgenera: 

 Rattus s. s. — Rattus rattus Mjahius (Allen). 



Rattus nigricauda loringi (Heller) . 

 ^ihomys. — Rattus kaiseri Jielleri Hollister. 



Rattus Icaiseri medicatus (Wroughton) . 

 Rattus Icaiseri norse (Wroughton) . 

 Rattus Icaiseri turneri (Heller) . 

 Rattus Icaiseri Tiindei (Thomas) . 

 Rattus Icaiseri manteufcli (Matschie) . 

 Rattus chrysopMlus voi (Osgood) . 

 Praomys. — Rattus tuUbergi jacksoni (de Winton) . 

 Rattus tuUbergi peromyscus (Heller) . 

 Rattus dennisd (Thomas) . 

 Rattus taitse (Heller) . 

 Rattus Stella Icaimosse (Heller) . 

 Myomys . — Rattus fumatus fum atus (Peters) . 



Rattus fumatus suhfuscus (Osgood). 

 Rattus tana (True). 

 Mastomys. — Rattus coucha ismailise (Heller) . 



Rattus coucha ugandx (de Winton) . 

 Rattus coucha tinctus Holhster. 

 Rattus coucha neumani (Heller) . 

 Rattus coucha panya (Heller) . 

 Rattus coucha liildehrandtii (Peters) . 

 Rattus coucha durumsc (Heller) . 

 The typical subgenus Rattus should probably be dropped from 

 the East African hst. The first species, Rattus rattus Icijahius, would 

 be better placed in a subgenus Epimys; and the proper allocation of 

 Rattus nigricauda loringi is uncertain. 



J Aim. and Mag. Nat. Hist., ser. 8, vol. 16, p. 477. December, 1915. 



