Mammals from the Upper Congo. 477 



56. Epimys (sEthomys, subgen. nov.) kaiseri, Noack. 



922, 932, 933, 934, 939, 948, 953, 965, 966, 967, 981, 

 982, 985, 992, 1016, 1022, 1029, 1042, 1045, 1052, 1083, 

 1096, 1108, 1109, 1137, 1187, 1197, 1215, 1217, 1246, 1257, 

 1425, 1427, 1436, 1441, 1442, 1446, 1447, 1451,1459, 1520. 

 Poko, Welle. 



These may represent Heller's E. k. centralis, if really 

 distinct from the older known forms. 



In working- out this series of African Epimys, I come, not 

 for the first time, to the conclusion that the classification of 

 these difficult animals would be advanced if certain of the 

 " groups " were given subgeneric names. Detailed characters 

 will need much further material and study, but the most 

 obvious characters of the subgenera lying in their mammary 

 formulae, I may give the following preliminary synopsis: — 



A. Mamma less than 14, separated into pectoral 

 and inguinal sets. 



a. Inguinal mammas 3 pairs. 



Mammas 2 — 3 or 3 — 3 = 10 or 12 Epimys, s. s. 



b. Inguinal mammas 2 pairs. 



a 2 . Pectoral mammas 2 pairs or less. 



a 3 . Size large ; form heavy ; mammas 



0—2=4 or 1—2 = 6 JEthomys *, subg. n. 



b ? \ Size small ; form delicate and mouse- 

 like ; mammas 1 — 2 = 6 or 2 — 2 = 8 . Praomys, subg. n. 



h 1 . Mammas 3 — 2 = 10 Myomysf, subg. n. 



13. Mammas more than 14, in continuous series . Mastomys, subg. n. 



The type of yEthomys would be Epimys hindei, Thos., of 

 Praomys E. tullbergi, Thos., of Myomys E. colonus, (Smith, 

 and of Mastomys E. concha, Smith. 



I hope to give later more detailed characters of these sub- 

 genera, with lists of the species that fall into them. 



57. Epimys (^Ethomys) longicaudatus ituricus, Thos. 

 T. c. p. 149. 



759, 767, 848, 849, 857, 869. Medje. 



970, 1013, 1017, 1031, 1129. Poko. 



As already stated, this rat is distinguished from true 

 E. longicaudatus, better known as E. sebastianus, by it3 

 greyish flanks and whitish lower side of tail. 



* From didos, the basis of the word Ethiopian. 

 f Mammary formula the same as in true Si us. 



