Mammals from the Upper Congo. 477 



56. Epimys (^ikomys, 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. 

 Toko, Welle. 



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

 distinct from the older known forms. 



In working out tiiis 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 characteis of the subgenera lying in their mammary 

 formulse, I may give the following preliminary synopsis : — 



A. Mamma less than 14, sepai'ated into pectoral 



and inguinal sets. 



a. Inguinal mammae 3 pairs. 



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



b. Inguinal mammae 2 pairs. 



a^. Pectoral mammae 2 pairs or less. 



a^. Size large ; form heavy ; mammae 



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



6'. Size small ; form delicate and mouse- 

 like ; mammae 1 — 2 = 6 or 2 — 2 = 8 . Praojnys, subg. n. 

 Z)2. Mammae 3 — 2 = 10 Mi/omysf, subg. n. 



B, ^Mammae more than 14, in continuous series . Mastoviys, subg. n. 



The tjpe of ^thomrjs would be Epimys hindei, Thos., o£ 

 Praomys E. tidlhergi, Thos., of Myomys E. colonus, Smith, 

 and of Mastoinys E. coucha. Smith. 



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

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



57. E2jimys (^^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 its 

 grevish flanks and whitish lower side of tail. 



* From ai66s, the basis of tho word Ethiopian. 

 t Mammary formula the same as in true Mus, 



