266 MESSRS. OLDFIELD THOMAS AND M. A. C. HINTON ON 



A very fine series of these difficult field-mice, which will be 

 of great use when a closer study can be made of the group. 

 There is considerable variation in size among them, and perhaps 

 more than one form is included. 



The two members of the subgenus Mastomys in this region are 

 respectively this wild-living form, more or less rufous, with a 

 white or whitish sharply defined underside, and a house-haunting 

 race, dark smoky grey, with little-defined dull greyish-bufl^y 

 belly — indeed, corresponding closely in colour to house-haunting 

 Mus muscidus. A co-type of Sundevall's AIus ')nac7-6lej)is in the 

 British Museum (No. 46. 6. 2. 58) certainly agrees more with the 

 former than the latter, and we have therefore used that name for 

 the species. We also consider that Wagner's 3Itcs Umbatus 

 should be placed as a synonym of it. 



45. Rattus (Mastomys) — ugandce group. 



S. 779, 866, 898, 899, 900, 904, 908, 913, 916, 917. 924. 

 $. 780, 843, 853, 895, 897, 902, 905, 910, 925, 927. Kulme, 

 Wadi Aribo. 3300'. 



5. 513, 643, 1017, 1030, 1031. ^. 1016, 1018, 1024, 1028. 

 Jebel Marra at various altitudes. 



6 . 879. 2 ■ 938, 953. Zalingei. 2800'. 



The house-haunting members of liastomys are very much alike 

 all over ISTorthern Africa, and may even be all of one species. 

 For the present, however, we do not venture to give an exact 

 determination of these specimens. 



46. AcoMYS wiTKEUBYi de Wint, 



c?. 420, 428. 448, 477, 1059,1138, 1142, 1177. $. 421,429, 

 430, 431, 432, 433, 437, 438, 449, 455, 1070, 1076, 1093, 1125, 

 1139, 1140, 1143, 1145. El Fasher and neighbourhood. 



$ . 1036. Kurra, Jebel Marra. 5200'. 



5 . 606. Niurmeya, Central Jebel Marra. 7100'. 

 2 . 1121. Near Togato Hill s. 



d. 407, 1184. 9.1119,1183. Neighbourhood of Nahud. 



6. 403, 405, 1190, 1195, 1196. $. 1191. El Obeid and 

 neighbourhood. 



6 . 1020. N.E. Jebel Marra. 6500'. 



S. 1096, 1099, 1100, 1107, 1108, 1115, 1116, 1117, 1118. 

 5 . 1097, 1101, 1103, 1109, 1111, 1113. Jebel Maidob. 2700'. 



47. Arvicanthis testiculakis Sund. 



S . 1021, 1042, 1044, 1045, 1046, 1050, 1051, 1052, 1053, 1054, 

 1055, 1057, 1066. $ . 434, 439, 440, 442, 454. 1039, 1040, 1041, 

 1043, 1047, 1048, 1049, 1056, 1074. El Fasher. 



5 . 1067, 1072, 1075. $ . 1073. 35 miles N. of El Fasher. 



6 . 630, 664. $ . 629, 697, 709. South Jebel Marra. 

 $ . 562. Niurmya, Central Jebel Marra, 



$ . 517, 1025. N. Jebel Marra. 



