MAMMALS OF ANGLO-EGYPTIAN SUDAN — SETZER 519 



density top and bottom. Upperparts not delineated from white of 

 belly by a line of pure color. Skull relatively small, anterior palatine 

 foramina short, upper molars small, pterygoid region nearly triangular 

 in form, zygomatic arches bowed downwards but not laterally, 

 auditory bullae relatively small, rostrum relatively long and narrow, 

 and supraorbital bead moderately developed and passing caudad into 

 lateral ridges on skull. 



Measurements of the Type Specimen: Length of head and body 

 120; length of tail 124; length of hind foot (s. u.) 22, dry c. u. 24; 

 length of ear 20; greatest length of skull 31.2; condyloincisive length 

 29.2; length of anterior palatine foramina 6.8; crown length of upper 

 toothrow 4.3; least interorbital width 4.4; width of rostrum at level of 

 antorbital foramen 3.9; length of nasals 12.2; greatest width across 

 zygomatic arches 15.1. 



Comparisons: From the type of Mastomys coucha (=natalensis), 

 M. kulmei differs in lighter, brighter color, somewhat longer hind feet, 

 longer tail, and longer ears. The skull differs in that the anterior 

 palatine foramina are shorter, the molars smaller, the pterygoid 

 region not flaring laterally but the pterygoid wings being carried 

 nearly straight back and the fossae being shallow instead of deeply 

 excavated, and rostrum longer and slenderer. 



From the type of M. n. ugandae, which is an immature male, M, 

 kulmei differs in smaller size, lighter and brighter color, and, in animals 

 of comparable age, a markedly smaller skull in all respects. The 

 teeth are smaller and the pterygoid region differs as described for M. 

 coucha. 



From the type of M. n. blainei, M. kulmei differs in lighter, brighter 

 color and longer tail. The skull differs in generally smaller size, 

 shorter anterior palatine foramina, pterygoid region as described for 

 M. coucha, and a longer, narrower rostrum. 



From M. n. macrolepis, as known from El Kowa, M. kulmei 

 differs in smaller size and lighter, brighter color. The skull is in all 

 respects smaller and far more delicate, with relatively as well as 

 actually larger auditory bullae. 



Remarks: Mastomys kulmei occurs with another member of the 

 genus in most of its range. They may be distinguished from one 

 another by the generally darker color of the coucha kinds and by 

 the skulls, which may be separated by the characters as set forth under 

 comparisons. 



Thomas and Hinton (1923, p. 266) remarked that there appeared to 

 be two kinds of Mastomys in the Lynes-Lowe collection but post- 

 poned any naming of these kinds, merely referring them to the earlier 

 known M. macrolepis and M. ugandae group. 



