List of the liodents of South Africa. 203 



Skull with the interorbital region somewhat wider than in M. 

 typicus ; teeth as in the other species. * 



Distribution. Western part of the Colony ; the types were 

 obtained on the Cape Flats near Cape Town, by Messrs. E. L. 

 Layard and M. Bishop. 



SUB-FAMILY MUEIXAE. 

 GEN. MUS. 



Mus, LINNAEUS, Syst. Nat., 12th ed., i., p. 79 (1766). 



Animals with bodies covered with soft, sometimes spiny, fur, 

 with pointed muzzles, no cheek pouches and prominent eyes ; the 

 ears are nearly naked, the tail more than half the length of the body, 

 covered with scales arranged in rings, with usually a sparse covering 

 of short bristles ; pollex rudimentary with a flat nail, all the other 

 digits with claws ; palms with five, soles with six rounded or oval 

 pads. 



Skull with the antorbital foramen usually forming a narrow slit 

 below, and the perpendicular plate which forms its outer wall well 

 developed ; palate compressed and the incisive foramina long. 



Dentition the same as in all Muridac, i.e., i. 1/1, c. 0/0, p.m. 0/0, 

 m. 3/3 == 16. Incisors not grooved, usually rather narrow; molars 

 when unworn with a triple longitudinal row of tubercles, lower jaw 

 with a double row, when worn crossed by curved transverse bands 

 of enamel, marking the position of the tubercles. 



This genus is the largest of the whole Mammalian class, con- 

 taining, according to Trouessart's list, 176 species, and doubtless 

 many still remain to be described. 



They range all over the Old World, with the exception of 

 Madagascar, but are not found in the New except where intro- 

 duced by human agency. 



The study of the South African species has been much neglected 

 since the time of Sir A. Smith, and it is very difficult to identify 

 some of his species owing to the fact that his descriptions are often 

 short and vague, and also that the types of those still in the British 

 Museum are all in a very bad state of preservation. 



MUS DECUMANUS, THE NOEWAY OR BROWN EAT. 



Mits decumaniis, PALLAS, nov. sp. Glir., p. 91 (1778); SMUTS, 

 Enum. Mamni. Cap., p. 35 (1832); LAYARD, Cat. Mamm. S. Air. 

 Mus., p. 51 (1862). 



* For dimensions see p. 23'J. 



