266 MR. O. THOMAS ON RODENTS FROM S.W. AFRICA. [Feb. 21, 



4. Saccostomus lapidarius. (Plate XIV. fig. 2.) 



Saccostomus lapidarius, Peters, Reise n. Mossamb., Saug. p. 167 

 (1852). 



Three specimens. Exact localities and dates not preserved. 

 This rare species has hitherto been recorded only from Mozambique, 

 where Prof. Peters collected his types. 



5. Mus (IsoMYs) puMiLio, Sparrm. K. Vet.-Ak. Handl. 1784, 

 p. 236. 



Two specimens, a, $ , Table Mountain, November 30 ; and b, S > 

 "between Aamhouf and Hountop," Great Namaqualand, June 8, 

 1862. 



6. Mus (Leggada) minutoides, Smith, S. Afr. Quart. Journ. 

 ii. p. 157 (1834). 



One specimen. Damaraland. 



7. Mus siLACEUS, Wagn. Arch. f. Naturg. 1842, i. p. 11. 



Four specimens, a &, b, Otjimbinque, August 19 and 27, 1866 ; 

 e & rf, no exact localities. 



8. Mus nigricauda, sp. n. 



One specimen, c?, Hountop R., Great Namaqualand, June 1, 

 1862. 



For description see below. 



9. Mus coucHA, Sm. App. Rep. Exp. p. 43 (1836). 

 One specimen. Elephant's Vley, October 30, 1859. 



10. Mus, sp. 



One specimen. No exact locality. 



There is thus one new species, No. 8, in the collection : and No. 10 

 might also turn out to be new ; but it is represented by such a very 

 indifferent specimen that I cannot determine this point with certainty. 



The following is a description of No. 8, a very well-marked species, 

 quite distinct from any other African Rat. 



Mus NIGRICAUDA, sp. n. (Plate XIV. fig. 1.) 



Fur rather long and coarse, composed of but one kind of hair, 

 there being no under- fur. ('entre of back m.ixed yellow and black, 

 the greater part of the hairs having yellow distal halves, while others 

 are wholly black. Sides of the head and body mixed white and 

 black, the separation from the upper yellowish colour fairly well 

 marked. Belly-hairs pure white to their bases. Ears rather large, 

 thinly covered with short greyish hairs. Feet white above, the 

 hairs longer at the ends of the toes, so as to conceal the claws. Tail 

 slightly shorter than the head and body, nearly naked at its base, 

 but thickly covered for its distal half both above and below with 

 rather long shining black hairs, which form more or less of a pencil 

 at the tip. Hind feet proportionally short, the six pads large and 



