220 Annals of the SoittJt African Museum. 



A. PUMILIO, Sub-Sp. DILECTUS. 



Arvicanthis pumilio dilcctns, DE WINTON, Proc. Zool. Soc., p. 803 

 (1896). 



A. PUMILIO, Sllb-Sp. BECHUA.NAE. 



Isomysp. bcchitanac, THOMAS, Proc. Zool. Soc., p. 551 (1892). 



Description. General colour greyish brown with a slight tinge of 

 yellow, under-fur soft, fine, and dark slaty in colour, through which 

 project considerably coarser hairs, white, black, and yellowish 

 brown ; along the back from the shoulders to the root of the tail run 

 four black longitudinal stripes, separated by three narrower inter- 

 spaces, of which the two outer are a little paler than the inner, of 

 the same colour as the back ; the black stripes vary considerably in 

 distinctness, the two median ones usually originating in a single 

 dark median stripe on the head from between the eyes and meeting 

 at the root of the tail ; below pure white, but the hair not very thick, 

 so that the slaty black of the skin is visible, giving the belly a dirty 

 white colour ; head rat-like, a pale ring round the eye, the ears 

 rounded, anteriorly and posteriorly with a fairly thick covering of 

 rufous hairs with a black edging along the inner margin of the 

 conch ; extremities the same colour as the back, but paler ; skin of 

 the soles and palms dark, almost black, toes as in Mus, but the first 

 and fifth proportionately shorter, pads as in Mus, but the second 

 proximal one very small ; claws black ; tail scaled and ringed, about 

 39 to the inch, covered with bristles increasing in length towards 

 the tip ; the bristles are chiefly black along the dorsal line, and pale 

 yellow below, but the skin of the tail is black throughout ; mammae 

 8 2 pairs pectoral, 2 pairs abdominal. 



Geographical Races. The striped rat varies very considerably 

 both in size and in colour. 



In Bechuanaland there occurs a large, almost sandy race with the 

 dorsal stripes very faint and with pale-coloured ears, described by 

 Thomas. 



In Mashonaland on the other hand a darker race than the normal 

 is found with very dark, well-defined dorsal stripes and dusky belly 

 washed with orange. 



The collection of the South African Museum consists chiefly of 

 spirit-preserved examples which are not of much service for the 

 discrimination of slight colour variations, but some skins from 

 Pondoland in the extreme east of the Colony appear to approach 

 Mr. de Winton's dilectus race, and are certainly distinctly darker 



