1904.] MAMMALS FROM NAMAQUALAND. 179 



be distinguished by the brownish fulvous of its dorsal area, which 

 approaches Ridgway's " russet," in strong contrast with the paler, 

 almost "cream-bufi'" of 0. hrantsii. The back is also of a more 

 uniform colour, less markedly lightening on the sides. Under 

 surface like that of the typical form. Tips of the hairs on the 

 head, back, and sides black. Tail strong buflfy yellow, darker 

 than in hrantsii, a line along the top and the whole of the tip 

 black. 



Dimensions of the type, measured in the flesh : — ^Head and 

 body 145 mm. ; tail 76 ; hind foot 25 ; ear 16. 



Skull — greatest length 34-7 mm. ; basilar length 27-5 ; greatest 

 breadth 21. 



Hcd). Deelfontein, Central Cape Colony. 



Type. Female. B.M. no. 2.9.1.47. Collected 8 April 1902. 

 Presented by Col. A. T. Sloggett. 



The grooving of the incisors in 0. hrantsii seems always to have 

 been considered the same as in 0. unisulcatus, i. e. with one 

 groove on the outer part of the upper incisors and none on the 

 lower. But we find a distinct groove on the inner edge of the 

 upper pair in addition to the larger groove on the outer half. 

 There is also an indistinct flattening, hardly amounting to a 

 groove, on the outer half of the lower incisors. 



" ' Sand-rot ' of the Dutch. 



" Yery common ; found all over the high and low flats, but not 

 observed within ten miles of the coast. They are gregarious, 

 living in colonies and digging their burrows in the open sandy 

 veldt. A diurnal animal only and a vegetarian. Numbers of 

 them are to be seen sitting on their haunches outside their 

 holes. On the appearance of danger they disappear at once, each 

 with a sharp squeak." — C. H. B. G. 



19. Mus AURicoMis de Wint. 



5 . 428, 401, 430, 497, 445, 457. $ . 504, 422, 498, 489, 496, 

 454, 447, 415. Klipfontein. 



Very similar to the original series collected by Mr. Selous in 

 Matabeleland. 



" Entirely a rock rat, very common everywhere on the flats and 

 mountains where there are rocks. Apparently entirely nocturnal 

 and vegetarian." — C. H. B. G. 



20. Arvicanthis pumilio oinereus Thos. & Schw. 

 Arvicanthis pumilio cinereus Thos. & Schw. Abstr. P. Z. S, 1904, 



no. 2, p. 5 (Feb. 9th). 



6. 427, 493, 391, 431, 488, 426, 436. $. 499, 514. Klip- 

 fontein. 



c^. 540. PortNoUoth. 



General colour of the face and upper surface, in the majority 

 of specimens, " smoke-grey," compared with the bufly-yellow of 

 the true ^J^6m^7^o. Long hairs tipped with orange-yellow or 

 black, dirty white proximally ; under-fur black at base. Flanks 



12* 



