OLDFIELD THOMAS AND E. C. WEOrGHTOX— MAMMALIA. 501 



Fur fairly long (18-22 mm. on back) and soft. General ground-colour above the 

 usual fawn, pure on the flanks, much mixed with black on the back ; individual hairs 

 dark slate-colour, with a subterminal buff ring (2 mm.) and a black tip (2 mm.) on the 

 back and a buff tip (4 mm.) on the flanks ; below pure white, the hairs white to their 

 bases. Hands white ; feet bufiy, with white toes. Tail very dark brown (almost 

 black) above, fawn below. 



Skull about the size of that of T. liodon, interorbital region and brain-case markedly 

 broader, anterior palatal foramina shorter, posterior longer than in that species. 



Dimensions of type taken in the flesh : — 



Head and body 160 mm. ; tail 166 ; hind foot 34 ; ear 22. 



Skull : greatest length 42-5 ; basilar length 34 ; zygomatic breadth 22"3 ; inter- 

 orbital breadth 7"5 ; brain-case breadth 17"2; anterior palatal foramina 7'5 (8-3 in 

 liodon) ; posterior palatal foramina 3 (a mere point in T. liodon) ; diastema 11*9 ; 

 upper molar series 7. 



Ti/pe. Adult female. B.M. no. 6.12.4.41. Original number 678. Collected 20th 

 May, 1906, by Mr. E. B. Woosnam. 



The long posterior palatal foramina in this species separate it sharply from T. liodon 

 and T. valida, the two species hitherto recognised as occupying the equatorial belt 

 across Africa. 



[These Eats were very numerous on the plains around the south end of Ruwenzori, 

 but were almost impossible to catch. We failed to locate them in any holes, and they 

 appeared to feed only upon young grass-stems, of which ihey cut up great quantities 

 into short lengths of from 2 to 4 inches long, but they refused all baits. They are 

 nocturnal.— E. B. W.] 



51. OtOMYS DARTMOUTH! Thos. 



d. 81, 82, 254, 653. $.642,655,656. Mubuku Valley, E. Ruwenzori. 12,500 ft. 

 (" seen up to 13,000 ft."). 



Lower incisors double-grooved. 21^ with only six laminse. 



Size rather larger than in 0. jacksoni. Fur very fine, long and woolly ; ordinary 

 hairs of back about 17 mm. in length. General colour above finely grizzled "mummy- 

 brown," not so coarsely marbled as in 0. jacksoni. Under surface drab-brown, the 

 ends of the hairs pale clay-colour. Head and ears of the prevailing body-colour. 

 Upper surface of hands and feet pale bufiy. Tail black along its upper surface, dull 

 buffy on the sides and below. 



Skull larger than in 0. jacksoni, its profile convex above the orbits. 



Upper incisors with a deep median and a fine internal groove. Lower incisors with 

 two well-marked subequal grooves, as in 0. jacksoni and typus. Laminar formula of 



3—2-6 



molars i_2—-2 - 



