Mammals from the Dinha Country ^ Bahr-el-DjeheJ. 101 



28. Acomys wilsoni argillaceus, subsp. n. 



38. Mongalla. 

 ? . 108. Bor. 



7ype.—BM. 20. 4. 26. 15, original no. 38. Collected 

 2nd .Tune, 1918, by Major Stevenson Hamilton ; presented 

 to the National Collection by the Wellcome Reseai-ch 

 Laboratory. 



Captured in scrub and undergrowth. 



Size a little less than in Acomys wilsoni, Thos., from which 

 it also ditFers in its less rufous colouring. ISpines thick, 

 annulated, their extreme tips being ''seal-brown/' succeeded 

 by a broad band of ^' clay-colour," which is followed by 

 " grey " (no. 6, Ridgway) to the base. General colour very 

 similar to that of A. to. ahlutus, Dollra., but lighter owing to 

 the clay-coloured annulations being broader in our animal. 



Skull very much as in A. wilsoni, conspicuously larger 

 than in A, w. ahlutus. 



Dimensions of the type (measured in the flesh) : — Head and body 

 76 miu. ; tail 51 ; hind foot 12 ; ear 10. 



Skull, type and no. 108 (in parentheses) : condylo-incisive length 22'4 

 (23'2) ; occipito-nasal length 24'6 ( — ) ; zygomatic breadth 12'1 (12'1) ; 

 interorbital constriction 4*5 (4'o) ; breadth of brain-case ll'l (ll'l); 

 length of anterior palatal foramina 6 (5-7) ; dental length 11*8 (12) ; 

 molars (crowns) 3'o (3'8). 



Remarks. — This member of t\\& wilsoni group is geographi- 

 cally isolated, its nearest neighbours on the north and south 

 Ijeing A. wit hei'byi and A. hystrella, from both of which it 

 differs widely in size and colour. 



29. Arvicanthis ahyssinicus ruhescens, Wr. 



S. 6, 7, 8, 959 ; ? . .3, 5, 10, 11, 12, 13, 14, 30, 45, 46, 

 124. Mongalla. 



S. 103, 105, 123, 126; ? . 104, 135, 137. Bor. 



30. Lemniscomys zebra, Heugl. 



cJ . 16, 19. Badigeru Swamp, 20 miles east of Mongalla. 

 S . 62. Mongalla. 

 ? . 121. Rejaf. 



