414 Mr. O. Thomas on 



Ilab. (of type). Likangala, Nyasaland. 

 Type. Old male. B.M. no. 2. 1. 6. 33. Collected June 

 1901 and presented by Sir Alfred Sharpe, C.B. 



28. Arvicanthis dorsaUs griselda, subsp. n. 



S . 174; ?. 175. Muene Coshi, Jinga Country. 



Like the true southern A. dorsalis in all essential respects, 

 but the colour is paler throughout, with less ferruginous 

 suffusion ; sides of head and flanks pale lined greyish with 

 scarcely a tinge of buffy. Orbital rings and sides of muzzle 

 pale yellowish, not ferruginous. Belly white. 



Molars rather smaller than in the typical subspecies. 



Dimensions of type (measured in flesh) : — 



Head and body 121 mm.; tail 135; hind foot 28; ear 14. 



Skull : greatest length 31 ; basilar length 25 ; breadth of 

 brain-case 12"5 ; palatal foramina G'l ; length of upper molar 

 series 6*1 j breadth of m l 2*1. 



Type. Adult, but not old, female. B.M. no. 4. 4. 9. 95. 

 Original number 175. Collected 26th September, 1903. 



The present is the furthest towards the north-west that 

 A. dorsalis has been recorded, and, considering the great 

 distance from the Cape, it is not surprising that there should 

 be a difference in colour worthy of subspecific recognition. 



On the eastern side of Atrica A. dorsalis goes slightly 

 farther north, but there, instead of being more pallid, the 

 colours are intensified, while the reduction in the size of the 

 molars is carried to an extreme. This eastern form may be 

 called 



Arvicanthis dorsalis rosalia, subsp. n. 



Essential characters of true dorsalis, but the colours strong 

 and dark, a large proportion of the rump strong ferruginous j 

 sides of muzzle, orbital rings, and ears rich rusty. 



Skull small and narrow, the molars conspicuously weaker 

 than in the typical form. 



Dimensions of the type : — 



Head and body (in skin) 119 mm. ; hind foot (wet) 28; 

 ear (wet) 15. 



Skull : back of interparietal to tip of nasals 31 ; zygomatic 

 breadth 14*2; interorbital breadth 4*4; brain-case, breadth 

 12*7 ; palatal foramina 6'5 ; length of upper molar series 5"6; 

 breadth of m 1 1*7. 



Hab. Monda, Nguru Mountains, German East Africa. 



Type. Adult female. B.M. no. 90. 6. 8. 28. Presented by 

 Emin Pasha. 



