lOS Mr. P. S. Kershaw on 



Smoky brown on tiic crest and down the back, drab on tlie 

 sides, and pure white below. A spot of white at the base of 

 the ear and a ri:i<; of white hairs at the back of the ear. 

 Feet white. Tail rather longer than head and body, brown 

 above, white below. 



Skull very much as in A. cahirinus, and differs from 

 A. witherhyi, de Wint., of the Su'laii, by having a longer, 

 narrower rostrum and less heavy molar teeth. 



Type-locality. Helwan, 10 miles south of Cairo. There 

 are other specimens in the British Museum Collection from 

 Giza Zoological Gardens. 



Type. Adult female. B.M. no. 22. 3. 15. 8. Original 

 number 4. Collected by Mahmoud Effendi Sabry on 

 l()th May, 1921, and presented to the British Museum by 

 the Giza Zoological Museum. 



Dimensions of the type (measured in the skin) : — 



Head and body 126 mm. ; tail (mutilated) ; hind foot 18*5 ; 

 ear 18. 



Skull: greatest length 29'4 ; condylo-incisive length 26'G ; 

 breadth of brain-case 12*7 ; length of nasals ll'O ; greatest 

 breadth of nasals (about the centre) 2"4. 



The following measurements of some younger specimens 

 show the relative lengths of body and tail : — 



A. sabryi is undoubtedly connected witli A. cahirinus, as 

 the cranial characters and the measurements prove. The 

 difference in colour may well be due to environment. One 

 specimen, B.^I. no. 22. 3. 15. 6, shows a distinct approxima- 

 tion to the sooty colour of A. cahirimis. It is, perhaps, 

 better to treat A. sahryi — for the present, at any rate — as a full 

 species until its affinities with other .species have been 

 established. Heuglin's account of A. nubicus is too meagre 

 to be of any value. He gives as the type-locality ** Nul>ia 

 along the Nile/^ and the dimensions as : head and body 

 111 mm., tail 118. He then merely adds that it is larger 

 and a paler brown than A. cinerascens. Specimens of 

 Acomys in the British Museum Collection from Merowe in 

 Nubia are remarkably like A. sabryi both in skull and colour. 

 On the other hand, a specimen from Kerma, at the third 

 cataract, is much more like A. xoitherhyi. At present there is 

 no material available for comparison in the British Museum 



