342 Mr. G. Dollman on Arvicantliis abyssinicus 



Type locality. Egypt. 



This species appears to be fairly generally distributed ia 

 Northern Egj'pt ; the Museum collection contains specimens 

 from Cairo, Giza, and thcFayoum. The specimens from the 

 latter locality represent the species described by Liclitenstein 

 as Hypudceus vari'eyatus, and are quite similar to the Cairo 

 specimens of niloticus ; thus the name variegatus must be 

 regarded as a synonym of niloticus, and not as referring to 

 any member of the testicularis group. 



Mus discolor, Wagner, is founded on a bleached specimen 

 of niloticus, the hind foot, which measures some .36 mm. in 

 length, showing its relation with the large-footed Egyptian 

 species. The type locality is given as Lower Egypt, so 

 there is no difficulty in regarding discolor merely as a 

 synonym of niloticus. 



(6) Arvicantliis ahyssinicus, Riipp. 

 Mtis abyssinicus, Riippell, Mus. Senck. iii. p. 104, pi. vii. fig. 1 (1842). 



A medium-sized species, greyisli olive in colour, with 

 dorsal stripe usually distinct and tail comparatively short. 



Size of body a great deal less than in niloticus, averaging 

 only 145 mm. in length ; hind foot ratlier small (27 mm.), 

 tail short. General colour of dorsal surface greyisli olive, 

 lined with black and washed over with buff, the general effect 

 somewhat similar to that of niloticus, but lighter and more 

 finely speckled. Flanks rather paler than back. Dorsal 

 stripe usually well marked, though in many cases it is almost 

 lost amidst the black speckling on the back, especially in 

 bleached individuals. Light markings under and behind ears 

 well marked, more so than in any other species ; this feature 

 is especially noticeable in the juvenile pelajre, an account of 

 which is given below under A. zaj^hiri. Face with buffy ocular 

 rings and yellowish-orange nasal region. Backs of hands 

 and feet dirty white, tinted with pale buff. Underparts 

 brownish or greyish white mixed with buff ; ventral surface 

 not differentiated at all from flanks, the general colour of the 

 flanks gradually passing into the mixed brownish or greyish 

 white of the belly. Tail short and rather more hairy than 

 in many of the subspecies ; dark above, pale buffy white 

 below. 



Skull smaller than in testicularis or niloticus. Zygoma 

 expanded, not markedly so in the squamosal region. Brain- 

 case short and broad. Auditory bullte rather more inflated 

 than in the preceding species. Teeth comparatively large ; 

 molar series equal in size to those of testicularis. 



