( 400 ) 



G. stigmoni;.i- Heiigliii, from Kliartdum, is a rather larger animal, richer 

 goldeu fawn in colour, with shorter and less pencilled tail, and belongs to the group 

 in which the soles of the feet have scattered hairs over the entire surface. 



At the request of Mr. Rothschild I name this species in honour of his assistant, 

 Mr. A. W. Waters. 



18. Gerbillus (Tatera) robustus Cretzschm. 



Eight skins, Nos. 13, 33, 48, 58, 50, 91, 92, 93, taken in February and March. 



This species has the most bushy tail of the Tatera group of Gerbillus ; the 

 distal third of the tail in some specimens being crested with black hairs about 

 12 mm. in length. 



19. Dipus jaculus L. 



Four skins, Nos. 4, 53, 54, 57. 



20. Mus musculus orientalis Cretzschm. 

 Three skins, Nos. 18,28,31. 



21. Arvicanthis testicularis Snndev. 



Five skins, Nos. 1, 5, 6, 7, 8. 



Two in sj)irit, Nos. 44, 49. 



'• The natives call this and the previously named species ' Far.' '" 



N. c. R. & -V F. R. vv. 



22. Acomys witherbyi sp. nov. 



? Shendi. No. 50, in alcohol, March 5, 19Ul. 



Size, smaller than A. cahirensis, ears rather small ; tail shorter than the head 

 and body ; feet very short and broad. Upper surface almost uniform smoky 

 fawn, rather more smoke-coloured on the head and dorsal surface, purer fawn 

 on the sides. The whole of the underparts, the feet, and a spot at the base of 

 the ears white. 



Measurements of specimen from Shendi, a young female, with unworn teeth, 

 preserved in alcohol. Head and body, So mm. ; tail, 76 mm. ; forearm and hand, 

 21 'O mm. ; hind foot, 155 mm. ; ear, 15-5 mm. 



1 have based the foregoing description on a specimen. No. 10, ?, from El 

 Kowa, to the south of Khartonm, collected in the spring of 1900 by Mr. H. F. 

 Witherby, in whose honour the species is named. 



The following are the measurements taken from animals in the flesh, as 

 recorded by the collector : — 



Head and body 



Tail ' 



Hindfoot ... 

 Ear 



