1885.] ON THE RODENT GENUS HETEROCEPHALUS. 845 



2. Notes on the Rodent Genus Heterocephalus. By Oldfield 

 Thomas^ F.Z.S.^ Natural History Museum. 



[Eeceived October 30, 1885.] 

 (Plate LIV.) 



On the 16th of June last I had the pleasure of exhibiting to the 

 Society a specimen obtained on the 29th of January last by Mr. E.Lort 

 Phillips, F.Z.S., at Gerlogobie, Ogardain, Central Somali-land, which 

 I doubtfully referred to Heterocephalus ylaher, RUpp., a species 

 discovered by Martin Bretzka in Shoa, Abyssinia, more than forty 

 years ago, and still, so far as I can ascertain, only represented by 

 the original type described by Dr. Riippell. 



By the kindness of the Directors of the Senckenberg Museum in 

 Frankfort I have been allowed to have this original type for 

 examination, and I am thus enabled to give the following notes on 

 the characters and differences of the two species which a comparison 

 of these two specimens proves the genus to consist of. 



The second species has been already named and briefly defined in 

 a footnote to the Report in our ' Proceedings ' of the exhibition of the 

 specimen ' ; and it was with much pleasure that I connected with 

 this very interesting animal the name of its discoverer, to whom we 

 are indebted for many additions to our knowledge of the mammals 

 and other animals of Central Somali-land. 



The type oi Heterocephalus glaber consists of a dried and mounted 

 skin, with a separate skull, while that of H. phillipsi is an adult 

 female preserved in spirit ; and I am therefore able to give a some- 

 what fuller and more exact description of its characters than Riippell 

 had any opportunity of doing. 



Heterocephalus phillipsi is a peculiar-looking little creature, about 

 the size of a Common Mouse, but looking almost more like a tiny 

 hairless puppy on account of its nearly naked skin, small eyes, and 

 peculiar physiognomy (see Plate LIV. fig. 1). 



The head is small and flattened from above downwards. The 

 mouth has the structure characteristic of Georychus and other 

 burrowing Rodents, the external skin passing right across the mouth- 

 opening inside the incisors. The lips and sides of the muzzle are 

 fairly well clothed with bristly hairs, which form well-marked 

 whiskers, and there are four or five hairs on each side springing from 

 a wart on the side of the face. The eyes are well-defined open slits, 

 with thickened fleshy lids covering the minute eyeballs, which are 

 barely half a millimetre in diameter. The ears are simple round 

 holes, not covered in any way, and unprovided with any trace of an 

 ear-conch. The skin all over the head and body is of a wrinkled 

 warty nature ; but this is perhaps partly due to the action of the 

 spirit on the naked skin, as the dried specimen of H. glaber shows 

 it much less markedly. The head and body, although apparently 



1 P. Z. S. 1885, p. 612. 

 Proc. Zool. Soc— 1885, No.LV. 55 



