Br. C. W. Andreics — Hotes on Egyptian Eocene Mammals. 213 



the same way as the latter differ from the premolars of G. mtrus, 

 that is to say, their selenodont character, particularly of the posterior 

 cusp, is more distinct. 



Megalohyrax minor, sp. nov. 



A left maxilla (No. 8188, Cairo) with the very well preserved 

 molars and premolars may be taken as the type of this species. 

 Except for their smaller size the teeth are very similar to those of 

 Megalohyrax eoccemis. The chief differences are that the premolars 

 are somewhat simpler. Thus, pm. 1 has an elongated crown without 

 a postero-internal cusp, and is very similar to the canine of the 

 larger form, and in the same way the succeeding premolars each 

 resembles the tooth in front of it in M. eoccenus. Another peculiarity 

 is that the parastyle is better developed. The molars are much 

 alike in the two species. 



The dimensions of the upper teeth in the type-specimens of 

 Megalohyrax minor and M. eoccenus are given below : — 



Length. 



m. 3 



m. 2 26 ,, 37 ,, (approx. 



m. 1 



pm. 4 



pm. 3 



pm. 2 ... 



pm. 1 



The total length of the molar-premolar series is 13 cm. 



Portions of a mandible perhaps referable to this species also occur in 

 the collection. The specimen consists of two pieces, one the greater 

 part of the right ramus with pm. 2-4 and m. 1-3, the other the anterior 

 portion of the left ramus with part of the symphysis, containing 

 pm. 3-4, m. 1-2, and in front two incisors, probably i. 1 and i. 2. 

 The incisors have very broad short spatulate crowns, greatly com- 

 pressed from within outwards, and bearing a continuous wear-surface 

 along their edges. It is difficult to see how such teeth could have 

 bitten against the large upper incisor, which it has been suggested 

 was present in Megalohyrax, but it is not impossible that they may 

 have worked against a ledge on the hinder surface of a tusk-like 

 incisor. Further material is necessary, particularly the anterior 

 portion of a skull of one of the species of this genus. 



The molars and premolars each consist of two crescents, and from 

 the inner end of the hinder limb of the anterior crescent a short 

 ridge runs back on the inner side of the tooth, partly closing the 

 opening of the hinder v of the tooth. The posterior premolars and 

 anterior molars are alike. The dimensions of the teeth are : — 



Length. Greatest width. 



m. 3 33 mm 20 mm. 



m. 2 23 ,, 18 „ 



m. 1 19 ,, 16 ,, 



pm. 4 18 ,, 16 ,, 



pm. 3 16 ,, 14 ,, 



pm. 2 17 ,, 11 ,, 



Length of series from pm. 2 to m. 3 inclusive, 12-7 cm. 



The TN-idth of the crowns of the incisors are: i. 1, 14 mm. ; i. 2, 16 mm. 



