40 Dr. J. E. Gray on the Species o/Hyrax. 



The species may be thus arranged : — 



1. Hyrax. 



a. Dorsal spot black. 1. Hyrax capensis. South Africa. 



b. Dorsal spot yellow. 



* Fur harsh 2. H. BuHonii. North and West Africa. 



3. H. Welwitsehii. Angola. 



•* Fur soft 4. H. Brucei. Abyssinia. 



5. H. Alpini. Abyssinia? 



6. H. sinaiticus. Sinai. 



2. EuHYEAX 1. E. ahjssinicus. Abyssinia. 



3. Dendbohyrax ... 1. D. dorsalis. West Africa. 



2. D. arhoreus. South Africa, Tete. 



3. D. Blainvillii. (Skull only.) 



These animals form themselves into three very natural 

 groups or genera, according to their skulls and teeth. 



1. Hyeax. 



Skull with a distinct narrow sagittal crest on hinder part of 

 crown when adult ; nose short. Diastema short, not equal 

 in length to the outer sides of the first three premolars ; 

 grinders in an arched line ; molars large, broad, square, much 

 larger and broader than the compressed premolars, the first 

 one very compressed. Orbit incomplete behind. Lower jaw 

 very broad behind. Bladebone elongate trigonal. 



Skull — nose short ; forehead flat or rather convex below 

 the orbit ; orbit incomplete behind ; the lower jaw much 

 dilated behind. The diastema between the canines and the 

 first premolar short, not so long as the outer edges of the first 

 three premolars. Lower cutting-teeth elongate, narrow at the 

 base, broader above, with three lobes ; but the lobes are soon 

 worn away, only leaving indistinct grooves on the surface of 

 the teeth. The lobes of the loAver cutting-teeth are distinct 

 in the very young animals which have not yet cut their pre- 

 molars and last grinder. The upper cutting-teeth of the milk 

 series are rounded in front, broad and spathulate at the end ; 

 those of the adult series are trigonal, with a strong central 

 keel in front. The grinders form an arched series ; the true 

 grinders large, much larger than the rather compressed pre- 

 molars ; the first (permanent) premolar (that is, the second in 

 the series) small, compressed ; the first premolar in the upper 

 jaw of the milk series is triangular, with three roots, the two 

 hinder ones being close together. 



De Blainville, in the ' Ostdographie,' figures the skeleton and 

 the skull of a species of this genus under the name of Hyrax 

 syriacus] but I am not able to determine to which of the 

 four species of this genus it belongs. H. syriaciis has almost 

 a generic signification. 



