MAMMALIA. 



567 



be traced by a continuous series of forms. Periptychus is 

 also regarded by many as being at or near the point of 

 origin of modern Artiodactyla. On the other hand, many 

 of the Condylarthra show structural resemblances to the 

 Hyracoidea especially in the serial carpal bones. Thus 

 they form the point of convergence for at least three of the 

 four modern sub-orders. They are all rather small animals 

 and are found in the Lower Pliocene of Europe and North 

 America. 



Fig. 387. — The Dasse (Hyrax capensis). 

 (From Flower and Lyddeker.) 



SUB-ORDER II. — HYRACOIDEA. 



This is a small modern sub-order, comprising a few furry 

 rodent-like animals of the genus Hyrax {Procavia and 

 Dendrohyrax) and a third extinct genus, Pliohyrax, The 

 first pair of upper incisors grow from persistent pulps as in 

 rodents, and the others are absent (the second pair being 

 rudimentary in the young). There are two pairs of incisors 

 in the lower jaw. Canines are absent, but the molars and 

 premolars are complete, all tending to resemble each other. 

 The enamel of the molars is folded, the pattern most nearly 

 resembling that found in the rhinoceros. 



