568 



MANUAL OF ZOOLOGY. 



especially to the Beasts of Prey. The dentition is of the carnivor- 

 ous type, the teeth being in three distinct sets viz., incisors, canines, 

 and molars, and the canines being large and pointed. 



In Cynodraco, which may be regarded as the type of the 

 group, the canines are not only of immense size, but are corn- 



Fig. 319. A, Front view of the skull of Lycosauriis, showing the dentition. B, Front 

 view of the jaws of Cynodraco serridens, showing the incisor teeth. C, Side view of 

 the jaws of Lycosaurns, showing the incisors and the laniariform canines; c Canines. 

 (After Owen.) 



pressed in shape, and have the hinder trenchant border of the 

 tooth minutely serrated, thus resembling the canines of the 

 Sabre-toothed Tiger (Machairodus). The humerus is, further, 

 furnished with a " supra-condyloid foramen " (similar to that 

 of the humerus of FelidcB and other carnivorous Mammals) for 

 the protection of the median nerve and brachial artery on 

 their way down the arm. Whilst Cynodraco is the type of the 

 Theriodontia, Prof. Owen is of opinion that a number of other 

 genera (such as Galesaurus, Cynochampsa, Lycosaurus, &c ), 

 principally of Triassic age, are likewise referable to the same 

 order. 



LITERATURE. 



[In addition to most of the systematic works quoted at p. 441, the follow- 

 ing are some of the more important sources of information as to the struc- 

 ture of recent and fossil Reptiles : ] 



i. " Erpetologie generale, ou histoire naturelle complete des Reptiles. " 

 Dumeril and Bibron. 1834-54. 



