58 



Theriodontia Galesauridce. 



Reptilia, for, as in the carnivorous mammals, the incisors are 

 separated from the molars by well-developed canines, and the 



Table-case, 

 No. 17. 



Teeth of 

 Therio- 

 dontia. 



FIG. 77. Anterior and right lateral aspects of a lumbar vertebra of Tapinocephalw 

 Athtrstond (Owen) ; from the Karoo Beds, South Africa. About nat. size. 



canines of the lower jaw cross those of the upper in front. In 

 many of the genera the upper canines are long and trenchant, and 

 the incisors large and close together (Lycosaurus, ^lurosaurus, 

 etc.), the molars, as a rule, being smaller than the incisors. In 

 most reptiles, living and extinct, the teeth that are worn away by 

 use, or otherwise lost, are replaced by others that are constantly 



FIG. 78. Left lateral aspect of skull of Galesaurus jilaniceps (Owen), from the Karoo 

 beds (Triassic), South Africa (^ nat. size), a, an upper cheek-tooth, and 6, an incisive 

 tooth. 



forming in the jaws ; but there is no evidence of preceding teeth, 

 like the milk-teeth in mammals, nor of successional teeth, in the 

 jaws of the Theriodonts. From this negative evidence Sir Richard 

 Owen assumes them to have been " Monophyodont " reptiles, 

 having but one set of teeth, which were permanent, during life. 

 He has described eleven genera, varying in the size and form of 



