VEKTEBEATA 



103 



The geological range of these orders is shown by the 

 table below : 



Species of Protodonta have been found thus far only in 

 the Triassic beds of North Carolina. Their molar teeth 

 bear some resemblance to those of some of the correspond- 

 ing teeth of the Theromorous reptilian genus Dimetrodon. 

 The oldest Multitubeeculata appear in the Trias of South 

 Africa in the Karoo beds, and in the Upper Trias (Keuper) 

 of Wiirtemburg (Europe). They are more abundant in the 

 Jurassic of England and of the Eocky Mountain region of 



