88 



MEMOIRS OF THE UNIVERSITY OF CALIFORNIA. 



Ichthvosauria 



Mixosauridae 



Mixosaurinae 

 Mixosaurus 



Shastasaurinae 

 Cymbospondylus 

 Merriamia 

 fToretoen&mus 

 Dclphinosaunis 



Ichthyosauridae 

 IcMhyosaurinae 



Ichthyosaurus 

 Baptanodontinae 

 Baptanodon 

 Opthalmosaurus 



Shastasaurus 



In this arrangement Toretocn<>>nu* is placed with the Shastasaurinae as a 

 type in which the rib articulation has remained more primitive than in the 

 others, or has been secondarily divided in the posterior dorsal region. J/. ( ?) 



EUROPE 



NORTH AMERICA 



