CLASSIFICATION. 37 



Order 2. SAUROPTERYGIA. 

 Family Mesosauridae. Mesosaurus. 

 Family Nothosauridae. Nothosaurus. 

 Family Plesiosauridae. Plesiosaurus. 



Pliosaurus. 



Order 3. CHELONIA. 

 Suborder (1). TRIONYCHIA. 

 Family Trionychidae. Trionyx snapping turtle. 



Suborder (2). CRYPTODIRA. 

 Family Dermochelydidae. Dermochelys (Sphargis) 



leathery turtle. 



Family Chelonidae. Ohelone green turtle. 

 Family Chelydridae. Chelydra terrapin. 

 Family Chersidae. Testudo tortoise. 

 Suborder (3). PLEURODIRA. 

 Family Chelydae. Chelys. 



Order 4. ICHTHYOSAURIA. 

 Family Ichthyosauridae. Ichthyosauriis. 



Order 5. RHYNCHOCEPHALIA. 

 Suborder (1). RHYNCHOCEPHALIA VERA. 

 Family Sphenodontidae. Sphenodon (Hatteria). 

 Family Rhynchosauridae. Hyperodapedon. 



Suborder (2). PROGANOSAURIA. 

 Family Proterosauridae. Proterosaurus. 



Order 6. SQUAMATA. 



Suborder (1). LACERTILIA. 



Group Lacertilia vera. 

 Family Geckonidae. Gecko. 

 Family Pygopodidae. Lialis scale-foot. 



