94 



BAUR. 



[Vol. I. 



Hyposternal and postabdominal bones not distinct ; two pos- 

 terior cranial arches ; ribs attached to one centrum ; no ster- 

 num ; a procoracoid. 7. Sauropterygia. 



IV. Os quadratum attached only at the proximal extremity, 

 and more or less immovable ; ribs with one head. Strepto- 

 STYLICA. 



Brain case membranous in front of prootic bone ; trabecula 

 not persistent. 8. Lacertilia. 



Brain case with osseous walls anterior to prootic ; a scapular 

 arch and sternum. 9. Pythonomorpha. 



Brain case with osseous walls anterior to prootic ; no scapular 

 arch nor sternum ; trabecular grooves of sphenoid and pre- 

 sphenoid bones. 10. Ophidia. 



The phylogeny of the Reptilia is expressed by Cope in the 

 following way : — 



Dinosauria Testudinata. 

 (Crocodilia). 



Rhynchocephalia. 



Lacertilia. 



Ophidia. 



Pterosauna 



Ichthyopterygia. 



Pythonomorpha. 



Sauropterygia 



Theromorpha. 



