TABLE OF CONTENTS. 



Page. 



Introduction 1 



The genus Antrodemus 2 



Antrodemus valens Leidy 5 



Osteology of Antrodemus 7 



Summary of Antrodemus specimens 7 



Skull 7 



Basioccipital 10 



Exoccipital and paraoccipital 11 



Supraoccipital 12 



Alisphenoid , 12 



Basisphenoid 13 



Parasphenoid 13 



Orbitosphenoid 13 



Ethmoid 14 



Parietal 14 



Frontals 15 



Prefrontal 15 



Postfrontal + postorbital 16 



Prootic 16 



Lachrymal 17 



Nasals 18 



Premaxillary 19 



Maxillary v . 20 



Jugal , 22 



Quadratojugal 22 



Quadrate 23 



Squamosal 23 



Ectopterygoid 24 



Pterygoid 24 



Comparative measurements of Antrodemus and Ceratosaurus skulls 25 



Lower jaw 25 



Dentary 25 



Supradentary 26 



Splenial 26 



Coronoid 26 



Angular 26 



Surangular 26 



Articular 27 



Prearticular 28 



External openings in the skull 28 



Lateral temporal fenestra 28 



Orbital opening 28 



First antiorbital fenestra 29 



Second antiorbital fenestra 29 



Anterior nares : 29 



Supratemporal fossa 29 



Teeth 29 



v 



