TABLE OF CONTENTS. 



Page. 



Introduction 1 



The genua 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 



ParieUl 14 



Frontals 15 



Prefrontal 15 



Postfrontal + postorbital 16 



Prootic 16 



Lachrymal 17 



Nasals 18 



Premaxillary 19 



Maxillary 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 



A rticular 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 



