THE SUBCLASS DIAPSIDA 289 



Upper Jurassic. Atoposaurus Meyer, Alligatorellus Jourdan, 

 Alligatoriiim Lortet, Germany. 



Family Goniopholidae. Vertebrae platycoelous. Internal nares 

 bounded by pterygoids and palatines. Face rather broad, not long. 

 Postorbital bar subdermal. A dorsal armor of two or more rows of 

 plates. 



Lowermost Cretaceous. Goniopholis Owen, Europe, North and 

 South America. N annosuchus Owen, Xheriosuchus Owen, Machimo- 

 saurus Meyer, Bernissartia Dollo, Europe. 



Upper Cretaceous. Coelosuchus WilHston, Teleorhinus Osborn, 

 Wyoming. Notosuchus Woodward, Cynodontosuchus Woodward, 

 South America. 



Family Dyrosauridae. Vertebrae platycoelous; internal nares 

 between palatines and pterygoids. Face very slender. Postorbital 

 bar subdermal. From fifteen to eighteen feet in length. 



Lower Eocene. Dyrosaurus Pomel, Africa. 



Family Hylaeochampsidae. Vertebrae probably procoelous. 

 Internal nares surrounded by pterygoids. Palate with large foramen 

 between ectopterygoid and maxillae. Skull short, broad. 



Wealden Cretaceous. Hylceochampsa Owen, ?Heterosuchus Seeley, 

 England. 



Family Gavialidae. Vertebrae procoelous. Posterior nares sur- 

 rounded by pterygoids. Face very slender. Postorbital bar sub- 

 dermal. Upper temporal openings large. Nasals remote from nares. 

 Dorsal but no ventral scutes. From ten to fifty feet in length. 



Pleistocene, Recent. Gavialis Oppel, Rhamphosuchus Owen, 

 PaleosMchus Falconer and Cautley, India. 



Family Tomistomidae. Vertebrae procoelous. Posterior nares 

 surrounded by pterygoids. Face less elongated, gradually merging 

 into cranium. Postorbital bar subdermal. Nasals extend into nares. 

 Sometimes an antorbital opening. From six to forty or more feet in 

 length. 



Upper Cretaceous. Thoracosaurus Leidy, Holops Cope, United 

 States, 



Eocene. [Tomistoma, Europe, Africa.] Eosuchus Dollo, Belgium. 



Pliocene. Tomistoma (?) [Gavialosiichus], Florida. 



