CLASSIFICATION 9 



In 1905 Case published two papers (13, 14) in which he demonstrated the 

 similarity of the Diadectidce to the Otocaelidce as defined by Cope, and suggested 

 that the Diadectida be placed with the Otoccelidce in the order Chelydosauria, leaving 

 the families Pariotichidce, Elginidce, and Pareiasauridce to form the Cotylosauria. 



In 1908 Williston (65) showed that Case was not within the laws of nomen- 

 clature in making this proposition and that the name Cotylosauria must go with the 

 Dtadectida, wherever they were placed. 



CLASSIFICATION. 



The following arrangement seems to the author to be the most advisable in the 

 present state of our knowledge of the group: 



Order Cotylosauria. 

 Suborder Diadectosauria. 

 Family Diadectida. 

 Genus Diadectes. 

 Bolbodon. 

 Chilonyx. 

 Diasparactus. 

 Desmatodon. 

 Diadectoides. 

 Family Bolosauridce. 

 Genus Bolosaurus. 

 Family Nothodontida (?). 

 Genus Nothodon. 



Incertae sedis. 

 Genus Eosauravus* 

 Bathyglyptus. 



Foreign forms. 

 Genus Sauravus.* 

 Suborder Pareiasauria. 

 Family Parioti chides. 

 Genus Pariotichus. 

 Isodectes. 

 Ectocynodon (?). 



*lt is believed that these two forms, fiom their lower geo- 

 logical position and primitive character may represent the most 

 primitive type of the reptilia and 6hould perhaps be placed in 

 a separate order, but as the head is unfortunately missing in 

 both specimens our knowledge is not sufficient to warrant any 

 definite conclusion as to their position. 



Order Cotylosauria — Continued. 

 Suborder Paret as auri a — Continued. 

 Family Captorhinidee. 

 Genus Captorhinus. 

 Labidosaurus. 

 Helodectes (?). 

 Family Seymouridce. 

 Genus Seymouria. 



Conodectes (?). 

 Stephanos pondylus (?). 



Foreign forms. 

 Family Pareiasaurida. 

 Genus Pareiasaurus. 

 Propappus. 

 Anthodon. 

 Elginia. 

 Phanerosaurus. 

 Sclerosaurus. 

 Suborder (?) Procolophonia, 

 Family Procolophonidee. 

 Genus Procolophon. 

 Thelegnathus. 

 Sauro sternum. 

 < Family Telerpetida. 

 Genus Telerpeton. 

 Suborder Pantylosauria. 

 Family Pantylidce. 

 Genus Pantylus. 



Attention is also called to the note at the end of the comparative tables (p. 66). 



