PALiEOZOIC AND MESOZOIC. 25 



close parallels, if not identities, of genera exist. Such are the OesfocepJialus 

 and Ceraterpeton of Ohio as compared with the Urocordylus and Ceraterpeton 

 of Great Britain. 



The Permian vertebrate faima which I discovered in Illinois and Texas 

 exhibits close parallels, but not yet generic identity, in the two continents. 

 Thus, the American Clepsydrops and Dimetrodon are near to the Beutero- 

 saurus of Penn, in Russia, and the Lycosaurus of the mountains of South 

 Africa. The Texan genus Parioticlms may, with further information, prove 

 to be identical with Procolophon Ow. from the Tafelberg. Humeri of the 

 type discovered by Kutorga in Russia, and by Owen in South Africa, are 

 found in North America, and the same remarkable type has been recently 

 discovered by Gaudry in France. The peculiar type of Ganocephalous 

 vertebrae described by me under the genus Rhachitomus from Texas, has 

 been discovered by Gaudry in France. The even more remarkable Cricotus 

 (Cope), type of the Emholomera, is paralleled by the Biplovertehron (Fritsch) 

 of Bohemia. Edosteorhachis represents in Texas the genus Ilegalichthys. The 

 present indications are that close similarity between the faunae of this period 

 in Europe and America will be discovered. Nevertheless, up to the present 

 time no representatives of the striking American forms Bolosaurus, Diadectes, 

 and Empedocles have yet been found in any other continent. 



As regards the Triassic fauna, it differs from that of the Permian in 

 being better known in Europe than America. As marine Trias is little devel- 

 oped in North America, so the vertebrate fauna of the Muschelkalk has not 

 been discovered in the latter country. It is otherwise with the Keuper. The 

 characteristic genus of that epoch, Belodon, existed in America, and parallels, 

 if not identity, are seen in the genera Thecodontosaurus and Palceosaurus. 

 These are known in America from teeth only. The reptiles are accompa- 

 nied in North America, as in Europe, by Stegocephalous BatracJiia, mostly 

 Labyrinthodonts, but their generic affinities are yet unknown. 



The great Jurassic fauna^. are as yet but sparsely represented in North 

 American paleontology. The marine Vertebrata of the Lias are either 

 unknown or are represented by a few provisional identifications of unsatis- 

 factory fragments. "We do not yet know any deposits in North America 

 which contain the typical reptilian genera Plesiosaurus, Ichthyosaurus, Plio- 



