34 BULLETIN UNITED STATES GEOLOGICAL SURVEY. [Yol.Y. 



Oestoceplialus and Geraterpeton of Ohio as compared witli tlie Urocordylus 

 and Geraterpeton of Great Britain. 



The Permian vertebrate fauna which I discovered in Illinois and 

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

 continents. Thus, the American Glepsydrops and Dimetrodon are near 

 to the Beuterosaurus of Perm in Eussia, and the Lycosaurus of the mount- 

 ains of South Africa. The Texan genus Pariotichus may, with further 

 information, prove to be identical with Frocoloplion Ow. from the Tafel- 

 berg. Humeri of the type discovered by Kutorga in Eussia, and by 

 Owen in South Africa, are found in North America, and the same re- 

 markable tjTpe has been recently discovered by Gaudry in France. The 

 peculiar type of Labyrinthodont vertebrae described by me under the 

 genus Bhaohitomus from Texas has been discovered by Gaudry in 

 France. The present indications are that close similarity between the 

 faunse of this period in Europe and America will be discovered, i^ever- 

 theless, up to the present time no representatives of the striking Ameri- 

 can forms Diadectes, Bolosaurus, Empedocles^ and Gricotus 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 

 developed in North America, so the vertebrate fauna of the Muschel- 

 kalk has not been discovered in the latter country. It is otherwise with 

 the Keux)er. The characteristic genus of that epoch, Belodon, existed in 

 America, and parallels, if not identity, exist in the genera TJiecodonto- 

 ■saurus and Falceosaurus. These are known in America from teeth only. 

 The reptiles are accompanied in North America, as in Europe, by Stego- 

 cephalous Batrachia, mostly Labyriuthodonts, but their generic affini- 

 ties are yet unknown. 



The great Jurassic faunae are as yet but sparsely represented in North 

 American palaeontology. The marine Vertehrata of the Lias are either 

 Tinknown or are represented by a few provisional identifications of un- 

 satisfactory fragments. We do not yet know any deposits in North 

 America which contain the typical reptilian genera Plesiosaurus, Ich- 

 ihyosauruSj Pliosaurus, and Bimorphodon, or the fishes of the Bapediidce. 

 This formation, so important in Europe, is ahnost omitted from the North 

 American series. A few more characteristic fossils of the Eocky Mount- 

 ain region represent the Oolite, particularly the Upper Oolite, while 

 Teleosaurns and Steneosaurus, and their allies, are not yet known from 

 North American beds. Strata said to be included in the Dakota (which 

 on the evidence of plants and invertebrate fossils has been placed at 

 the bottom of the Cretaceous series) have produced a genus not yet 

 distinguishable from Megalosaurus. This genus has not been identified 

 beyond doubt from above the Oolite in England. From the same beds 

 in the Eocky Mountain region come genera which nearly resemble the 

 one from the English Oolite (Forest Marble) called by Phillips, Getiosau- 

 rus, and the genus from the Oxfordian of Honfleur, called by von Meyer, 



