32 THE HISTORY OF THE PELYCOSAURIA, WITH 



" Therochelonia comprise : 



Dicynodontia. 



" Mesosauria or Proganosauria : 



Nothosauria (?)" 



In a footnote the author says of the Theromora : " This group has no authority at 

 present and is subject to future definition." 



Pelycosauria from the Permian of Eussia. 



In 1838 Kutorga 46 reported the discovery of vertebrate remains on the west 

 slope of the Ural mountains. He considered the remains to belong to mammals and 

 thought that the rocks were of Carboniferous age. Several genera were described, 

 Brithopus, Orthopus and Syodon. 



In 1841 Fischer de Waldheim 47 described from the same locality a new genus, 

 Rophalodon, which he characterized as follows : " Gesteilte Zahnen mit hohlen Stielen 

 und mit soliden keulenformiger Krone. R. Wagenheimi, mit vorn gehielten Zahne, der 

 kiel gezahnte. R. Mantelli, mit langsgefurchten Zahne." 



In 1842 the same author described a second genus, 48 Eurosaurus, from the same 

 material that had been used by Kutorga in his description of Orthopus. 



In 1845 Wagenheim von Qualen 49 announced in a letter to Fischer the dis- 

 covery of a specimen in the Russian deposits, which he considered a Carboniferous plant 

 related to Pecopteris. This specimen was recognized by Fischer as a skull and described 

 by him 50 in the Bull, of the Soc. of Moscow as Dinosaurus Murchisonii. 



In 1848 Eichwald 51 more fully described the forms Rhophalodon Wagenheimi 

 and Dinosaurus Murchisonii. The latter genus he regarded as a synonym of the first. 

 Two new genera, Deuterosaurus and Zygosaurus, were described in the same paper. 



In 1857-1858 Herman von Meyer 52 described a few forms from the Permian of 

 Russia and later a second article discussed the same specimens more fully. 53 



In 1860, in his Lethce Rossica, Eichwald 54 described all the known genera from 

 the Russian Permian. He regarded all the Reptilian forms as belonging in two genera 

 only, Rhophalodon and Deuterosaurus. He gave the following classification : 



Fam. Theriodontisaurier. 



Genus Deuterosaurus. 

 Rliophalodon. 



Fam. Labyrinthodonten. 



Genus Eurosaurus- 

 Zygosaurus. 

 ArcJimgosaurus. 



