1871.] RAMSAY PEBTRIASSIC EED EOCKS. 251 



or less overlaid Avith the deposits of the Keuper series. The Thecodonto- 

 saurus and Palceosaurus described by Dr. Riley and Mr. Stutchbury 

 occnr in a magnesian conglomerate of Keuper age, which was long con- 

 sidered to be the equivalent of part of the strata now called Permian. 

 My explanation of their stratigraphical position is, that these Dino- 

 saurian reptiles lived upon land moderately elevated all through the 

 Permian and Bunter epochs, and that subsequently their remains 

 were buried in the shingly beds of the Keuper inland sea, which 

 formed the last of a long series of inland continental waters that 

 prevailed over a large part of the territory now called Europe, from 

 the close of the Silurian period onward to the Ehsetic beds. First, 

 there are the great lake-formed strata of the Old Red Sandstone ; 

 secondly, the Carboniferous formations, to a great extent terres- 

 trial ; thirdly, the Permian series ; and, fourthly, the Triassic 

 and partly the Ehsetic beds ; after which, during Liassic times, by 

 subsidence, the sea invaded the land, and a mere group of islands 

 occupied the site of much of what is now Europe. Further, I 

 think it may be proved that the great continental areas of North 

 America and Europe, and even of Asia and Africa, were already 

 sketched out during the long geological period I have indicated, and 

 that the great similarity in lithological character between the 

 Permian and Triassic areas of Europe, America, and India is owing 

 not to any cause producing depositions of red strata from all the 

 waters of the world at these periods, but simply to special conditions 

 of inland continental waters at various epochs of time. 



This leads to the important question of the possible continuity of the 

 same types of terrestrial as distinguished from marine life during the 

 whole of this long period. Writers on geological subjects have often 

 been apt to treat of the fossil records of the earth's history as being 

 chiefly marine. If, however, the reasoning used in the foregoing 

 pages is good, then we have a series of records indicating continental 

 land surfaces containing great fresh and salt lakes, extending over a 

 very large portion of all known geological time ; and this, as far as time 

 is concerned, possesses a significance quite as great as that of the 

 marine formations, even though some of these inland-formed strata 

 are almost destitute of the remains of life. Geographical continuity of 

 continental land during a period that embraces several great geological 

 epochs implies probable continuity of continental genera, if not of 

 species. The Labyrinthodontia common to all the formations from 

 the Upper Trias to the Coal-measure Anihracosaurus bear upon this 

 point. Thecodont Saurians are both of Triassic and Permian age. 

 " Hyperodapedon, Stagonolepis, and Telerpeton," says Professor Hux- 

 ley, " had no stronger affinities with Mesozoic Eeptilia than the Pro- 

 terosauria (Permian), or than some of the Labyrinthodonts of the Coal 

 have with those of the Trias "* ; Telerpeton, he has little doubt, was 

 altogether terrestrial. Seeing that Hyperodapedon is as nearly 

 allied to the living lizard Sphenodon as to its Triassic congener JRhyn- 

 chosaurus, he sees no reason why it may not hereafter be " discovered 

 in Permian, Carboniferous, or even in older rochs." With this I 

 * On HyperodcvT^edon (Quart. Journ. Geol. Soc, 1869, vol. xxr. p. 149). 



