Prof. Huxley on Ilyperodapedon. 239 



skeleton described by the author were the ribs, scapula, coracoid, 

 and part of the humerus, the pelvis, femur, and proximal ends of 

 the tibia and fibula, and the abdominal false ribs, which are largely 

 developed in this Reptile. 



The author declared the affinities of Ilyperodapedon to be de- 

 cidedly Lacertilian. Its nearest fossil ally is the Triassic genus 

 Rhyncliosaurus, and in the present day its type of structure is 

 most closely reproduced by the singular genus Sphenodon ( = Hat- 

 terici) of New Zealand. In its habits Ilyperodapedon was probably 

 terrestrial, or perhaps fluviatilc ; in Warwickshire and India it is 

 associated with Labyrinthodonts. The remains hitherto met with 

 do not justify the formation of more than one species, Ilyperoda- 

 pedon Gordoni ; and the genus ranges from Britain to Central India, 

 indicating a great extent of dry land during the period to which it 

 belongs. 



Specimens of Hyperodapedon from the Trias of Warwickshire, 

 collected many years ago by Dr. Lloyd, were exhibited; but 

 in discussing the question whether Ilyperodapedon is to be re- 

 garded as determining the Triassic age of any rock in which it may 

 be found, the author referred to the fact that Crocodiles bridge over 

 the whole interval between the Mesozoic and existing conditions, 

 and Beryx in like manner connects the Cretaceous with our present 

 fish-fauna. As Hyperodapedon is at least as nearly allied to the 

 existing genus Sphenodon ( = Hatteria) as it is to the Triassic li liyn- 

 chosaurus, the author inquires why may it not have inhabited the 

 dry land of the Permian, Carboniferous, or Devonian period ? Car- 

 rying the idea thus raised still further, he indicates, from certain rela- 

 tions between the Reptilian faunae of Europe, S. Africa, and India at 

 the period when Hyperodapedon lived in the first and third of these 

 localities, not only that there must then have been a vast extent of 

 continental land, but that this may have persisted with but little 

 change in the nature of its inhabitants, while the fauna of the 

 neighbouring seas underwent great alterations. He remarked that 

 our geological chronology rested too much upon a marine founda- 

 tion, and that such a persistence of dry land as was now suggested 

 by him was not only possible, but, in the present case, probable. 

 He suggested the use of Conybeare's term "Poikilitic" for the 

 series of deposits containing the remains of terrestrial and fluviatile 

 plants and animals and corresponding with the marine beds deno- 

 minated Permian and Triassic. Finally, the author remarked upon 

 the important light thrown upon the question of the geographical 

 distribution of animals as affected by the discovery of these Reptiles 

 and other recently detected fossils, and upon the interest attaching to 

 them from their high grade of development. The five great classes of 

 Vertebrata were represented during the " poikilitic " epoch by 

 species so high in the scale that we can hardly doubt their having 

 been preceded by other forms, so that some of us may hope to see 

 the fossil remains of a Siluriam mammal. 



Sir R. I. Muechisox argued in favour of the overwhelming im- 

 portance of palaeontological evidenco, and maintained that Ilypero- 



