1869.] HUXLEY — HYPERODAPEDON. 149 



words, are common to two of the great divisious of geological time. 

 The like is true of the Teleostean fish Beryx. Moreover it has been 

 seen thdit ITi/j^erodajyedon is nearly allied to the living ]iza,YdSphenodon, 

 — as nearly, I am inclined to think, as to its Triassic congener 

 Mhynchosaurus. And if this extraordinary form has persisted with 

 so little modification from the Trias till now, why may it not have 

 inhabited the dry land of the Permian, of the Carboniferous, or of 

 the Devonian Epoch ? 



In discussing the question of the age of the Elgin sandstones in 

 years gone by, refiections of this nature led me always to admit the 

 possibility that these problematical beds might be of Devonian age ; 

 for Hyper odapedon, JStagoiwl&pis , and Telerpeton, though clearly 

 allied to Triassic and IVIesozoic genera, were distinct from them, and 

 had no stronger afiinities with Mesozoic Heptilia, than the Protero- 

 sauria have (which yet are Palaeozoic and not Mesozoic), or than 

 some of the Labyrinthodonts of the Coal (e. g. Anthracosaurus) have 

 with those of the Trias. 



Even now that Hyperodapedon is distinctly determined to be a 

 Triassic genus, the possibility that it may hereafter be discovered in 

 Permian, Carboniferous, or even older rocks, remains an open ques- 

 tion in my mind. Considerations of this kind should have their just 

 weight when we attempt to form a judgment respecting the reptili- 

 ferous strata of the Karoo in South Africa, and of Maledi and else- 

 where in India, 



In India, Hyperodapedon occurs associated with Labyrinthodonts, 

 with Thecodont reptiles (some of which have Crocodilian characters), 

 and with Dicjnaodonts. 



In South Africa, Hyperodapedon has not yet been discovered ; but 

 Labyrinthodont and Thecodont Eeptilia (some of them Crocodiliform) 

 have been found, and, associated with them, abundant Dicjnodonts. 



In England and Scotland, Hyperodapedon is found with Labyrin- 

 thodonts and Thecodont Heptilia of such distinctly Crocodiliform 

 type as Stagonolepis, but no Dicynodon has been found. 



In Wiirtemberg, Labyrinthodonts and Thecodont Eeptilia, some 

 of them, like Belodon, eminently Crocodilian, are associated together, 

 probably with Dinosauria; but neither Hyperodapedon nor Dicy- 

 nodon have yet been discovered. 



All these four faunae are connected by reptilian genera, which are 

 respectively common to two of them : thus the British and the Indian 

 by Hyperodapedon ; the Indian and the African, by Dicynodon ; the 

 British and the German by Labyrinthodon (which according to Yon 

 Meyer occurs in Germany). The Labyrinthodonts and Crocodiliform 

 reptiles are common to all four. 



As the age of the beds in question is determined stratigraphically 

 in Britain and in Germany to be Triassic, it may seem over-refine- 

 ment to hesitate in declaring the African and Indian formations to 

 belong to the same period ; but I confess that the arguments I have 

 mentioned lead me greatly to prefer some more general term, which 

 should indicate a wider chronological range for the duration of the 

 terrestrial fauna in question. The term PoiMliiic, originally used 



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