560 Geological Society. Anniversary AddresSi\S^2. 



SECONDARY ROCKS. 



Pursuing the inquiry in the ascending order, the long period 

 which is specially marked by the presence of gigantic reptiles is 

 now before us. It commences with the magnesian limestone (the 

 Zechstein and associated rocks), and terminates with the cretaceous 

 system. In this wide field Professor Owen has taken the lead as a 

 palaeontologist, and will shortly lay before the world the results of 

 his researches into the extinct Saurians of our island. Of this 

 work I cannot speak, but from the knowledge we possess of Pro- 

 fessor Owen's consummate acquaintance with comparative anatomy, 

 and of his wonderful ability in detecting the minutest character in 

 masses of bones obscured by matrix and mutilated by accident, we 

 may anticipate that this work will enjoy the proud distinction of 

 becoming a text-book with every natural philosopher in every part 

 of the world. The points of this great inquiry to which he has 

 called our attention during the last year, are the teeth and ske- 

 letons of five species of his newly-formed genus Labyrinthodon, 

 found in the new red sandstone of Warwick ; the whole of which, 

 after a most elaborate comparison with all collateral and congenerous 

 forms of diflerent families of reptiles, he proves to belong to Batra- 

 chians, but with striking and peculiar affinities to the higher Sauria. 

 From the evidence afforded by the comparative dimensions of one 

 species of Labyrinthodon found in the same quarry, Professor Owen 

 likewise shows that the anterior and posterior extremities must have 

 been of disproportionate magnitude, according well with those of 

 the Cheirotherium, and he therefore infers, and with great apparent 

 justness, that the Labyrinthodon and the Cheirotherium were one 

 genus. In a second memoir upon certain remains from the Oolitic 

 Series, he has established a genus of Saurians equal in size to the 

 whale, and in a third upon the remains of a crocodilian Saurian 

 from the "Lower Greensand;" he concludes, from the same uner- 

 ring evidence in the form and texture of the bones and teeth, 

 that they are quite distinct from any Saurian hitherto described ; 

 and he therefore refers them to his new marine genus Polypty- 

 chodon. Whilst I delight in seeing that the tenants of those ancient 

 oceans have met with so competent an expositor, I cannot but re- 

 gret that my place should not at this moment be occupied by our 

 own Conybeare ; for the founder of the genus Plesiosaurus would 

 have taught you to admire a multitude of comparisons and osteo- 

 logical adjustments contained in the results of Mr. Owen's researches. 

 Though unequal to enter into a discussion of his merits, I can, how- 

 ever, in common with all my brother geologists, express to him my 

 deep sense of gratitude for the successful eftbrts he has made to 

 point out to us new links in the scale of nature's works. 



On the subject of Saurian remains our knowledge has also been 

 increased during the past year by Dr. Mantell, in a memoir commu- 

 nicated to the Royal Society, on the lower jaw of the Iguanodon, 

 and on the remains of the Hylasosaurus and other Saurians disco- 

 vered in the strata of Tilgate Forest. Not pretending to have ade- 

 quate acquaintance with the subject treated of by Dr. Mantell, I am 



