ANNIVERSARY ADDRESS OF THE PRESIDENT. XXXVll 



Regarding reptiles, the additional remains of Iguanodon, Ilylaeo- 

 saurus, Megalosaurus, Streptospondylus, Poecilopleuron, Goniopholis 

 and Cetiosaurus are mentioned, and specimens are also noticed of 

 Trionyx, Plesiosaurus, and Macrorliyncbus. But the discovery 

 most gratifying to Dr. Mantell was that of the lower jaw of his Igua- 

 nodon, which, most properly, found its way to him for description*. 

 He infers, from the examination of these remains, that there is 

 "now unquestionable proof that the Iguanodon, like the colossal 

 Edentata, possessed a large prehensile tongue and fleshy lips, capable 

 of being protruded and retracted, and which must have formed most 

 efficient instruments for seizing and cropping the foliage and branches 

 of ferns, Cycadese and coniferous trees." 



Dr. Mantell, referring to a previous notice of a jaw which he 

 then (1841) thought might be that of a yovmg Iguanodon, now pro- 

 poses the name of Regnosaurus Northamptoni for the reptile to 

 which it belonged, considering that it is subgenerically, if not gene- 

 rically, distinct from the Iguanodon, though evidently of the same 

 family. In a summary of the Vertebrata found in the Wealden de- 

 posits. Dr. Mantell enumerates about thirty-two species of fishes, one 

 a Cycloid, sixteen Placoids, and fifteen Ganoids. Of reptiles it is 

 stated that there are twelve genera of saurians already determined, 

 with indications of four or five others, one flying reptile, — the Ptero- 

 dactyle, and four or five genera of Chelonians. There are also bones 

 considered referable to birds. From the length of time (nearly 

 thirty years) which has elapsed between the discovery of the teeth 

 of the Iguanodon to that of the jaw with teeth in place above men- 

 tioned, our colleague is led to infer that the palaeontology of the 

 Wealden is as yet but imperfectly explored, and that many a relic of 

 the past has still to be brought to light. 



Though so much has been said, and well said, respecting the ac- 

 cumulations to which the name of Wealden has been given, the 

 interest attached to them can scarcely be considered less now than 

 when, in years past, we were first made acquainted with their general 

 character. To detect fluviatile and estuary deposits of that geolo- 

 gical epoch (a fortunate bending, squeezing, and denuding of the 

 rocks of part of England, exposing them for examination) was no 

 small advance in our knowledge of the distribution of land and sea 

 of the period. Additions, as you are well-aware, have since been 

 made to this first knowledge, and we see Dr. Mantell losing no op- 

 portunity of increasing it, so that now we can embrace a wider area 

 upon which to reason, and can better understand the spread of dry 

 land, in the area at present occupied by western Europe, anterior to 

 the submergence of so much of it beneath the adjoining seas, in 

 the waters of which the cretaceous deposits were effected. These 

 great changes in the relative areas overspread by sea and land at 

 different geological times possess the highest interest, particularly 

 when we consider them with reference to the various ranges of high 



* The original memoir on the Iguanodon having been communicated to the 

 Royal Society, the paper in which these remains were described, with the assist- 

 ance of Dr. Melville, was also transmitted to that Society. 



