68 Geological Society : 



Vlaming's Manuscript, nos. 16f>, 166. This fish is called Sturgeon of 

 Banda, and has the fork of the snout not more largely developed 

 than in Trigla lyra. Like P. ffiffas, it grows to a considerable size. 

 A third species is mentioned by Cuvier in few words : " Ainsi Ton 

 doit croire qu'il y a dans la mer des Indes une espece de ce genre 

 differente de la notre." This third species of Cuvier is perhaps P. 

 orient alis, or my new P. Rieffeli. 



GEOLOGICAL, SOCIETY. 



December 14, 1859, Prof. J. Phillips, President, in the Chair. 

 The following communications were read : 



1. "On some Remains of Polyptychodon from Dorking." By 

 Prof. Owen, F.R.S., F.G.S. 



Referring to the genus of Saurians which he had founded in 1841 

 on certain large detached teeth from the Cretaceous beds of Kent 

 and Sussex, and which genus, in reference to the many-ridged or 

 folded character of the enamel of those teeth, he had proposed to 

 call Polyptychodon, Prof. Owen noticed the successive discoveries of 

 portions of jaws, one showing the thecodont implantation of those 

 teeth, which, with the shape and proportions of the teeth, led him to 

 suspect the crocodilian affinities of Polyptychodon ; and the subse- 

 quent discovery of bones in a Lower Greensand quarry at Hythe, 

 which, on the hypothesis of their having belonged to Polyptychodon, 

 had led him to suspect that the genus conformed to the Plesio- 

 sauroid type. 



The fossils now exhibited by Mr. G. Cubitt of Denbies, consisted 

 of part of the cranium (showing a large foramen parietale), frag- 

 ments of the upper and lower jaws and teeth, of the Polyptychodon 

 interruptus, from the Lower Chalk of Dorking, and afforded further 

 evidence of the plesiosauroid affinities of the genus. Professor Owen 

 remarked that in a collection of fossils from the Upper Greensand 

 near Cambridge, now in the Woodwardian Museum, and in another 

 collection of fossils from the Greensand beds near Kursk in Russia, 

 submitted to the Professor's examination by Col. Kiprianoff, there 

 are teeth of Polyptychodon, associated with plesiosauroid vertebrae 

 of the same proportional magnitude, and with portions of large limb- 

 bones, without medullary cavity, and of plesiosauroid shape. 



Thus the evidence at present obtained respecting this huge, but 

 hitherto problematical, carnivorous Saurian of the Cretaceous period 

 seemed to prove it to be a marine one, more closely adhering to the 

 prevailing type of the Sea-lizards of the great mesozoic epoch, then 

 drawing to its close, than to the Mosasaurus of the Upper Chalk, 

 which, by its vertebral, palatal, and dental characters, seemed to 

 foreshadow the Saurian type to follow. 



Prof. Owen exhibited also drawings of specimens in the Wood- 

 wardian Museum and in the Collection of Mr. W. Harris, of Charing, 

 which show the mode and degree of use or abrasion to which the 

 teeth of Polyptychodon had been subject. 



