AND SAUROPTERTGIANS OF THE PURBECK ETC. 47 



shows that the former bones are characterized not only by their 

 larger size, but also by their relative length aud the great excess in 

 the length of the second over the fourth. Moreover, both these 

 bones have their antero-internal borders rounded, while the distal 

 surface of the fourth is comparatively narrow. In No. 2559, on 

 the other hand, the bones are absolutely smaller and apparently 

 relatively shorter, the second being but slightly longer than the 

 fourth ; while both these bones have sharp antero-internal borders 

 and the distal surface of the fourth metatarsal is broad and squared. 



Seeing, therefore, that there is clear evidence of the existence of 

 two species of Megalosaurians in the English Weald en it remains 

 to determine which should be referred to M. Dankeri ; for I have 

 no hesitation in believing that the British and Continental forms 

 were specifically identical. Now the type tooth of 31. Dunheri is of 

 comparatively large size, and was obtained from the lower division 

 of the Hastings beds, which must be equivalent either to the Wad- 

 hurst Clay or the underlying Ashdowns ; while No. 2559 came from 

 the higher division of the overlying Tunbridge sands at Cuckfield. 

 The Hollington metatarsus agreeing, therefore, in relative size with 

 the type tooth and coming from approximately the same geological 

 horizon, there is every probability that it belongs to the same species, 

 to which I accordingly propose to refer it. It is of course unsatis- 

 factory to have a species founded upon such an uncharacteristic 

 portion of the skeleton as a single tooth ; but being so, we are bound 

 to accept and make the best we can of it. So far as it goes, the 

 circumstance that the Iguanodons of the Wadhurst Clay appear to be 

 all specifically different from those of the Tunbridge beds and Weald 

 Clay is in favour of the view that the Hollington metatarsus really 

 belongs to the species to which I propose to refer it. 



Finally, seeing that the Cuckfield metatarsus is decidedly specific- 

 ally distinct from the latter, I have made it the type of a distinct 

 species, under the name of Megalosaurus Oweni *. 



III. CiMOLiosATJEUS POETLANDiCDs/rom the PiirbecJc. 



In part II. of the British Museum ' Catalogue of Fossil Reptilia 

 and ximphibia ' 1 1 have referred the vertebra} from the Portlandian 

 described under the names of Plesiosaurus lulnspitensis and P. cari- 

 nntus { = P' PhilUpsi) to Cimoliosauriis {Pliosauriis) portlundiciis 

 of Owen, on the ground that all the known vertebra) from these beds 

 are of one type, and are therefore almost certainly referable to the 

 species typically represented by the bones of the pelvic limb. 



Hitherto this species has been known solely from the Portlandian, 

 but I am now able to bring evidence that it ranged upwards into 

 the Middle Purbeck. This evidence is afforded by the ira])erfect 

 centra of two posterior cervical vertebras which I procured during 

 the past summer from the (juarries at Portland. They were obtained 

 from the ' Cinder-bed ' of the Middle Purbecks, which, as is well 



* Geol. Mag. deoiid. 3, vol. vi. p. 325 (1889). 

 t Pp. 227, 228 (1889). 



