o2 ME. E. LYDEKKEE ON DINOSAUES OF THE WEALDEN 



their terminal faces, and in their smooth external surface. Compared, 

 indeed, with the cervical vertebrae, of Pelonevstes philarclius there is 

 such a close resemblance, that I think there is little doubt that Plio- 

 S'dtriis Evansi should be transferred to Feloneustes ; and from the 

 agreement in relative size between the cervical vertebrae and the 

 mandible and paddle from the Oxford Clay in the Eyebury collec- 

 tion figured by Phillips as PUosaurns^ which I have shown * to be 

 referable to Feloneustes, it appears probable that those specimens 

 are likewise referable to P. Evansi. 



The only other bones to which it will be necessary to refer are 

 the epipodials (radius and ulna, and tibia and fibula). A reduced 

 figure of the tibia and fibula is given in PI. V. fig. 4, from which 

 it will be apparent that these bones differ from their horao- 

 logues in the Kimeridgian species of Fliosaurus in that they are 

 vertically instead of transversely elongated, in which respect they 

 agree precisely with the corresponding bones of Feloneustes. 



Summing up the result of the foregoing observations, it appears 

 that we have to do with a large Pliosaur which in dental characters 

 cannot be satisfactorily distinguished from Fliosaurus ferox., and 

 may accordingly be referred to that species, a reference which will 

 confirm the conclusion that the vertebrae named P. pacliydirus are 

 likewise referable to the same species. This Pliosaur, while agreeing 

 with the typical Kimeridgian forms in the character of the 

 mandibular symphysis and vertebrae, is allied by the teeth and 

 epipodial bones to the smaller forms knoAvn as Feloneustes, and 

 therefore serves to connect the latter with Fliosaurus, although not 

 necessarily leading to its abolition. 



Further, the available evidence points to the transference of 

 Fliosaurus Evansi to Fdonevstes, and also indicates that the more 

 elongated centra of the cervical vertebrae may be added to the dis- 

 tinctive characters of that genus 



The evidence now clearly shows that Feloneustes, which ma^'have 

 been descended from the Longirostrine group of Flesiosaurus, is 

 the direct ancestral tj'pe of Fliosaurus, which has gradually become 

 more specialized in the characters of tlie teeth, in the imperfect 

 articulation between the centra and appendages of the vertebrae, in 

 the shortening and widening of the epipodial bones, in the shorter 

 mandibular symphysis, and, finally, in the increase in absolute 

 corporeal bulk. 



EXPLANATION OF PLATE V. 



Eemains of Fliosaurus feo^ox froiu the Oxford Clay, near Peterborough. 



Fig. L A tooth, natural size. 



2. Anterior aspect, of a late cervical vertebra, with the rib (r) of the right 



side, f nat. size. 

 'd. Imperfect neural arch of a cervical vertebra, | nnt. size, pf.z, post- 



zygapophysis ; pr.z, broken base of prezygapophysis. 

 4. A tibia (7V) and fibula {F.), I nat. size. 



* See ' Catalogue,' p. 154 



