190 CHELOtfTA. 



The following specimens probably belong to this species. 



40654. Fragment of rock exhibiting the dorsal aspect of the fourth 

 neural bone ; from the Purbeck of Swanage. In its 

 elongated and narrow form this bone resembles the neurals 

 of the type of H. latiscutata, but is of larger size. 



Purchased, 1867. 



28620. Slab exhibiting the ventral aspect of the 4th (?) costal of 

 the left side ; from the Purbeck of Swanage. This speci- 

 men agrees very closely with the corresponding costal 

 of the type. Purchased, 1853. 



44817. Slab exhibiting the dorsal aspect of an immature fourth 

 costal of the left side ; from the Purbeck of Swanage. 

 The great width of the vertebral shield is shown by the 

 position of its lateral sulcus. 



Presented by Benjamin Bright, Esq., 1873. 



Hylseochelys belli (Man tell 1 ). 

 Syn. Chelone belli, Mantell 2 . 



Chelone mantelli, Fitzinger 3 . 

 Chelone costata, Owen 4 . 

 (?) Emys mantelli, Gray 5 . 

 Platemys mantelli, Owen 6 . 

 Platemys dixoni, Owen 7 . 



Known only by fragments of the shell and limb-bones. Of large 

 size, with the outer extremity of the rib supporting the first costal 

 bone very large and prominent ; the plastron with a large persistent 

 vacuity, which does not, however, impinge on to the hyoplastral. 



The identity of Chelone costata with C. belli was clearly pointed 

 out by Mantell ; and there would seem to be no reasonable doubt 

 but that the fragments of plastron which were made the types of 

 Platemys mantelli and P. dixoni are referable to the same form. 



Some of the specimens included under this heading may be re- 

 ferable to the preceding forms. 



Hab. Europe (England). 



36529. The distal extremity of the second left costal of an immature 

 (Fig.) individual ; from the Wealdcn of Cuckfield, Sussex. The 



Medals of Creation, 1st ed. p. 776 (1844). — Chelonia. 2 Loc. cit. 



Ann. Mus. Wien, vol. i. p. 128 (1835). 



Wealden and Purbeck Eeptilia (Mon. Pal. Soc.), pt. i. p. 10 (1853). 



Synopsis Keptilium, p. 33 (1831). — No description. 



Op. cit. p. 11. 7 Ibid. p. 12. 



