102 CHELONIA. 



Nearly the whole of the carapace remains, but the 5th 

 and 6th costals have been cut away on the right side in 

 order to exhibit the dorsal aspect of the hypoplastral. 

 The inguinal buttress is thus seen to occupy precisely the 

 same relative position as in Ocadia. The pygal and 

 suprapygal bones, as well as the vertebral shields, agree 

 very closely in contour with those of the latter ; but the 

 form of the neurals is quite different. Purchased. 



Genus non det. 



The undermentioned specimen differs from the epiplastrals of the 

 following genera in the presence of a thickened ridge on the outer 

 half of the dorsal surface occupied by the gular shield, and thereby 

 agrees with the corresponding bone of Nicoria, to which genus it 

 may belong, or it may be referable to Paleeochelys. 



Hab. Europe (England). 



R. 1582. The right epiplastral bone ; from the Upper Eocene (Lower 

 Oligocene) of Hordwell, Hampshire. 



Hastings Collection. Purchased, 1855. 



Genus EMYS, Dumeril \ 

 Syn. Lidremys, Gray 2 . 



Neural bones short, hexagonal, with the antero-lateral surfaces 

 much shorter than the postero-lateral : nuchal not distinctly emar- 

 ginate. Plastron united to the carapace by ligament, and in the 

 adult more or less distinctly divided into two lobes movable upon a 

 ligamentous hinge situated between the hyo- and hypoplastrals, 

 both of which enter into the formation of the bridge ; entoplastral 

 cut by the humero-pectoral sulcus ; xiphiplastrals not distinctly 

 notched. Skull without oral palatal ridges. The vertebral shields 

 are hexagonal and of moderate width. 



In this and the following genera the costal bones do not alternate 

 in length at their extremities ; the epiplastrals are not distinctly 

 thickened anteriorly ; and the sulcus between the marginal and 

 costal shields is placed entirely on the costal bones. 



None of the extinct species referred to this genus appear really to 

 belong to it, in the sense in which the term is now employed. 



1 Zoologie Analytique, p. 76 (1800). 



2 Catalogue of Tortoises, p. 31 (J844). 



