CHELONID.E. 67 



R. 919. A split nodule showing the inner surface of the imperfect 

 carapace of a smaller individual, together with a cast of 

 the same; from Harwich. The under surface corresponds 

 precisely with that of the type carapace figured by Owen, 

 op. tit. pi. x. The equal- sided neurals are well shown ; 

 and the slender ribs on the broad costals are equally 

 distinctive. The cast exhibits the narrow grooves formed 

 by the ribs, which are precisely the same as in the fore- 

 going specimens. No history. 



28768. An imperfect immature shell, specifically identical with the 

 next specimen ; from the London Clay of the Isle of 

 Sheppey. The carapace shows the 2nd to the 6th neurals, 

 and portions of the corresponding costals. The 4th 

 neural is very narrow, and the middle line of the carapace 

 somewhat depressed. Purchased, 1853. 



R. 3. An imperfect shell, probably belonging to a young individual 

 of this species ; from the London Clay of the Isle of 

 Sheppey. This specimen exhibits the first seven neurals 

 and portions of the corresponding costals, the imperfect 

 hyo- and hypoplastrals, and the scapulo-precoracoids. 

 The neurals have the same contour as in the two preceding 

 specimens, and the ribs have the same slenderness. The 

 condition of the carapace and plastron of the present 

 specimen indicates immaturity: and it would agree 

 approximately in relative size with the skull jNo. 37215. 



Purchased, 1880. 



37207. The imperfect shell of a younger individual; from Sheppey. 

 The plastron is greatly damaged, but the middle region of 

 the anterior two thirds of the carapace is well preserved. 

 The equality in the size of the two lateral facets of the 

 middle neurals is well shown. Bell Collection. 



R. 913. Nodule showing a cast of the inner surface of a carapace 

 probably referable to this species ; from Harwich. 



No history. 



R. 914. A nearly similar specimen ; from Harwich. No history. 



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