66 CHELOtflA. 



agrees well in general characters with the type. It is 

 evidently specifically the same as the next specimen. 



Bell Collection. Purchased, 1863. 



38949. The imperfect skeleton of a younger individual specifically 

 (Fig.) identical with the preceding ; from Sheppey. Figured by 

 Owen in his ' Eeptilia of the London Clay, &c.' vol. i. pt. i. 

 pi. ii., and also in his ' History of British Fossil Eeptilia/ 

 Chelonia, pis. i., xvi., and xvii. fig. 6, as Chelone 

 breviceps. The only ground for referring it to that species 

 is the roughness of the bones ; this character being due 

 to immaturity in the present specimen, and to erosion in 

 the type of the latter (see p. 42). The skull agrees 

 closely with the preceding specimen, and shows the long 

 and flattened mandibular symphysis characteristic of the 

 present genus. The neurals of the carapace have the 

 equal-sized lateral facets characteristic of the type shell ; 

 and the specimen is almost indistinguishable from the 

 reduced figure of the larger carapace given in pi. xi. of 

 the ' Eeptilia of the London Clay.' The two sides of the 

 plastron have been somewhat squeezed together, and the 

 marginals are wanting. The left coracoid is shown, and 

 is somewhat less suddenly expanded at the distal extremity 

 than in the type ; but this difference may well be due to 

 immaturity. BoiuerbanJc Collection. Purchased, 1865. 



R. 916. Nodule showing the cast of the inner surface of a very 

 large carapace ; from Harwich. The slenderness of the 

 ribs and the width of the costals are well shown. The 

 characters of this specimen agree closely with those of the 

 one figured by Owen in his ' Eeptilia of the London Clay, 

 &c.' vol. i. pt. i. pi. x. a. No history. 



R. 917. Nodule with cast of the inner surface of a similar carapace ; 

 from Harwich. The boundaries of the wide costals and 

 the narrow impressions formed by the ribs are clearly 

 shown. No history. 



R. 915. Nodule exhibiting a cast of the inner surface of a very 

 similar carapace. In addition to the features displayed 

 by the preceding specimens, the outlines of the equal-sided 

 neurals are indistinctly shown. No history. 



