36 CHELONIA. 



49918. Fragment of chalk showing the inner surface of the first 

 costal bone of a medium-sized turtle which may perhaps 

 belong to this form ; from the Lower Chalk near Lewes, 

 Sussex. In form, and also in the double articular sur- 

 face for the first and second neurals, this specimen agrees 

 with C. hoffmanni, and differs from C. benstedi. 



Capron Collection. Purchased, 1879. 



Chelone jessoni, Lydekker 1 . 



An imperfectly known large form, with which the preceding is 

 not improbably specifically identical. Known typically by the man- 

 dible, which comes nearest in general characters to that of C. im- 

 bricata, having a long and narrow symphysis, with a prominence 

 near the posterior border, but considerably deeper and more mas- 

 sive, with a more sudden descent from the beak to the inferior 

 surface, and a median oral ridge approximating to that of C. mydas. 



There is at present no decisive evidence to show that this form is 

 specifically distinct from 0. benstedi, but if it be identical with the 

 unnamed form mentioned above there is a probability that such is 

 the case. The reference to the present genus is provisional. 



Hab. Europe (England). 



47209. The imperfect palatal region of the cranium of a very large 

 turtle probably referable to this species ; from the Gault 

 of Eolkestone, Kent. The palate, which appears to have 

 been ridged, agrees in its narrow form with the under- 

 mentioned mandibles. This specimen is noticed by the 

 writer in the 'Quart. Journ. Geol. Soc' vol. xlv. p. 231. 

 Gardner Collection. Purchased, 1876. 



R. 1497. Cast of the symphysis of a mandible agreeing in size with 

 the preceding specimen, and almost certainly referable to 

 the same species. The original was obtained from the 

 Cambridge Greensand, and is in the possession of T. Jesson, 

 Esq. ; it is noticed by the writer, op. cit. p. 231. 



Made in the Museum, 1889. 



35186 b. The symphysis of a similar but somewhat smaller mandible; 



(Fig.) from the Cambridge Greensand. The type. Eigured by 



the writer, op. cit. p. 232, fig. 1. Purchased, 1859. 



46372. An imperfect mandibular symphysis agreeing very closely 

 with the preceding specimen ; from the Cambridge Green- 

 sand. Cunnington Collection. Purchased, 1875. 



1 Quart. Journ. Geol. Soc. vol. xlv. p. 231 (1889). 



