180 CHELONIA. 



Esq., of Northampton ; it is figured by the writer in the 

 1 Quart. Journ. Geol. Soc' vol. xlv. pi. viii. figs. 3, 3 a. 

 The oral ridges on the palate are well shown. 



Made in the Museum, 1889 



Rhinochelys jessoni, Lydekker 1 . 



Skull much depressed, and the beak markedly hooked ; narial 

 aperture small, with the nasals antero-posteriorly elongated and 

 narrowing superiorly ; prefrontals very large, almost meeting in the 

 middle line above the nares, and entering to a small extent into the 

 formation of the nares : frontals very short and wide ; parietals 

 much wider than in the other species. 



This species should perhaps form the type of a distinct genus. 



Hob. Europe (England). 



R. 1506. Cast of the slightly imperfect cranium. The original, 

 which is the type, was obtained from the Cambridge 

 Greensand, and is preserved in the collection of T. Jesson, 

 Esq., of Northampton ; it is figured by the writer in the 

 ' Quart. Journ. Geol. Soc' vol. xlv. pi. viii. figs. 6, J3 a, 6 b. 

 The extremity of the premaxillse is broken off. This speci- 

 men differs from the skulls of the other species by the 

 strongly marked impressions of the epidermal shields in 

 the fronto-nasal region, which are liable to be mistaken 

 for sutures. The indistinctness of many of the sutures 

 apparently shows that this specimen belongs to an adult 

 individual, and consequently that the species was of smaller 

 size than either of the preceding. The specimen is im- 

 portant as showing that the squamosal, if not actually 

 articulating with the parietal, was at all events closely 

 approximated to that bone. The conformation of the ante- 

 rior border of the tympanic ring is very clearly displayed. 



Made in the Museum, 1889. 



Rhinochelys, sp. 



The undermentioned specimen indicates a larger form appa- 

 rently allied to the preceding species, but with the prem axillae more 

 prominent, the nasals square, and the prefrontals consequently 

 widely separated from one another. 



Hah. Europe (England). 



R. 1509. Cast of the anterior portion of the cranium. The original 

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



