178 



CHEL0NIA. 



35196. The corresponding portion of a still smaller cranium ; from 

 the Cambridge Greensand. The oral surface of the palate 

 is well preserved. Purchased, 1859. 



R. 1558. The anterior part of a cranium, agreeing closely with the 

 preceding specimen ; from the Cambridge Greensand. 



Presented by Prof. T. Rupert Jones, 1889. 



Rhinochelys elegans, Lydekker 1 . 



Allied to the preceding, but with the nasals relatively wider and 

 shorter, and the premaxillse considerably deeper. The latter cha- 

 racter causes the beak to have a decidedly hooked appearance. 

 There is also a peculiar lateral swelling of the prefrontal region, 

 which appears to be wanting in E. macrorhina. 



It does not appear that the characters of the present form are 

 due to the abrasion of the alveolar walls in the last-named species. 

 In the present form the vertical diameter of the nasals considerably 

 exceeds that of the nares, whereas in U. macrorliina the former 

 dimension is slightly the smaller of the two. 



The largest specimens in the Collection are referred to this form. 



Hob. Europe (England). 



41796. The cranium, wanting the parietal and occipital region, and 

 (Fig.) with the palate obscured by phosphate ; from the Cam- 

 bridge Greensand. The type ; figured by the writer in 

 the < Quart. Journ. Geol. Soc' vol. xlv. pi. viii. figs. 5, 5 a. 



Purchased, 1869. 



35194. The anterior portion of a somewhat larger cranium ; from 



the Cambridge Greensand. The characteristic depth of 

 the premaxillse is well shown. Purchased, 1859. 



35195. The anterior extremity of a similar cranium ; from the 



Cambridge Greensand. Purchased, 1859. 



R. 1496. Cast of a nearly entire cranium, probably belonging to a 

 large individual of this species. The original was ob- 

 tained from the Cambridge Greensand, and is in the col- 

 lection of T. Jesson, Esq., of Northampton ; it is figured by 

 the writer, op. cit. pi. viii. fig. 4. This skull is remark- 

 able for the absence of any trace of a suture between the 

 nasals and prefrontals, which at first sight suggests that 

 it belongs to Ohelone. The peculiar form of the suture 

 between the frontals and prefrontals shows, however, 



1 Quart. Journ. Geol. Soc. vol. xlv. p. 2a) (1889). 



