CHELYDRIDJE. 145 



pelvic attachment. The transverse diameter at the prox- 

 imal extremity is 0,070 (2-75 inches). 



Hastings Collection. 



Genus PSEUDOTRIONYX, Dollo 1 . 

 Syn. (?) Ap7wlidemys, Pomel 2 . 



Contour of anterior portion of carapace unknown : plastral bridge 

 of considerable length, with a distinct inguinal notch ; suture 

 between hypo- and xiphiplastral forming a perfectly straight line, 

 dorsal surface of neurals sculptured ; posterior border of carapace 

 entire. 



The skull provisionally referred to this genus agrees in its rela- 

 tively large size and general characters with that of Macroclemmys, 

 but is more vaulted, with the orbits larger and directed somewhat 

 upwardly, larger nares, a narrower bar between orbit and nares, and 

 a wider and more concave palate. 



This genus is probably the same as the imperfectly described 

 Apholidemys of the Lower Eocene of Cuysse-la-lfotte. 



Pseudotrionyx delheidi, Dollo 3 . 



The type and only described species. Of the approximate di- 

 mensions of small individuals of Macroclemmys temmincki. 



The type specimen is from the Middle Eocene of Belgium, and it 

 is therefore possible that the undermentioned Lower Eocene speci- 

 mens may be specifically distinct. 



Hob. Europe (Belgium and England). 



38953. The imperfect cranium; from the London Clay (Lower 

 {Fig.) Eocene) of the Isle of Sheppey. Eigured (when much 

 concealed by matrix) by Owen in his ' Eeptilia of the 

 London Clay ' (Mon. Pal. Soc), pt. ii. pi. xxix. figs. 1, 2 ; 

 and noticed by the present writer in the ' Quart. Journ. 

 Geol. Soc' vol. xlv. p. 242. In its general characters this 

 skull accords so closely with that of Macroclemmys that 

 there can be little, if any, hesitation in referring it to the 

 present form ; this reference being confirmed by the total 

 absence of the impression of horny shields, indicating 

 that the skull, as in the Trionychidce, was merely covered 

 with skin. The chief characters in which this skull 



1 Bull. Mus. R. Hist. Nat. Belg. vol. iv. p. 96 (1886). 



2 Arch. Sei. Phys. Nat. ser. iv. vol. iv. p. 328 (1847). 3 Loc. cit. 



PART III. L 



