184 CHELONIA. 



Genus IDIOCHELYS, Meyer 1 . 



Syn. Chelonemys, Jourdan 2 . 



Shell with deeply emarginate nuchal ; neurals frequently short 

 and interrupted, never exceeding seven in number, and not con- 

 nected with the one suprapygal ; entoplastral narrow and diamond- 

 shaped ; hypoplastrals short. Vertebral shields very broad, with 

 the underlying areas smooth ; inframarginal shields (if present) 

 broad, and extending on to the marginal bones ; sulcus dividing 

 abdominal and plastral shields extending nearly straight across the 

 plastron, and joining the inframarginal (? marginal) sulcus. Number 

 of phalangeals in manus 2, 2, 3, 3, 3. Ossification of carapace 

 apparently not completed till late in life. 



This genus was provisionally referred by Eiitimeyer 3 to the 

 Pleurodira, by whom it was pointed out that the cervical vertebrae 

 have distinct transverse processes. This reference is strongly con- 

 firmed by the resemblance of the shell to that of the next genus ; 

 and likewise by the number of phalangeals in the digits of the 

 manus being the same as in Paraclielys (infra). Further, the 

 evidence derived from the flexure of the neck in the undermentioned 

 specimens is also confirmatory of this view. Eiitimeyer states that 

 while the skull shows some resemblance to that of AcicJielys, it 

 approximates in contour to that of Podocnemis. 



Idiochelys fitzingeri, Meyer 4 . 



Syn. Idiochelys ivagnerorum, Meyer 5 . 

 Idiochelys tvayneri, Meyer 6 . 

 Chelonemys plana, Jourdan 7 . 

 Chelonemys ovata, Jourdan 8 . 



The type and only described species, the whole of the forms to 

 which the above-mentioned names have been applied being con- 

 sidered by Eiitimeycr as specifically identical. All the figured 

 specimens indicate immature individuals, and are of relatively small 

 size. The number of neural bones is subject to considerable varia- 

 tion in the posterior half of the carapace, the specimen figured in 



1 Neues Jabrb. 1839, p. 77. 



2 Extr. Proces-Verb. Soc. Agric. Lyon, ser. 3, vol. vi. p. xxxiii (18G2). 



3 N. Denkschr. schvv. G-es. Nat. vol. xxv. art. 2, p. 140 (1873). 

 1 Neues Jahrb. 1831), p. 77. 



6 In Bronn's Index Palreontologicus, p. GOG (1848). 



6 Ibid. The authority for this name is given by Bronn as Minister's ' Beitriige 

 z. Pctrefactenkuncle,' but in the 2nd ed. of that work the name is given as 

 /. fitzingerl. ' Loc. cit. 8 Loc. cit. p. asxiii. 



