CHELONIA. 67 



Genus — Emys. 



Emys testudiniformis. Owen. Plate 36. 



Report on British Fossil Reptiles, Trans. British Association, 1841, p. 161. 

 Emys de Sheppy. Ctw. (?) 



From the preceding genus of the Chdonia paludinosa the present species differs in 

 the depth of the bony cuirass, the convexity of the carapace, and the concavity of the 

 plastron (PI. 36, fig. 6). The more immediate affinities of the present fossil are 

 elucidated by the comparison of the points of structure which it displays with the 

 anatomical characters of the carapace of the Plateiuijs and Testudo. 



The specimen, on which the species here called Evii/s testudimfonnis is founded, 

 includes a large proportion of the first, second, third, fourth, fifth, and sixth, with a 

 fragment of the seventh costal plates of the left side ; a small proportion of the second, 

 third, fourth, fifth, and sixth neural plates ; the hyosternals and hyposternals, and part 

 of the entosternal bones of the plastron. 



The first costal plate is one inch ten lines in greatest breadth, one inch five lines 

 broad at its junction with the neural plates, and four fifths of the vertebral margin is 

 articulated with the second neural plate ; one fifth part, divided by an angle from the 

 preceding, joins a corresponding side of the lateral angle of the third neural plate ; in 

 this structure it resembles both the genus Teshido and some species of Emys. 



The third, fourth, fifth, and sixth neural plates are of equal broadth, as in Emydes ; 

 not alternately broad and narrow as in the Testudines ; they are likewise of uniform 

 figure, as in most Emydes ; not variable, as in Testudines; the neural plates also 

 resemble those of the existing Emydes., and particularly of the Box- terrapin {Cistudo) 

 in form. The lateral margin of each is bounded by two lines, meeting at an open 

 angle, the anterior line is only one fourth part the length of the posterior one ; and 

 this resemblance may be stated with confidence, since the portion of the entosternal 

 piece preserved in the plastron determines the anterior part of the fossil. 



The costal plates preserved in the present Chelonite differ from the corresponding- 

 ones of the tortoises, and resemble those of the Emydes in their regular breadth, and 

 the uniform figure of the extremities articulated with the vertebral pieces ; the anterior 

 line of the angular extremity is nearly three times as long as the posterior one. 



Further evidence of the relation of the present Chelonite to the fresh- water family 

 is given by the impressions of the epidermal scutes ; those covering the vertebral 

 plates {scuta vertebralia) agree with those of most Emydiuns in the very slight production 

 of the angle at the middle of their lateral margins, which is bounded by a line running 

 parallel with the axis of the carapace, except where it bends out to form that small 

 angle. 



