71 



EMYS MOBlLENSlS.—HolbrooL 



Plate IX. 



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Characters. Shell oval, ecarinate; convex anteriorly, depressed posteriorly, 



entire in front, emarginate and sub-serrate behind; jaws serrated; inferior 

 furnished with a hook. 



Description. The shell is regularly oval, broadest and flattened posteriorly; 

 convex, entire in front, but emarginate and sub-serrate behind. Of the five 

 vertebral plates, the anterior is urceolate, smallest in front, with three articulating 

 margins, larger behind and convex; the second, third and fourth are hexagonal; 

 the third slightly concave on its anterior margin; the fourth smaller and concave 

 on its posterior; the fifth is irregularly triangular, its apex rounded, and directed 

 upwards, and its basis cut into four articulating margins. The lateral plates are 

 very large, the anterior triangular, the second and third pentagonal, and the 

 fourth quadrilateral; all these plates are longitudinally rugous. The marginal 

 plates are twenty-five in number; the nuchal is a parallelogram; the first is 

 irregularly quadrilateral, rounded posteriorly, broad and straight anteriorly; the 

 second is also quadrilateral, with its superior internal angle greatly elongated, to 

 enter between the first marginal and first dorsal plates; all the remaining 

 marginal plates are quadrilateral, the posterior and internal angle of the three 

 last are salient, which gives a shghtly serrated appearance to the shell, at its 

 posterior margin; all these plates, except the intermediate and anterior, are 

 marked with one or more concentric striag, at the junction of the lateral and 

 vertebral plates. 



