123 



EMYS TROOSTII.—HolbrooL 



Plate XX. 



Characters. Shell sub-round, much depressed, ecarinate; posterior part of the 

 margin very slightly serrated; lateral and marginal plates marked with blotches or 

 hues of horn-colour; sternum broad, dirty yellow, each plate having a large black 

 spot near its centre; head long, narrow; upper jaw emarginate; lower jaw 

 furnished with a tooth. 



Description. The shell is greatly depressed, ecarinate, sub-round, and slightly 

 serrated behind: its surface is smooth above, and shghtly Avrinkled on the sides, 

 more particularly at the junction of the lateral and marginal plates. Of the 

 five vertebral plates, the anterior is pentagonal, the second, third and fourth 

 hexagonal; the second has its anterior, and the fourth its posterior margin 

 re-entering, to receive the borders of the adjoining plates; the fifth vertebral is 

 triangular, with a rounded basis. The first lateral plate is irregularly triangular, 

 with its basis united to four marginal plates; the second and third are pentagonal, 

 with an acute angle passing upwards between the vertebral plates; the fourth is 

 quadrilateral. The marginal plates are twenty-five in number; the nuchal, or 

 intermediate, is ahnost linear, with its anterior extremity pointed; the adjoining 

 plates are pentagonal, with their anterior border emarginate, the outer and 

 anterior angle extending beyond the second marginal plate, which, like all the 

 others, is quadrilateral; the four posterior plates are very slightly serrated. 



The sternum is oblong, full and entire in front, and slightly emarginate behind. 

 The gular plates are triangular, with the apex of the triangle directed backwards; 

 the brachial are irregularly quadrilateral, broad without and narrow within, where 



