55 



EMYS TROOSTII. 



Plate IV. 



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

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

 or hnes 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 depressed, ecarinate, sub-round, and slightly serrated 

 behind: its surface is smooth above and slightly wrinkled on the sides, more par- 

 ticularly at the junction of the lateral 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 plate 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 one is almost linear, its anterior 

 extremity pointed; the adjoining plates pentagonal, with their anterior border 

 emarginate, the outer and anterior angle extending beyond the second marginal 

 plate, Avhich, 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 plates are irregularly quadrilateral, broad without and narrow within, 



