species of North American Tortoises. 109 



posterior side of each plate. First vertebral plate hexagonal, 

 slightly and sharply pointed in front, the posterior face curved 

 in form of a prolate cycloid, the second, third and fourth hex- 

 agonal, the lateral angles acuminate, the anterior face of the 

 second with a deep sinus receiving the projecting curve of 

 the first plate, the fourth w^ith a deep sinus on its posterior face, 

 the fifth hexagonal, its anterior face curved like the posterior 

 face of the first plate, and entering the sinus of the preceding 

 one : first lateral plate six-sided, second and third pentagonal, 

 the lov^^er faces slightly divided into three, the fourth quadran- 

 gular, its lower face divided into two : marginal plates edged 

 outwardly with yellow, the intermediate one triangular, its 

 apex pointing forward, truncate and three-toothed, the first 

 pentagonal, projecting at its posterior aad exterior angle be- 

 yond the next, the rest square or oblong, the second projecting 

 like the first, the eighth, ninth, tenth and eleventh wider and 

 spreading, each projecting beyond the preceding one, the 

 ninth, tenth, eleventh and twelfth two-toothed, so that the pos- 

 terior edge of the shell is serrate, with eight teeth. Sternum 

 deeplyemarginate behind, and with the lateral plates beneath 

 yellow ; scapular plates small, triangular with a small projection 

 at the outer angle directed forwards ; brachial plates triangular 

 with the 'apices truncate ; pectoral plates narrow, oblong ; ab- 

 dominal plates large, square ; femoral and caudal plates four- 

 sided, the posterior face of the former and the anterior face of 

 the latter oblique, the former also extends beyond the latter at 

 the inferior and exterior angle ; marginal plates beneath 

 marked with concentric lines of dusky ; wings striped with 

 the same. Skin black : head and neck striped with yellow, 

 the stripes frequently red towards their base, stripe on the top 

 of the head reaching from the point of the nose, abbreviated 

 and more distinct than the others, a large triangular yellow spot 

 behind each eye, chin and throat striped with black and yel- 

 lowish, the black stripes conduplicate. Legs and tail scaly ; 

 legs striped and varied with yellow, particularly on the fore 

 part ; claws yellow, with a black spot at the base of each : 



