60 EMYSMUHLENBERGII. 



behind; the gular plates are convex, triangular with the apex directed backwards, 

 the lateral angles and the sutures straight, projecting a little; the brachial plates 

 quadrilateral, the internal border short and straight, the external longer and 

 rounded; the thoracic, femoral, and abdominal plates are quadrilateral, and more 

 extensive in the transverse than in the antero-posterior direction; the sub-caudal 

 are rhomboidal. The supplemental plates are unusually small; the axillary, circular, 

 and the inguinal, slightly triangular. 



The head is short and broad; the tip of the snout pointed; the nostrils are small 

 and near together; the eye is large, the pupil dark, with the iris brown, and 

 surrounded by an orange coloured circle. The jaws are strong and cutting; the 

 upper deeply notched, with a tooth on each side; the lower is furnished with a 

 single tooth. 



The extremities approach in their structure those of the Cistudo, in being but 

 slightly compressed, and in having the nails short and very slightly curved. The 

 anterior extremities are covered with scales, larger in front and smaller behind; 

 the fingers are five in number, and but slightly palmated, each furnished with a 

 nail. The posterior extremities are flattened, and covered with small scales; the 

 toes are five in number and imperfectly palmated; the four internal ones only are 

 provided with nails. The tail is large and nearly conical, thick at the base and 

 pointed at the extremity; its superior surface is covered with scales. 



Colour. The shell is very dark brown, almost black; all the plates are relieved 

 by blotches of obscure yellow, mingled with pale brown; in some individuals the 

 plates are marked by sub-radiating lines, of the same colour as the blotches. 

 The sternum is almost black at the margin, and bright yellow, approaching to 

 orange, in the middle, sometimes varied with red. Black however, often predomi- 

 nates both on the shell and sternum. 



The head is black; a short indistinct yellow line runs from the snout to the orbit 

 of the eye, which is partially surrounded by a circle of the same colour; the upper 



