TRIONYX FEROX. 13 



the snout small, cylindrical, and greatly prolonged. The nostrils are anterior and 

 closely approximated; they are sub-round, the greatest extent being in the vertical 

 direction, and their long axes are parallel to each other. The eyes are large, 

 prominent, and very closely approximated; the pupil is black, the iris of pale 

 lemon colour, very brilliant, and marked with an interrupted longitudinal black 

 band. The mouth is large, naked in front, but with large, revolute, movable, thick 

 hps at the sides, both above and below. The jaws are entire, or without serrse, 

 and the lower is received within the upper. 



The anterior extremities are large, flattened, and covered at the fore-arm with 

 three broad scales placed transversely; there are five fingers, extensively palmated, 

 but the three anterior alone are furnished with nails, the two posterior are far 

 apart, and seem useful only in supporting the web. The posterior extremities 

 are equally large, and still more flattened at the tarsus, which sustains five 

 broadly palmated toes, the three anterior fui'uished with short strong curved 

 nails, a little grooved on their inferior face; the two posterior toes are far apart, 

 and sustain the web, which is here extensive, and continued along the posterior 

 margin of the limb; and further, there is behind the little toe a large oblong piece 

 of cartilage imbedded in the membrane or web, continued along the leg, which 

 must be still more instrumental in keeping it extended. The tail is thick, conical, 

 short, passing but slightly the carapace, and has the vent near the tip. 



Colour. The shell above is umber coloured, more or less bright, and marked 

 with large irregularly dusky blotches; these are circumscribed in the young, but 

 are spread out with irregular margins in adults, and sometimes they disappear 

 altogether and leave the shell of one uniform colour. The sternum is white, and 

 beautifully marked with waving red lines, caused by the blood-vessels being seen 

 through the transparent skin. 



The superior and lateral parts of the head and neck are umber coloured, the 

 lips a little lighter; the inferior surface is dirty white, with a tinge of green. On 

 each side of the head and behind the eye is a yellowish oblong blotch, bordered 



