CHELONURASERPENTINA. 25 



The anterior extremities are large, and covered with a granulated and warty 

 skin, with transverse rows of large scales both above and below, a remarkable 

 range of which exists along the ulnar margin of the fore-arm; there are five 

 fingers, each furnished with a strong, short, and curved nail, like those of a bird 

 of prey. The posterior extremities are equally strong, well developed, and 

 covered in like manner, but with larger scales beneath, and have a remarkable 

 fold of skin along the fibular margin of the leg; there are four toes, well palmated, 

 and furnished each with a strong, pointed nail, less curved than those of the 

 anterior extremities. The tail is very long, thick at the base, but soon becomes 

 smaller and ends in a pointed tip; it is covered about the vent with a warty and 

 granulated skin, while along the superior border is placed a series of wedge- 

 shaped tubercles, decreasing in size towards its tip, which gives to the tail a 

 strongly marked serrated crest; on either side of these tubercles is a series or 

 two of smaller spiny warts or processes, much less regular, the upper being the 

 larger; the inferior surface of the tail behind the vent is covered with double 

 plates or scales, as in the genus Coluber. 



Colour. The head above is dusky; the jaws are horn colour, marked with 

 dark waving lines; the neck above is also dusky, but fighter than the head; the 

 throat and chin are dingy yellowish-white; the shell is dusky or dark cinereous; 

 the sternum is yellow, as well as the inferior surface of the marginal plates; the 

 extremities and tail are dusky or dark cinereous above, and dingy yellowish-white 

 below. 



Dimensions. Length of head, 85 inches; length of neck, 3j inches; circum- 

 ference of neck, 7J inches; length of shell, 9 inches; breadth of shell, 8 inches; 

 elevation, 3i inches; length of sternum, 7 inches; length of tail beyond the vent, 

 65 inches; space from shell to vent, 2 inches; total length, 24J inches. This 

 was the size of the animal here described, but they not unfrequently arrive at 

 dimensions much greater. Dr. Pickering assures me that he met with one near 

 Salem, in Massachusetts, which from its great size he was induced to measure, 

 and he found it to exceed four and a half feet in length. 

 Vol. IV. 



