188 Proceedings of the 



slowly. If the water be on a level with its body, it elevates 

 its head, curves its neck, and projects its long, notched tongue 

 into the fluid, withdrawing and projecting it sluggishly for a 

 considerable time. When satiated it seems delighted, raises 

 its head high, waving it to and fro, performing something 

 like smacking the lips, and accompanying the act with an 

 audible chirp, a sound rarely heard at other times. Many were 

 easily trained to take a drop of water from the tip of the finger. 



Upon a flat surface the motions of the animal are awkward 

 and ineffectual ; among grass, on the contrary, it urges itself 

 on sweepingly, in a sinuous course, the sides of the body and 

 tail being the motive agents. It has a very perfect reversing 

 action — the retrograde motion without the slightest doubt ; 

 and, in addition, it has a sort of prehensile power in its tail, 

 by which it can suspend its body. The respiration is peculiar ; 

 the animal expires at distant intervals, but no sooner is the 

 expiration made than inspiration follows. In motion, like 

 serpents, the animal is constantly darting out its long, par- 

 tially-cleft tongue. When in vigour, as in a fine warm day, 

 the act is like one rapid dash ; but when less energetic, as in 

 the cold of the morning, the action can be made out very dis- 

 tinctly to consist of three distinct waggles of the tongue up 

 and down. I have long sought to interpret this singular act 

 without success ; but I am disposed to think it has something 

 to do either with the search after food, or with discerning ob- 

 stacles. 



Skeleton. — The most notable peculiarity of the bony frame- 

 work of this animal, andthose of the same type, is the well-known 

 existence of vestiges of the agents of locomotion — the rudi- 

 ments of a quadruped form. In the shoulder there are most 

 distinct scapulae, clavicles, and a sternum ; in the pelvis, be- 

 sides an expansion of vertebrae, with fixed and enlarged lateral 

 spines, there is a small bone on each side, scarcely connected 

 with the wings of the superior sacral vertebra, which may be 

 viewed either as a sort of completion of the circle of the 

 pelvis, or as representing the bones of the leg. 



But there are other peculiarities in the skeleton worth noting, 

 which may not have been recorded. 



In determining the co-relation of scale-plates and scales, I 



