LONG-NECKED SEA-LIZARDS. 91 



the skeletons of these reptiles appear to those early 

 pioneers in the study of fossil animals, that they were 

 not inaptly compared to a snake threaded through the 

 body of a turtle. 



The easiest manner in which we may gain a general 

 idea of the structure of these reptiles will be by com- 

 paring them with the Fish-Lizards. Apart from the 

 great difference in the length of the neck, one of the 

 most striking points of distinction between the Fish- 

 Lizards and the Long-Necked Lizards is to be found 

 in the , structure of their paddles. Thus, it will be 

 remembered, in the former group the bone of the arm 

 was extremely short, while all the bones of the fore- 

 arm, wrist, and fingers were modified into a polygonal 

 shape, and articulated together so as to convert the 

 whole framework of the limb into a solid pavement- 

 like structure. 



In the Long-Necked Lizards, on the other hand, the 

 arm bone (as seen in Fig. 25) is comparatively long, 

 and shaped somewhat like a flattened club ; while the 

 bones of the fore-arm (Fig. 26), although remarkably 

 short and flat, are by no means so short as they are in 

 the Fish-Lizards. The greatest difference in the struc- 

 ture of the paddle is, however, to be found in the form 

 of the bones of the fingers (Fig. 25), which, in place 

 of being polygonal, are long and slender like those of 

 ordinary reptiles. It is true, indeed, that the number 

 of bones in each finger is considerably greater than in 

 living reptiles, but the number of the fingers them- 

 selves does not exceed the normal five, and the bones 



