STRUCTURE OF REPTILES AND AMPHIBIANS. 



27 



and limb-bones to the bony shell. Lizards and Snakes are 

 mostly represented by coloured casts. The extinct Dinosaurs 

 are represented by a small-sized model of the Iguanodon, 

 together with a photograph of the skeleton and a plaster-cast 

 of the bones of the hind-foot showing the three toes. 



The adjacent side of the table-case shows the modifications 

 of the backbone, or vertebral column, of the ribs, and of the 



A 



Fig. 8. — Skull of the Giant Tuatera {Byperodapedon gordoni), from the 

 Triassic Sandstone of Lossiemouth, Elgin, (i nat. size). A, upper surface 

 of skull; B, palatal aspect of skull; C, under-side of front of lower 

 jaw ; Pmx, premaxUlary bone ; Mx, maxillary ; PI, palatal teeth ; 

 Md, lower jaw; 0, orbit, or eye-socket; JV, nostrils; 8, temporal pit; 

 S', lateral temporal fossa. 



limbs, in the different groups of the class. Specially noticeable 

 are examples of five types of Skink-like Lizards, exhibiting the 

 gradual diminution in the size of the limbs and their final 

 disappearance. 



The opposite, or north, side of the table-case displays the 



