74 



GUIDE TO REPTILES AND AMPHIBIANS. 



Fig. 



Older III.— APODA. 



Limbless Amphibiaks. 



The few representatives of this group (often known as Coecilians) 

 are wonu-shaped burrowing creatures (568) 

 from Tropical America and some of the warmer 

 parts of the Old World (fig. 74). Limbs and 

 their supporting girdles are lacking, the tail 

 is short, and the vertebrsB, which articulate 

 by concave surfaces, carry long ribs, none 

 of which meet a breast-bone. The body is 

 covered with a slimy skin, which may contahi 

 embedded scales, thrown into transverse folds 

 or rings. The skull is solid, with much of the 

 upper surface roofed in by bone, although this 

 roof is not comparable with that of the Stego- 

 cephala. In some species, at any rate, the 

 external gills are shed while in the egg, but 

 the larva inhabits the water, although the 

 burrowing adult is so completely terrestrial 

 that it will drown in that element. The eggs 

 of some Indian and African species are ranged 

 in a cluster, round which the parent coils her- 

 self. Coecilians feed on worms, etc. Some 

 kinds are viviparous, and their larvae do not 

 enter water. 



Order IV.— STECIOCEPHALA {extinct). 



Labyrinthodonts. 



The earliest known terrestrial four-footed 

 creatures occur in the Carboniferous strata, 

 and are succeeded by allied types in the Permian 

 and Trias. They take their name of Stego- 

 cephala from the circumstance that the whole 

 upper surface of the skull is roofed in by 

 membrane-bones, which are frequently sculp- 

 tured. The complicated internal structure of 

 the teeth in one group has given rise to the 

 name Ijabyrinthodonts, by which they are also known. Although 



A Limbless Am 

 phibian ( UrcBotyph 

 lus africamcs). 



