37 

 CHAPTER VII. 



CLASSIFICATION OF AMPHIBIA. 



20. Order 1, Gymnophiona. A small group of 

 worm-like forms, with no limbs, rudimental eyes 

 (hence they are called C(Kcilia\ which are found in 

 tropical countries burrowing in the ground. These, 

 with one exception, have the body provided with 

 dermal scales. They are usually marked with super- 

 ficial rings like an earth-worm, and range in size from 

 one to two feet, rarely exceeding this length. At 

 present only a few species exist, but many fossil forms 

 have been found which probably resembled these in 

 structure. 



A large and structurally complex order of fossil 

 amphibians, named Labyrinthodonts, formerly in- 

 habited the earth, which in some respects seem to 

 have been related to the Ccecilians, but were much 

 larger, and many of them were defended by dermal 

 coats of bony mail something like the armour clothing 

 of a crocodile. 



2 1 Order 2, TIrodela. Limb-bearing amphibians 

 provided with a permanent tail, which is retained 

 during life. There are two sections in this order, in 

 one of which the animals retain their embryonic gills 

 through their whole existence, and are thus peren- 

 nially or permanently branchiate, while in their adult 

 condition they also possess lungs, which become de- 

 veloped gradually in process of growth. In the other 

 section the gills are only transitory or caducous, 



