156 



THE CHAIN OF LIFE. 



those of modern alligators ; and in the vast swamps of the 

 Coal-period, full of ponds and sluggish streams swarming with 

 fish, they must have found a most suitable abode. While rigid 

 anatomy may ally these animals rather with the batrachians 

 than the true reptiles, it is evident that their great size, their 

 capacity for walking with the body borne well above the ground, 

 their bony and scaly armour, their powerful teeth and their 

 capacious chests, with well-developed ribs, indicate conditions 



Fig. 137. — Baphetes planiceps (Owen). 



a. Fragment of maxillary bone showing sculpture, four outer teeth, and one inner tooth. 

 Natural size, b. Section of inner tooth. Magnified, c. Dermal scale. Natural size. 



of respiration and general vitality quite comparable with those 

 of the highest modern members of the class Reptilia. 



The third line of progress leads to some slender and beau- 

 tiful creatures (Mkrosaurta), chiefly known to us by remains 

 found in erect trees, and which resembled in form and habits 

 the smaller modern lizards. They have simple teeth, a well- 

 developed brain-case, limbs of some length, and bony and 



