DRAGONS OF THE DE$P. 205 



may have been we do not know, but the struc- 

 ture of the teeth seems to point to a descent 

 from the giant Salamanders or Labyrinthodonts, 

 and for the reason that these teeth present the 

 remarkably complicated infoldings of enamel so 

 wonderfully developed, and so characteristic of 

 the ancient amphibians. 



Remembering that both Ichthyosaurs and 

 Plesiosaurs were not only contemporaries but pro- 

 bably lived side by side, one cannot help suspecting 

 that conflicts between members of the two rival 

 houses were not unusual. They were indeed the 



" Dragons of the prime, 

 That tare each other in the slime." 



perchance rending the air the while with hoarse 

 bellowings, like the crocodiles of to-day. With but 

 a slight effort of the imagination, one can picture 

 some such contest, can see the water lashed into 

 foam as the combatants writhe and twist about, 

 whilst overhead those dragons of the air, the 

 Pterodactyles, flutter in the hope of picking up 

 some newly-swallowed fish disgorged by the 

 excited and infuriated monsters. Suddenly the 

 fray is over. The bull-necked Ichthyosaur has 

 seized his neighbour by that long neck of his 

 and dragged him down to die ! 



Whether studied individually as separate 

 groups, or collectively, the creatures described 

 in this chapter present us with a series of 

 peculiarly instructive object lessons in evolution 

 and adaptation to environment. The simul- 

 taneous development of monsters like the 

 Plesiosaurs and Ichthyosaurs, from totally distinct 



