DRAGONS OF THE DEEP. 197 



As touching the scientific name of these crea- 

 tures, we may remark that it is derived from two 

 Greek words, plesios, nearer, sauros, a lizard, 

 apparently on account of the structure of the 

 paddles, for these, though strangely different 

 from the feet of the lizard, are still structurally 

 nearer this type than are the paddles of the 

 "Fish-lizards," to which we now pass. 



Returning for a moment to the Lariosaurus, 

 we may remark that these creatures are regarded 

 as the connecting links between the "Sea- 

 dragons" just described and certain equally 

 remarkable fresh-water and terrestrial animals 

 forming a group known as the Nothosauria, 

 among the most remarkable of which were the 

 " Placodonts," or Plate-toothed Eeptiles. These 

 were singularly flat-headed creatures, and have 

 become notorious on account of their teeth, 

 which were unique among reptiles, though 

 closely resembling those of many fishes. 



One of the best known of the Placodonts is 

 Cyamodus laticeps. Herein the teeth have the 

 form of large flattened knobs, and are borne not 

 only by the edges of the jaws, but on the palate 

 as well, the largest of all being a pair on the 

 back of the roof of the mouth. From their shape 

 it is supposed that these teeth were used for 

 crushing the shells of molluscs, and hence it is 

 assumed that the beast frequented the sea-shore. 

 Only recently parts of the skeleton of the trunk 

 have come to light, and these show that the 

 body was armour-clad. 



The exact opposite of the Plesiosaurs, inas- 

 much as the head passed imperceptibly into the 



