ANCIENT SALAMANDERS 93 



useless ; but the chances are rather against the notion. All 

 the lizards have this pineal eye. It is probable that we have 

 here a relic from some much older and now lost form of life 

 possibly a fish, but possibly also a still lower type. These rudi- 

 mentary structures, of which Darwin speaks in his great work, 

 The Origin of Species, always possess a high degree of interest for 

 the palaeontologist, as being survivals from very early days in the 

 world's history. To the latter they are as interesting in their 

 way as are ancient customs and old superstitions to a student of 

 folk-lore or of ancient history. 



We must also notice the forward position of the creature's 

 nostrils as indicated by the two small openings at the apex of the 

 skull (see Fig. 16). If we were to examine the under side of a 

 skull such as that of the Mastodonsaurus, we should see that the 

 bony palate is formed chiefly of two broad and flat bones, called 

 the " vomerine," which generally support teeth. Now, this is a 

 character not exhibited by the skull of any true reptile, and we 

 must go to modern amphibia, such as our frogs and toads, to 

 find a parallel. There is also a corresponding series of small 

 teeth on the mandible of the lower jaw (see Fig. 25). The 

 eyes often show the peculiar sclerotic plates seen so well in the 

 " fish-lizards." 



In studying an extinct vertebrate, or backboned animal, one 

 of the first points to be considered is the nature of the vertebrae, 

 or joints of the backbone. Now, in all fishes, and also in their 

 distant cousin the Ichthyosaurus (fish-lizard), these bones have 

 their articulating surfaces (centra) hollow, hence the popular 

 term " cup bones " applied to the vertebrae of the latter. Need 

 we be surprised, then, to learn that the Labyrinthodonts possessed 

 similarly cup-shaped vertebras ? This is one more link to connect 

 them with fishes. In some of the more primitive and ancient 



