Fossils. 
139 
— Batrachos, a frog. Joining in their uncouth forms 
the character of frog and a true reptile, they have 
been called frog-reptiles, showing at the same time 
some affinities to fishes. The name Mastodonsaurus 
was given them by Professor Jager, but it must not be 
taken to indicate any affinity with the true Mastodon , 
which was an extinct elephant of a much later 
geological age. We have also made use of the term 
‘‘frog-like reptiles,” but, curiously enough, although 
not by any means an unsuitable name, it is not now used 
in the sense it was originally intended. The first 
restoration of the creature was made by Mr. Water- 
house Hawkins, whose models of extinct monsters are 
so well known in the Crystal Palace Grounds. Al- 
though wonderfully successful in other reconstructions, 
Mr. Hawkins was somewhat unfortunate in clothing 
with flesh the dried bones of the Labyrinth o don. The 
fact is, he had not enough bones at his disposal, and 
so his restoration was based on imperfect materials. 
Mr. Hawkins’ idea of a Labyrinthodon in life is seen 
in Fig. 39, and as we know now, it gives the creature 
too much of a frog-like aspect. In later years, more 
perfect fossils have been discovered. They show us 
that a tail was well developed, with legs quite as much 
adapted for walking as for swimming. We can, as 
already stated, with propriety retain the name frog- 
lizard, for it has been discovered that some, at least, of 
the Labyrinthodonts underwent a series of changes 
similar to the metamorphosis of the common frog. 
