THE SALAMANDERS, 217 
period, more especially in the Trias, by Mastodonsaurus, 
Trematosaurus, Capitosaurus, etc. The shape of these 
formidable rapacious animals seems to have been between 
that of crocodiles, salamanders, and frogs, but in their 
internal structure they were more closely related to the 
two latter, while by their solid coat of mail, formed of 
strong bony plates, they resembled the first animals. 
These gigantic mailed Batrachians seem to have become 
extinct towards the end of the Triassic period. No fossil 
remains of mailed Batrachia are known during the whole 
of the subsequent periods. However, the still living blind 
Snakes, or Cecilie (Peromela)—small-scaled Phractamphibia 
of the form and the same mode of life as the earth-worm— 
prove that this sub-class continued to exist, and never 
became completely extinct. 
The second sub-class of Amphibia, the naked Batrachia 
(Lissamphibia), probably originated even during the 
primary and secondary epochs, although fossil remains of 
them are first found in the tertiary epoch. They are 
distinguished from mailed Batrachia by possessing a naked 
smooth, and slimy skin, entirely without scales or coat of 
mail. They probably developed either out of a branch of 
the Phractamphibia, or out of the same common root with 
them. The ontogeny of the three still living orders of naked 
Batrachia—the gilled Batrachia, tailed Batrachia, and frog 
Batrachia—distinctly repeats the historical course of de- 
velopment of the whole sub-class. The oldest forms are the 
gilled Batrachia (Sozobranchia), which retain throughout 
life the original primary form of naked Batrachia, and 
possess a long tail, together with water-breathing gills. 
They are most closely allied to the Dipneusta, from which, 
