THE SALAMANDEES. 21 J 



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 Ccecilice (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. 



