70 ANIMAL LIFE PAST AND PRESENT. 



of the Labyrinthodont, or Chiro there formed on the 1 

 model of a gigantic frog ; and although it was sub- 

 sequently shown that the idea of a frog with a skull of 

 a yard in length was totally impossible, yet, with the 

 tendency of all errors to perpetuate themselves, we 

 still see books (even some of them published within 

 the last few years) disfigured by reproductions of this 

 impossible tailless creature. 



Instead of the Primeval Salamanders being modelled 

 on the lines of a frog, they were, indeed, constructed 

 after the fashion of a modern Eft or Salamander, 

 having, in the adult state, four limbs adapted for 

 walking, and a well-developed tail. Nearly the whole 

 of them differed, however, from modern Salamanders, 

 in that the chest was defended by an armour of three 

 bony plates one central and two lateral ornamented 

 with a sculpture similar to that shown in the skull 

 represented in Fig. 21. In addition to this, other 

 species had the whole of the under surface of the body 

 protected by a series of bony scales, arranged in a 

 chevron pattern ; while in a few rare instances the 

 whole of the body was covered with an armour of 

 these bony scales. We thus see that the earlier 

 members of this group come under the designation of 

 mail-clad animals, of which we have treated in a 

 previous chapter. 



Another absolutely distinctive feature of the Primeval 

 Salamanders is to be found in the structure of the 

 skull. It will be seen from Fig. 21 that the whole of 

 the upper surface of the skull behind the eye-holes, or 



