238 VERTEBRATA: JJATRACHIA OK BATRACHIAXS. 



Besides these there is an extinct group, known only by 

 the fossil remains of its representatives, and this is added 

 as an additional order, thus 



4. LABYRINTHODONTA or Labyrinthodonts, so called from the 

 internal structure of their teeth. 



SUB-SECTION II. 

 THE ORDER OF ANOURA OR TAILLESS BATRACHIANS. 



THIS order includes the Frogs and Toads, and is some- 

 times called the order of Batrachoids. The name Anoura 

 comes from the Greek an, privative, and oura, a tail. 



The Anourans have the body short and thick, and cov- 

 ered with a skin which does not adhere to the muscles, 



FIG. 270. 



Leopard Frog, Sana halecina, Kalm. 



but covers them somewhat loosely as a sack. Their tongue 

 is long and fixed to the front of the jaw, and its tip is 

 turned backward in the mouth, whence it can be instantly 

 darted forth ; and it is in this way that these animals so 

 quickly snap up living insects which constitute their food. 

 The young are tadpoles, which have a large head, short, 



