43 



MANUAL OF ZOOLOGY SECT. 



absent. In some again, there is no 

 fish-like gill-bearing larva or tadpole 

 the young animal emerging from the 

 egg with the limbs formed, and with no 

 gills and no tail. All the Frogs and 

 Toads are grouped together to form 

 an order of Amphibia the Anura or 

 Tailless Amphibia. 



The Newts and Salamanders (Fig. 

 243) with a number of other less 

 widely known forms, differ from the 

 Frogs and Toads in the possession in 

 the adult of a well-developed tail. 

 These constitute the order Urodela or 

 Tailed Amphibians. Of these, some, 

 such as the Newts and Salaman 

 ders, lose both gills and gill - slits 

 completely in the adult : while in 

 others (such as Proteus and Siren, Fig. 

 244), either gills are retained through- 

 out life, or gill-slits remain as a per- 

 manent record of their presence in the 

 larva. In some of the Tailed Am- 

 phibians the limbs are well-developed ; 

 in others they are very small. 



Widely different in many respects 

 from both the Anura and Urodela are 

 a group of Amphibia the Gymno- 

 phiona which are quite snake-like in 

 appearance, owing to the elongated 

 and narrow form of the body and the 

 entire absence of limbs. 



