88 



HIGH SCHOOL ZOOLOGY. 



11. Class Batrachia or Amphibia. This class is sixbdivided 

 into several orders of which three ai'e represented by living 

 forms, the Urodela, Anura, Gymnophiona, the others being 

 known merely by their fossil remains. The first order contains 

 the Menobranch and forms allied to it ; the second, the frogs and 

 toads ; and the third, certain tropical earthworm-like forms. 

 It is, therefore, the first two which we have to examine more 

 closely, the ordinal names of which refer to the most striking 

 character, the presence (Urodela) or absence (Anura) of a tail in 

 the adult. 



1 2. Among the nearest Urodelous allies of the Menobranch 

 are some which like it retain their gills throughout Jife : they ai-e 

 said to be perennibranchiate forms, and in this respect are unlike 

 some other Urodeles which lose their gills at a later stage ; 

 these are caducibranchiate. Undoubtedly the nearest relative of 

 our Nectunis is the Proteus (P. anguinus) (Fig. 65) which is 

 found in underground waters in Carinthia and Carniola. Like 

 the blind-fish of the Mammoth cave it has suffered the almost 

 complete loss of the eyes and the loss of the pigment of the 





Fig. 65.— Proteus anguinus. (After Brehm); 



