266 



AMPHIBIA 



Order i. Apoda (Gymnophiona or Coecilians). — In this family 

 there are about forty species, placed in seventeen genera, on slight 

 grounds, the characters probably having been developed independ- 

 ently in various countries. (Figure 142.) The Apoda have no 

 limbs or girdles. The eyes are subcutaneous and probably only 

 serve as a means of distinguishing light from dark. They burrow in 

 the ground feeding on small invertebrates. They have a protrusible 

 sensory tentacle between the eyes and nose. Fossil Apoda are 

 unknown, as their subterranean life does not favor preservation. 

 Some are oviparous and some are viviparous. 



C B 



Fig. 142. Group of Apoda. A, Caecilia, emerging from burrow; B, Ichthyophis 

 glutinosus (nat. size), female guarding her eggs, coiled up in hole in the ground; C, a 

 nearly ripe embryo, with cutaneous gills, tail-fin, and still a considerable amount of 

 yolk. (Redrawn after P. and F. Sarasin.) (trom Newman, Vert. Zool. Courtesy 

 of The Macmillan Company.) 



After hatching, when the gills have disappeared, the young of 

 Ichthyophis glutinosa (Ceylon, Malay Islands) take to water and 

 move about like an eel, coming to the surface occasionally to breathe. 

 This form has from 200 to 300 vertebrae. Apoda have apparently 

 degenerated from the ancestral amphibians. 



Order 2. Urodela (Gr., visible tail) or Caudata. — The tailed 



amphibia have many vertebrae and are not so pronounced in their 



metamorphosis as the Anura. 



Trunk Tail 



Vertebrae Vertebrae 



Amphiuma dz 35 



Cryptobranchus 20 24 



Necturus 19 29 



