AMPHIBIA 



203 



of the skin and in the mucous membrane of the mouth 

 and throat. 



The mud puppy (Necturus maculatus), abundant in 

 the Great Lakes and the waters near by, is remarkable 



FIG. 233. Desmognathus, the mountain salamander. Photograph natural size. 



in that it possesses both gills and lungs in the adult state. 

 Like characters are exhibited by the blind salamander (Pro- 

 teus anguineus) in the caves of Austria and an allied form 



FIG. 234. Photograph of Amblystoma eggs in water. Natural size. 



found in the caves of Texas. The hellbender (Crypto- 

 branchus alleghaniensis) is the largest of our salamanders. 

 It lives in the streams of the Ohio and the Susquehanna 

 valleys. The congo snake, which reaches a length of 

 nearly three feet, inhabits the ditches and stagnant ponds 



