THE FliOG 



339 



its vibrations are conveyed to the inner ear by a single rod 

 instead of tlie flexible chain present in man. 



Families of Urodela. — Of the American Urodela/ the 

 mud-eel, or Siren, of the Southern States has external 

 gills and persistcmt giU-glits. This species becomes sixty 

 centimetres long and snake-hke, has lost its hmd legs, and 

 is of a dark lead color (Fig. 317). It is needlessly feared by 

 the negro rice cultivators, who slaughter it in great nmiibers. 



Fri. 318 n. — Typlilomolge, a blind, neeturus-like salamandrr from tho 

 caves of Texas. Photo, from life. After W. W. Norman, from "The 

 American Naturalist." 



The mud-puppy (Necturus), frequently known also as water- 

 dog, is found from the Hudson River to the Mississippi Valley, 

 and is very abundant in the Great Lakes. Its external gills 

 are very large, and red with the blood flowing in them. It 

 feeds on small water animals. In April or May it lays eggs 

 about the size of a pea. A curiously modified form of Nec- 

 turus occurs in caves of North America (Fig. 318). An- 

 other member of this familj' is the cave " olm " of western 

 Austria. 



The Congo snake (Amphiumidse) is found in the Carolinas 

 and Gulf States. This black, snake-like urodele is about a 

 metre long, and lives in bayous and muddy ditches (Fig. 319). 

 It has the entirelj' undeserved reputation of being injurious. 



^ oura, tail ; deJos, conspicuous. 



