148 VERTEBRATE ANIMALS OF THE UNITED STATES 



C2 Costal grooves absent; vomerine teeth in longitudinal 



series (Fig. 71) 4. Salamandridce. 



bo Naso-labial groove present (Fig. 64) ; parasphenoid teeth 



present (Fig. 80) ; costal grooves present; lungs absent. 5. Plethodoniidce. 



Family i. Amphiumidae.^ — Body serpentine in form, with about 100 

 vertebrae; a pair of small gill slits; vertebrae amphicoelous; carpus and 

 tarsus cartilaginous; no eyelids; vomerine teeth prominent, forming an 

 arched series parallel with those of the jaw; 2 pairs of weak legs; tail 

 short, compressed: i genus. 



Amphiuma Garden. With the characters of the family: 2 species. 



A. means Gard. Congo snake. Body dark brown above, light 

 below; length 886 mm.; tail 182 mm.; 2 toes on each foot; costal grooves 

 about 60: Virginia to Florida and westward to Louisiana; northward to 

 Arkansas; in swamps, sometimes on the land; eggs about 150 in number 

 and with a diameter of 9 mm. 



A. tridactylum Cuvier. Similar to A. means but more distinctly 

 bicolored and larger and with 3 toes on each foot: northern Florida 

 to southern Louisiana, and up the Mississippi Valley to Missouri. 



Family 2. Cryptobranchidae. — Giant salamanders. Body stout and 

 of large size; a pair of small gill-slits usually persistent; vertebrae amphi- 

 coelous; carpus and tarsus cartilaginous; no eyelids; vomerine teeth form 

 an arched series parallel with the jaws: 2 genera, one of which, Megalo- 

 bactrachus, is found in China and Japan and contains but one species, 

 M. maximus (Schlegel), which grows to a length of 5 feet and is the 

 largest salamander. 



Crj^tobranchus F. S. Leuckart. Fore legs with 4 and hind legs 

 with 5 toes each; gill slits always persistent: i species. 



C. alleganiensis (Daudin). Hellbender. Body dark brown in 

 color; head and trunk depressed, tail compressed; prominent lateral 

 fold present; length 480 mm.; tail 160 mm.: western New York and 

 central Pennsylvania to Georgia and Louisiana; westward to Iowa; 

 aquatic; often common. 



Family 3. Ambystomidae. — Body of medium size; a transverse 

 (gular) fold of skin just in front of the fore legs; digits 4-5 ; a transverse 

 series of teeth, more or less interrupted, on the hinder margin of the 

 vomers; tongue thick, free in front; vertebrae amphicoelous; carpus and 

 tarsus ossified; eyelids present; lungs and ypsiloid cartilage present: 3 

 genera in the United States; habitat usually terrestrial. 



Key to the United States Genera of Ambystomidae 



ai Lungs rudimentary; ypsiloid cartilage aborted; on Pacific slope. i. RJiyacotriton. 

 a,i Lungs and ypsUoid cartilage (Fig. 65) well developed. 



