AMPHIBIANS 147 



Key to the Suborders of the Caudata 



Hi Two pairs of legs present. 



hi Adults with gills and gill-slits throughout life i. Protcida. 



h-i Adults without gills (except in Typhlomolge) 2. Mutabilia. 



Vi-i But one pair of legs present 3. Mcantcs. 



Suborder i. Proteida. — Body elongate, with 2 pairs of weak legs; 

 3 pairs of gills and 2 pairs of gill slits persistent throughout life; vertebrae 

 amphiccrlous; maxillaries absent; eyelids absent; both jaws with teeth: 

 I family. 



Family Proteidae. — With the characters of the suborder: 2 genera, 

 the species of one of which, Proteus, are found in caves in southern 

 Europe, and are blind and colorless. 



Necturus Rafinesque. Toes 4 on all four feet; eyes very small: 2 

 species. 



N. maculosus {Ra.(.). Mudpuppy; waterdog. Body subcylindrical; 

 head flattened, with a fold of skin across the throat; tail compressed; 

 color of adult dark brown above, lighter beneath, more or less spotted 

 and splotched with darker brown and black; young striped; length 360 

 mm.; tail no mm.; extreme length 600 mm.: valleys of the Great Lakes 

 and the Mississippi north of the Gulf States, as well as the upper waters 

 of many streams flowing into the Atlantic and the Gulf; Lake Cham- 

 plain and the upper Hudson; Manitoba; southward into northern 

 Alabama and Arkansas; often very common in rivers and lakes. 



N. punctatus (Gibbes). Head short, elevated; length 170 mm.; 

 tail 50 mm.; color pale, unspotted: North and South Carolina, in rivers 

 of the coastal plain. 



Suborder 2. Mutabilia. — Salamanders and newts. Body elongate, 

 without gills in the adult, except in certain cave species; vertebrae 

 amphicoelous or opisthoccelous; carpus and tarsus cartilaginous or bony; 

 eyelids absent or present; maxillaries present; both jaws with teeth: 5 

 families. 



Key to the Families of Mutabilia 



ai Adult with a pair of gill slits (but without gills). 



bi Body eel-shaped; legs very small and rudimentary i. Ampliiinnidcc. 



hi Body salamander-shaped; legs not rudimentary 2. Cryptob)\uichid(e. 



aj Adult without gill sHts. 



bi No naso-labial groove present (Fig. 64) ; parasphenoid 

 without teeth. 

 Ci Costal grooves present (Fig. 72); vomerine teeth in a 



transverse series (Fig. 6g) 3. A mhystomidce. 



