154 VERTEBRATE ANIMALS OF THE UNITED STATES 



tid<B, except in Hemidadyliiun, in which the larva has an extremely short 

 larval life. It is also much smaller than the larva of the Ambyslomidce 

 and the PleurodelidcB and has 4 digits on the hind feet. 



Key to the Larvae of the Plethodontidae (except Hemidactylium) 



ai Blind, white larvae; costal grooves 12; legs very 



long Typhlomolge. 



&2 Eyes functional; body pigmented; legs normal, 

 bi Gills short, glistening white; legs very stout. 



Ci Definite color-pattern of light dorsal spots . Desmognatlms fusciis. 

 C2 No definite color-pattern. 



di Chin and throat light; eyes smaller, 



lateral Desmognathus quadramaculatus. 



di Chin and throat pigmented; eyes 



larger, more dorsal Leurognathus marmorata. 



hi Gills longer, not gUstening white; legs shmmer. 

 ci Back and sides the same color. 



di Sides irregularly streaked Stereochilus. 



d2 Sides not so streaked. 



d Chin and throat pigmented; head 



longer Gyrinophilus. 



62 Chin and throat not pigmented; 

 head shorter. 



fi Costal grooves 16 Pseudotriton ruber. 



U Costal grooves 17 Pseudotriton montanus. 



fs Costal grooves 18 Typhlotriton. 



02 Back lighter than the sides Eurycea. 



di Digits on hind leg 5. 



ei No sharp demarcation between the 

 Ughter back and the darker sides; 

 a gray band on the sides; 

 costal grooves 14-15 Eurycea lucifuga. 



62 A sharp and uninterrupted demar- 



cation between the lighter back 



and the darker sides; sides black; 



costal grooves 13-14- 



fi A definite stripe on side Eurycea guttolineata. 



U No definite stripe on side Eurycea longicauda. 



Eurycea melanopleura. 



63 A sharp but broken demarcation 



between the lighter back and the 



darker sides. 



fi Costal grooves 14-15 Eurycea hislineata. 



U Costal grooves 20 Eurycea midtiplicata. 



d2 Digits on hind leg 4 Eurycea quadridigitata. 



Family 5. Amphiumidae. — Body serpentine in form, with about 

 100 vertebnc; a pair of small gill slits; vertebrae amphicoelous; carpus 



