AMPHIBIANS 165 



//. platycephalus (Camp). Body elongate; tail cylindrical, rather 

 short; color dark chocolate, mottled with black; length 106 mm.; 

 tail 35 mm.; costal folds 12: Yosemite National Park, California. 



ON THE IDENTIFICATION OF THE LARVvE OF THE 

 PLETHODONTIDiE 



Aquatic larvae are known to occur in the genera Desmognathus, 

 Leurognathus, Typhlotriton, Typhlomolge (a permanent larva), Grino- 

 philus, Pseudotriton and Eurycea : these larval forms have all been iden- 

 tified in the eastern and middle western States. They may be distin- 

 guished from the larvae of the AmhystomidcB and Salamandridm which 

 inhabit the same region by the presence of a dorsal fin on the body of the 

 larva in these two families. This fin is universally absent in the larvae 

 of the Plethodontida. 



Key to the Larvae of the Plethodontidae 



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



long Typhlomolge. 



a2 Eyes functional; body pigmented; legs normal. 

 bi Gills short, glistening white; legs very stout. 



Ci Definite color-pattern of light dorsal spots .Destnognathus fusca. 

 C2 No definite color-pattern. 



di Chin and throat light; eyes smaller, 



lateral Desmognathus quadramaculata. 



d2 Chin and throat pigmented; eyes 



larger, more dorsal Leurognathus marmorata. 



hi GUIs longer, not gUstening white; legs slimmer, 

 ci Back and sides the same color. 



di Sides irregularly streaked Stereochilus. 



d2 Sides not so streaked. 



Ci Chin and throat pigmented; head 



longer Grynophilus. 



62 Chin and throat not pigmented; 

 head shorter. 



fi Costal grooves 16 Pseudotriton ruber. 



ii Costal grooves 17 Pseudotriton montamts. 



fs Costal grooves 18 Typhlotriton. 



C2 Back lighter than the sides Eurycea. 



di Digits on hind leg 5. 



ei No sharp demarcation between the 

 lighter 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 



