186 BATRACHIANS. 



f f External branchiae and gill clefts persistent through life ; no 

 eyelids. , PROTEIDA, Y. 



W. FAMILIES OF ANURA. 



* Fingers and toes tapering or cylindrical, not dilated into a disk 



at their tips. 



f Upper jaw with teeth; toes completely webbed. 

 a. No spur at the heel ; fingers often webbed ; chiefly aquatic. 



RANID.E, 77. 



aa. One of the bones of the heel forming a sharp, flat-edged 

 spur ; fingers scarcely webbed ; chiefly terrestrial. 



SCAPHIOPID^E, 78. 



f f Jaws toothless ; toes webbed ; skin more or less warty ; ter- 

 restrial BUFONID.E, 80. 



** Fingers and toes dilated at their tips, forming a viscous disk ; 

 arboreal HYLID.E, 79. 



X. FAMILIES OF URODELA. 



* No spiracles or openings in the sides of the neck in the adult. 



* Sides (in our species) with a row of round red or yellowish spots 

 which are bordered with black (these very rarely obsolete) ; 

 belly dotted with black ; tarsus and carpus ossified ; verte- 

 bra opisthoccelian (not biconcave). SALAMANDRID^E, 81. 

 f f Spots, if any, not as above. 

 \ Carpus and tarsus cartilaginous; tongue much smaller and 



more extensively free than in the next. 

 a. Vertebrae concave behind only (opisthocoelian); teeth on 

 parasphenoid (behind vomer). DESMOGNATHID.E, 82. 

 aa. Vertebras biconcave (amphiccelian); parasphenoid teeth 

 present. PLETHODONTIDJE, 8?. 



ft Carpus and tarsus ossified ; vertebrae amphicoeli an ; tongue 

 large, thick, papillose, attached by its base, with i narrow 

 free margin; salamanders usually of large si/e and dark 

 colors; no teeth behind the cross band on vomer. 



AMBLYSTOMID^E, 84. 

 ** With a spiracle or rounded opening in each side of th neck? 



size large. 



b. Limbs well developed ; toes 4-5. . . MENOPOMID^E, 85. 

 bb. Limbs rudimentary ; toes 2-2 or 3-3. . AMpmuMiDyE, 86. 



