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^, 77. 



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

 spur ; fingers scarcely webbed ; chiefly terrestrial. 



SCAPHIOPID^, 78. 



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

 restrial BUFONID^, 80. 



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

 arboreal Hylid^, 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 rarel}^ obsolete) ; 

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

 brae opisthocoelian (not biconcave). Salamandrid^, 81. 



If Spots, if any, not as above. 



X Carpus and tarsus cartilaginous; tongue much smaller and 

 more extensively free than in the next. 



a. Vertebra? concave behind only (opisthocoelian); teeth on 



parasphenoid (behind vomer). Desmognathid^e, 82. 



aa. Vertebrae biconcave (amphiccjelian); parasphenoid teeth 



present. Plethodontid.*:, 8 5. 



XX Carpus and tarsus ossified ; vertebrae amphicoeli an; tongue 



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



free margin; salamanders usually of large size and dark 



colors; no teeth behind the cross band on vomer. 



AMBTA'STOMIDiE, 84. 



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

 size large. 



h. Limbs well developed; toes 4-5. . . Menopomid^, 85. 



6&. Limbs rudimentary; toes 2-2 or 3-3. . Amphiumid^, 86, 



