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. 



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

 spur; fingers scarcely webbed; chiefly terrestrial. 



SCAPHIOPUXE, 78. 

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



restrial BUFONIIXE, 80. 



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

 arboreal HYLIIXE, 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 veiy rarely obsolete) ; 

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

 bra opisthoccelian (not biconcave). PLEURODELUXE, 81. 

 ff Spots, if any, not as above. 

 \ Carpus and tarsus cartilaginous ; tongue much smaller and 



more extensively free than in the next. 

 a. Vertebras concave behind only (opisthocoelian.) 



DESMOGNATHIIXE, 82. 

 aa. Vertebrae biconcave (arnphiccelian.) 



PLETHODONTID.E, 83. 



\\ Carpus and tarsus ossified; vertebrae amphicoeliau; tongue 

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

 free margin ; salamanders usually of large size and dark 



colors AMBLYSTOMUXE, 84. 



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



size large. 



b. Limbs well developed ; toes 4-5. . . MENOPOMHXE, 85. 

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



