266 ZOOLOGY 



on the back ; the wood-frog, living in damp woods, pale 

 reddish brown, with a brown band on the side of the head ; 

 the green frog, of uniform bright green to brown color, 

 with numerous small dark spots, and with glandular folds 

 (Fig. 250) ; and the bull-frog, of great size, green, with 

 small faint spots on the back. 



APPENDIX TO CHAPTER XVII 



KEY TO THE ORDERS OF AMPHIBIA 



i. Appendages and tail lacking; body worm-like ; 



skin furrowed transversely .... GymnopMona 



a 2 . Appendages present. 



61. Body elongated ; tail present ; generally 4, 

 but rarely only the 2 anterior appendages 

 present . ..... Urodela 



&2- Body short ; in adult condition tailless . Anura 



KEY TO THE FAMILIES OF URODELA 



a\. External gills persistent throughout life ; maxil- 

 lary bone small or wanting. 

 61. Body eel-like ; hind legs absent ; jaws with 



horny sheath ...... Siroii'lir 



1>> 2 . Body salamander-like ; hind limbs present ; 



teeth on jaws Proteidcu 



2 - External gills normally disappearing in adult ; 



limbs 4 ; maxillaries present. 

 &i. Side of neck with spiracular opening ; no 



eyelids. 



ex. Limbs rudimentary .... Amphiwnidai 

 c-2. Limbs well developed .... Cryptobranchidce 

 b->. Side of neck without spiracular opening in 

 adult ; eyelids present. 



