CADUCIBRANCHIATA. 21 



2 Ampliiuniii tridactylum. 



Body widest above, nearly ovate in section; color 

 brown to dark gray, paler beneath; skin transversely 

 wrinkled upon the sides, smooth above, with numerous 

 mucous pores; vomero-palatine teeth nearer together, 

 eyes more distant, than in the preceding species; toes 

 on each foot three ; tail short, with a small ridge rising 

 above its surface. 



Length \ x / 2 feet. 



Habitat South- Western States. 



MEirOPOMII>A. 



PROTONOPSID^, COPE, 



Skull broad; parasphenoid edentulous; vomer with 

 teeth along its anterior margin; praemaxillae and denta- 

 ries dentigerous ; maxillae and nasalia large ; pterygoid 

 present and very broad; two separate praemaxillary 

 bones; prefrontals and parietals prolonged so as to em- 

 brace the frontals ; fronto-temporal arch absent ; occipi- 

 tal condyles sessile; basihyal cartilage present; gill 

 holes open or closed ; branchial arches may be reduced 

 to two : upper and lower eyelids distinct ; vertebrae am- 



