14 PEREXXIBRAXCHIATA. 



PROTEIDA, Midler. 



Skull elongated; parasphenoid edentulous: vomer 

 with teeth along its anterior margin; praemaxillas and 

 dentaries dentigerous ; pterygoid present and anchylosed 

 with the palatines; occipital condyles sessile; first two 

 ceratohyals connate ; branchiae, branchial apertures, and 

 three pair of arches persistent; eyelids wanting; pelvic 

 and pectoral arches and limbs developed ; anterior digits 

 three or four, fourth finger, or in this case the third, the 

 first being absent, with a single phalanx. 



Toes, two or three on each foot; trunk verv much 



elongated Proteus (i) 



Toes four on each foot; trunk short and thick. 



Mexobraxchus (2) 



(1) Proteus, Laurenti. 



Teeth in the upper jaw in four rows converging 

 towards the front, or the two on each side uniting medi- 

 ally with the corresponding rows of the other side; 

 tongue small ovate, free anteriorly and laterally; eyes 

 concealed; muzzle truncate and shaped like a duck's 

 bill; toes three in front and two behind. 



But one species is ordinarily recognized as belonging 

 to this genus. Cope (24, o) however, from characters 



