EXTINCT BATRAOHIA. 353 



wanting; epiotic and squamosal not distinct; nasalia present ; ethmoid 

 composed of two lateral pieces, each forming part of palate ; quadrate 

 osseous; mandible toothless, with condyle for the quadrate; teeth pleu- 

 rodont; no "postorbital and supratemporal bones"; first pair haemal 

 branchihyals distinct. 



PROTEIDA. 



Caudal vertebrae and frontal bones distinct; inferior pelvic elements 

 not confluent. 



0, o, supraoccipitalia, maxillaria, prefrontalia, and nasalia wanting; 

 palatine and pterygoidea present; ethmoid a vertical plate on each side 

 of the cerebral lobes; squamosal and epiotic jiresent; quadrate osseous; 

 mandible toothed ; teeth pleurodont ; haemal branchihyals, first pair con- 

 nate; no "postorbital and supratemporal bones." 



Fig. 1. 



Pmz 



Amphiuma meani, profile of cranium (from Georgia; ; Fma. premaxillary bone ; N. nasal ; Prf. pre- 

 frontal; P. frontal; Pa. parietal; Mx. maxillary; E. ethmoid; Pro. prootic; Sq. squamosal; Exo. exoc- 

 cipital; Pt. ijtcrygoid ; Q. quadrate; Sta. stapes, natural size., 



UEODELA. 



Usual cranial bones present, but pterygoids reduced or wanting ; quad- 

 ratum osseous, covered by the squamosal ; no " postorbital nor supratem- 

 poral bones " ; no epiotic nor supraoccipital ; caudal vertebrae and frontal 

 bones distinct ; ethmoid, a vertical plate on each side ; mandible dentig- 

 erous; teeth pleurodont; inferior pelvic elements horizontal, in contact; 

 no osseous pubis ; ilium suspended to a sacral rib. (Mostly no quadrato- 

 jugal.) 



GYMNOPHIDIA. 



Usual cranial bones present and distinct, including frontals and ptery- 

 goids ; no supraoccipital nor epiotic ; quadrate osseous ; caudal vertebrae 

 distinct; no " postorbital nor supratemporal bones" *; ethmoid annulus 

 surrounding cerebral lobes; mandible dentigerous; teeth anchylosed by 

 their bases. f (Quadrato-jugal present.) 



* When the temporal fossa is overarched it is by expansion of the maxillary and 

 quadrato-jugal. (Stannius says, "squama temporalis.") 



t The teeth of Ccecilia are compressed, with a trenchant posterior edge, which is 

 crenate after the manner of Megalosaurus, Carcharias, etc. Thus to the numerous 

 genera of Saurians and Selachians possessing this character must be added a Batra- 



chian. 



23 



