VI.] 



THE COMMON FROG. 



75 



Yet it can hardly be conceived that serpents have 

 carried off from Piscine ancestors and carefully 



Fig. 37. — Upper Surface of the Skull of a Froj (after Parker), e, os en ceinture, or 

 girdle-bone ; eo, exoccipital \ f, frontal part ot frontoparietal bone; inx, maxillary- 

 bone ; «, nasal ; o/>, opisthotic ; /, parietal part of fronto-parietal bone ; pm, pre- 

 maxilla; po, pro-otic: pt, pterygoid; q, quadrato-jugal ; sq, squamosal; sus, 

 suspensorium of lower jaw. 



Fic. 38. — Under Surface of the Skull of a Frog (after Parker), e, girdle-bone; 

 eo, exoccipital : vtx, maxilla ; par, parasphenoid : /w, pre-maxilla ; po. pro-otic ; 

 /;", pterygoid ; q, quadrato-jugal ; sus, suspensorium of lower jaw, the lower end 

 of which represents the quadrate bone ; v, vomer ; 1, optic foramen ; 2, foramen 

 ovale ; 3, condyloid foramen. 



preserved this peculiarity of structure which all their 

 other class fellows have lost. It seems much more 



