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 Frog (after Parker), e, os en ceinture, or 

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

 bone ; «, nasal ; op, opisthotic ; /, parietal part of fronto-parietal bone ; p7n, pre- 

 maxilla; fo, pro-otic; //, pterygoid; q, quadrato-jugal ; sq^ squamosal; szts, 

 suspensorium of lower jaw. 



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

 eo, exoccipital ; mx, maxilla ; par, parasphenoid ; ptn, pre-maxilla ; po. pro-otic ; 

 pt, 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 



