.MOEPHOLOGY OF CRANIAL .A[USCLES IN SO^IE VERTEBRATES. 201 



external (Acipenser), grows up to the skull. In Sauropsidau 

 embryos the depressor palpebrse inferioris is given off from 

 the anterior margin of the levator maxilhe superioris, which 

 becomes inserted into the palato-quadrate — this is preserved 

 in birds, whereas in reptiles various changes, modifications 



Text-fig. 28. 



aMJte.,t 





Cti/L.tTvoruL 



Text-figs. 28-3.3.— Amia, eml .ryo 8A mm. Text-fig. 28 is the most 

 anterior. 



or atrophy, occur; and the adductor maudibula) divides into 

 external and internal portions, of which the former grows up 

 to the skull, whilst the primitive origin of the latter was 

 probably to the palato-quadrate and the hind end of the 

 palato-pterygoid bar — this is preserved in Chelouia, but is 

 variously modified in other groups (loc. cit.). 



A comparison of the various forms of the interinandibularis 



