186 



Y. H. EDGEWORTH. 



these the pterygoid and temporal are together the homologue 

 of the internal adductor, and the masseter the homologue of 

 the external adductor, of Lepidosteus and Amia. 



Text-pig. 14. 



Text-fig. 15. 



Text-figs. It and 15. — Scyllium, embryo 28 mm., loncjitiidinal 

 horizontal sections. Text-fig. 14 is the more dorsal, throug-li 

 second, third, and fourth branchial segments on left side. 



of Add. /3 of Selachians, Imt this is not possible. In Text-figs. 35 and :>(> I 

 have denoted his " masset<er " l)y the term " external addvictor," and his 

 pteiygoid and temporal might be called parts of the internal adductor. 



