PLATE 9 



EXPLANATION OF FIGURES 



Cross-sections of the adult. X28 



22 Level of anterior end of first basibranchial, showing lingual cartilage 

 and 'horn' in tongue. 



23 Level of the origin of M. ceratohyoideus internus, showing M. suprapo- 

 duncularis and the tongue stalk. 



24 Level of articulation of the first ceratobranchials with basibranchial. 



