THE LATERAL SENSE ORGANS OF ELASMOBRANCHS. 493 



capsules are shown ; the superficial ophthalmic and inner and outer buccal ampulla? are not exposed by 

 a superficial dissection. 



COMMON REFERENCE LETTERS FOR PLATES. 



S.O. Superficial ophthalmic ampullary canals. 

 O.B. Outer buccal canals. 

 LB. Inner buccal canals. 



H. Hyoid ampullae. 



A. Anterior canals of hyoid ampullae. 



0. Outer canals of hyoid ampullae. 



P. Posterior canals of hyoid ampullae. 

 I. Inner canals of hyoid ampullae. 



M. Mandibular canals. 

 S.C. Sensory canal. 



E. Eye. 



S. Spiracle. 



G. Gills. 

 Mth. Mouth. 

 M.R. Muscle ridges. 



PRESENTED 

 1 9JUN.191Z 



