282 



THE EYE IN EVOLUTION 



Figs. 297 to 299. — Selachian Eye^ 



Fig. 297. — Diagram of a Euselachiaii Fig. 298.— Diagram of a Batoid eye. 



eye. 



CF, ciliary fold ; Ch, choroid ; CP, ciliary papilla ; Ec, epichoroid ; 

 ON, optic nerve ; P, optic pedicle ; S, sclera with complete cartilaginous oiip ; 

 SL, suspensory ligament. 



Fig. 299. — The eye of the dogfi.sli. 



Tlie retina has been torn at the ora and the uvea detached in the ciliarj' 

 zone. In the section the iris seems to adhere to the back of the cornea. Note 

 the great thickness of the corneal eiDithelium and the well-fornied eyelids ; the 

 latter f-ature is unique to Selachians among Fishes ( X 20) (Norman Ashton). 



