X E R \' O U S SYSTEM 



J4I 



which are said to be capable, Hke those of man, of distinguishing 

 between saltness, sweetness, sourness, and bitterness. The eyes 



otFb. 



obi. sup. 



cil.a. 



Fig. 259.— Orbit of the dogfish [Scyliorhimis). —Yrom Young. The Life of 



Vertebrates, 1950. Clarendon Press, Oxford. 



ant. red.. Rectus anterior ; cereb., cerebellum ; ctl.a., cil.p anterior ^'^d Postenor cili^ nen-es ; ^-^^^^^ 

 efferent pseudobranchial arter>- ; ./>., epiphysis ; g.c./cibar>- gangbon ; '^fJ-'J^^^"^"]^^^^^^^^ 

 lam., lamina tenninabs ; OV + VII., superticial ophthalmic; «*'-^^«f ' °^l«'l""y"^^^^^^^ 

 olfactorv bulb ; opt.l., optic lobe ; post, rect., rectus posterior ; r.op. /^'^ 'deepophthainc branch of 

 trigeminal ; r.s., sensor/ root of ciliary gangbon ; sup. rect., rectus superior ; thai.. thaKinn,- . fl \, 

 cranial ner\-es. 



have the same general structure as those of mammals (p. 4^\5) 

 and each is held in position by six eyeball muscles (Figs. 258 

 and 259). In the front of the orbit is a pair, the obliquus superior 



