LATERAL LINE 



221 



(L. 



A. 



SO 



ps. 





Diagrams showing the relation of the lateral-line canal to the scales on the trunk of Perca 

 fluviatilis, L. A, longitudinal section. B, the scales and the canal seen from the side, a, 

 arch covering the canal ; a.s, anterior region of scale ; ep, epidermis ; l.c, lateral-line canal ; 

 ?.n, lateral-line nerve ; n, nerve to sense-organ ; op, external opening of canal ; p.g, posterior 

 ctenoid edge of scale ; s.o, sense-organ in canal. 



cw: 



SO. 



CO 



FIG. 195. 



Gadus vwrrlim, L. Surface view of the skin, enlarged, showing the lateral line, c.o, cut 

 wall of canal to opening ; c.w, cut wall of main canal ; o, opening ; s, scale ; s.o, sense-organ 

 (neuromast). 



