of the Fishery Board for Scotland. 
299 
Fig. 32. Veliger embryo — dorsal view, — showing extended velum, v ; two valves of 
shell, sh; and liver through the shell, Iv. 
Fig. 33. Embryo with shell well developed, showing velum, v, with cephalic disk, 
c.d.; re tracter musch-s of velum, — anterior retractor, ar, posterior retractor, 
pr; mouth, m; oesophagus, ce; stomach, st; intestine, in; anus, a; liver, Iv. 
adductor, ad; mantle ma. 
Fig. 34. Adult Pecten opercularis — natural size — with reproductive organs mature. 
The left valve, left lobe of the mantle, the outer of the left pair of labial 
palps and the left pair of gills have been removed. Ovary, ov; testes, t; 
generative duct, g.d; organ of Bojanus, k ; opening of organ of Bojanus, 
ko ; foot, / ; liver, Iv ; labial palp, I.}) ; rectum, r ; heart, h ; adductor, 
ad; mantle, ma; reflected part of mantle, r.ma ; eyes, o; sensory 
papilla?, p ; ligament, Ig ; gill, br. 
