.VAN MUSSEL, (Anodonta cygnea.) . 



. I. Shell of Anodonta cyg: 

 1 ma -i <Utto. a, MaM ■ . .-.'. i I itto, folded back, b, Foot, c, Labral palpi, inner f 



, Outer gi] i embryos, e, Inner gills, f, Outer gill, 



valves and serrated hooks, b. Closed val' 

 i. *c, 0\r muscles (s) and origin of b; ament (v 



oc, Rec . ugh ventricle 



eaxt ee, Auricles, c', Anus, f, Portion 



Fig. 5. Portion of ou ■ ■ ■ pta or divisioi t <>n of eggs, ■ 



Fig. 6. f fin of fish, with parasitic embryos. 



