Fig. l?lc. Anatomy of the oyster, aw, auricle; ve, ventricle; bm, body-mass; 

 cl, cloaca; g, gills; i and i', intestine; I, liver, with its ducts 9pening into the 

 stomach; M, adductor muscle; m, mouth; mt, mantle; o, the line of section of 

 figure passing through the stomach; p, outer wrinkled surface of inner or lower 

 palpi; v, vent. After Ryder. 



Fig. 171<2 1. Young oyster seen from the side immediately after fixation by 

 the mantle-border (m); v, ciliated velum, or paddle; 2, four young European oys- 

 ters taken from the beard of the parent, enlarged 96 times; 6, very young spat, 

 showing the peculiar form of the true larval shell and that of the spat X 35 

 times; 7. twenty-days-old spat (natural size); 10, young oyster, 2J to 3 montlis 

 old. After Ryder. 



[2V> /ace wage 238.] 



