Fig. 171c.—Anatomy of the oyster. au, auricle; ve, ventricle; bm, body-mass; 
el, cloaca; g, gills; 7 and 2’, intestine; J, liver, with its ducts opening into the 
stomach; M, adductor muscle; m, mouth; mt, mantle; 0, the line of section of 
figure passing through the stomach; p, outer wrinkled surface of inner or lower 
palpi; v, vent.—After Ryder. 
ig, 171d —1. Young oyster seen from the side immediately after fixation by 
tee tiahtetorder Gane > eiliated velum, or paddle s 2, four young European oys- 
from the beard of the parent, enlarged 96 times; 6, very young spat, 
eee the ces form of the true larval shell and that of the spat x 35 
times; 7, twenty-days-old spat (natural size); 10, young oyster, 2} to 3 months 
old.—After Ryder. [To face page 238 } 
