Bull. U. S. B. F., 1930. (Doc. 1100.) 
Figure 3. — Bay scallop lying on its right side, with left valve, left gill, and most of left mantle lobe removed. A. M., 
adductor muscle; B., byssal notch" (overgrown by Ostrea equestris ); C, cartilage; D. D., digestive diverticula over- 
lying stomach; F., foot; 0., gill: H., hinge; K., execretory organ or kidney; M. M., mantle margin with eyes and 
sensory tentacles along outer edge and guard tentacles along inner edge; Pa., palps; Pe., pericardium; R., rectum; 
V. M., visceral mass 
Figure 4. — TJnretouched photograph showing sensory tentacles somewhat extended, eyes with 
their centers gleaming in the sun light, the flap of the lower mantle lobe, and the guard 
tentacles of both flaps 
572—2 
