NATURAL HISTORY OF THE BAY SCALLOP 
587 
The stomach is of a very complex shape which is better illustrated than described. 
In Figure 9, a and b are from plaster casts, and c and d from dissections. The numer- 
ous, small branches are the beginnings of the diverticula. A considerable portion 
of the stomach walls are ridged or folded in a complex manner. Many ridges (fig. 
Figure 9.— a, Dorsal aspect of stomach; b, posterior aspect of stomach (a and b from plaster 
casts); c, dextral view of section through esophagus, stomach, and portion of mid-gut; d, in- 
terior view of right (lower) side of stomach; e, crystalline style; /, posterior, and g, lateral 
views of gastric shield; ft, cross-sectional sketch of mid-gut close to stomach, antero-ventral 
view (looking toward stomach) ; C., caecum; D. R., duct of right diverticula; F., foot; F. L., 
food lumen; L., lips; L. I)., duct of loft diverticula; M. Q., mid-gut, with style lumen; 0., 
oesophagus; R. D., basal portion of right diverticula 
9 d) on the right or lower side converge toward the opening to the mid-gut. This sys- 
tem of ridges leads, in part, from the ducts of the diverticula. 
The epithelium of the stomach is possessed of very active cilia which produce a 
complex circulation of the stomach contents. In an opened stomach, introduced 
fine particles of chalk (superior to carmin in visibility in such a situation) can be seen 
