This view of the interior (anterior is to the left) shows the general shell shape, the adductor muscle scars and pallial sinus, and the slight yellow cast present in some shells. Although these two clams are just slightly different in length they differ sharply in thickness. The ventral edge of the shell to the left is 0.7 mm thick, while the same region in the shell to the right is 2.7 mm thick.
There are two cardinal hinge teeth on each valve, plus at least one lateral tooth. The lateral tooth is most easily seen on the right valve (bottom valve in this photo). Anterior is to the left.
This ventral view (anterior end down, right valve to the right) shows the slight rightward bend to the anterior and especially the posterior end of the shell. The clam lies on its side in the sediment with the right valve upwards and extends its siphons up from there. Compare the curvature of this species' shell to that of Macoma nasuta.
