The teeth on the occludent margin are sharp, and stand some way apart from each other.
Scutum, plainly striated longitudinally: the teeth on the occludent margin small.
Excluding this very narrow, prolonged, occludent margin, the adductor plate projects for a length equalling the rest of the valve.
The lines of growth obscurely indicate a tendency to the formation of a slight "occludent ledge" along the carinal margin.
This is the first species in the genus in which the occludent ledgea structure peculiar to the genushas been amply developed.
This tooth is in part a development of the occludent ledge; it varies much in shape.
The occludent ledges of both valves support some fine spines.
It is articulated by a convex surface, and by a hollow on its under side with the occludent ledge of tergum.
The scutum cannot be said to have any tergal margin; without, indeed, the articular surface of the occludent ledge be thus called.
The scutum has its occludent margin always sinuous, but to a variable degree.