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.
The occludent ledges of both valves support some fine spines.
This tooth is in part a development of the occludent ledge; it varies much in shape.
This is the first species in the genus in which the occludent ledgea structure peculiar to the genushas been amply developed.
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.