Adula H. Adams & A. Adams 1857

The inside of this mussel is a pearly blue-white or blue-gray.

This small individual was boring into soft sandstone at Toleak Point, WA (on the open coast). Scale is millimeters, with centimeters marked.

A dorsal view of the same individual. The dorsal margin of the shell appears slightly inflated in most individuals.

Here is an individual, also from Toleak Point, in situ inside a rock. Note how the dorsal margin (facing the camera) appears inflated beyond the hinge (which is hidden between the inflated valves)

Adula californiensis from Kalaloch, WA. Burrowing into shale. Scale = mm (Photo by: Dave Cowles, July 2005)