Penitella Valenciennes 1846

An inside view of the same individual as above. The upper (left) valve has been broken off somewhat at the posterior end.

Penitella turnerae found in shale near Lincoln City, OR by Bob Mead. Longest shell is 5.5 cm long and 2.6 cm wide. Right valve is above, left valve is below. Anterior end is to the right. (Photo by: Dave Cowles, May 2006)

Piddock clams are usually found embedded in their burrows in rock, as is this individual.

A view of the inside of the left valve. Note the projecting myophore near the hinge. There are no hinge teeth. The siphonoplax, which would normally be attached to the posterior end of the shell at the left, is detached from this specimen.

The chitinous siphonoplax flares out from the posterior end.

The flaring siphonoplax (on the posterior end, at the left; the mesoplax, and the protoplax (right) can be clearly seen in this dorsal view.

This posterior view clearly shows the flaring siphonoplax.

This ventral view shows that the anterior gape of the shell (to the right) has been nearly completely sealed by the callum.

A Penitella penita shell from Toleak Point, WA. No animal is present. The right valve is shown. Anterior is to the right. The siphonoplax plates flare on the left. The protoplax covers the top right of the shell. (Photo by: Dave Cowles, Sept. 2006