penita (Conrad, 1837)
be a Teredo navalis (L., 1758 ) the shipworm ... AvrilB -
is a Piddock. Maybe Penitella penta....Russ W.
I agree with
Russ that the mystery shell 2009 #2 is Penitella
penita (Conrad, 1837). There is some possibility it might
be a closely related Penita species but the flat tip is the most
significant reason for my identification. See a photo of this species
collected in Washington State at the Pacific
Northwest Shell Club Website. ..Bert B.
The second mystery
shell is Conrad's Piddock Penitella conradi Valenciennes,
Best regards, ...Henk K. Mienis (Common name: abalone piddock)
appears to a piddock, most likely P. penitella.... Rick H.
to think it's a boring clam, Penitella Penita or Common Piddock.