I had the impression that the scallop pattern on the dorsal surface of
Crepidula was due to lying directly against the surface of a pecten.
Now I think it's more likely that the pattern is due to a Crepidula
following the ribs of the scallop on which it is attached. The surface of
the scallop "guides" the development of the Crepidula's edge.
What do folks say?
David Kirsh
Durham, NC