Allen Aigen wrote:

>Jim,
I am far from being an expert on the scallops, and you are most likely
right, but if we always use a process of elimination, we will never
describe new species.  Perhaps there are two distinct sister species
under the name of C. islandica.  Can anyone show a progression between
the suspect form and the common forms?

Sometimes there is a rare mutation in a species that affects shell
morphology.  This can be usually distinguished from a
different-but-similar species by the fact that the rare form occurs
simply mixed in with populations of the more common forms, and is never
found as a separate popultation.  In this case,  i have seen many, many
thousands of Chlamys islandica and have found only a half-dozen of this
interesting form -  but i have never seen it in isolation.  There are no
intergrades that i am aware of, but it is fairly certain that this is a
simple variant, and not a different species.

From the Hot old north (35 C at my place today!);
-Ross Mayhew.