Dear George;
        I thought it had been established that alveus Conrad was a valid
species, and not just a form.  With DNA, surely this is an easy thing to
establish?  At any rate, it is almost certainly extinct (or expatriated,
if the species can be confirmed for the Pacific Coast) in the Atlantic.
The populations i referred to are specialized individuals of
testudinalis Muller, that have colonized Zostera in at least a couple of
localities in Nova Scotia, and i have heard it also occurs in Maine.  I
don't think these deserve a forma name, and most certainly they are not
alveus: they appear to simply be testudinalis's beginning adaptation to
a niche rich in food: the population density is quite low so far, so
they are not all that successful at this early date after the niche was
vacated by the competition - give them a few hundred years and i think
you'll have a legitimate form here, with much higher population
densities utilizing the under-exploited food source much better.

        It is interesting to note that the demise of the Atlantic alveus seems
to have had little or nothing to do with our species! I don't know if
this can be considered good or bad....

-Ross.

George P. Holm wrote:

Ross;
 The eelgrass limpit you describe from Nova Scotia was mentioned in
American Seashells (Abbott 1956 Seventh Printing p.105 and in the Second
Edition pp.32-33. as Acmaea testudinalis testudinalis (Müller, 1776) form
alveus Conrad, 1831. The specimens found in Boundary Bay compare to a
specimen of Lottia alveus I have in my collection which was collected by G.
Willett at Grants Island, Alaska.
 Material for DNA study has been sent to Dr. Lindberg in California so
there should be no question about what we have after that is done.
George

>First, Splendid site
>(http://modena.intergate.ca/personal/seashell/bcframe.html) - great
>Photos, especially of live animals!!  Bravo.  The species you are
>calling Lottia alveus (Conrad), seems to be an elongated form of pelta
>Rathke, or perhaps strigatella - it is lighter, more transluscent, but
>if you take a look at the specimens you find in the vicinity, NOT on
>Zostera, i think you will find they are the same species.......