Thank you very much for the great information




At 05:56 PM 7/4/2004, you wrote:
>Hi Ellen,
>
>I'm a New England collector also, presently in Rhode Island, formerly in
>Massachusetts. But I still do more collecting in MA than in RI.  The two
>species you mention can be confusing at first, and as you say the book
>illustrations are not very helpful, but once you get used to them you can
>tell them apart at a glance. L. saxatilis has a taller spire, more impressed
>suture, less well defined spiral sculpture, and a less inflated body whorl.
>Interestingly, L. littorea has a noticeably sharper apex, even though it is
>a much larger shell, because of the smaller size of its embryonic shell.
>But these facts are not particuilarly useful for quick field identification.
>Color is often helpful.  Small L. littorea are almost always black, whereas
>L. saxatilis come in many shades - brown, yellow, white, gray, and often
>with lighter color bands, which L. littorea never has. Black L. saxatilis
>are possible, though not common.  Perhaps the easiest criterion to use is
>interior color.  L. littorea has a distinct black band along the inner edge
>of the lip, but is lighter colored deeper inside.  L. saxatilis is often
>chocolate brown interiorly, or may be the same color as the exterior of the
>shell, but in any case does not have the dark band along the inner lip.
>
>I have collected L. saxatilis at Manomet Point in Manomet, MA.  This
>location is also where I have found the largest L. littorea I have seen
>anywhere - some over 40 mm.  There are many huge intertidal boulders here,
>covered with Fucus (rockweed).  At low tide you can walk out a bit to where
>some of the larger boulders are.  Grab a handful of Fucus and shake it over
>a box or other container and most likely at least a couple of dozen L.
>obtusata will fall into the box.  Do this a half dozen times and you will
>probably have over a hundred L. obtusata.  Look through them carefully and
>you will most likely find several L. saxatilis mixed in. Out in the
>mid-tidal area anything that is not L. obtusata is most likely L. saxatilis.
>The L. littorea are not primarily rockweed snails.  They stay in closer to
>shore where there is less rockweed, and they can crawl on bare rocks.
>
>If you do collect here, be careful.  The vertical tidal range is about 8
>feet, and the tide comes in pretty fast. If you are a good distance out and
>are not alert, you may find yourself cut off from the shore by a fast-moving
>channel of water.
>
>Regards,
>Paul M.
>
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