>Nearly all of the eulimids I've collected, here in Puget Sound, in
>Alaska, Mexico, Costa Rica, the Philippines and Thailand have been
>partially embedded in the outer layer of the holothurians skin and not
>near either end of the animal. Sometimes on the dorsal surface, other
>times on the ventral.

Eulimids have all sorts of habitats. The larger Melanella species
(syn=Balcis) live free in sand; they come out and attach themselves
to a specific species of holuthurian when they want a feed. Other
genera may be permanently attached to their hosts eg I have collected
bulbous Echineulima mittrei near the mouth of Cidaridae in Fiji; they
are external but the proboscis is permanently attached deep within
the host's tissues (I only found one male/female pair, despite
picking up numerous urchins related to Diadema, being stabbed only
once by a spine; found not one holuthurian parasitized). Entoconcha
is a shellless parasitic worm more specialized than a tapeworm,
living entirely within the holothurian host's coelom. Thyca lives
attached limpetlike to the arms of Linckia stars. Stilifer and
several other shelled genera live internally within galls in cidaroid
spines or the bodies of asteroids & ophiuroids; the apex of the shell
often protrudes. All feed on body fluids.

Some species have very solid shells; others are very fragile, though
solidity tends to win out in externally-living forms. Stilifer seems
fragile.

An INTERESTING family. The largest Melanella reaches about 40mm!

Tyen expert on the family is Anders Warén.
--
Andrew Grebneff
165 Evans St, Dunedin, New Zealand
64 (3) 473-8863
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Fossil preparator
Seashell, Macintosh & VW/Toyota van nut
I want your sinistral gastropods!