> northern species like Neptunea decemcostata sometimes do produce
> "communal" clumps, containing capsules from several individuals.  I
> don't know if any southern species do this.

Several murex species produce communal clumps, and Haustellum ruthae lay so
many that many of the parents end up inside the egg mass and die there. We
once found an egg mass over a yard across with at least 400 shells entombed
in it.

Solenostira also lay eggs together and atop each other.

Peggy
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