Hi Linda,

The operculums of Melongena corona can be quite varied, even
within localized colonies, and certainly with widely scattered
populations. It is very easy (once you get a feel for it) to recognize
'percs, even without the shell. Tulips have a very smooth 'perc,
while M. corona has a somewhat rougher 'perc with distinct
growth lines. Obviously, the size of the shell may be a factor,
as well. Without seeing the "pointed ones" you are describing,
I couldn't tell you if it's a mistake or just the way those shells
grew their "doors."

Jim


>I was examining a lot of old shells (collected in the
>1970's) from Sanibel, some of which have opercula in them.
>My problem - the Melongena corona I collected recently,
>fairly small ones, have a rounder operculum than these old
>ones.  Their opercula have a distinctive point, i.e., they
>look more like Fasciolaria tulipa opercula to me.
>


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