Tom,

On a dive trip to northwestern Australia a couple of years ago I found a specimen of Mitra sowerbyi form kingae at Cassini Island.  The shell was cream colored with slightly darker clouds on the body and dark red spiral lines.  The red spiral lines turned out to be periostracum for after slight bleaching they virtually disappeared but the cloud pattern stayed.  Clay Bryce from the Western Australia Museum was on the trip and said that several of the "sowerbyi" subspecies have this characteristic (most are hard to ascertain as the species and most subspecies are Miocene fossils).

That is the only marine shell where I have seen a color pattern disappear when bleached.


Wayne Harland
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"The trouble with doing something right the first time
is that no one realizes how difficult it really was."