Some of our Cypraeaologists may disagree with me, and if so I'll be
interested to hear it, but as far as I know there are no differences in shell
or soft parts between "typical" Cypraea tigris and the "form" Cypraea tigris
schilderiana.  The only difference is that Cypraea tigris tends to grow
larger in Hawaii, and it is those large Hawaiian specimens that got tagged
with the name "schilderiana".  Since size alone is not a valid criterion for
taxonomic separation, I personally think the name schilderiana should be
declared invalid.  And if size is accepted as a criterion, what is the
cutoff?  Is a 120 mm Cypraea tigris from the Philippines a "schilderiana"?
If not, then it would seem that geography, rather than any characteristic of
the animal is really the deciding factor, and that would be strange indeed!
While I am on this kick, I feel the same way about the South African "Cypraea
arabica immanis".  Why can't we just say that Cypraea arabica grows bigger in
South Africa?  Why does it have to have a different name?
Paul M.