A "schilderiana" is just a big regular tigris that happens to be from
Hawaii.  There are no morphological differences between large Hawaiian
Cypraea tigris and equally large Cypraea tigris from anywhere else.  It is
true that the largest known specimens have come from Hawaii, and also that
large specimens are more common in Hawaii than elsewhere.  But that is not a
valid reason for taxonomic separation.  I currently have a 118 mm specimen
from the Philippines.  The name "schilderiana" should be trashed once and
for all, IMHO.

Regards,
Paul M.