Ed, "Half-breed" is only a popular term implying mixed parentage. As I suggested in the brief text piece which accompanies that page, there are ample shells which gradually intergrade from schilderorum to sulcidentata to strongly suggest that these are all manifestations of one genetic entity. This would mean that none of these shells represent hybrids, just intergrading forms of the same gene pool. Of course, this is not a readily accepted idea but that doesn't make it invalid. Though much of the data for the shells are given there, other notes show that one "cross-breed," #268, was one of a 'mated pair' (two live animals taken in very close proximity of one another). Its mate, #269, is a typical schilderorum. I hope that clarifies my perspective on these shells. I have a few other 'hybrids' of this type but they are less mature and not fit for incusion on that page. This isn't the forum for long explanations so I'll leave it at this. I hope that helps. Aloha, Bob Dayle http://www.cowrys.org/research/xbreeds.htm _________________________________________________________________ The new MSN 8: advanced junk mail protection and 2 months FREE* http://join.msn.com/?page=features/junkmail