Hello Thomas. I would not recognize this at the subspecies level. I (several of us actually) can't understand why Tom Watters included some of the subspecies in his treatise and I think this is one of them. I haven't studied it in detail, but I don't think any of the subspecies will stand the test of time. There's a long-standing history of malacologists classifying mere forms as subspecies with regard for nothing but shell shape. The Freshwater Mollusk Conservation Society has initiated a names committee to maintain a list of species that the society currently recognizes, similar to what American Fisheries Society has done for decades. The bivalve names subcommittee voted on their petitions last month and Tom's names were among them. I'm on the gastropod subcommittee and haven't looked at the results for the bivalves (I just checked the FMCS website and they haven't been posted). I sent Jim Williams an email requesting them. I'll let you know how they voted.

Hello Thomas. It looks like the Bivalve subcommittee of the FMCS Names Committee did not address the subspecies. I was pretty sure they didn't but wanted to be sure.