Diario de dabrock

I apologize for submitting an observation prematurely. I decided to be more vigorous in cleaning my purported Vertigo with very small artist brushes and weak peroxide. And then what I took for a lamella was no longer there. Of course, with my expertise, this identification has to be considered tentative as well.

Retinella rhoadsi or Retinella roemeri? I guess I need to train my eyes to the viewpoint of John Burch. I see the key leading me to rhoadsi, supposedly not in Texas. But I can overlook one point and then arrive at a comfortably Texan snail. Note to self: has anyone looked into the species concept as applied to Retinella?