The Anomphalidae differ from the Euomphalcea to which they have been reassigned in being more trochoidal, in lacking the angulation on the upper whorl surface characteristic of Euomphalacea, and in having the inner shell layer seemingly nacreous . ( The inner shell layers of the Euomphalacea may be of laminar arragonite, but are never nacreous . ) The Anomphalidea differ from the Pleurotomariacea in lacking the often deep slit or selenizone, which is characteristic of that taxon.
