Group C. Beehive or domed shape
There are five genera in this group - Euconulus, Strobilops, Ventridens, and two from the Helicinidae (Oligyra orbiculata and Hendersonia occulta). The first two are small (less than 3 mm) while Ventridens is larger - from 7 to 11 mm in diameter. The shape of the shell, looked at toward the aperture, spire up, is a good clue. The two Helicinidae are very round, the Drop snails.