Since last April I have been studying Pedipes ovalis, a little semi-terrestrial snail from Florida. They only grow to be ~3 mm long. When I first collected these snails, their affiliation confused me, but once I spotted the pneumostome (the opening of the lung) of one individual under the microscope and noticed, at the same time, that it didn't have an operculum, I knew they were ellobiids. A quick search thru Martins (1996) narrowed the genus down to Pedipes and the subsequent examination of the protconch helped me identify the species as ovalis.
An interesting characteristic of the genus is their foot, which is divided by a transverse groove into an anterior propodium and a posterior metapodium.
Since last summer I have also been writing 2 manuscripts about these snails. Expect more related posts in the future.
Martins, A.M.F., 1996. Anatomy and systematics of western Atlantic Ellobiida (Gastropoda: Pulmonata). Malacologia 37:163-332.