Cherrystone Drop
Hendersonia occulta (Say)

Hold mouse over picture to view a photo of the underside.

Status: State Threatened (August 1, 1989).

Occurence: Occurs in Brown, Door, Kewaunee, Manitowoc, Sheboygan, Ozaukee, Milwaukee, Sauk, Crawford, Iron, Vernon and Grant Counties of Wisconsin.

Aid to ID: The shell is thick, wider than high, reddish or yellowish in color, marked by fine spiral lines across the surface of the whorls, and about 0.25 inches (5-8 mm) in diameter. The domed shaped spire (top part of shell above the aperture) has 6½ whorls with the sutures (seams between the whorls) unimpressed. The base is rounded and without an opening, the umbilical area covered by a callous pad. In adults, the outer lip is greatly thickened forming a heavy projecting ridge.

Habitat: Inhabitants of small areas of algific habitat or the similar cool, moist, shaded sites of cliffs where algific conditions occur without substantial talus or ice. The species is most often found on wooded alluvial-soil banks and bluffs along the Lake Michigan shore. Driftless Area sites are on north-facing slopes supporting oak-maple woodland. This snail is found in the soil and leaf litter along cliffs, soil-covered ledges on cliff faces, and on talus and soil and leaf litter near the cliff base.

Management Considerations: The location of the snails in soil and leaf litter at the base of the cliffs makes them vulnerable to trampling. Preservation of habitat along the Lake Michigan shoreline will be a decisive factor in the long-term status of the snails in Wisconsin.

The content for this page was originally presented in the Endangered and Threatened Invertebrates of Wisconsin, a free publication available by contacting the Endangered Resources Program.