The Poweshiek Skipper Project

Terrestrial Snails


Discus whitneyi (Newcomb, 1864)

Forest disc

The nomenclature of snails can be pretty frustrating to deal with.  I used the keys in the books I have to identify this snail--it keys out to Discus cronkhitei (Newomb, 1865) in books by Baker, Taft, and Pilsbry.  D. whitney is apparently the currently recognized valid name.

Other names for this species included Helix stiatella Anthony, Patula striatella Anthony, Pyramidual striatella Anthony, and Pyramidula cronkhitei anthony Pilsbry, and Helix Cronkhitei Newcomb.



Hubricht shows records for most of the counties in Iowa that have snail records (listed as cronckitei).  Distribution of the snail nationally is in the northern and Midwestern states, from Maine south to North Carolina, and west as far as North and South Dakota.  There are extant records as far south as the Ohio River corridor 

The genus Discus is a group of small, (around 3-4 mm) brownish colored snails that have a conspicuous rib-like sculpturing to the shell.  Note the very wide aperture and the rib-like sculpturing on the bottom of the shell.


I have found this snail underneath decaying wood--wood that has not decayed will usually not have this snail.  It can be quite common under the very old stuff, however.  I have also found empty shells of this snail on mound building ant nests.

In Iowa, at least in my yard, I find this snail to be fairly common, but one which requires a little bit of extra searching to find.