Pillsnails are easily distinguished from other land snails by their size and shape. They are “pill shaped” with a slit-like aperture and long parietal tooth. They lack a notch in their basal lip, unlike another genus – Stenotrema, which has such a notch. Their umbilicus is rimate, but varies from narrowly to slightly wider.

There are likely two species in Indiana: Euchemotrema fraternum, the Upland Pillsnail, and Euchemotrema leai, the Lowland Pillsnail.

Identification:

Euchemotrema fraternum - umbilicus imperforate to nearly covered perforate; 8-11 mm; periphery rounded and near the middle of the body whorl; more loosely coiled.

Euchemotrema leai - umbilicus larger and only covered perforate; less than 9 mm; periphery shouldered (that is, rounded above the center line of body whorl); more tightly coiled.

Lowland Pillsnail
Euchemotrema leai (A. Binney 1841)

Characters: Heliciform, pill-shaped, aperture slit-like, no notch in basal tooth. ~6 - 9 mm in diameter; umbilicus rimate (umbilicus moderately large but slightly covered by the reflected lip; large transverse parietal tooth, lacks marginal teeth; shell may be covered with short hairs.

There have been considered to be two subspecies of the Lowland Pillsnail. The Lowland Pillsnail proper (Euchemotrema leai A. Binney 1841) (left or 1st image) and Alice’s Pillsnail (Euchemotrema leai aliciae Pilsbry 1893) (right or 2nd image). They differ by the former’s more open umbilicus and more loosely coiled whorls and the latter’s more rimate umbilicus and more tightly coiled whorls (Oesch et al. 2013). Hotopp et al. (2013) suggest that the subspecies Euchemotrema leai leai is more northerly and that E. leai aliciae is more southerly.

Habitat: Has been collected associated with grasslands (grass litter, clumps) and woodlands (leaf litter, woody debris). Alice’s Pillsnail is found mostly in mesic woodlands, but occasionally on prairies and more xeric hillsides. (Oesch et al. 2013)