Genus Cycloplectoceras Ulrich, Foerste, Miller & Furnish, 1942

Type species

Cycloplectoceras miseri Ulrich, Foerste, Miller & Furnish, 1942, from the Smithville Formation (Floian Stage), north of Smithville, Lawrence County, Arkansas, USA; by original designation.

Diagnosis

Small discoidal conch with nearly circular whorls in cross section; whorls are in contact and slightly impressed dorsally; extremely small umbilical perforation; surface ornamented with strong annulations and prominent growth lines, which form v-shaped ventral sinuses; sutures simple and nearly straight; siphuncle near the ventral wall of the conch (from Ulrich et al. 1942).