Small or moderate-sized; antennae slender, inserted under a feeble ridge on front of head, three basal segments glabrous; pronotum with two setigerous punctures each side; elytra margined basally, with dorsal punctures; metacoxae contiguous; tarsi smooth, claws serrate. The members of this genus are found under stones, logs, and leaves in dry upland woods.

a. Calathus gregarious

Elongate-ovate, slender, subdepressed; dark reddish brown to piceous, shining; pronotal margins paler; antennae and legs reddish brown. Pronotum feebly elongate; two setigerous punctures each side near margins; side margins slightly reflexed; posterior angles narrowly rounded; basal impressions obsolete. Elytral striae shallow, impunctate; intervals feebly convex, smooth; two dorsal punctures on third interval. Length 10 - 11 mm.