Tachalus Ball & Nègre, 1972

Schmidt, Joachim & Will, Kipling, 2020, A new subgenus for “ Acalathus ” advena (LeConte, 1846) and the challenge of defining Calathina based on morphological characters (Coleoptera, Carabidae Sphodrini), Zootaxa 4722 (4), pp. 326-338 : 334

Subgenus Tachalus Ball & Nègre, 1972

Third antennomere without pubescence. Mentum tooth bifid. Pronotal laterobasal seta removed from side margin. Lateral bead of prosternal process absent. Parascutellar seta present. Elytra glabrous, with discal setae absent. Elytral microsculpture distinctly isodiametric. Metepisternum short. Male protarsomeres dilated. Lateral grooves present on metatarsomeres I-II, poorly developed (externally) or absent (internally) on III, absent on IV. Apical gonocoxite moderately elongated, slender, with one ensiform seta at external margin; sensory pit of apical gonocoxite well developed. Aedeagus right side up in repose; median lobe apical disc absent; apical hook of long paramere absent; membranous lobe of short paramere absent.