Plinthisus longicollis Fieber, 1861a: 178. ST(S): Italy; lost.
?Pachymerus brevipennis (non Latreille, 1807): A. Costa, 1847a: 35. Misidentification.
Plinthisus flavipes var. brevicollis Ferrari, 1874: 157 (syn. Horváth, 1876b: 731; restored by Josifov, 1987b: 6; syn. Péricart, 1997b: 484). LT (Péricart, 1998c: 7): female (brach.), Italy, Piemonte; MCSN.
Plinthisus pubescens Ferrari, 1874: 157 (syn. Horváth, 1876b: 731). LT (Péricart, 1998c: 7): female (brach.), Italy, Piemonte, Stazzano; MCSN.
Plinthisus hungaricus Horváth, 1875b: 59 (syn. Péricart, 1999b: 135, suspected). STS: Hungary; lost?
Plinthisus (Plinthisus) convexus (non Fieber, 1864): Horváth, 1876b: 729. Misidentification (see Horváth, 1886b: 218).
Plinthisus hungaricus var. globosus Horváth, 1886b: 218. ST(S): no locality given.
Plinthisus elongatus Horváth, 1886b: 218 (syn. Josifov, 1987b: 6, with brevicollis Ferrari). LT (Scudder, 1970a: 200): male, Greece, Attica; HNHM.