Mecistostethus marseuli sp. n. Figs 3D4B6 E–F 7

Type material.

Holotype male: "GUYANE FR: Itoupé, Mont tabulaire alt. 600m, 3°1.38'N, 53°5.73'W, piège d’interception 3, 23 Mar 2010 SEAG leg." / "Caterino/Tishechkin Exosternini Voucher EXO-00498" / "HOLOTYPE Mecistostethus marseuli Caterino, Tishechkin & Dégallier”; deposited in MNHN.

Diagnostic description.

Length 2.0mm, width 1.5mm; frontal stria largely effaced, not prominently carinate; frons and epistoma with microsculpture; anterior submarginal pronotal stria absent; pronotum with>10 discal setae, scattered on disk in addition to submarginal row (Fig. 3D); lateral pronotal punctures absent; pronotal microsculpture more conspicuous at sides, lacking at base; prosternal striae absent; metaventral stria interrupted at middle (Fig. 4B); microsculpture at apex of elytra conspicuous; elytral stria 1 complete, with numerous setae; elytral striae 1 and 2 abbreviated at base; tegmen (Figs 6 E–F) widest near apex, tapering in basal two-thirds, basoventral concavity well developed, occupying basal three-fifths, delimited by strong basolateral carinae and with conspicuous fine median keel; tegmen with strong ventral swelling just apicad midpoint; median lobe only about one-fourth tegmen length.

Distribution.

This species is only known from the type locality, in southeastern French Guiana.

Etymology.

This species is named for French entomologist Sylvain Auguste de Marseul (1812-1890), whose superb work on the family Histeridae remains almost unequaled to this day.