Incoltorrida zahamena, new species

Figs. 11 (habitus); 12 (genitalia); 36 (map); 50, 51 (habitat)

Type Material. Holotype (male): Madagascar: Toamasina: Alaotra-Mangoro: Zahamena National Park, Antanandava Sect., midaltitude rainforest: Manambato river ~ 100m downstream of Camp Cascade, hygropetric rocks at night, 17.5438S, 48.7230E, 1280m, 10.III.2018, MAD 18-111, Leg. J. Bergsten & T. Ranarilalatiana (NHRS) . Paratypes, same data as holotype (2 females NHRS, BMNH) .

Differential Diagnosis. Differentiated from other members of the genus by the combination of small size (ca. 1.97 mm), oval habitus (Fig. 11), pronotum without median longitudinal ridge, and elytron with eight costae. The elytral series are irregular, giving the elytra a scabrous appearance.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.97/1.19; head width 0.39; pronotum 0.43/0.92; elytra 1.21/1.19. Dorsum dark brown to black, venter reddish brown, legs reddish brown except femoral-tibial articulations and tarsi dark brown.

Sides of frontoclypeal shield slightly arcuate. Clypeus about as long as frons.

Pronotum with short oblique carinae on anterior 1/3 moderately developed, no indication of midlongitudinal carina, area posterior to carinae transversely rounded, with no indication of ridges or depressions. Cuticle rough, subgranulate.

Elytron with eight costae of varying height; costa #6 very low and short, costa #8 generally higher and stronger than other costae; transverse ridges between costae absent or very indistinct. Serial punctures large and coarse, producing scabrous appearance.

Metaventral tabella with very faint, indistinct transverse grooves; midlongitudinal groove in posterior 1/2 of metaventral tabella widest at about midlength.

Midlongitudinal carina of first abdominal ventrite strong and extends length of ventrite.

Male genitalia in lateral view distinctively thickened in basal 1/2, apical 1/2 narrowing, with tip slightly widened and spinose (Fig. 12).

Etymology. Named in reference to the type locality.