Diagnosis.--Key characters: Ommatidial size coarse (Fig. 39b); prosternal process not linear, expanded at apex (Fig. 18); mesal antennal spines present (Figs. 8b, 9b); elytral humeri without epipleural tooth; pronotum with impunctate regions present; pronotum without longitudinal rugosities, transverse ridges, or large, uniformly-sized confluent punctures; pronotum with several dorsal tubercles and posterior constriction; femoral carinae absent; procoxal cavities closed laterally (Fig. 24); mesal profemoral apices rounded (as in Fig. 26d); elytra not metallic and without dense golden and/or silver pubescence; procoxal cavities open posteriorly (Fig. 18); tibial carinae present (Fig. 22); lateral metafemoral apices rounded or dentiform (Fig. 26c); metafemora strongly clavate (Fig. 37b); pronotum and head without dense yellow or white pubescence; antennomeres carinate, not sulcate (Fig. 45b, c); spine of antennomere three acute (Fig. 45a, b); antennomere shape at apices greatly expanded and appendiculate (Fig. 13). Length: 10-12 mm.

Distribution and Diversity.--Brazil, French Guyana. Monotypic.

Discussion.--No specimens were available for dissection and inclusion in the phylogenetic analysis. I hypothesize that Hemilissopsis may be near the polytomy consisting of the Sphaerion and allies clade (Fig. 60) and the Mallocera and allies clade (Fig. 59). The tribal relationships of this genus have been equivocal. When Lane (1959) erected the genus, he placed it in the Piezocerini primarily due to the structure of the antennae.

Hemilissopsis is easily recognized by the strongly laterally expanded antennomeres, very strongly clavate femora, and pronotum with posterior constriction and small dorsal tubercles.