Unionicola subg. Unionicola Haldeman, 1842

Diagnosis. Genital field with 5 or 6 pairs of acetabula. Palps not flattened, well sclerotized. Without sexual dimorphism in legs, I-II-L with large blunt setae associated with basal projections of the segment surface, III-IV-L with swimming setae. Males with one pair of genital plates forming a rounded genital field. Females with two pairs of genital plates, each with 2–3 acetabula. Anterior genital plates of female each with two and posterior plates with one long inner setae. (Gerecke et al. 2016)