Type species. Cancer planatus Fabricius, 1775, by original designation.
Remarks. Hymenosomatidae MacLeay, 1838, comprises 24 genera and over 130 species (Poore et al., 2016) of which Halicarcinus White, 1846, was the most diverse and morphologically heterogeneous. Poore et al. (2016) have revised Halicarcinus and reassigned the species to seven genera to accommodate the diversity previously encompassed in the genus. Currently Halicarcinus includes seven species characterised by the complete hymenosomian groove, well-developed epistome, rostrum developed as median tubercle with paired pseudorostral elements, strongly curved gonopod 1, pleomeres 1-5 free, pleomere 6 fused to telson (pleotelson), pereopodal dactylar teeth shorter than in other genera, and propodi of male chelipeds frequently swollen and barrel-like (Naruse and Komai, 2009; Poore et al., 2016).