A new species of the genus
Lacydonia is described from shallow waters off Oahu, Hawaii. This species is unique among its congeners by the presence of two pairs of small eyes; other lacydoniids may have either one pair of large or small eyes or no eyes at all. The description of
Lacydonia quadrioculata sp. nov., brings the number of valid species within
Lacydonia to 10 but the taxonomy of this genus is still confusing as most species are very similar morphologically and the majority of the descriptions are based merely on the single type or very few specimens. We discuss the relevance of some taxonomic characters used in species-level descriptions and provide a comparative table with selected characters of all valid species.