An illustration from "British Entomology" by John Curtis. "Lasioglossum tricingulum" Curtis the Long-tongued Melitta Synonym "Halictus xanthopus". This is the type description of "Lasioglossum" Curtis, but this species was referred to "Lasioglossum xanthopum" (Kirby) by Fitton et al., and subsequently transferred to "Halictus".