Halacarus ctenopus from the English Channel coast and described by Gosse (1855a) proved to be identical with Acarus basteri Johnston, 1836, nowadays known under the generic name Thalassarachna, whereas a redescription of H. ctenopus, prepared by Lohmann (1893) and based on a specimen fromm off the Bermuda Isalands, proved to be neither conspecific nor congeneric with Gosse s species. Subsequent records or redescriptios of H. ctenopus refrred to the species described by Lohmann (1893). For the purpose of stability in nomenclature a neotype was selected and is described herein.