The pedunculate barnacle Gruvelialepas leguillouxi n. sp. (Crustacea, Cirripedia), is described from the north east Atlantic (Armorican margin). It was collected on Madrepora oculata (Linnaeus, 1758), at a depth of 1000 m and represents the third known living species in the genus, besides G. pilsbryi (Gruvel, 1911) and G. kempi (Annandale, 1911), both recorded from Northern and Eastern Atlantic deep waters. Gruvelialepas leguillouxi n. sp. can be distinguished from its congeners in having the following characters: carina strongly arched, scutum with the apico-basal ridge dividing the plate unequally, tergum with a flat apico-basal ridge marked by a deep squared groove, rostrum higher than wide and rostrolatus strongly curved inwards. Moreover, the new species differs from G. pilsbryi in having the rostrolatus overlapping the carinolatus. Differences among all described Gruvelialepas Newman, 1980 species, based on morphological features of the plates, are discussed in detail. The geographic distribution of Gruvelialepas and the related genera Aurivillialepas Newman, 1980 and Scillaelepas Seguenza, 1876, are also reported. Frequent misidentifications in examining fossil taxa point out a necessary review of fossil material.
Crustacea, Cirripedia, Gruvelialepas, Aurivillialepas, Scillaelepas, Recent, Armorican margin, new species.