The genus <i>Kelliella</i> (Bivalvia) in the Atlantic Ocean

ABSTRACT Kelliella M. Sars, 1870 is a genus of small epibenthic bivalves inhabiting muddy bottoms of the outer shelf and slope worldwide, commonly in habitats that are oxygen-poor or enriched in organic carbon. Currently, there are five accepted species of Kelliella with an Atlantic type locality, and six more Atlantic species, including Vesicomya atlantica (Smith, 1885), the type species of Vesicomya Dall, 1886, were at some time placed in Kelliella. In this work, we revise the genus Kelliella from the North Atlantic waters, based on large amounts of new material from both sides, and describe a new species from Martinique (Kelliella madininae n. sp.). We here propose, after revision of the shell morphology, the synonymy of K. biscayensis Allen, 2001 with K. miliaris (Philippi, 1844), and consider a single West European and Mediterranean species of Kelliella. The fossil “Kelliella” barbara is also excluded from the genus Kelliella and reallocated as Coralliophaga barbara (Studencka, 1987) n. comb. In the Atlantic margin of America, we consider that Diplodonta pilula Dall, 1881 remains a nomen dubium. The type material of K. concentrica Allen, 2001 is figured, and this species considered a member of the Vesicomyinae. The new Caribbean species, K. madininae, resemble K. brasuca Passos, Machado &amp; Fantinatti, 2017 from southeastern Brazil. We recorded new localities for Kelliella goesi Odhner, 1960, so far known only from its original description. Diagnostic characters discriminating Vesicomya from Kelliella, stated by Krylova et al. (2018), Journal of Molluscan Studies, 84: 69–91, are discussed, and we consider the hinge architecture as the most robust.