A new species of Tetragoniceps Brady, 1880 (Copepoda, Harpacticoida, Tetragonicipitidae) from an anchialine cave in Bermuda, with an updated key to the species of the genus

<i>Tetragonicepsbermudensis</i> <b>sp. nov.</b> (Copepoda, Harpacticoida, Tetragonicipitidae) is described based on an ovigerous female collected from Roadside Cave, a tidally influenced anchialine cavern in Bermuda. The new taxon represents the 16^th recorded species of <i>Tetragoniceps</i> Brady, 1880. It can be distinguished from congeneric species by the length:width ratio of the caudal rami (approximately 10 times longer than wide), its cephalothorax with a smooth dorsal surface, and the diagnostic setal formula of its pereiopods 1-5. <i>Tetragonicepsbermudensis</i> <b>sp. nov.</b> is the first record of <i>Tetragoniceps</i> from Bermuda and the first known anchialine species in the genus globally. Based on our description of the new species, we provide a revised key to the species of <i>Tetragoniceps</i>. In addition, we include an updated table of salient morphological characters for the females of the genus, providing grounds for a preliminary analysis of the phylogenetic relationships of its constituent species.