New genera of Bogidiellidae (Amphipoda: Gammaridea) from SW Pacific and Mediterranean marine caves

Two new genera and species of the stygobiont gammaridean amphipod family Bogidiellidae are described from anchialine or fully marine subterranean habitats in Mediterranean and SW Pacific Islands. Fidelidiella pectinata, from a littoral cave in Lifou (Loyalty Islands), differs from any other bogidiellid known thus far by the presence on the left mandible of a modified lacinia which is hypertrophied and expanded laterally, and by the possession of a transverse row of strong rounded processes on the anterior side of the distomedial corner of the fourth segment of the maxillipedal palp. This is the most easterly record of bogidiellid amphipods in the SW Pacific. Racovella uniramea, discovered in a Mallorcan anchialine cave, is remarkable among the Bogidiellidae in exhibiting a combination of only six distal spines on the basal endite of the maxillule, and presence of coxal gills on pereopods 3–6. We place particular emphasis on the determination of segmental homologies of all limbs and on the resolution of fine‐scale integumentary details, in order to provide a sound basis for future comparison with other family members.