Amsterdam Expeditions to the West Indian Islands, Report 47. Stygobiont amphipod crustaceans of the hadzioid group from Haiti

The stygobiont gammarids of Haiti are more diversified than anywhere else in the world: not less than 13 species (all new) in 7 genera (5 new) and 4 subgenera (all new) are described of a somewhat loosely delimited group called the hadzioids/weckelioids. Practically all species have limited ranges within Haiti, whose stream systems apparently have acquired a great deal of isolation. The morphology of these amphipods makes even more indefinable the various supra-generic units proposed in the last 10 years for the “Gammaridae s.l.”