Three new species of Hemicyclops (Copepoda: Poecilostomatoida: Clausidiidae) from northwestern Madagascar

Three new species of the copepod genus Hemicyclops (Clausidiidae) from Nosy Bé, northwestern Madagascar, are described, ofrom burrows of unknown origin, probably those of crustaceans, one from the scleractinian Favia sp., and one from a gastropod shell occupied by a hermit crab. Hemicyclops acanthophorus, new species, may be recognized by a pair of posterolateral spiniform processes on the genital double-somite of the female, and by the triangular form of the free segment of leg 5. Hemicyclops apiculus, new species, is characterized by its elongate genital double-somite with anterior rounded lateral expansions, its subquadrate caudal ramus, and the small sharply pointed lateral projections on the first segment of leg 5. Hemicyclops vicinalis, new species, may be distinguished by the absence of setules on the inner side of the caudal ramus and on the outer margin of the second segment of the antenna proximal to the seta.