In Anis paper are listed 19 different species of Hydrozca collected during a trip to the oceanic island of Trindade, located at lat. 20º 30' 00" S. and long. 29º 22' 00" W., 600 miles off the brazilian coast. During the trip hawls and dredges were done at different points of the island and of banks that exist between the coast and the island. Of the 19 listed species one is here considered new to science: Hebellopsis besnardi (p. 83), characterized by having thecae with a single curvature and a strongly everted margin. Its measures are intermediate between those os H. hartmeyeri and H. sinuosa, which are its closest allies. H. besnardi was found epizoic on D. quadridentata. Of the remainder 18, 14 were already known from the brazilian coast. Of these 14, 4 were previously known only from the coast south of Cabo Frio, and 10 are at present known only from the region north of Cabo Frio. Five species are found both north and south of this Cape. As a whole, 5 species are recorded now for the first time on the brazilian coast, of these are given a full description and figures. This paper has the purpose of increasing the faunistical knowledge of this region of the Atlantic Ocean as a first step towards the understanding of the zoogeographical relationships with the other oceans and the establishment of the zoogeographical regions of this coast.
