Additions to the hydroids (Cnidaria: Hydrozoa) from the fjords region of southern Chile

This report considers five species of hydroids collected during a scientific expedition to the Northern Patagonian Zone of Chile in March 2007. Two poorly known species, Halecium fraseri Ralph, 1958 (Haleciidae) and Thuiaria polycarpa Kirchenpauer, 1884 (Sertulariidae), are redescribed from new, fertile material. The genus Parathuiaria Leloup, 1974 is assigned to the synonymy of Thuiaria Fleming, 1828, and notes are provided on the taxonomy of its type species, T. polycarpa. Three other hydroid species, Halecium tenellum Hincks, 1861 (Haleciidae), Amphisbetia operculata (Linnaeus, 1758) (Sertulariidae), and an athecate hydroid tentatively assigned to the genus Turritopsis McCrady, 1857 (Oceaniidae), are mentioned and accompanied by figures and brief remarks.