We redescribe and illustrate Halcurias pilatus McMurrich, 1893 and H. mcmurrichi Uchida, 2004 (Endocoelantheae, Halcuriidae) from newly collected specimens from Southern Chile and deep-water reefs off Florida, respectively. Halcurias pilatus was previously considered to have a disjunct distribution until Uchida (2004) described a new species for the material from the Bahamas. However, the description of H. mcmurrichi does not meet modern taxonomic standards. We provide new anatomical and cnidae data for H. pilatus and H. mcmurrichi. Both species differ in the distribution and cnidom of nematocyst batteries in the column, development of microcnemes mesenteries, cnidae and geographical distribution. We find that H. pilatus can have a weak mesogleal marginal sphincter and amend accordingly the diagnoses of the genus Halcurias, family Halcuriidae, and suborder Endocoelantheae. These new records represent the first time both species have been collected since their original descriptions.
