has been widely reported in all kinds of marine environment. A total of 286 names have been applied to taxa originally described in, or subsequently referred to, the genus. All such taxa published prior to 1985 have been accounted for below. Of these, some or all types of about 175 are available and are described below. Twenty-five species are incompletely known; types are missing and original descriptions (or subsequent descriptions of types) are insufficient to relate these species to the rest. The descriptions of these species have been briefly summarized. A key to species includes nearly all species for which types were available. Species considered incompletely known are excluded from the key, but are included when possible in a set of tables comparing similar species. Forty-seven named taxa are indeterminable. Twenty-two have been referred to other genera, including some new combinations. In some cases the type lot included two species; some of these types could be referred to other, known species; however, four species are described as new. Seven species have been given new names for nomenclatural reasons. Attempts to group the 206 reasonably well-characterized species into supra-specific taxa using cladistic techniques did not lead to interpretable results. The reasons might include the very large number of species compared to the number of characters. A detailed analysis of the characters has been started using freshly collected material in an attempt to expand the number of characters and measure the variability of currently used characters. Similar reviews are planned for the remaining eunicean genera.