[Introduction as:]
In 1911 the present author published a paper entitled "Polychaetous Annelids from the Dry Tortugas, Florida." This was the first of a proposed series of systematic papers on the polychaetous annelids of the West Indian region, collected under the auspices of the Department of Marine Biology of the Carnegie Institution of Washington, my main object having been the preparation of a monograph of the West Indian Leodicidae. It has seemed best, since the final publication must be deferred, to publish a preliminary description of some new species belonging to this family, as well as new species of other families which have been collected incidentally in this work. I have included also a description of a new sabellid belonging to the collection of the American Museum of Natural History.