The Hydrozoan Taxa (Cnidaria) of Addison Emery Verrill (1839–1926), with a Checklist of His Records of Hydroids and Hydromedusae

Abstract A review is given of the zoological names and current taxonomic status of two genera and 21 species-group taxa of hydroids attributed in this work to Addison Emery Verrill of the United States. Information is provided on type localities of his new species, and on locations and kinds of type material known to exist. The genus Blastothela Verrill, 1878 is held to be congeneric with Candelabrum de Blainville, 1830, and its type species, B. rosea Verrill, 1878, is provisionally assigned to the synonymy of C. phrygium (Fabricius, 1780). Syntypes of Halecium robustum Verrill, 1873a, once thought lost, have been rediscovered at the Peabody Museum of Natural History at Yale University and the Smithsonian National Museum of Natural History, and an earlier neotype designation of the species is set aside. Sertularia achilleae Verrill, in Coues and Yarrow, 1878, a widely overlooked nominal species, is taken to be conspecific with Tridentata marginata (Kirchenpauer, 1864). Sertularia carolinensis Verrill, 1872b, another poorly known species, is recognized as valid and a senior synonym of Thuiaria plumulifera Allman, 1877. A review is given of the taxonomic and nomenclatural status of the polyseriate sertulariid genera Pericladium Allman, 1876 and Polyserias Mereschkowsky, 1877. Authorship and date of the binomen Laomedea angulata, usually attributed to Thomas Hincks with a date of 1861, is shown to have been made available earlier by Hincks in an 1859 article. Plumularia gracillima G.O. Sars, 1873, assigned at present to the halopteridid genus Polyplumaria G.O. Sars, 1874, is taken to be a plumulariid. It is provisionally returned to Plumularia Lamarck, 1816, although that genus is considered polyphyletic and in need of revision. Bibliographic work was undertaken to determine, as accurately as possible, dates of publication of the 47 papers authored by Verrill containing information on hydroids and hydromedusae. An annotated checklist of 138 species of hydrozoans reported in those works, including 47 anthoathecates, 90 leptothecates, and 1 trachymedusa, is included as an appendix.