Sea Pens (Cnidaria: Octocorallia: Pennatuloidea) From The Mar Del Plata Submarine Canyon And Outskirts Author Risaro, Jessica Museo Argentino de Ciencias Naturales, “ Bernardino Rivadavia ” - CONICET. Av. Ángel Gallardo 470, Buenos Aires, Argentina. Author Abstract, Daniel Lauretta text Zootaxa 2023 2023-12-21 5389 4 401 433 https://www.mapress.com/zt/article/download/zootaxa.5389.4.1/52527 journal article 10.11646/zootaxa.5389.4.1 1175-5326 10417392 E192E86A-185D-4FEE-B978-30248ADE6CC5 Family Umbellulidae Lindahl, 1874 Diagnosis (adapted from Williams 1990 ): Long and slender rachis. Conspicuous autozooids growing in the distal region of the rachis forming a terminal cluster. Siphonozooids are little dots located all along the rachis and at the base of the autozooids. Axis quadrangular or X-shaped in cross-section. Sclerites present in all tissues or completely absent, with diverse morphology (bare-shape, needles or three-flanged spindles), in all cases circular in cross-section. Included genera: Umbellula Cuvier, 1798 . Type genus: Umbellula . Distribution: Cosmopolitan. From about 400 m to more than 6000 m depth (Williams 2011). Umbellula Cuvier, 1798 Type species: Isis encrinus Linné, 1758 . Valid species (after López-González & Drewery 2022 ): Umbellula encrinus ( Linné, 1758 ) ; Umbellula thomsoni Kölliker, 1874 ; Umbellula carpenteri Kölliker, 1880 ; Umbellula huxleyi Kölliker, 1880 ; Umbellula magniflora Kölliker, 1880 ; Umbellula pellucida Kükenthal, 1902 ; Umbellula spicata Kükenthal, 1902 ; Umbellula dura Thomson & Henderson, 1906 ; Umbellula rosea Thomson & Henderson, 1906 ; Umbellula antarctica Kükenthal, 1902 ; Umbellula hemigymna Pasternak, 1975 . Diagnosis: Same as the family. Distribution: Same as the family. Nomenclatorial remark: Originally Cuvier (1798) create the genus Ombellula . In 1800 he started to use the name Umbellula for Umbellula encrinus and some other species of the genus, so this name started being used for other authors instead of Ombellula ( Cuvier, 1800 ) . This variation of the name was maintained during more than 150 years. Williams (1995) detected the change and used the original spelling. Due to Umbellula was fully accepted for authors and Ombellula hasn’t been used again since its first mention, a request to the International Commission of Zoologic Nomenclature was made to give priority to spelling Umbellula over Ombellula ( Bayer & Grasshoff 1997 , case 2999). This request was accepted and the current valid spelling for the genus name is Umbellula Cuvier, 1798 .