Table 2 in Umbellula pomona sp. nov., a new sea pen from Mar del Plata Submarine Canyon (Cnidaria: Octocorallia: Pennatulacea)

Table 2 Comparative descriptions of the spiculated species of Umbellula Cuvier, 1798 and known distribution of each species.
SpeciesPolyp’s size (mm)Maximum number of polyps in the clusterCluster shape (data taken from original descriptions)Axis form in cross sectionMeasurements of scleritesDistribution / depth (m)Umbellula thomsoni * Kölliker, 187415–2010Polyps distributed in a circle, forming an ‘umbrella’.Quadrangular near the terminal cluster and becoming cylindrical to the peduncle.Rachis, polyps’ column and base of the tentacles: <300 μm. Terminal section of tentacles and pinnules: 500–1300 μm. Peduncle: 80–110 μm (ovals).Cosmopolitan / 1300–6200One terminal and large polyp, twoPolyps and tentacles: 2000–2800 μm.Umbellula durissima * Kölliker, 1880215undeveloped ones. Two or three small and undeveloped polyps.Cylindrical in all its extension.Distal zone of rachis: 190–260 μm. Proximal zone of rachis: 76–200 μm.North Pacific Ocean, south of Tokyo Japan / 1000Umbellula dura * Thomson & Henderson, 1906–3–6In juvenile, one central and smaller polyp and two lateral ones. In developed states, four large and two small autozooids.Cylindrical in all its extension.Polyps: 140–1500 μm. Rachis: 140–110 μm (X-shaped).Indian Ocean / 1300Umbellula rosea * Thomson & Henderson, 1906125Two pairs of lateral polyps (2 and 2) and one terminal.Quadrangular in all its extension.Polyps: 220–300 μm. Rachis: 90–160 μm (ellipses).Indian Ocean / 3200Umbellula monocephalus Pasternak, 1964401Formed by a unique terminal polyp.In the original description of the species and different tabular keys don’t specify the form of its internal axisIn the original description of the species and different tabular keys don’t specify the dimensions of its sclerites.Indian Ocean and Atlantic Ocean / 4635–4700Umbellula pomona sp. nov.363One central terminal polyp and one pair of lateral, smaller polyps growing from the base of the central one. All of them are completely developed.Cylindrical in all its extension.Polyps: 490.6–1413.3 μm. Rachis: 262.4–404.6 μm. Tentacles: 536.6–1503.3 μm. Pinnules: 218.8–319.4 μm.38º5.310′ S, 53º39.988′ W Southwestern Atlantic Ocean / 3300
Some authors consider U. dura as a synonym of U. durissima and U. rosea as a synonym of U. thomsoni (Broch 1958)