SEM study of species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa, Kirchenpaueriidae), with an annotated checklist of the species of the genus Author Molinero, A. González Author Peña Cantero, A. L. text Zootaxa 2015 4052 4 401 441 journal article 10.11646/zootaxa.4052.4.1 93f6d085-8e63-4d1e-89c1-f950128b2a61 1175-5326 245887 47EF6E9D-9064-4899-B3DD-276FF7C969EB Oswaldella elongata Peña Cantero, García Carrascosa & Vervoort, 1995 ( Figs 3 , 16 C, 17C, 19C) Material examined. Spanish Antarctic Expedition Antártida 8611 : Stn 161 , 14 December 1986 , 54°53.80'– 54°54.60'S , 34°49.60'– 34°47.70'W ( South Georgia , Clerke Rocks), 150–250 m (Department of Zoology, University of Valencia, ANT 161); Stn 182 , 18 December 1986 , 54°33.60’– 54°33.40’S , 35°48.20’– 35° 44.40’W ( South Georgia ), 86–176 m (Department of Zoology, University of Valencia, Coel. n° 3/ANT 182). Description. Monosiphonic, unbranched stems, up to 210 mm high, divided into internodes. Angle between cauline apophyses and stem ca. 45°. Cauline apophyses with four nematophores: two axillary ones, each emerging through slot-shaped hole in the perisarc, and other two nematophores, each emerging through “mamelon” ( Fig. 3 B–C). Hydrocladia bifurcated ( Fig. 3 A). First hydrocladial internode bifurcated, with two similar prongs ( Fig. 3 A). Mesial inferior nematophore emerging from strongly marked swelling at proximal third of internode ( Fig. 3 D–E); deprived of nematotheca ( Fig. 3 D–E). Hydrotheca elongate, tubular, placed on middle of internode ( Fig. 3 A, D–E). Adcauline wall mostly adnate ( Fig. 3 D–E). Abcauline hydrothecal wall slightly convex. Hydrothecal aperture circular, even and adcaudally directed ( Fig. 3 E). Gonothecae unknown.