(Fig. 3C)
Staurotheca pachyclada —Peña Cantero & Vervoort, 2003: 2698 –2702, figs 14–15 (synonymy).
Material examined. 29EV55 , a stem 300 mm high (IK–2009–0370).
Description. Stem erect, polysiphonic, 300 mm high, with some perisarc constrictions. Branching only present in upper half of stem, alternate, almost in one plane. Branches up to third order present, narrowed basally. Hydrothecae present over entire colony, but only visible in monosiphonic parts. Hydrothecae arranged in verticils of three hydrothecae, forming siX longitudinal rows. Hydrotheca cylindrical (Fig. 3C), immersed into branch for two-thirds of its volume. Hydrothecal aperture circular, forming an acute angle with long aXis of stem.
Ecology and distribution. Our material was collected at depths between 471 and 499 m in George V Basin.
Circum-Antarctic distribution (Peña Cantero & Vervoort 2003).