Corymorpha nana Alder, 1857
Corymorpha nana Alder, 1857: 108, pl. 9 figs 7, 8; Kramp, 1949: 184, 189, fig. 7b; Svoboda & Stepanjants, 2001: 58, 59, 60.
Polyp 20-25 mm high, with thin, membranous perisarc on pedicel, which is basally attached in sediment with fine attachment filaments and apically separated from hydranth by a constriction. Hydranth body with 15-25 proximal (aboral) tentacles, 5-7 mm long; distal (oral) tentacles number 16-18 and are placed in one whorl. Ten-15 blastostyles in a whorl on hydranth body above proximal tentacles, unbranched, stubby, with a small number (4-5) of gonophores developing into free medusae with one fully developed tentacle and 3 tentacle rudiments (description mainly taken from Bonnevie, 1899). Distribution: dispersed localities in the North Sea and along the coast of southern Norway. The medusa phase of this species is insufficiently known.