FIGURE 3. A–D. Lygdamis nasutus n in Sabellariidae from Lizard Island, Great Barrier Reef, including a new species of Lygdamis and notes on external morphology of the median organ

FIGURE 3. A–D. Lygdamis nasutus n. sp., holotype, AM W.47372, preserved. A. Operculum, thoracic and parathoracic chaetigers, lateral view; arrowheads point to notopodial cirri; B. Anterior end, ventral view; C. Same, dorsal view; D. Same, but with exposed well-developed median organ. E–F Paratype AM W.44467. E. Detail of median organ, dorsal view; F. Cross section of paratypes, showing half of the operculum with whole median organ. Abbreviations: br = branchia, bo = building organ, cn1 = cirrus neuropodia segment 1, chn1 = chaetae neuropodium segment 1, dc = dorsal cirrus, es = eyespots, ip = inner paleae, li = lips, m = mouth, mo = median organ, nh = nuchal hook, op = outer paleae, opa = opercular papillae, pa = palp, rtf = row of tentacular filaments, tf = tentacular filaments. Small arrow indicates conical dorsal cirrus. Photo: A–D—E. Wong.