Idiellana lepida Watson, 2000

Hydrorhiza tubular, thick, entwining substrate.

Stems to 90 mm long, monosiphonic, gracefully plumose, proximal part of stem long, ahydrocladiate, nodes if present, transverse, faint; lower stem perisarc thick, thinning distally; two rows of opposite hydrothecae on stem, a distinct internal coenosarc tube running up centre of ahydrocladiate stem region.

Hydrocladia alternate, close-set, up to 15 mm long, borne on a short, distinct apophysis directed upwards at an angle of 40° to cauline axis, distal apophysal node a transverse constriction, this followed by an athecate internode with strong hinge joint. Most hydrocladia unsegmented; if segmented, internodes with at least four pairs of hydrothecae, nodes strongly oblique, constricted.

Hydrothecae biseriate, paired, not protruding, tubiform, base of one of pair sometimes slightly displaced downwards with respect to other, each pair slightly overlapping that above, adcauline walls in contact, straight to convex, free length of adcauline wall minute, adcauline wall slightly inturned at base, ending in a small knob of perisarc, abcauline wall almost straight, a small internal submarginal thickening in perisarc. Cauline hydrothecae alternate, same as those on hydrocladia but separated laterally and vertically, one beside apophysis and two or three in a row above. Margin of hydrotheca facing outward and tilted slightly upwards; margin with two prominent ear-shaped lateral cusps, perisarc thin, aperture oval. Operculum a single very thin adcauline valve.

Hydranth without caecum and with 16 - 20 tentacles.

Gonothecae abundant throughout hydrocladiate part of stem, borne on caulus or hydrocladia; cauline gonotheca inserted just above hydrocladial apophysis, hydrocladial gonothecae proximal on hydrocladia, arising behind hydrothecal pairs; gonotheca standing erect on a long, bent pedicel with basal constriction or twist, body large, barrel-shaped, faintly undulated to almost smooth, narrowing to a short, wide, slightly outturned collar, operculum a low domed plug. Perisarc of gonotheca very thick, distal collar of thick, rough strands.

Colour: Pale brown.