Holotype: TM K1716, TM K1698, CSIRO F.R.V. “Southern Surveyor” Cruise SSO1/97, Stn 6, 44 27°S 147.07°E to 44.27°S 147.11°E, depth 1110 m, 76.7 km SSE of South East Cape, Tasmania. Part of fertile stem 35 mm high bearing two corbulae; microslides MV F83464 & 83465, RMNH-Coel. 29010, slide 4460, from holotype colony.
The hydrocladia arise from several frontal tubes of the stem. Cauline nodes are sometimes absent, but when present are well marked by a constriction in the perisarc. In anterior view many of the supramarginal hydrothecal cusps show several overlapping replications, these probably representing punctuations to growth of the hydrotheca.
The species name is taken from the latin adjective “lepidus”, pretty, and refers to the graceful appearance of this new species.
Stem plumose, lightly fascicled, polysiphonic tubes almost parallel, running to top of stem. Cauline internodes long, node an indistinct transverse constriction in perisarc; three nematothecae unlike laterals on cauline internode, broad, saccate, one at base of hydrocladium, with orifice facing toward hydrocladium, one opposite hydrocladium, with orifice facing away from hydrocladium, and one behind hydrocladium.
Hydrocladia given off from frontal tube of stem, up to 18 mm long, lax; internodes long, nodes transverse, distinct; five equidistant partial intranodal septa passing into internode from base of hydrotheca, proximal septum oblique, originating beneath a notch in base of hydrotheca, followed by three more or less transverse septa, the fifth (sometimes absent) at base of lateral nematotheca.
Hydrotheca slipper-shaped, laying along internode, divided into an anterior and posterior chamber by a long diagonal blade-shaped septum passing from the basal notch in floor to anterior margin; hydrotheca rounded posteriorly, with posterior abcauline wall convex, becoming flatly convex to slightly sinuous.
Mesial nematotheca less than half length of hydrotheca, free part short, abcauline wall convex, terminal orifice large, circular, a secondary orifice of similar size just above hydrotheca, the two sometimes coalescent. Lateral nematothecae long, tubular, almost straight, extending just beyond hydrothecal margin, terminal orifice canaliculate, extending back to internode or sometimes comprising two discrete circular orifices. Hydrothecal margin almost perpendicular to internode with sharp apex of intrathecal septum overtopping a broad tongue-shaped anterior cusp, followed by four pairs of cusps: the first pair bluntly pointed, symmetrical, the second and third pairs symmetrical, taller, the fourth pair larger, hatchet-shaped, obscured behind lateral nematothecae.
Corbula replacing a hydrocladium; peduncle long, proximal internode with one hydrotheca, following internode with a nematotheca and a short distal branch bearing a single hydrotheca and two transverse nodes distal to the branch; rachis thereafter cladiate, rachial nodes transverse, indistinct. Corbula closed, straight, each side with seven to nine imbricated, unfused nematocladia; a long, free nematocladium arching outward near distal end of corbula.
Nematocladia bifurcated into two jawbone- shaped segments, distal segment the smaller having two abaxial nematothecae and a long narrow opening along distal margin; larger segment recurved to form roof of corbula, with three (or more) adaxial nematothecae, one nematotheca in axil between segments. Margins of nematocladial nematothecae deeply excavated, a hydrotheca with reduced marginal cusps and two lateral nematothecae at base of each nematocladium, a nematotheca between posterior wall of hydrotheca and base of nematocladium.
Colour: Pale brown.
Tasmania.
Deep water sea mounts.