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Taxon
Nemertesia cylindrica (Kirchenpauer, 1876)
Nomenclature
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Family: PlumulariidaeGenus: Nemertesia
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Synonyms: 1
SUMMARY
Colonies to 200 mm high, up to 30 stems arising from a large fibrous, hydrorhizal mat up to 50 mm wide; stolons also enmeshing basal region of stems in a spongy sheath.
Stems erect, long, monosiphonic, single or forked at an acute angle more or less in the same plane, internodes thick, short, nodes transverse, deeply incised in proximal and distal stem regions, often indistinct in mid-stem region.
Hydrocladia crowded, arising at an acute angle in verticels of up to eight around each internode, reducing to four or five in distal stem region. Apophyses with a short, slightly oblique, often indistinct node, a truncated tubular mamelon on adcauline side. Hydrocladial internodes long, straight, nodes distinct, slightly oblique, sometimes replicated.
Hydrotheca occupying more than half of internode, tubiform, adcauline wall completely adnate, weakly convex, posterior wall slightly convex to straight, abcauline wall slightly sinuous, margin circular, cut obliquely away to join internode.
Mesial inferior nematotheca seated on a prominence of the internode, lying along internode to touch base of hydrotheca, bithalamic, basal chamber long, tapering, freely movable, cup deep, excavated on adcauline side; lateral nematotheca bithalamic, seated on a minute pedicel at hydrothecal margin, basal chamber short, inflated, side of cup deeply excavated and closely adpressed on side facing hydrotheca, obscuring hydrothecal margin. Cauline nematothecae same as mesials, one on each side of stem internode, just proximal to node, two or three flanking mamelon at base of apophysis.
Female gonothecae large, distributed along entire length of stem, several on internode, upwardly tilted, without pedicel, irregularly saccate to sausage-shaped (depending on angle of view), perisarc moderately thick, up to eight nematothecae similar to laterals distributed a long frontal margin, orifice distal, subcircular to elongate, flanked by two blunt lateral lobes, orifice closed by a sheet of tissue, gonotheca containing three globular planulae.
Colour: Stems of live colonies dark shining brown, hydrocladia and gonothecae paler brown to almost white.