Thyroscyphus torresii (Busk, 1852)

Hydrorhizal stolons tightly entwining substrate. Clusters of up to 20 pinnate stems to 100 mm high arising from hydrorhiza, basal stem region lightly fascicled by hydrorhizal stolons, stems thereafter monosiphonic, tubular, stiff and robust, perisarc of basal region very thick and smooth, thinning distally.

Hydrocladia pinnate, alternate, well separated, long, no secondary branching, two alternate hydrothecae on stem between each branch and one axillar. Stem and hydrocladial internodes fairly long, nodes slightly oblique to transverse, marked by a notch in perisarc. Hydrocladial apophysis long, inclined upwards, proximal side marked by an indentation in perisarc in stem; first hydrocladial internode long, internodes shorter thereafter, nodes transverse, usually distinct.

Hydrothecae alternate, pedicel short, thick, smooth or with several ridges; hydrotheca asymmetrical, abcauline wall straight, proximal third of adcauline wall convex, the curve straightening out distally, diaphragm distinct, down-curved, often asymmetrically tilted , hydrothecal margin circular, rim quadrate with four low, equidistant, sharply pointed cusps separated by four shallow emarginations; operculum thin, of four triangular flaps.

Hydranths stubby, with at least 30 tentacles.

Gonothecae immature, top -shaped, arising in proximal stem region beside a hydrotheca or on stem, hydrocladium or apophysis from which a hydrotheca has been shed; perisarc thin.

Colour: Golden-yellow to golden brown.