Thyroscyphoides sympodialis Watson, 2003

Description from holotype:

Hydrorhiza tubular, rather contorted, reptant on substrate. Stems simple, to 12 mm high, proximal part of stem of same diameter as stolon; basal-most part of stem with 2 to 4 broad, indefinite annulations, stem thereafter sympodial, sometimes a side branch given off from lower stem. Internodes long, smooth, tubular, becoming shorter along stem, widening distally to below hydrotheca; nodes usually with 1 or 2 deep, oblique constrictions almost parallel with adcauline wall of hydrotheca, a slight tumescence in perisarc above node, sometimes 1 or 2 additional constrictions along internode.

Hydrothecae alternate, arising just below node, body tubular, wide, most sessile but some pedicellate; in sessile hydrothecae abcauline wall smoothly contiguous with outward bend of internode, free adcauline wall smooth, weakly convex to almost straight, a short length of wall adnate to internode; floor of hydrotheca flat, saucer-shaped or funnel-shaped (depending upon angle of view), hydropore slightly offset, fairly wide, a row of desmocytes above marking place of attachment of hydranth. Pedicellate hydrothecae arising from floor of a broken hydrotheca; pedicels of variable length, smooth to corrugated with some internal thickenings; floor of hydrothecae rounded to sinusoidal. In both forms, hydrothecal margin almost circular (anterior view) with 4 sharply pointed triangular cusps separated by deep embayments; operculum of 4 thin pyramidal valves.

Hydranth without diverticulum, but with a distinct annular fold; hydranth with c. 20 tentacles.

Perisarc of lower stems comparatively thick, thinning apically along internodes, hydrothecal margin and operculum extremely thin and fragile.

Colour: Transparent, colourless.