Orthopyxis crenataformis Watson, 2005

Hydrorhiza reticulating, stolons tubular, smooth with a narrow marginal flange strongly adherent to substrate. Hydrothecal pedicels erect, unbranched, variable in length, predominantly undulated throughout but some almost smooth, distal shoulder supporting spherule of smaller diameter than pedicel.

Hydrothecae deeply cylindrical, a few expanding slightly to margin, walls moderately and evenly thickened around circumference, basal chamber supporting a thickened platform of perisarc (diaphragm). Margin circular to slightly compressed with 8 -10 broad crenulations, embayments between of same size and shape as crenulations.

Gonotheca large, conical, compressed, recumbent to substrate, given off from hydrorhiza on a short, bent pedicel, body increasing in width to about one third distance up from base, then becoming more or less parallel to apex, walls mostly smooth, some with indentations, two or three thin longitudinal pleats extending downwards from apex, fading out proximally; apex transverse, truncate, without operculum. Blastostyle with one medusoid gonophore packed with large ova at maturity.

Perisarc of hydrorhiza and pedicels thick, perisarc of gonotheca fairly thin.

Colour: Colony transparent white, gonophores creamy-pink.