Ventromma

Colony erect, branched or unbranched, arising from a creeping hydrorhiza, hydrocladia unbranched, alternate. Hydrotheca only on hydrocladia, cup-shaped, without intrathecal septum, with even rim; nematothecae two-chambered, hydrothecate internode with a median inferior and a median superior nematotheca, no lateral nematothecae; gonophores fixed sporosacs, gonotheca solitary with transverse annulations.