New species, new records and redescriptions of Thecate hydroids (Cnidaria: Hydrozoa: Leptothecata) from Southern Australia Author Watson, Jeanette E. text Zootaxa 2011 3122 1 36 journal article 45833 10.5281/zenodo.203966 473b918b-d698-4f39-bcbb-f19a2667753a 1175-5326 203966 Genus Ventromma Stechow, 1923 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.