original description
Agassiz, L. (1862). Contributions to the natural history of the United States of America. <em>Little Brown, Boston.</em> 4: 1-380, pls 1-19., available online at https://www.biodiversitylibrary.org/page/16068829
page(s): 350 [details]
basis of record
Bouillon, J.; Boero, F. (2000). Synopsis of the families and genera of the Hydromedusae of the world, with a list of the worldwide species. <i>Thalassia Salent. 24</i>: 47-296 (look up in IMIS) [details]
Present Inaccurate Introduced: alien Containing type locality
From editor or global species database
Diagnosis Medusa with marginal cordyli, cordyli with or without nematocysts; with or without marginal cirri; with four or eight simple radial canals; marginal tentacles hollow; gonads on radial canals, on radial canals and lobes of manubrium, or on manubrial pouches; with or without adaxial ocelli; without statocysts.
Hydroid colony stolonal, hydrotheca sessile, tubular, turning gradually into a pyramidal operculum formed by numerous converging flaps, with visible crease-line basally; hydrotheca often with transversal growth-rings, sometimes with basal constriction at origin, or exceptionally a poorly delimited pedicel; hydranth without intertentacular web, tentacles amphicoronate; gonotheca like hydrotheca but larger. [details]
From editor or global species database