Integrative systematics illuminates the relationships in two sponge-associated hydrozoan families (Capitata: Sphaerocorynidae and Zancleopsidae) Author Maggioni, Davide Author Schuchert, Peter Author Arrigoni, Roberto Author Hoeksema, Bert W. Author Huang, Danwei Author Strona, Giovanni Author Seveso, Davide Author Berumen, Michael L. Author Montalbetti, Enrico Author Collins, Richard Author Galli, Paolo Author Montano, Simone text Contributions to Zoology 2021 2021-11-02 90 487 525 http://dx.doi.org/10.1163/18759866-bja10023 journal article 10.1163/18759866-BJA10023 1875-9866 8343324 Family Sphaerocorynidae Prévot, 1959 Diagnosis: Colonies stolonal or erect; hydrocauli unbranched or sparingly branched, with terminal hydranths; perisarc thin, reaching hydranth; hydranth pyriform, with bulbous base and proboscis-like hypostome; no oral tentacles, but single, or partially fused capitate tentacles in whorls around broadest part of body; gonophores arising above or among tentacles as free medusae or fixed eumedusoids. Eumedusoid or free medusa with thick bell-shaped or conical umbrella; with or without apical projection, when present conical or dome-shaped, with broad apical chamber; manubrium flask-shaped, quadrate, or cruciform, mouth simple, round or cruciform; four tentacles, when present, with adaxial, evenly distributed, or spirally arranged nematocyst clusters, with a terminal, ellipsoid or spherical capitation; with or without abaxial ocelli; gonads adradial, confluent in perradii in mature specimens.