Some new Hydroidomedusa (Cnidaria) from the northern South China Sea Author Wang, Xuefeng College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China Author Lin, Kun College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China Author Xu, Zhenzu College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China Corresponding author, E-mail: guodh @ xmu. edu. cn Author Guo, Donghui College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China Corresponding author, E-mail: guodh @ xmu. edu. cn Author Huang, Jiaqi College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China Corresponding author, E-mail: guodh @ xmu. edu. cn text Zoological Systematics 2019 44 3 191 205 journal article 10.11865/zs.201923 2095-6827 5366458 DC69BC63-5B4D-4851-9A40-715353079BFC Family Corymorphidae Allman, 1872 Corymorphidae Bouillon et al. , 2006: 226–227 ; Schuchert, 2010: 377–378 ; Xu et al. , 2014: 366–367 . Diagnosis. The family is diagnosed by: medusa dome-shaped or with apical projection, no exumbrellar cnidocyst tracks, but sometimes long abaxial spurs of marginal bulbs; manubrium mostly not extending beyond umbrella margin, tubular to fusiform, mouth simple, circular; either only one fully developed marginal tentacles, or one fully developed tentacle and three shorter ones differing also in structure; four radial canals and four marginal bulbs present, ocelli lacking; gonad undivided surrounding all length of manubrium and exceptionally also in sac-like processes of manubrium ( Gotoea ). Remarks. The taxonomic history and synonymies see Calder (1988) , Petersen (1990) , Pagès & Bouillon (1997), Brinckmann-Voss & Arai (1998) , Bouillon et al. (2006) , Schuchert (2010) and Xu et al. (2014) . The family comprises 10 medusa genera: Corymorpha M Sars, 1835 , Gosta Huang, Xu & Lin, 2012, Eugotoea Margulis, 1989, Euphysora Maas, 1905 , Gotoea Uchida, 1927 , Mayeri Xu, Huang & Guo, 2012 , Octovannuccia Xu, Huang & Lin, 2010 , Paraeuphysilla Xu, Huang & Guo, 2011 , Paragotoea Kramp, 1942 and Yakovia Margulis, 1989 ( Bouillon et al. , 2006 ; Xu et al. , 2010 , 2014 ; Wang et al. , 2011 ; Huang et al. , 2012 ), of which 8 genera are reported in China seas. Key to the known genera (medusa) of family Corymorphidae . 1. With 8 radial canals.............................................................................................................................................................................. 2 With 4 radial canals.............................................................................................................................................................................. 3 2. With one developed marginal tentacle, ending in a large knob of cnidocyst, and three small marginal bulbs ....................................... ............................................................................................................................................ Octovannuccia Xu, Huang & Lin, 2010 * With 4 equally developed tentacles with numerous adaxial transverse cnidocyst claps and 1 small terminal cluster............................ .......................................................................................................................................... Paraeuphysilla Xu, Huang & Guo, 2011 * 3. With 1 fully developed marginal tentacle............................................................................................................................................. 4 Usually with 3 short or rudimentary marginal tentacles and one long, full developed marginal tentacle, different in structure ............ ....................................................................................................................................................................... Euphysora Maas, 1905 * 4. Exumbrella with longitudinal grooves or ridges and ribs.....................................................................................................................5 Exumbrella with uniform surface......................................................................................................................................................... 6 5. Exumbrella divided in 4 proximal leaf-shaped facets separated by 4 longitudinal large and deep grooves; umbrella without marginal bulb; one developed hollow marginal tentacle; without mesenteries ........................................................... Eugotoea Margulis, 1989 Exumbrella with 4 longitudinal ridges and ribs; umbrella with 3 marginal bulbs; with one well developed solid tentacle; with mesenteries.......................................................................................................................................... Costa Huang, Xu & Lin , 2012 * 6. Umbrella margin slightly oblique to vertical axis; one developed marginal tentacle, short and thick, ending in a large knob of cnidocysts and three small marginal bulbs ....................................................................................... Mayer Xu, Huang & Guo, 2012 * Umbrella margin at right angle to vertical axis ....................................................................................................................................7 7. Gonads on manubrium and on 4 sausages like interradial manubrium pouches ................................................ Gotoea Uchida, 1927 * Gonads simple; manubrium without interradial pouches .....................................................................................................................8 8. Fully developed marginal tentacle slender, long, moniliform; pointed apical process ............................. Corymorpha M. Sars, 1835 * Fully developed marginal tentacle ending in single cnidocyst capitation or in cluster of cnidocyst capitation; no pointed apical process ............................................................................................................................................................................................................9 9. Fully developed marginal tentacle with a terminal cnidocyst knob; with one tentacle and three non-tentacular bulbs.......................... ................................................................................................................................................................... Paragotoea Kramp, 1942 * Fully developed marginal tentacle with terminal ramifications ending in numerous cnidocyst cluster, with only one marginal bulb bearing tentacle ............................................................................................................................................... Yakovia Margulis, 1989 * Present in China Seas