Bythotiaridae

Zhenzu Xu, Jiaqi Huang, Mao Lin, Donghui Guo & Chunguang Wang, 2016, Taxonomic notes on Hydroidomedusae (Cnidaria) from South China Sea II: Family Bythotiaridae (Anthomedusae), Zoological Systematics 41 (2), pp. 149-157 : 151

Key to the genera of Bythotiaridae medusae of South China Sea.

1. Centripetal canals present, blindly ending or joining base of manubrium............................................................................................2

Without centripetal canals.................................................................................................................................................................... 3

2. All tentacles hollow; cnidocysts only in the terminal knob........................................................................... Calycopsis Fewkes, 1882

Two kinds of tentacles, large, hollow, with rings of cnidocysts and a terminal knob, and small, solid dwarf tentacles without terminal knob ................................................................................................................................................ Eumedusa Bigelow, 1920

3. Radial canals simple, unbranched ........................................................................................................................................................4

Radial canals branched; gonads folded or smooth ...............................................................................................................................6

4. Gonads smooth adradial ............................................................................................................................ Pseudotiara Bouillon, 1980

Gonads smooth interradial ...................................................................................................................................................................5

5. 8 radial canals; marginal tentacles with abaxial basal ocelli ........................................................................... Bythocellata Nair, 1951

4 radial canals; no ocelli............................................................................................................................. Protiaropsis Stechow, 1919

6. Radial canals branching repeatedly at various levels ........................................................................................... Sibogita Maas, 1905

Radial canals simple or bifurcated .......................................................................................................................................................7

7. 4 radial canals simple or bifurcated; gonads interradial, with transverse furrows; marginal bulbs absent ..... Bythotira Günther, 1903

2 simple and 2 bifurcated radial canals; gonads smooth perradial; marginal tentacles with basal swellings embedded in mesoglea .... ..................................................................................................................................................... Gymnogonium Xu & Huang, 1994