(Gosse, 1853)
Description
Umbrella somewhat bell-shaped or hemispherical, usually wider than high; jelly thick, especially in apical region; velum broad. With four straight, unbranched radial canals and ring canal narrow; centripetal canals absent.
Gastric peduncle absent; manubrium small, 1/3 to 1/2 the length of bell cavity; mouth with four simple or slightly folded lips [G.corynetes-medusa ].
The four gonads form deep hanging pouches hanging from wide central section of each radial canal [G.corynetes-habitus ].
Marginal tentacles 24, large and solid, in four perradial and four interradial groups of three tentacles each; tentacles with hemispherical adaxial nematocyst pad; 8-16 small rudimentary marginal tentacles situated singly or in couples between the groups of larger tentacles; all tentacles with nematocyst rings, adhesive pads absent; without ocelli. Usually 24 internal statocysts imbedded in mesogloea on exumbrellar side of ring canal; 3 between adjacent groups of tentacles.
Size
Umbrella 12-16 mm wide, 8-10 mm high.
Colour
Manubrium greenish; mouth and gonads pinkish; marginal tentacles pinkish or yellowish-brown. Medusa appears fluorescent, changing from pink to green and yellowish-brown.
Ecology and depth range
Neritic. In British waters encountered in the last six months of the year, the young medusa probably released from the still unknown polyp in July and August.
Distribution in the North Sea
Probably only a visitor, carried into the North Sea through the English Channel; in water of at least 35 รค salinity.
World distribution
E North Atlantic Ocean.
[After Russell, 1953a; Kramp, 1959]