Umbrella bell-shaped, slightly higher than wide [Coryne prolifera ]; jelly moderately thick; margin quadrangular; velum broad. Four radial canals and ring canal narrow.
Manubrium small, cylindrical, 1/3 to 2/3 the length of bell cavity, not reaching beyond umbrella margin when fully extended. Mouth circular, simple.
Gonads continuous, surrounding manubrium leaving both ends free.
Four, very extensile, perradial marginal tentacles, with irregularly scattered nematocyst clusters. [C.prolifera-medusa ]. Marginal tentacle bulbs large and tapering, with one ocellus each; the bulbs are, even in young medusae, the site of prolific asexual budding.
Umbrella about 3 mm high and wide.
[C.prolifera-habitus ] Manubrium and tentacle bulbs sage green, yellowish brown or reddish brown; tentacle tips sometimes light reddish brown; ocelli black or brownish.
Ecology and depth range
In British waters taken in the plankton from April to October, occasionally also in March or November; usually becoming abundant in the latter half of this period.
Distribution in the North Sea
Southern and northern North Sea, English Channel.
Northwest European waters and the Black Sea.
[After Russell, 1950b; Russell, 1953a; Kramp, 1959]