Clytia linearis (Thornely, 1900)

Hydroid: colonies reptant, up to 40 mm high, bearing erect pedicels unbranched or subsympodially branched; pedicels and branches ringed basally and distally, topped by hydrothecae; branches arising laterally, at the upper part of the axis; hydrothecae very deep, cylindrical, sides almost parallel, narrowing basally, with a thin diaphragm, straight or slightly oblique; margin wide, 10-12 acute cusps with characteristic longitudinal central perisarcal band or ridge extended further of the cusps. Gonothecae usually axilar, borne on short and ringed pedicels, elongate-oval, truncate distally, narrow sub-distally and basally; enclosing up to eight developing medusa buds.
New born medusa: umbrella hemispherical, with ring canal, four perradial canals; four perradial bulbs with tentacles; four interradial developing bulbs; 4-8 adradial statocysts, each with one statolith. Gonads on median region of radial canals. Manubrium quadrate or laterally collapsed, -0.5 height of bell; lips smooth. Velum broad. Tentacles hollow, with a terminal nematocyst cluster of nematocysts.
Adult medusa: umbrella almost flat when relaxed (max diameter: almost 4 mm); bell margin with up to 29 bulbs with tentacles, and 28 statocysts, each with one statolith. Gonads oval on distal half of radial canals.
Manubrium long, cruciform, with four simple lips. Marginal tentacles hollow, long, with a terminal cluster of nematocysts; other clusters, with nematocysts also found along the tentacles. Exumbrella without nematocysts. Bell transparent; gonads, manubrium, bulbs and tentacles assuming the colour of food.