Corydendrium parasiticum (Linnaeus, 1767)

Stems consisting of a bundle of fascicled, irregularly branched hydrocauli; branching of three orders more or less in same plane by forking of perisarc tubes. Adnate tubes proximally narrow, free part diverging at an acute angle to stem; perisarc thick, wrinkled, corrugated to almost smooth.

Hydranths with approximately 20 long tentacles scattered over body.

Cnidome:

i) Microbasic euryteles in tentacles, capsule 9.5-10.5 x 4.5-6.5 µm, shaft 7 µm, tubule proximally thick with 4 spirals of fine spines; few discharged, not common.

ii) ?Desmonemes, capsule ovoid, 5 x 4.5 µm; rare, none discharged, not common.

Colour: Pale honey brown.