(b) Tentacles capitate, simple; type of Coryne and Syncoryne; Myriothela is an aberrant form with some of the tentacles modified as “claspers” to hold the ova.
(c) Tentacles capitate, branched, wholly or in part; type of Cladocoryne.
(d) Tentacles filiform or capitate, tending to be arranged in definite whorls; type of Stauridium (fig. 2), Cladonema and Pennaria.
2. Hydranth more shortened, daisy-like in form, with two whorls of tentacles, oral and aboral.
(a) Tentacles filiform, simple, radially arranged or scattered irregularly; type of Tubularia (fig. 4), Corymorpha (fig. 3), Nemopsis, Pelagohydra, &c.
(b) Tentacles with a bilateral arrangement, branched tentacles in addition to simple filiform ones; type of Branchiocerianthus.
3. Hydranth with a single circlet of tentacles.
(a) With filiform tentacles; the commonest type, seen in Bougainvillea (fig. 13), Eudendrium, &c.
(b) With capitate tentacles; type of Clavatella.
4. Hydranth with tentacles reduced below four; type of Lar (fig. 11), Monobrachium, &c.