Antennella

Description. Stems up to 9 mm high, arising from creeping hydrorhiza. Basal part, of variable length, divided by means of 2 – 3 transverse nodes; last node oblique; segments with up to 8 frontal nematothecae in two parallel, alternate rows. Remainder of caulus heteromerously segmented. Hydrothecate segments, up to 13 per stem, with proximal oblique node and distal transverse node; with one hydrotheca in middle part and up to 4 nematothecae: one median inferior and a pair of laterals; the 2 – 3 basalmost hydrothecae often with a supra-axillar nematotheca, arising a short distance above axil, rim not surpassing free adcauline wall (fig. 7 M). Intersegments, longer than segments, with 2 frontal nematothecae in a row parallel to stem axis. Hydrothecae nearly tubular, lateral walls parallel, rim circular, slightly everted. All nematothecae bithalamic; lateral nematothecae with circular rim, not scooped. Gonothecae not seen. Nematocysts: large microbasic mastigophores, in coenosarc and nematophores; microbasic mastigophores, in tentacles (for dimensions, see table 13).

Remarks. Antennella sp. comes very close to A. secundaria (Gmelin, 1791). However, there is no axillar nematotheca in the former, but some of its basalmost hydrothecae bear one nematotheca a short distance above the axil. Additionally, the cnidome of the latter contains several egg-shaped capsules of unidentified type, apparently not present in the former. In the absence of gonothecae, no positive identification of the present material could be made. A morphometrical comparison between Antennella sp. and A. secundaria is given in table 13.

Distribution. The present material originates from Les Saintes.

Material examined. Stn. 6: 23.03.2008 — numerous sterile colonies, up to 9 mm high, on Halimeda sp. and Caulerpa sp. (MHNG INVE 60984); 24.03.2008 — one sterile colony, ca. 9 mm high, on Caulerpa sp. Stn. 7: 25.03.2008 – numerous sterile stems, up to 6 mm high, on concretions and green algae. Type locality. Plage de Pompière, Terre-de-Haut, Les Saintes, Guadeloupe.