Halopteris diaphana (Heller, 1868)

(fig. 8E)

Anisocalix diaphanus Heller, 1868: 42, pl. 2 fig. 5.

Halopteris diaphana — Schuchert, 1997: 47, fig. 15.— Ansín Agís et al., 2001: 163, fig. 69.— Peña Cantero & García Carrascosa, 2002: 102, fig. 19A–D.

Halopteris constricta — Migotto, 1996: 44, fig. 9A–C (not Halopteris constricta Totton, 1930: 217, fig. 56A).

Material examined. Stn. 3: 01.04.2008 —a few sterile stems, up to 8 mm high, on concretions. Stn. 7: 27.03.2008 —a few sterile colonies, up to 6 mm high, with both Antennella -like and pinnate stems, on algae and concretions.

Type locality. Capocesto, Croatia, Mediterranean.

Remarks. Though sterile, this species is recognizable by the heteromerous segmentation of the stem, the presence of generally 2 (rarely 3) nematothecae on cauline segments, and the occurence of Antennella -like stems in some colonies, as for instance those observed in the material from Stn. 7. For a complete description of H. diaphana and its synonymy, see Schuchert (1997).

Distribution. Circumtropical (Peña Cantero & García Carrascosa 2002). For a detailed list of records, see Ansín Agís et al. (2001).