Filellum

Galea, Horia R., 2010, Notes on a small collection of thecate hydroids (Cnidaria: Hydrozoa) from Tristan da Cunha, south Atlantic, Zootaxa 2336, pp. 1-18 : 4

Filellum spp.

( fig. 3A , B)

Material examined. Stn. T10, 15.ii.2005: numerous hydrothecae on Halecium cf. beanii (Johnston, 1838) , no coppinia. Stn. I10, 28.xi.2007: numerous hydrothecae on algae, no coppinia.

Remarks. The present material is unidentifiable in the absence of coppinia. The hydrothecae from Stn. T10 are slightly smaller than those from Stn. I10 (150–165 µm vs. 160–190 µm wide at aperture), though both are provided with striae on the upper surface of the adnate part of the hydrotheca. They could therefore belong to two different species.

Figures

FIGURE 3. A and B: Filellum sp. (material from station Stn. I 10) – portion of colony (A); hydrotheca (B). C: Halecium sp. – four erect stems. D: Halecium cf. beanii (Johnston, 1838) – fragment of monosiphonic part of stem with origin of a side branch. E and F: Halecium cf. delicatulum (Coughtrey, 1876), morphotype 1 – portion of stem (E); hydrotheca (F). G to P: Halecium? delicatulum (Coughtrey, 1876), morphotype 2 (part) – whole colony on piece of alga (G); cross section through the stolon (H); basal part of stem (I); portion of colony (J); various branching patterns (K – M); fragment of stem showing internodes (N); various shapes of primary hydrophores (O); gonotheca arising from primary hydrophore (P). Scale bars: 50 µm (H); 100 µm (F); 200 µm (B, F, O); 300 µm (A, E, I, P); 400 µm (D, K, L, M); 500 µm (N); 2 mm (J); 1 cm (G).