Halecium tenellum Hincks, (1861)

Watson, Jeanette E., 2012, Some hydroids (Hydrozoa: Hydroidolina) from Dampier, Western Australia: annotated list with description of two new species., Memoirs of Museum Victoria 69, pp. 355-363 : 357

Halecium tenellum Hincks, (1861)

Figure 1E– G

Halecium tenellum Hincks, 1861a: 252 , pl. 6, figs 1–4.– Vervoort, 1959: 229, fig. 8.– Vervoort, 1966: 102, fig. 2.– Millard, 1975: 156, fig. 50F–L.– Vervoort and Watson, 2003: 98, fig. 19A, B.

Material examined. WAM Z31849. Abundant infertile colonies on Eudendrium racemosum ; one microslide, malinol mount.

Description. Hydrorhiza creeping on host, stolons tubular, undulating. Hydrocaulus monosiphonic, cylindrical, variable in length, mostly unbranched but some branched once or twice. Hydrophore smooth, cylindrical, a few transverse proximal septa marking site of branching from below or within a hydrotheca; hydrophore expanding slightly to below hydrotheca. Hydrotheca shallow dish–shaped, expanding to margin, rim strongly outrolled, diaphragm transverse, a row of desmocytes above, no marginal replications. Perisarc smooth, thin.

Figures

Figure 1A–G. A. Eudendrium racemosum from photograph of whole colony. B. Filellum serratum, regenerated hydrotheca. C, D. Lafoeina amirantensis. C, small hydrotheca and nematotheca on hydrorhiza. D, large hydrotheca. E–G. Halecium?tenellum. E, unbranched stem. F, basally annulated hydrophore. G, hydrotheca with strongly everted rim and desmocytes. Scale bar, mm: A, 20. B, C, E, F, G, 0.2. D. 0.1.