Diphasia digitalis Busk, (1852)

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 : 359

Diphasia digitalis Busk, (1852)

Figure 3B, C

Sertularia digitalis Busk, 1852: 387 , 393.

Diphasia digitalis (Busk) .– von Lendenfeld, 1885a: 415, 633.– Bale, 1884: 101.– Bale, 1915: 265.– Jäderholm, 1920: 4.– Billard, 1931: 249.– Vervoort, 1972: 99.– Pennycuik, 1959: 191.– Millard, 1975: 257.– Watson, 1996: 78.– Watson 2000: 14, fig. 10A, B.– Schuchert, 2003: 166, fig. 25.

Material examined. WAM Z31867. Two broken infertile stems, the longer 22 mm; microslide, malinol mount.

Description. Hydrorhiza creeping, stolons tubular. Stems sparingly branched, proximal athecate stem segment long, tubular, with a strong distal hinge joint. Hydrothecae paired, one pair per internode, nodes transverse, indistinct to absent, marked only by a narrowing of internode. Hydrotheca long, tubular, expanding from base to margin, free adcauline wall convex, abcauline wall concave. Margin quadrangular, with a low abcauline cusp and an indistinct longitudinal pleat extending downwards from margin, fading out near base of hydrotheca. Remains of operculae visible inside many hydrothecae. Perisarc smooth.

Figures

Figure 3A–D. A. Hebella costata. Hydrotheca with proximal corrugations. B, C. Diphasia digitalis. B, branched stem. C, stem internode with opposite hydrothecae. D. Halopteris glutinosa. Hydrocladial athecate and thecate internodes. Scale bar, mm: A, 0.5. B, 1.0. C, D, 0.25.