Hydroids (Cnidaria, Hydrozoa) of the Danish expedition to

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204 apophyses demarcated by node; hydrotheca usually less curved (60°) with opening inclined towards above, margin usually sinuous. Measurements: hydrothecal opening diameter 0.18–0.21 mm, free adcauline part 0.28–0.31 mm, adnate part 0.50–0.55 mm. Large isorhiza (49) x (12– 13) µm, smaller isorhiza 24 x 6 µm. Description of gonotheca Only male gonothecae seen, develop inside hydrocladial hydrothecae, pod-shaped, flattened, 1.7 mm long, diameter in middle 0.7 mm, pedicel inserted at right angle slightly above lower end, broad sides gently undulated, upper end pointed with small opening. P. SCHUCHERT Fig. 55. Synthecium campylocarpum Allman, 1888. A. Colony silhouette, note apical tendril on second hydrocladium on right. B. Internodes of distal part of stem. C. Typical hydrothecae. D. More rare hydrothecae with sharper bend; from same colony and scale as shown in C. E. Hydrothecal margin with typical sinuous outline. F. Pair of male gonothecae, twisted so that broad sides are in plane of view, same scale as B. – Scales: A = 1 cm; B & F = 0.5 mm; C-D = 0.2 mm; E = 0.1 mm. Female gonothecae not seen, according to Ralph (1958) and Watson (2000) resembling the one of S. orthogonium. Remarks The identification of this material as Synthecium campylocarpum was largely influenced by Watson (2000), but I am not sure whether the differences from S. orthogonium are significant or represent intraspecific variation due to larger grown colonies. The material strongly resembles S. orthogonium and the traits of the trophosome used to distinguish it from the latter species are given in the section “Differential diagnosis”. The most important differences are the larger
HYDROIDS OF THE DANISH EXPEDITION TO THE KEI ISLANDS stem, the less curved hydrothecae, and the sinuous hydrothecal margin. Although these traits generally agree with Watson’s material of S. campylocarpum, they also show variation within the same plume that approached the characteristics of S. orthogonium. Some few hydrothecae are longer and curved for 90° (Fig. 55D), while other hydrothecae quite frequently lack the sinuous margin. A quite distinct difference to the material identified here as S. orthogonium is the paucity of cauline hydrothecae, even in internodes bearing hydrocladia. Only more distal stem internodes have hydrothecae (Fig. 55A–B). The figures by Allman (1888) show a similar situation. However, Watson (2000) indicates that also the basal internodes of S. orthogonium may lack hydrothecae. One dimension did not agree with Watson’s measurements: the length of the free adcauline side of the hydrotheca. While Watson measured 0.1–0.17 mm, here 0.28–0.31 mm were found. It seems that new material of both species from different localities is needed to evaluate their status. Distribution Eastern Australia, northern Australia, Indonesia, Japan, ?New Zealand. Type locality: Off Sydney, Australia, 55–64 m. Family Halopterididae Antennella campanulaformis (Mulder & Trebilcock, 1909) Fig. 56. Plumularia campanulaformis Mulder & Trebilcock, 1909: 31, pl. 1: figs 6, 9, 10. Plumularia campanulaformis var. dubia Mulder & Trebilcock 1911: 115, pl. 2: fig. 6. Antennella campanuliformis. – Watson 1973: 182, figs 43– 44. Halopteris diaphana. – Millard & Bouillon 1973: 82, fig. 10L–M. Antennella campanulaformis. – Schuchert 1997: 24, fig. 7. Material examined: Kei Islands Expedition, Banda Islands, Kombir, 70–90 m, 6 Jun 1922, numerous shoots with gonothecae, on sponge and presumable polychaete tubes made of sand grains. Description Colonies erect, shoots thread-like, not branching, 205 Fig. 56. Antennella campanulaformis (Mulder & Trebilcock, 1909). A. Part of stem with main- and intersegment. B. Lateral nematothecae and apophysis seen from outer side. C. Male gonotheca. D–F. Female gonothecae, same scale as C. – Scales: A = 0.1 mm; B = 50 µm; C–F = 0.2 mm. lacking hydrocladia, 1–1.5 cm high. Stolons creeping, tubular, ramified. Stems heteromerously segmented by alternating, distinct, oblique nodes and less distinct transverse nodes, delimiting main segments bearing a hydrotheca and intersegments without hydrotheca. First node oblique, in stem region below first node 1– 3 median nematothecae, sometimes on a separate segment flanked by two oblique nodes. Main
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Family Solanderiidae HYDROIDS OF TH
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