Two new genera and nine new species of hydroids (Cnidaria: Hydrozoa) from off New Caledonia Author Galea, Horia R. text European Journal of Taxonomy 2015 2015-08-31 135 1 19 journal article 22396 10.5852/ejt.2015.135 4ebe05f4-f39b-4770-85c2-8de0fcda0cb3 2118-9773 3785289 F5F578C8-4CA7-4ADA-9DAF-0DA5170E9F9F Solenoscyphus decidualis sp. nov. urn:lsid:zoobank.org:act: E4FDE6E2-065E-43CC-B978-126563826AA9 Figs 3B , 4 C–D; Table 2 Diagnosis Colonies regularly pinnate, stems polysiphonic, cladia always monosiphonic; nodes indistinct; stem internodes composed of two alternate hydrothecae, an apophysis, and an axillary hydrotheca; cladial internodes each with one hydrotheca; the latter alternate, long, tubular, free part slightly convex basally, then straight; operculum deciduous. Etymology From the Latin dēcĭdŭus , meaning "deciduous", with reference to the condition of the hydrothecal operculum. Material examined Holotype NEW CALEDONIA : campaign Biocal, station DW38, 23°00’ S , 167°15’ E , 360 m , 30 Aug. 1985 ; 4.0 cm high, sterile colony (IK-2012-10294). Description Essential part of hydrorhiza missing, but remains of what appears to be a rhizoid stolon, firmly attached to substrate, could be seen. Colony erect and pinnate, ca . 4 cm high. Stem lightly fascicled basally, grading to monosiphonic distally; auxiliary tubes fused to one another, forming outer layer of perisarc enveloping main tube; monosiphonic part of stem with indistinct nodes; equivalents of internodes composed of proximal “node”, two alternate hydrothecae, short lateral apophysis (supporting cladium) on side opposite to second hydrotheca, axillary hydrotheca, and distal “node”. Cladia up to 1.2 cm long, inserted on corresponding stem apophyses, occurring at an angle of about 70° with stem; nodes indistinct; equivalents of internodes relatively short, each carrying a hydrotheca on its distal half. Hydrothecae of both stem and cladia biseriate, alternate, given off at 70–75° to “internodes”; tubular, adnate for onefourth of adaxial length; both free adaxial and abaxial walls parallel, imperceptibly convex to almost straight; rim even, aperture circular, placed at right angle to axis of theca; rare, rounded opercula close apertures of some hydrothecae. Gonotheca unknown.