taxonID	type	description	language	source
03AA0A13FF95B665FF0DFB9BFBBB1DEE.taxon	description	Figs 1 A, 2 A – C, 3 A – C, E, F, 15, 16; Table 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF95B665FF0DFB9BFBBB1DEE.taxon	materials_examined	Material examined. KANADEEP, Stn. DW 4977, MNHN-IK- 2019 - 2056: two colonies, 2.0 and 2.4 cm high, both bearing ♀ gonothecae; GenBank: MZ 099691 (16 S). — KANADEEP, Stn. DW 4979, MNHN-IK- 2019 - 2060: two colonies, 1.7 and 1.9 cm high, smallest bearing ♀ gonothecae, largest sterile; GenBank: MZ 099692 (16 S). — KANADEEP, Stn. DW 5042, MNHN-IK- 2019 - 2055: a 1.1 cm high colony fragment bearing ♀ gonothecae. — Com- parison material: MUSORSTOM 8, Stn. CP 1083, MNHN-IK- 2012 - 16537 and - 16538: Gonaxia nova Galea, 2016, type series, as described in Galea (2016: 16).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF95B665FF0DFB9BFBBB1DEE.taxon	discussion	Remarks. The present material, especially that from sample MNHN-IK- 2019 - 2056 (Figs 2 A, 3 A, E), agrees well with the original account. However, intraspecific variability, mostly dealing with the morphology and position of the hydrothecae, could be noted among specimens from different stations: slenderer thecae occurred in sample MNHN-IK- 2019 - 2055 (Figs 2 C, 3 C) and thecae more distant from one another were met with in sample MNHN- IK- 2019 - 2060 (Fig. 2 B). Only female gonothecae have been observed in the material at hand (Fig. 3 E, F), and they conform to those described and illustrated by Vervoort (1993). As noted by Galea (2016: 19), G. bulbifera and G. nova Galea, 2016 are morphologically similar. Part of the type series of the latter has been reexamined in the frame of the present study, and the opinion expressed earlier that G. nova has larger hydrothecae and gonothecae could be confirmed (compare Figs 3 A – C and 3 D, and Figs 3 E – F and 3 G, respectively). In addition, it should be noted that the inflexion point of the abaxial wall of the hydrotheca is situated halfway in G. nova (conferring the theca a decidedly arched appearance, Figs 2 D, 3 D), and in the proximal third in G. bulbifera (Fig. 2 A – C); moreover, the free adaxial wall of the former varies from straight, or nearly so, to slightly concave halfway (Fig. 3 A – C), while it is constantly convex all the way long in G. nova (Fig. 3 D). Last but not least, the gonothecae of G. bulbifera (Fig. 3 E, F) observed here are devoid of the dense proximal striae reported by Galea (2016) in G. nova (Fig. 3 G). Bathymetric distribution. Between 108 – 530 m (Vervoort 1993; present study).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF95B665FF0DFE18FF1719B9.taxon	diagnosis	Diagnosis. Hydroids forming upright colonies of macroscopic size built up along a fascicled, simple or branched main stem. Cladia biseriate, alternating along the stem and, when present, its branches forming either simple-pinnate or multi-pinnate, planar colonies with straight stems, or pinnate cladia-bearing branches spirally arranged along a strongly geniculate stem. Division into internodes often indistinct in both stems and cladia; usually a hydrotheca per equivalent of cladial internode; on stems, two successive cladia separated by three consecutive hydrothecae, of which the proximal most is axillar; cladia borne on short stem apophyses. Hydrothecae flask-shaped to tubular, immersed for a varied degree into their corresponding internodes, free part variably projecting out- to upward, aperture distal, transverse, margin provided with three rounded cusps (two latero-adaxial, one abaxial) separated by shallow embayments, operculum composed of three triangular flaps. Gonothecae arising from the component tubes of the stems, either club-shaped and fully free above their origin, or long, tubular, partly adnate to the stem proximally and diverging distally, in all cases provided apically with a rounded, transverse aperture, broader in females than in males.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF90B66FFF0DFA6AFB2C1B5E.taxon	description	Figs 1 B, 4, 5 A – B, 6 A – E, 15, 16; Table 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF90B66FFF0DFA6AFB2C1B5E.taxon	materials_examined	Material examined. KANACONO, Stn. DW 4743, MNHN-IK- 2019 - 2087: a 6.3 cm high colony, with groups of ♀ gonothecae; GenBank: MZ 099693 (16 S). — KANACONO, Stn. DW 4763, MNHN-IK- 2019 - 2089: two colonies, 4.2 and 6.1 cm high, smallest bearing a ♂ gonotheca, largest sterile. — KANACONO, Stn. DW 4764, MNHN-IK- 2019 - 2088: three colonies, 6.0 – 7.8 cm high, one sterile, one bearing ♂ gonothecae, and one bearing ♀ gonothecae; GenBank: MZ 099694 (16 S). — KANACONO, Stn. DW 4768, MNHN-IK- 2019 - 2076: a 5.7 cm high colony bearing ♂ gonothecae.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF90B66FFF0DFA6AFB2C1B5E.taxon	discussion	Remarks. Although the cladia are generally unbranched, a case of branching occurs in sample MNHN-IK- 2019 - 2076. Second-order cladia are given off from two primary cladia, pointing in front and the back side of the colony; in one case, the secondary cladium is given off from a site near the base of a hydrotheca, while in the other case, it is given off from near the axil formed between the free and fused parts of the adaxial wall of another hydrotheca. Some intraspecific variations occur in this species, and they rely in the size of the free part of the hydrothecae, and the length of internodes (compare Figs 4 A and 4 B). In this species, the coenosarc lies in an inner gutter of perisarc built up on one side (“ anterior ” or “ posterior ”) of the longitudinal axis of the stem / cladia (Fig. 6 E); occasionally, the coenosarc passes from one side to the other, and the inner gutter is then formed on the opposite side. Vervoort’s (1993: figs 19 A – B) and Galea’s (2016: fig. 4 A) illustrations show that side of the colony to which the gutter of perisarc is confined. Another feature of this species, not elucidated by Vervoort (1993: 146) but highlighted by Galea (2016: 13), is the distinctive U-shaped hydrothecal floor, when the hydrothecae are seen frontally. In lateral view, the insertion of lateral walls of hydrotheca into the corresponding internode adopts a convex shape (Figs 4 C and 6 A), forming two diverticula, one in front, and the other on the backside of the hydrotheca, particularly noticeable when the hydrotheca is seen frontally (Fig. 6 C). In a cross-section of the internode at the lowest level of the hydrothecal floor, a narrow, drop-shaped hydropore can be seen (Fig. 6 D). Female gonothecae (Figs 4 D, 5 A), not previously described, occur in one colony from sample MNHN-IK- 2019 - 2087. Similar in shape to their male counterparts (Figs 4 E, 5 B), about 3.2 mm long and 1160 µm wide, they have comparatively wider (ca. 425 µm) apertures. In this material, they arise from the main tube of the stem, in the vicinity of an axillar hydrotheca. Bathymetric distribution. Between 160 – 650 m (Vervoort 1993; Galea 2016; present study).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9FB66FFF0DFE3CFBBB1E10.taxon	description	Figs 1 C, 6 F – G, 15, 16; Table 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9FB66FFF0DFE3CFBBB1E10.taxon	materials_examined	Material examined. KANACONO, Stn. DW 4744, MNHN-IK- 2015 - 2678: a 2.8 cm high, sterile colony; GenBank: MZ 099695 (16 S).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9FB66FFF0DFE3CFBBB1E10.taxon	discussion	Remarks. The present material, without gonothecae, is immediately recognizable as being G. crusgalli, due to the pair of fronto-dorsal spurs on its hydrothecae (Fig. 6 F, G), a character not met with in any of its congeners. As with Vervoort (1993), the presence of a basal foramen communicating with the hydrothecal lumen could be noted (their distal tips are always closed in the available specimen), but no traces of coenosarc investing their own lumina could be observed, making their role uncertain. Although no reports of branched cladia are available (Vervoort 1993), aberrant branches were seen in the material at hand: 1) in one instance, a short branch is given off from within the proximal most hydrotheca; 2) in another case, an equally short branch takes the place of one of the lateral spurs of a proximal hydrotheca on the original cladium. For a thorough description of this species, refer to Vervoort (1993). Bathymetric distribution. Between 255 – 310 m (Vervoort 1993; present study).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9FB66FFF0DFBF2FB2C1C3F.taxon	description	Figs 1 D, 5 C, 15, 16; Table 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9FB66FFF0DFBF2FB2C1C3F.taxon	materials_examined	Material examined. KANACONO, Stn. CP 4691, MNHN-IK- 2015 - 2669: two colonies, of which one is 10 cm high and bears ♂ gonothecae, while the other is 5 cm high and sterile; GenBank: MZ 099696 (16 S), MZ 099684 (18 S), MZ 099669 (28 S). — KANACONO, Stn. DW 4728, MNHN-IK- 2015 - 2666: two sterile colonies, both 5.5 cm high; GenBank: MZ 099697 (16 S). — KANADEEP, Stn. DW 5027, MNHN-IK- 2019 - 2064: a 4 cm high colony bearing ♀ gonothecae.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9FB66FFF0DFBF2FB2C1C3F.taxon	discussion	Remarks. For descriptions of this quite easily-recognizable species, refer to both Vervoort (1993) and Galea (2016). Bathymetric distribution. Between 150 – 850 m (Vervoort 1993; Galea 2016; present study).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9FB66DFF0DF9DBFB1E1DA3.taxon	description	Figs 1 E, 7, 8, 15, 16; Table 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9FB66DFF0DF9DBFB1E1DA3.taxon	materials_examined	Material examined. KANACONO, Stn. CP 4675, MNHN-IK- 2015 - 2668: a 8.5 cm high, sterile, unbranched colony; GenBank: MZ 099698 (16 S), MZ 099685 (18 S). — KANACONO, Stn. DW 4786, MNHN-IK- 2019 - 2059: two unbranched colonies, 8 and 12.7 cm high, both sterile; GenBank: MZ 099699 (16 S). — KANACONO, Stn. DW 4668, MNHN-IK- 2015 - 2677: two branched colonies, of which one is ca. 13 cm high, devoid of its basal part, but bearing a couple of mature gonothecae, and a second, sterile colony, originally ca. 13.5 cm high, now broken into three pieces. — KANACONO, Stn. DW 4670, MNHN-IK- 2015 - 2673: a branched colony, 6.3 cm high, and two fragments, 2 and 3 cm high, all sterile. — KANACONO, Stn. DW 4715, MNHN-IK- 2015 - 2676: a branched colony, ca. 15 cm high, bearing a few incipient gonothecae whose sex could not be ascertained. — KANACONO, Stn. DW 4748, MNHN-IK- 2015 - 2674: a branched, sterile colony, 9 cm high. — KANACONO, Stn. DW 4786, MNHN- IK- 2015 - 2672: many branched colonies up to 25 cm high, some bearing incipient gonothecae whose sexes could not be ascertained; GenBank: MZ 099705 (16 S) (colony A); MZ 099706 (16 S), MZ 099686 (18 S), MZ 099670 (28 S) (colony B). — KANADEEP 2, Stn. CP 5109, MNHN-IK- 2015 - 2675: upper portion of a branched colony, 5.5 cm high, sterile.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9FB66DFF0DF9DBFB1E1DA3.taxon	discussion	Remarks. As noted earlier by Galea (2016: 14), the branching pattern of the stems is peculiar in this species: although the nodes are indistinct, each equivalent of internode is composed of four alternating hydrothecae, of which the proximal- and the distalmost become axillar through the insertion of two cladial apophyses given off on opposite sides (Galea 2016: Fig. 4 E). The account of Vervoort (1993: 154), however, is misleading in stating that “ zero to three hydrothecae [occur] between two successive apophyses ”, suggesting that either one, two or three hydrothecae could be present. Nevertheless, the branching pattern observed both earlier (Galea 2016) and presently proved always regular. Among the genus, only the stems of G. errans and G. plumularioides Galea, 2016 share the same division into internodes. Besides the occurrence of several simply pinnate colonies (Fig. 1 E), the material studied herein comprises well-developed, lofty (up to 25 cm high) colonies (Fig. 7), much taller than those on which both the holo- and paratype (2.8 and 7.7 cm high, respectively) of G. plumularioides were based upon. Concomitantly, it is realized that the latter merely represents the fully-grown stage of G. errans, a hydroid previously known based on young, unbranched colonies, not exceeding a few centimeters in height (Vervoort 1993: 154; Galea 2016: 13). Consequently, G. plumularioides is assigned to the synonymy of G. errans. The largest colonies met with herein provide additional, crucial data on the general aspect of this hydroid, granting a comprehensive understanding of its morphology. A strongly reticulated hydrorhiza, firmly anchoring the colony to a hard substrate, gives rise to a fascicled (though rather slender, not exceeding 3 mm in width), strongly geniculate stem forming, at regular intervals (6 – 10 mm), up to 6.5 cm long, spirally-arranged cladia-bearing branches. In the largest colonies, some lower cladia-bearing branches may branch again twice. Along the stem and on the proximal parts of cladia-bearing branches, all cladia are shed, although most axial hydrothecae still protrude from the fascicle of auxiliary tubes. The cladia are up to 17 mm long and comprise an alternation of up to 24 hydrothecate internodes, not delimited by distinct nodes. Although the microscopical structure of the trophosome was described thoroughly earlier (Galea 2016: 14), the so far unknown gonothecae are present in a number of samples, although fully-formed ones are only met with in sample MNHN-IK- 2015 - 2677. These originate from below the bases of axillar hydrothecae of the cladia-bearing branches (Fig. 8 A), and are broadly club-shaped (Fig. 8 D), provided with 6 – 7 prominent, longitudinal ridges (Fig. 8 E), ca. 2.8 mm long and 770 µm wide; their ca. 350 µm wide aperture is at the top of a truncate summit, irregularly rounded in shape and apparently closed by a flimsy, deciduous operculum. Bathymetric distribution. Between 350 – 1508 m (Vervoort 1993; Galea 2016; present study).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9AB668FF0DFF38FC6A1BCE.taxon	description	Figs 1 F, 5 D, 9, 15, 16; Tables 2, 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9AB668FF0DFF38FC6A1BCE.taxon	materials_examined	Material examined. Holotype: KANACONO, Stn. DW 4670, MNHN-IK- 2015 - 2679: a 4.5 cm high colony bearing ♂ gonothecae. — Paratype: KANACONO, Stn. DW 4670, MNHN-IK- 2015 - 2670: many colonies, 2 – 6 cm high, old- er ones bearing either ♂ or ♀ gonothecae; GenBank: MZ 099700 (16 S). — Additional material: KANACONO, Stn. DW 4670, MNHN-IK- 2019 - 2061: two colony fragments, 0.9 and 2.2 cm high, both bearing presumably ♀ gono- thecae. — KANACONO, Stn. DW 4671, MNHN-IK- 2015 - 2667: six colonies, 1.8 – 6.0 cm high, the five largest bear- ing either ♂ or ♀ gonothecae; GenBank: MZ 099701 (16 S), MZ 099687 (18 S), MZ 099671 (28 S). — KANACONO, Stn. DW 4672, MNHN-IK- 2015 - 2681: three colonies, 1.6 – 6.5 cm high, the two largest bearing gonothecae. — KA- NACONO, Stn. DW 4677, MNHN-IK- 2019 - 2062: three colonies, 3.8 – 4.5 cm high, smallest bearing presumably ♀ gonothecae, while the two largest bear presumably ♂ gonothecae. — KANACONO, Stn. DW 4681, MNHN-IK- 2015 - 2680: a 5 cm high colony bearing ♂ gonothecae. — KANACONO, Stn. DW 4682, MNHN-IK- 2019 - 2063: a 3.2 cm high colony bearing presumably ♂ gonothecae.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9AB668FF0DFF38FC6A1BCE.taxon	etymology	Etymology. From Latin incîsus, - a, - um, meaning notched or incised, to describe the shape of the adaxial, proximal part of its hydrothecae.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9AB668FF0DFF38FC6A1BCE.taxon	description	Description. Colonies firmly anchored to hard substrates be means of dense, rhizoid stolons; erect, up to 6 cm high, of rigid appearance, able to support themselves when out of liquid. Stems brownish, unbranched, fascicled for most of their length, proximally 2 mm thick, distal tip monosiphonic; main tube with smooth perisarc; accessory tubes tortuous, anastomosed, with wrinkled perisarc; division into internodes indistinct, but equivalents of internodes comprising three alternating hydrothecae and a short cladial apophysis given off laterally below the distalmost hydrotheca, the latter becoming axillar; an ovoid fenestra below the base of each axillar hydrotheca; stem “ internodes ” slightly geniculate, each cladial apophysis introducing a bend along the longitudinal axis of the stem. Cladia up to 15 mm long, straight, straw-colored, alternate along the stem, strictly coplanar, always monosiphonic, and generally unbranched; a distinct constriction at junction between cladium and the corresponding stem apophysis; cladial nodes indistinct, except for the proximal-most that is distinctly longer; equivalents of internodes short, gradually widening distally, and there bearing a hydrotheca; up to 30 hydrothecae arranged in two alternate, strictly coplanar rows. Hydrothecae similar on both stem and cladia; long, tubular, ca. 1 / 6 adnate to their corresponding internodes, given off at ca. 60 ° with their longitudinal axes; free adaxial wall distinctly notched immediately above origin from internode, then straight throughout; adnate adaxial wall thick, slightly arched, basally forming a short perisarc plug projecting abaxially into the lumen of internode; floor of hydrotheca incomplete, formed adaxially by this perisarc plug and, on the abaxial side, by an internal, upward projection of the perisarc at the origin of the abaxial hydrothecal wall; the latter with a slight proximal concavity, and straight for most of its remaining length. Hydrothecal aperture almost triangular in frontal view; margin with three, slightly raised, obtuse, triangular cusps (two latero-adaxial, one abaxial) separated by wide, shallow embayments; opercular apparatus composed of three similar triangular flaps, one adaxial and two latero-abaxial, forming a low, pointed roof when closed; hydranths with ca. 14 – 16 filiform tentacles surrounding a dome-shaped hypostome; abaxial caecum absent. Gonothecae borne on middle and upper parts of the stems; given off from the accessory tubes of the caulus and, consequently, adnate proximally, often forming a median, longitudinal row on both the front and back sides of the stem; when two or more accessory tubes give rise to neighboring gonothecae, the latter are shifted on alternately left and right; gonotheca tubular, tapering distally into an upwardly-bent neck region bearing distally a rounded aperture set transversely; perisarc thick and generally smooth, though distal undulations could be noted in certain gonothecae. Colonies dioecious; gonothecae sexually dimorphic, although their differences are only slight: female gonothecae appear broader and have wider apertures than their male counterparts.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF9AB668FF0DFF38FC6A1BCE.taxon	discussion	Remarks. The large-sized, long, straight, tubular, barely-adnate, basally-notched hydrothecae, with free adaxial walls not adjacent proximally to the following internode, are distinctive within the genus. Although the cladia are generally unbranched, occasional exceptions occur (as noted in sample MNHN-IK- 2015 - 2670): 1) a second-order cladium is given off laterally by means of a short apophysis from below one of the cladial hydrothecae; 2) an evidently aberrant secondary cladium is given off from within a cladial hydrotheca. Bathymetric distribution. Between 290 – 806 m (present study).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF98B668FF0DFD8CFB2C1E10.taxon	description	Figs 1 G, 10, 15, 16; Table 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF98B668FF0DFD8CFB2C1E10.taxon	materials_examined	Material examined. KANADEEP, Stn. DW 4945, MNHN-IK- 2015 - 2671: a 4.7 cm high, sterile colony; GenBank: MZ 099702 (16 S).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF98B668FF0DFD8CFB2C1E10.taxon	discussion	Remarks. This sterile material is only provisionally assigned to G. intermedia Vervoort, 1993 based on morphological similarities of its hydrothecae, despite their being more distant from one another compared to the original account (a similar variation was also observed in G. sinuosa Vervoort, 1993, see under that species). However, their size approaches that of the holotype material (free adaxial wall 335 – 360 µm vs. 340 – 375 µm; adnate adaxial wall 300 – 335 µm vs. 230 – 250 µm; abaxial wall 400 – 470 µm vs. 320 – 370 µm; maximum width 220 – 240 µm vs. 220 – 235 µm; diameter at rim 150 – 165 µm vs. 135 – 150 µm). Bathymetric distribution. Between 108 – 630 m (Vervoort 1993; Galea 2016; present study).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF99B669FF0DFF38FBBB190D.taxon	description	Figs 1 H, 5 E, 11, 15, 16; Table 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF99B669FF0DFF38FBBB190D.taxon	materials_examined	Material examined. KANADEEP, Stn. DW 4977, MNHN-IK- 2019 - 2068: a 2.3 cm high colony bearing ♀ gono- thecae. — KANADEEP, Stn. DW 5021, MNHN-IK- 2019 - 2057: five colonies, 1.8 – 4.6 cm high, of which two bear ♀ gonothecae, and the remaining three bear ♂ gonothecae; GenBank: MZ 099703 (16 S), MZ 099688 (18 S), MZ 099672 (28 S). — KANADEEP, Stn. DW 5037, MNHN-IK- 2019 - 2058: four colonies, 3.2 – 4.5 cm high, two of which bear ♂ gonothecae, and the other two bear ♀ gonothecae; GenBank: MZ 099704 (16 S). — KANADEEP, Stn. 5042, MNHN- IK- 2019 - 2067: a 3 cm high colony bearing ♀ gonothecae.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF99B669FF0DFF38FBBB190D.taxon	discussion	Remarks. The distinctive hydrothecal shape (Fig. 11 A, B) and the partly adnate male gonothecae (Fig. 11 C) make this species easily recognizable. For a comprehensive description, refer to Vervoort (1993). One of the male colonies in sample MNHN-IK- 2019 - 2057 has one of its lowest cladia branched in the same manner as the stem, i. e. giving rise to 6 alternate, second-order cladia. The so far unknown female gonothecae (Figs 5 E, 11 D) occur in several colonies examined here; similar to their male counterparts, about 660 µm wide, they only differ through their much wider apertures (ca. 330 µm). Bathymetric distribution. Between 280 – 360 m (Vervoort 1993; present study).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF99B677FF0DF9B6FB3A1ED7.taxon	description	Figs 1 I, 5 F, 12, 13, 15, 16; Table 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF99B677FF0DF9B6FB3A1ED7.taxon	materials_examined	Material examined. KANACONO, Stn. CP 4674, MNHN-IK- 2019 - 2086: several unbranched colonies, 1.5 – 5.8 cm high, some bearing ♂ gonothecae; GenBank: MZ 099709 (16 S). — KANACONO, Stn. DW 4724, MNHN-IK- 2019 - 2070: three colonies, 9.5 – 10.0 cm high, all bearing ♂ gonothecae, and two of which are branched; GenBank: MZ 099708 (16 S), MZ 099689 (18 S), MZ 099673 (28 S). — KANACONO, Stn. DW 4726, MNHN-IK- 2019 - 2084: seven colonies, 2.2 – 8.0 cm high, of which two are branched; all bear either ♂ or ♀ gonothecae. — KANACONO, Stn. CP 4730, MNHN-IK- 2019 - 2082: a branched colony, 6.5 cm high, bearing ♂ gonothecae. — KANACONO, DW 4741, MNHN-IK- 2019 - 2077: several colonies, of which one is branched, and fragments, up to 9 cm high, some sterile, and some others bearing either ♂ or ♀ gonothecae. — KANACONO, Stn. DW 4742, MNHN-IK- 2019 - 2073: two colonies, 2.2 and 4.2 cm high, largest bearing ♂ gonothecae, while the other is sterile. — KANACONO, Stn. DW 4743, MNHN-IK- 2019 - 2071: four colonies, 4.3 – 8.5 cm high, all unbranched and bearing presumably ♂ gono- thecae. — KANACONO, DW 4763, MNHN-IK- 2019 - 2078: numerous unbranched colonies, 4.0 – 7.5 cm high, some bearing either ♂ or ♀ gonothecae, while some others are sterile. — KANACONO, Stn. DW 4764, MNHN-IK- 2019 - 2085: many unbranched colonies, 1.8 – 7.3 cm high, mostly bearing either ♂ or ♀ gonothecae. — KANACONO, Stn. DW 4765, MNHN-IK- 2019 - 2083: five unbranched colonies, 4.4 – 7.4 cm high, bearing either ♂ or ♀ gono- thecae. — KANACONO, Stn. DW 4768, MNHN-IK- 2019 - 2075: five colonies, 5.0 – 8.5 cm high, of which two are branched, some bear ♂ gonothecae, while others bear ♀ gonothecae; GenBank: MZ 099707 (16 S). — KANACONO, Stn. DW 4770, MNHN-IK- 2019 - 2072: a 3.2 cm high, sterile colony. — KANACONO, Stn. DW 4776, MNHN-IK- 2019 - 2081: two colonies, of which one is 2.8 cm high and sterile, while the other is 6.5 cm high and bears ♀ gono- thecae. — KANACONO, Stn. CP 4779, MNHN-IK- 2019 - 2079: two colonies, of which one is 4.3 cm high and bears ♀ gonothecae, while the other is 5.3 cm high and bears ♂ gonothecae. — KANACONO, Stn. DW 4782, MNHN- IK- 2019 - 2080: two unbranched colonies, 4.4 and 7.9 cm high, both bearing ♂ gonothecae. — KANACONO, Stn. DW 4784, MNHN-IK- 2019 - 2069: a sterile colony, 8.1 cm high, and two colony fragments, one 3.1 cm high and sterile, the other 3.2 cm high and bearing numerous ♀ gonothecae.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF99B677FF0DF9B6FB3A1ED7.taxon	discussion	Remarks. This species shows a high degree of intraspecific variation that mainly relies in the shape (Fig. 13 A – C) of, and the spacing between hydrothecae (Fig. 12), giving the colonies slightly different appearances. However, all have in common their gonothecae that are free from the stem (Figs 5 F, 13 D – E). Similar observations regarding the hydrothecae were made earlier by Vervoort (1993: figs 37 A – B and 38 A). Bathymetric distribution. Between 80 – 856 m (Vervoort 1993; Galea 2016; present study).	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF87B675FF0DFAB3FB0219D2.taxon	description	Figs 1 J, 14 – 16; Tables 2, 3	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF87B675FF0DFAB3FB0219D2.taxon	materials_examined	Material examined. Holotype: KANACONO, Stn. DW 4742, MNHN-IK- 2019 - 2065: a colony, 6.3 cm high, bearing presumably ♀ gonothecae. — Paratype: KANACONO, Stn. DW 4743, MNHN-IK- 2015 - 2665: two colonies, 9.5 and 13.5 cm high, former sterile, latter bearing gonothecae; GenBank: MZ 099710 (16 S), MZ 099690 (18 S), MZ 099674 (28 S). — Additional material: KANACONO, Stn. DW 4785, MNHN-IK- 2019 - 2066: one colony, 15.5 cm high, with remains of a few gonothecae.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF87B675FF0DFAB3FB0219D2.taxon	etymology	Etymology. The specific epithet is a combination of the words Solenoscyphus, a hydroid genus (Galea 2015: 7), and the Greek suffix εἶΔΟΣ, meaning resembling, to illustrate the morphological similarities of the new species with members of that genus.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF87B675FF0DFAB3FB0219D2.taxon	description	Description. Colonies in the examined material reaching as much as 15.5 cm high; very rigid, arising from what appears to be the remains of a rhizoid stolon firmly anchoring them to hard substrates. Stems generally simple in appearance, strongly fascicled, up to 5 mm thick basally, grading to monosiphonic distally, perisarc brown; accessory tubes anastomosed, with wrinkled perisarc; main tube with smooth perisarc, longitudinal axis slightly geniculate, division into internodes indistinct, although equivalents of internodes composed of three alternating hydrothecae and a latero-distal apophysis below the distalmost hydrotheca, the latter becoming axillar; an elongated, vertical fenestra below the base of axillar hydrothecae. Cladia alternate along the stem in two coplanar rows, up to 20 mm long, generally unbranched, straight, bearing a succession of up to 25 very short internodes; nodes indistinct, except at junction between a cladium and its corresponding stem apophysis, marked by a distinct constriction. Stem and cladial hydrothecae alike, arranged in two alternate, coplanar rows; large-sized, long, tubular, free from the internode for ca. 2 / 3 their length; free adaxial wall straight or nearly so; abaxial wall slightly convex proximally, then straight for most of its length; adnate adaxial wall arched downwards, almost meeting an internal perisarc projection given off nearly horizontally from the origin of abaxial wall, thus leaving only a short passage for the hydranth into the hydrothecal lumen; thecal margin with eroded, indistinct cusps, producing an even rim, often renovated, renovations closely-set; closing apparatus lost in all specimens. Hydranths generally highly contracted near bases of hydrothecae; small compared to the size of the thecae, body columnar, without abaxial caecum, bearing distally a whorl of 16 – 18 filiform tenacles encircling a dome-shaped hypostome. Gonothecae arising from secondary tubes of the stem; arranged in a row on front and back sides of the colony, confluent with one another; when multiple accessory tubes produce neighboring gonothecae, the latter are shifted on laterally along the longitudinal axis of the stem. Gonothecae thick-walled, flask-shaped, adnate for more than half their length, free part gradually tapering distally, aperture transversely-set, large, circular, closed by rounded, deciduous operculum; gonothecae presumably female in the material at hand.	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
03AA0A13FF87B675FF0DFAB3FB0219D2.taxon	discussion	Remarks. As suggested by the specific epithet, sterile specimens of this hydroid are indistinguishable morphologically from members of the genus Solenoscyphus Galea, 2015. Only the presence of gonothecae along the caulus, as noted in material MNHN-IK- 2015 - 2665, vouches for their belonging to the genus Gonaxia Vervoort, 1993. Hydrothecae of G. solenoscyphoides Galea, sp. nov. are the largest within the genus. Only G. robusta Vervoort, 1993 has morphologically-similar hydrothecae, but their size is about 60 % that of the new species [total depth 800 – 815 µm vs. 1255 – 1450 µm, abaxial wall 725 – 760 µm vs. 1080 – 1225 µm, free adaxial wall 560 – 590 µm vs. 890 – 1060 µm, maximum width 260 – 280 µm vs. 465 – 490 µm, diameter at rim 235 – 260 µm vs. 395 – 415 µm; measurements of the cladial hydrothecae of G. robusta are taken from Vervoort (1993: Table 21)]. Cauli of this species, as long as they appear from this rather scarce material at hand, are generally unbranched; however, one colony from sample MNHN-IK- 2015 - 2665 possesses a stump (devoid of cladia) on the proximal part of its stem. The other colony, for its part, has a cladium bearing several second-order cladia, similarly to the stem; the original cladium, in addition, bears along its axis a few gonothecae derived from the caulus. Bathymetric distribution. Between 290 – 403 m (present study). G. bulbifera 0.8 ± 0.4 G. crassicaulis 6.0 ± 0.8 ± 1.0 0.4 G. crusgalli 4.9 ± 1.7 ± N. C. 0.9 0.5 G. elegans 6.0 ± 4.1 ± 4.6 ± 0.0 ± 1.0 0.8 0.8 0.0 G. errans 8.3 ± 8.3 ± 8.1 ± 9.5 ± 0.4 ± 1.2 1.2 1.2 1.2 0.2 G. incisa 10.3 ± 8.8 ± 8.3 ± 9.1 ± 8.0 ± 0.0 ± 1.3 1.1 1.1 1.2 1.1 0.0 G. cf. intermedia 5.1 ± 5.0 ± 5.0 ± 6.4 ± 10.1 ± 10.0 ± N. C. 0.9 0.9 0.9 1.0 1.3 1.3 G. perplexa 5.2 ± 4.8 ± 4.9 ± 6.2 ± 8.9 ± 9.6 ± 4.5 ± 0.2 ± 0.9 0.9 0.9 1.0 1.2 1.2 0.8 0.2 G. sinuosa 7.5 ± 3.0 ± 2.3 ± 5.7 ± 8.5 ± 8.7 ± 5.7 ± 6.6 ± 0.4 ± 1.1 0.7 0.6 0.9 1.2 1.1 1.0 1.0 0.2 G. solenoscy- 10.2 ± 8.0 ± 7.7 ± 8.7 ± 7.2 ± 4.0 ± 10.8 ± 8.4 ± 8.3 ± N. C. phoides 1.3 1.1 1.2 1.2 1.1 0.8 1.3 1.2 1.2	en	Galea, Horia R., Maggioni, Davide (2021): An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa). Zootaxa 5004 (3): 401-429, DOI: 10.11646/zootaxa.5004.3.1
