This deep water genus, formerly represented by only one species in the recorded New Zealand fauna, figures prominently in the deepest Cook Strait hauls made by the Victoria University deep sea expeditions at the head of the great depression that leads north-east from Cook Strait towards the Kermadec Trench. Seven species now can be assigned to the fauna, and consequently a key will be useful.

Ophiacantha levispina Lyman

• Lyman, T., 1882. Challenger Ophiuroidea, p. 196–7, Pl. 25 (1–3).

Material Examined: Three specimens, all from abyssal stations. 1,300 fathoms, Cook Strait, VUZ Station 58, 1 specimen (3 oral papillae, the outer one broad); 1,200–1,300 fathoms, Cook Strait, VUZ Station 56, 2 specimens (one with 4 oral papillae, the other with 3, in both cases the outer papilla is broadened).

The species was taken by the Challenger at Station 214, off the Philippine Islands, in 500 fathoms.

Mr. J. C. Yaldwyn recorded that the arms were pink in the two specimens obtained from Station 56.

Ophiacantha imago Lyman

• Lyman, T., 1882. Challenger Ophiuroidea, p. 186, Pl. 25 (4–6).

Material Examined: Three specimens, all from a deep-water haul, 550 fathoms, Cook Strait, VUZ Station 83.

The species is viviparous. The arms of young individuals can be seen protruding from the genital clefts. In alcohol the specimens are pure white, but colour notes from life made by Mr. J. C. Yaldwyn state that the specimens were all pink when brought to the surface.

Ophiacantha yaldwyni sp. nov. Plate 4, Figs. F, H, I, holotype.

Diagnosis: Similar to Ophiacantha truncata Koehler, but having rhomboidal mouth-shields, shorter arm-spines and shorter oral papillae.

Description: Disc carrying thorny granules, about 12 to the square millimeter, not densely packed but permitting the outlines of the disc scales to be seen between them, usually one granule to each disc scale. Disc, arm and mouth-plates all invested in skin, making the borders between the plates somewhat indistinct when dried. Oral papillae 5 to 9, very irregularly arranged, with spiniform and leaf-shaped papillae indiscriminately mingled and crowded, some spines encroaching upon the adoral plates. Oral shields small, transversely rhombic, an angle within and without. Adoral plates rectangular, meeting broadly within, and resting upon the first lateral arm-plate without. Ventral arm-plates pentagonal, an obtuse angle within, the distal borders more or less rounded. Tentacle-scale single, prominent on the first arm-joint, smaller on the second, very minute or lacking on the third and fourth joints, and lacking from the rest of the joints. Lateral arm-plates not meeting above on the basal joints, but meeting very narrowly below, somewhat prominent, carrying 6 thorny spines, the upper ones longer than an arm-joint, the lower ones shorter. Further out on the arm all the spines become relatively shorter, forming a close, robust comb shorter than the arm-joint at that level. Dorsal arm-plates of the so-called "cup-shaped" form at the base of the arm, broadly in contact, with a narrow proximal border, long concave lateral borders, and a broad convex distal border; they are a little longer than broad at the base of the arm, as also further out. The basal one or two dorsal plates carry two or three granules in a transverse row along the distal margin, these two plates having a somewhat different shape from the rest of the basal dorsal armplates. Genital cleft longer than three arm-joints.

Holotype: In the Department of Zoology, Victoria University of Wellington; R approximately 25 mm, r 5 mm.

Material Examined: The holotype from 550 fathoms, Cook Strait, VUZ Station 75. Mr. J. C. Yaldwyn recorded that the colour in life is pink. The specimen, with other ophiuroids, was taken from crevices in a rock fragment from the sea-floor.

Ophiacantha rosea Lyman. Plate 4, Figs. J, K.

• Lyman, T. 1882. Challenger Ophiuroidea, p. 184, Pl. 25.

Material Examined: 275 fathoms, Canyon A ENE of Otago Heads, Alert Station 54.13, E. Batham, 2/3/54. The specimen is in the collection of the Portobello Marine Station, Otago.

The specimen, recorded by Dr. Batham as pink when taken, is a large one, R ca 70 mm, r 9 mm. It differs from Lyman's Pl. 25 in having fewer and blunter and broader outer oral papillae (Fig. J). The length of the 11 arm-spines differs a little from Lyman's account, being, in terms of the length of a segment, ·5, 3·5, 3·5, 3·5, 3, 2·8, 2·5, 2·2, 2, 1·5, 1·5 respectively as taken from upper to lower. The dorsal spines of the disc also appear to be longer than in Lyman's (somewhat obscure) illustration. The differences may be regarded as relatively trivial.

This large, deep-water species was originally taken by the Challenger in 310 fathoms off the Crozets (S. Indian Ocean), in 420–775 fathoms off Japan, and in 175 fathoms off southern Chile. Its occurrence in New Zealand waters is therefore not surprising, and indeed it may prove to be cosmopolitan. It has not yet been reported from Australia.

Plate 4

A, E, Ophiuraster symmetricus sp. nov; A, adoral and E, aboral aspect. B, C, D, Ophiomastus admiral sp. nov.; B, laeral aspect of arm; C, aboral and D, adoral aspects. F, H, I, Ophiacantha yaldwyni sp. nov.; F, aboral aspect; I, adoral aspect; H, spinules from upper side of disc. G, L, Ophiacantha abyssicola otagoensis var. nov.; G, aboral aspect of arm-joint; L adoral aspect. J. K, Ophiacantha rosea Lyman; J, jaw-region and K, spinules from up per surface of disc.

Ophiacantha abyssicola G. O. Sars var. otagoensis var. nov. Plate 4, Figs. G, L, holotype.

Diagnosis: Differing from the typical form in having transversely rhombic oral shields, which lack the distal lobe.

Holotype: In the Portobello Marine Station, Otago.

Material Examined: 3 specimens from 275 fathoms, Canyon A off Otago Heads, Alert Station 54.13, E. Batham.

Remarks: The difference in the oral shields is the only significant one I can observe in the material, when it is compared with Mortensen's (1928) account of the North Atlantic form. It does not seem sufficient for establishing a new species, even though the geographical separation is that of the globe itself; for, as is now becoming increasingly evident, deep-sea ophiuroids tend to have very widespread distribution patterns.

Since the species has not hitherto been taken in the Pacific, it is desirable to list the features that have influenced me in assigning the Otago material as O. abyssicola, and these are illustrated in Figs. G, L. The dorsal arm-plates have the form that Mortensen (1928) calls "cup-shaped": the ventral plates are very broad; the disc is finely granulated above and laterally, but the plates are naked on the lower surface; there is a single round tentacle-scale; three oral papillae, of which the outer one is somewhat widened; the disc diameter is ca. 5 mm.

Ophiacantha vepratica Lyman

• Lyman, T. 1882. Challenger Ophiuroidea, p. 182, Pl. 13.

Material Examined: Two individuals, one from 300 fathoms, the other from 260 fathoms, from Stations 5 and 52 respectively of the Chatham Islands 1954 Expedition.

The holotype was taken by the Challenger at Station 171, in 600 fathoms off the Kermadec Islands. The presence of the species in New Zealand waters was therefore to be expected.

Ophiacantha vilis Mortensen

• Mortensen, Th. 1924. Vid. Medd. dansk naturh. For., 77, p. 114, Fig. 7.

Material Examined: Six specimens from the following stations: 600 fathoms. Cook Strait, VUZ Station 75, 1 specimen; 400 fathoms, NE of Mayor Island, Bay of Plenty, Dominion Museum Station B.S.210, 1 specimen; 200–300 fathoms, Cook Strait, VUZ Station 51, 4 specimens.

The holotype was from Cook Strait, 200 fathoms (Mortensen, 1924).

Ophiactis abyssicola (M. Sars)

• Amphiura abyssicola M. Sars. 1861. Oversigt Norges Echin., p. 18.

Material Examined: Nine specimens; 1,300 fathoms. Cook Strait, VUZ Station 58, 8 specimens (arms pink in life, J. C. Yaldwyn); 1,200–1,300 fathoms, Cook Strait, VUZ Station 56, 1 specimen.

var. poa Lyman: 22 specimens from 600 fathoms, Cook Strait, VUZ Station 75 (2 individuals) and 550 fathoms, Cook Strait, VUZ Station 83, 20 individuals; these were taken from burrows in hard mud brought up from the sea-floor. The colour was recorded as pink. They differ from var. cuspidata, which occurs with them, in having many more spines on the disc, and lacking the prominent primary plates.

var. cuspidata Lyman: 2 specimens, one each from 400 fathoms, Cook Strait, VUZ Station 87, and 550 fathoms, Cook Strait, VUZ Station 83. This form has been recorded from 600 fathoms, Tasman Sea, 400 miles NW of Wellington (Fell, 1951, p. 3), and from Challenger Stations 170 and 171, 520–600 fathoms, off the Kermadec Islands. The Cook Strait specimens were pink when taken.

Ophiactis hirta Lyman

• Lyman, T., 1882. Challenger Ophiuroidea, p. 118–9, Pl. 20.
• Mortensen, Th., 1924. Vid. Medd. dansk naturh. For., 77, p. 126.

Material Examined: Three specimens, all six-armed; 200–300 fathoms, Cook Strait. VUZ Station 51, 1 specimen; 150 fathoms, Cook Strait, VUZ Station 98, 2 specimens.

Ophiactis profundi var. novaezelandiae Mortensen

• Mortensen, Th., 1924. Vid. Medd. dansk naturh. For., 77, p. 128–31, Fig. 13.

Material Examined: 8 specimens—130 fathoms, Station 34, Chatham Islands 1954 Expedition, 3 specimens; 100 fathoms, Island Bay shelf, 5 specimens.

The holotype was from Cook Strait, 120 fathoms, and the Discovery took the species at Discovery Station 941, 128 metres, also in Cook Strait.

Ophiactis resiliens Lyman

• Lyman, T., 1882. Challenger Ophiuroidea, p. 115, Fig. 20.

Material Examined: Four specimens, two of them from the Island Bay shelf at ca. 100 fathoms (Fell, 1952, p. 22) and two from VUZ Station 55. at 40–100 fathoms in Cook Strait.

Mortensen (1924, p. 124) records the species from 120 fathoms in Cook Strait.

Amphiura angularis Lyman

• Lyman, T., 1882. Challenger Ophiuroidea, p. 134–5, Pl. 24.

Material Examined: Three specimens which I take to be of this species, from 550 fathoms, VUZ Station 83, Cook Strait.

Remarks: R 30 mm approximately, r 3 mm. The disc is rather strongly indented at the interradii, without spines, the scales imbricating above but, save at the ambitus, the disc is more or less naked below. The outer oral papilla is spiniform, erect, the inner pair scale-like. The adoral plates are barely contiguous within. Oral shield triangular, the apex proximad. Radial shields about one-third r, twice as long as broad, divergent proximad. their outer margins convex, their inner margins straight, separated by a narrow wedge of 7 or 8 scales. Dorsal arm-plates transversely elliptical, broadly in contact on the proximal half of the arm. Ventral plates quadrangular. Two tentacle-scales at the base of the arm, elsewhere one only. Five to six subequal arm-spines, which are no longer than a segment, and form an erect comb.

The type locality of this species is Challenger Station 150, in 150 fathoms, off Kerguelen Islands. The New Zealand material seems to resemble the Kerguelen form so closely as to warrant regarding both as of the same species. Amphiura angularis has not previously been reported from Australasia.

Amphiura heraldica Fell.

• Fell, H. B., 1952. Zoo. Pubs. Vict. Univ., 18, p. 16–18, Figs. 5–7.

Material Examined: Three specimens, two of them from 350 fathoms, Canyon C, off east Otago (E. Batham), the other one from 300 fathoms, off east Otago, Dom. Mus. Station B.S.190.

The holotype was from Discovery Station 2733, Chatham Rise, west of Chatham Islands, in 300 metres.

Amphiura norae Benham

• Benham, W. B., 1909. Rec. Cant. Mus. 1 (2), p. 104–5, Pl. 10.

Material Examined: Sixteen specimens, from the following archibenthal stations: 300 fathoms, Chatham Rise, Station 5, Chatham Islands 1954 Expedition, 1 specimen; also from the same expedition, 290 fathoms, Station 59 (2 individuals), and 260 fathoms, Station 52 (4 individuals); 154 fathoms, Milford Sound, N.Z. page 27Oceanographic Institute Station A 319, 5 specimens; 113–120 fathoms, off Mayor Island, Bay of Plenty, Dom. Mus. Station B.S.208, 1 specimen; 145 fathoms, off Cape Kidnappers, Kotuku Station 3, J. A. F. Garrick, 2 specimens.

As no specimens of Amphiura abernethyi Fell appear in the deep-water collections, it is still not possible to establish the relationship between it and A. norae. It is possible that A. abernethyi is a larger, more robust and more fully developed form of A. norae, perhaps confined to the continental shelf.

Amphiura pusilla Farquhar

• Farquhar, H., 1897. J. Linn. Soc. Lond. Zool., 26, p. 191, Pl. 14.

Material Examined; Twelve specimens—ca. 275 fathoms, Canyon A, east of Otago Heads, E. Batham, 3 specimens; 150 fathoms, Cook Strait, VUZ Station 98, 4 specimens; 120 fathoms, Cook Strait, NW of Mana Island, Dom. Mus. Station B.S.197, 5 specimens.

Amphiura hinemoae Mortensen

• Mortensen, Th., 1924. Vid. Medd. dansk naturh. For., 77, p. 148–50. Fig. 24.

Material Examined: Three specimens from 400 fathoms, NE of Mayor Island, Bay of Plenty, Dom. Mus. Station B.S.210.

The species was originally described on the basis of 2 specimens taken in 55 fathoms off White Island, Bay of Plenty. It has since been taken on other shelf localities off the South Island (Fell, 1952, p. 15), from as far south as Dusky Sound. This is the first record of the species as an abyssal form, and it is desirable to indicate certain atypical features of the new material, making its identification not entirely clear. In particular the radial shields are relatively larger and more exposed in the deep-water specimens, and the six primary plates are not at all prominent. I do not feel that the evidence warrants our establishing a separate species for the form. One specimen has the outer oral papilla distinctly spiniform—thus showing that the difference between Amphiura hinemoae and the North Pacific A. seminuda Ltk. & Mrtsn. is not so great as Mortensen (1924) believed.

Amphiura aster Farquhar

• Farquhar, H., 1901. Trans. N.Z. Inst., 33, p. 250.

Material Examined: 260 fathoms, Canyon A, off east Otago, Alert Station 54.17, 3 juvenile specimens.

Of the material seen, only the largest specimen (disc 4 mm in diameter) shows the characteristic arrangement of the tentacle-scales. The smaller ones show no tentacle-scales at all. All specimens have the disc incompletely scaled, especially below, where it is almost naked. The external lobe is lacking from the oral shield. All these differences, however, are probably an expression of immaturity.

This amphiurid genus has not hitherto been recorded from New Zealand, though a species is recorded from Torres Strait in Australian waters. The genus is characterized as follows:

Oral papillae three or four in number, subequal; radial shields divergent; disc covered by scales, without any specially distinguished marginal scales, and without disc-spines.

Amphiodia destinata Koehler

• Koehler, R., 1922. Sci. Rpts. Australasian Antarctic Exped. 1911-14, Ser. C, 8 (2), p. 32 Pl. 79.

Material Examined: 12 specimens from three stations: 400 fathoms, Cook Strait, VUZ Station 87, 4 specimens; 290 fathoms, NW of White Island, Bay of Plenty, Dom. Mus. Station B.S.203, 7 specimens; 270 fathoms, off Mayor Island, Bay of Plenty, Dom. Mus. Station, B.S.209, 1 specimen.

Remarks: The specimens from Station 87, Cook Strait, agree in most respects with Koehler's description. His material was from 350 fathoms, off the Australian quadrant of Antarctica, and the species has not till now been reported from beyond Antarctica. The largest specimen I have before me is 10 mm across the disc, and has 6 arm-spines on basal segments. The others from Station 87 have 6, occasionally 7, arm-spines. Koehler's type had only 5 arm-spines, but this character may depend on age. On the basal segments two or three spines of a cluster may be slightly recurved, not merely the second lowest spine, as stated to be the case in Koehler's material. However, Pl. 79 of Koehler's work (Koehler, 1922) seems to show more than one recurved spine on the basal segments. The Bay of Plenty specimens have a disc diameter of 7 mm or less, and differ in having the proximal spines less recurved proximad, whilst some of the middle joints of the arms have the second lowest spine recurved weakly distad.

It is possible that this New Zealand form is not identical with the Antarctic one.

Amphipholis squamata (Delle Chiaje)

• For synonymy see Mortensen, Th., 1924. Vid. Medd. dansk naturh. For., 77 p. 161–2.

Material Examined: Five deep-sea examples from three stations: 300 fathoms, Canyon A, ENE Otago Heads. 2 specimens; 200–300 fathoms, Cook Strait, VUZ Station 51, 2 specimens: 150 fathoms, Cook Strait, VUZ Station 98, 1 specimen.

Ophiura chathamensis Fell

• Fell, H. B., 1952. Zool. Pubs. Vict. Univ., 18, p. 25–8, Figs. 15–18.

Material Examined: 113–120 fathoms, off Mayor Island, Bay of Plenty, Dom. Mus. Station B.S.208, 3 specimens; 60–100 fathoms, off Mayor Island, Dom. Mus. Station B.S.207, 6 specimens.

The holotype was from Discovery Station 2733, Chatham Rise, 300 metres. The specimens from Station B.S.207 have the tentacle-pore at the margin of the lateral plate, instead of within the plate, as in the holotype. The species is presumably widely distributed on the New Zealand continental slope and shelf.

Ophiura rugosa (Lyman)

• Ophioglypha rugosa Lyman, T., 1882. Challenger Ophiuroidea, p. 68–9, Pl. 3.

The holotype was taken by the Challenger at Station 169, off East Cape, in 700 fathoms. No examples have been found in our collections.

A deep-sea genus established by H. L. Clark for a single species, O. perissus H.L.C. from off Aden, in 1,100 fathoms. It has not since been reported, and the species here referred to the genus is evidently new. The generic characters include:

The first lateral arm-plate enlarged, so as to meet its fellow of the adjoining arm, thus ringing the disc with a circle of radial and lateral plates, the disc not clearly demarcated from the arms. Oral shield small, lying proximal to the contiguous laterals. Tentacle-pores large, close together, near the ventral mid-line.

The structures which Clark (1939) called "radial shields" in his description of the type species are evidently the enlarged first lateral arm-plates, as can be inferred from his diagrams.

Ophiuraster symmetricus sp. nov. Plate 4, Figs. A, E, holotype.

Description: Disc circular in outline, with what appears to be a deep interradial notch; this notch, however, is really the space between the first lateral plates of adjoining arms. Aboral surface of the disc completely covered by scales, of which the imbricating primaries occupy the central region; beyond these lie the five pairs of polygonal radials, which are broadly contiguous. Interradially the radial shields are separated by a single prominent scale, and a few smaller scales are wedged between the primaries and the radial and interradial plates. The first pair of laterals make up the greater part of the oral surface of the disc, and also define the ambitus. The oral shields are small and transversely rhombic, distally wedged between the first laterals, proximally wedged between the adoral plates. The small adoral plates are broadly contiguous within, and separated without from the ventral plates by the large tentacle-pore, which carries three scales on its interradial margin. The oral plates each carry 6–7 oral papillae, in linear series, largest at the apex.

Arms: Upper arm-plates rhombic, declining rapidly distad, so that the distal arm-joints have none. The first upper arm-plate adjoins the radial shields and also the second upper arm-plate. The other upper arm-plates are widely separated. On the holotype there are only 7 upper arm-plates as against 10 lateral arm-plates. The lateral arm-plates are broadly contiguous above and below, except on the two basal joints. Each carries one larger and one smaller arm-spine, both arm-spines close together, conical in form, distally directed. The lower arm-plates are small; they vary in shape, and are nowhere contiguous. The basal tentaclepore carries 3 tentacle-scales, and others each carry one, relatively large, circular scale, attached to the corresponding lateral arm-plate.

Colour in Spirit: White.

Holotype: In the Dominion Museum, Wellington. R 5 mm, r 2 mm.

Material Examined: A single specimen, from 400 fathoms, NE of Mayor Island, Bay of Plenty, Dom. Mus. Station B.S.210, R. K. Dell, 28/2/1957.

Remarks: Ophiuraster symmetricus differs from O. perissus H. L. Clark in having three tentacle-scales on the basal arm-joint (instead of one only), in lacking the peripheral ring of plates within the ring of first lateral plates, and in its more regular arrangement of the aboral disc-scales. There is no "notch" at the interradial junction of the first laterals in O. perissus.

Attention may be drawn to the resemblance between Ophiuraster and Ophiomidas Koehler, both genera having the first lateral arm-plates similarly developed. The similarity extends also to the large, round tentacle-scales, the arm-spines and the adoral plates. The genera are easily distinguished by the first tentacle-pore, which is internal in Ophiomidas, external in Ophiuraster, differences which would lead to their classification, under Matusmoto's (1915) proposals, in the sub-families Ophiolepidinae and Ophiomastinae respectively. It would appear that Matsumoto's distinction of these two subfamilies is rather unnatural (though convenient) since it leads to the separation of forms which may well prove to be nearly related.

Ophiomastus tegulitius Lyman

• Lyman, T., 1882. Challenger Ophiuroidea, p. 100–1. Pl. 8.

Material Examined: None.

The holotype of the species is from Challenger Station 165, in 2,600 fathoms, 900 miles west of Cape Farewell. Further examples were taken at Station 166, in 275 fathoms, 199 miles north-west of Cape Farewell, so that the species is to be expected in Cook Strait.

Ophiomastus stellamaris Fell

• Fell, H. B., 1952. Zool. Pubs. Vict. Univ., 18, p. 30–2, Figs. 23–7.

Material Examined: The holotype and 10 other specimens, from Discovery Station 2733, in 300 metres, Chatham Rise; no other specimens have since been taken; the remarks made above, under Ophiomisidium irene, may well apply in this case also.

Ophiomastus admiral sp. nov. Plate 4, Figs. B, C, D, holotype.

Description: Disc pentagonal, tumid above. The centrodorsal is extremely large. It is surrounded by 5 small interradials, then the 5 primary radials. Two other interradial plates lie on the inter-radial axis of symmetry. One other radial plate occurs distal to the primary radial, wedged between the two radial shields at the base of the arm. The lower surface of the disc is mainly covered by the very large, obcordate oral shield; beyond this plate lie relatively few, and rather irregular, plates. The conspicuous genital clefts are equal in length to the first arm-joint, and lie beside it. The adoral plates meet narrowly within; distally, they meet both the first lateral and first ventral arm-plates. The oral angle is relatively wide and gaping, the 5 papillae flattened, square, adjoining one another so closely as to form a continuous series, the proximal and distal ones larger than the intervening ones. The upper armplates are fan-shaped, with a right-angled proximal apex and a rounded distal border, about as broad as long, not contiguous. The lateral arm-plates meet very narrowly above and below beyond the two basal arm-joints. They carry two conical spines, the lower one the larger, though scarcely half as long as its arm-joint. The ventral arm-plates are pentagonal, a little longer than broad, with an acute proximal angle, a broad convex distal margin, and concave lateral margins, within which the tentacle-pore is placed on either side. The single, large, round tentacle-scale is carried on the adjoining margin of the lateral plate.

Material Examined: Four specimens including the holotype, all from 400 fathoms, Cook Strait, VUZ Station 87. Two poorly preserved juvenile ophiuroids from 300 fathoms, off east Otago, Dom. Mus. Station B.S.190, possibly belong to the same species.

Holotype: In the Department of Zoology, Victoria University of Wellington. R 15 mm, r 2·5 mm. Colour in alcohol white, colour in life probably pink (a mixed collection of ophiuroids from this station was so described, J. C. Yaldwyn).

Remarks: Ophiomastus admiral differs from O. secundus Lyman in that the arm-spines are not subequal, the disc contains a number of plates other than the primaries, and the oral papillae are separate. The two species agree in having a single large tentacle scale. O. admiral differs from O. tegulitius Lyman in having one large tentacle-scale (instead of two small ones). From O. stellamaris Fell the species differs in having two lateral (instead of one ventral) arm-spines, and the tentacle-scales are relatively and absolutely smaller, despite the fact that the body is larger than in O. stellamaris.