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.

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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.