Notes on the Genus Haliotis (Mollusca) A New Subgenus from New Zealand and a New Species from the Late Cenozoic of Ohope, Bay of Plenty

By C. A. Fleming, Geological Survey, Wellington

Sanhaliotis Iredale, 1929, Mem. Queensland Mus., 9 (3) : 270. Type (o.d.): H. varia Linn. (Indo-Pacific).

Schismotis Gray, 1856, P. Zool. Soc. Lond, 1856: 148. Type (haplotype): H. excisa Gray = albicans Q. and G. (Southern Australia and Tasmania).

Sulculus H. and A. Ad., 1854, Gen Rec. Moll., 1. 443. Type (s.d., Cossmann, 1918): H. incisa Reeve.

None of the known New Zealand species, fossil or Recent, has any close affinity with the types of Haliotis (s.str.), Exohaliotis, Marinauris, Neohaliotis, Ovinotis, Padollus, or Schismotis.

Sulculus H. and A. Adams was diagnosed as a subgenus of Padollus and has been synonymized with the latter by most revisers, but of the nine species listed, only one (parvus Linn.) is closely related to Padollus; the others, including incisa Reeve, which was designated type by Cossmann, are small oval species without the dorsal spiral rib of the Padollus group. H. incisa Reeve (Conch. Icon., 3: 57) is a small shell with the characters of H. coccoradiata Reeve and thus closely related to many small oval depressed Haliotis, including the European H. tuberculata Linn. Pilsbry's (1890) equation of incisa with japponica is apparently an error.

The name Sulculus must apply to shells grouped around the type species, incisa, and not to shells agreeing with H. and A. Adams' diagnosis. Sulculus is thus the earliest name for small oval Haliotis with the pillar coiled in an open spiral, sculptured by spiral cords, crossed by growth-lamellae or radial ribs in some species, with excentric nucleus, lacking the characteristic dorsal fold of Padollus and its allies. It is difficult to find conchological characters of subgeneric rank to subdivide a widespread group of species with these general characters, including the European tuberculata Linn. (and its extreme development, lamellosa Lk.), the Australian forms ranked in Notohaliotis, including the type, H. naevosa Mart. (= ruber Leach) and the Indo-Pacific H. squamata Rve. and H. varia (type of Sanhaliotis Iredale). Cotton (1943), in his review of Australian Haliotidae, recognized Notohaliotis and Sanhaliotis as separate genera, but failed to indicate the diagnostic differences in his key (p 175). They are therefore synonymized with Sulculus in this paper.

The New Zealand Haliotis australis Gmelin is conchologically close to naevosa, and H. virginea Gmelin may also be located in Sulculus in the meantime, in spite of its somewhat discrepant coiling.

Haliotis iris Martyn,^* the well-known paua of New Zealand, cannot be accommodated in any of the above subgenera.

Subgenus Paua nov.

Type: Haliotis iris Martyn, 1784, Universal Conchologist, 2, fig. 61 (Recent, New Zealand).

Shell large, oval, with a broad, flattened columellar flange continued below the spire, to meet the outer lip. The whorl profile slopes outward to the columellar flange which forms the periphery, whereas in other subgenera the periphery is between the columella and the perforations. Whorls more rapidly increasing than in Sanhaliotis and spire filled with callus. Pillar short, steeply descending,

not coiled in an open spiral as in Sulculus. Muscle scar well defined, wrinkled. Animal black, with dark bluish-grey sole; visceral mass forming a simple hump without notable spiral form (in contrast with Sulculus).

The radula of the type species (Hutton, 1882: 127, pl. 15, f. H) differs in almost every tooth from that of H. tuberculata Linn. (Fischer, 1885: 843) and H. glabra: “Chemn.” (Theile, 1931: · 29); in particular, the central tooth bears “a long process projecting backward and upward on each side below the reflexed portion.”

The subgenus Paua is to be regarded as feminine.

Subgenus Sulculus H. and A. Adams

Type (by subsequent designation, Cossmann, 1918, Essais II · 315): Haliotis incisa Reeve (? Japan)

Haliotis (Sulculus) powelli Fleming n.sp. Plate 47, figs. 1–3.

A rather small, much depressed Haliotis more elongately-oval than New Zealand Recent species, approaching H. tuberculata, lamellosa, and squamata in outline. Nucleus more central than in H. virginea, but more eccentric than in australis, naevosa, coccoradiata, and varia. Shell less elevated than in most of these species except coccoradiata and tuberculata, and like them, depressed medially in a shallow spiral zone between the perforations and the suture, slightly swollen above and below the depressed zone. Outer lip sinuous, with a median concavity corresponding with the depressed zone, ascending steeply outside the marginal perforation. Inner and outer lips both arched gently above the plane of the animal's foot, as in squamata. Perforations on low tubercles, fewer and larger than in most species of the same size, open perforations four, as in H. varia alone of related species compared. Sculpture: on young shell, of 21 spiral threads, regularly alternating in strength, between suture and perforations, slightly moniliform or scaly where crossed by irregularly spaced, rather distant, narrow sinuous growth-folds; on adult quarter-whorl, radial sculpture reduced to fine, well-marked growth lines. Periphery angled, with a sharp spiral cord, a second cord between periphery and outer edge of columella, and three spaced rounded cords in a shallow depression between periphery and perforations. H. coccoradiata has a similar periphery with two cords below and 4–5 cords above it, alternating in strength; most species have many more peripheral cords. Interior not exposed.

Length, 47 mm.; breadth, 30.5 mm.; height above plane of aperture, 8.2 mm.

Holotype, the only specimen, in collection of New Zealand Geological Survey (3893.1)

Locality: G.S. 3893, exposed face of cliff behind Ohope Beach, Bay of Plenty, New Zealand; collected by C. A. Fleming, May, 1948. Horizon: Castlecliffian Stage, Putikian Substage (see Fleming, in press).

Remarks: Of the species available for comparison, Haliotis powelli is closest to H. coccoradiata Reeve (New South Wales, Victoria). I am grateful to Mr. A. W. B. Powell, Auckland War Memorial Museum, for indicating this affinity and for supplying a tracing of Reeve's figure of Haliotis incisa. I am glad to have the opportunity to dedicate a handsome species to his name. Specimens of H. squamata Reeve from Java are also related, but have more perforations and peripheral spirals.