Opalia australis
(Lamarck, 1822)
Description:
Dimensions range from 43.1 mm high and 15.02 mm wide.
Shell: tall, variable in height to width ratio, slender, elongate, moderately elevated, somewhat blunt, and variable in height to width ratio; thick; medium. Exterior colour uniformly white internally and externally, white to greyish, white, white, or dark purple between varices., greyish. About 9 whorls, rounded, whorls increasing slowly, contiguous, somewhat compressed, rounded below the shoulder, , connected, contiguous. Suture impressed, suture barely excavated. Imperforate: umbilicus closed. Approximately 8 - 11 costae on the body whorl. Costae are sculptured with strong axial ribs,, ribs which join to form a spiral band at the base of th ebody whorl, varices, which are also thick, prominent, and smooth, arices thick, somewhat spaced, slightly raised, continuous. Costae aligned from whorl to whorl; not separated, continuous. Intritacalx present, thick and relatively hard in shells of this species. Intercostal spaces Interspaces smooth or with faint spiral threads, extremely fine spiral striae. Base Axial ribs end at strong spiral rib on base, ribs end in thick basal spiral rib, encircled by a strong keel at the front;. Aperture ovate; peristome incomplete. Operculum corneous.
This species is relatively large, solid and heavy, and is the one most commonly found in beach washup. See also O. ballinensis.
Distribution:
Habitat:
Under rocks on rocky shores in association with anemones, low intertidal and shall subtidal. Moderately common.
Type Material:
Mermod and Binder (1963: 164) report that there are five specimens in the Lamarckian collection bearing the label

Sowerby, G. B. II. (1844). Plate xxxv. Fig. 135.
Distribution
as listed in source literature
Lamarck, [J.-B. M.] de. (1822).

pp: 228.
translation of original description:
Shell turreted, slender, with a blunt apex, white; with smooth, perfectly straight ribs placed below the last whorl above the keel; sutures somewhat excavated.
Inhabits the seas of New Holland (Australia). Mr. Macleay. My collection.
It is imperforate, smooth, without spots, and only one inch in length.
Sowerby, G. B. II. (1844).
Shown in text as Scalaria australis Lamarck, 1822








