Opalia australis
(Lamarck, 1822)
Description:
Dimensions range from 19.5 mm - 43.1 mm high and 8 mm - 15.02 mm wide.
Width to height ratio: 0.41:1 ~ 0.35:1
Shell: tall, variable in height to width ratio, slender, elongate, moderately elevated, somewhat blunt, and variable in height to width ratio; thick; small to medium. Exterior colour uniformly white internally and externally, white to greyish, white, white, or dark purple between varices., greyish. About 10 whorls, rounded, whorls increasing slowly, contiguous, somewhat compressed, rounded below the shoulder, , connected, contiguous; teleoconch with ~9 whorls contiguous, barely prominent whorls. Suture impressed, suture barely excavated. Imperforate: umbilicus closed. Approximately 8 - 12 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:
Iluka, NSW, around southern Australia to Perth, Western Australia [Wilson 1993: 280]. Cotton & Godfrey [1906: 7], also report Middleton, SA to Yallingup, WA; Victoria and Tasmania [Macpherson & Gabriel, 1962:114]
Habitat:
Under rocks on rocky shores in association with anemones [Beechey, 2008]
Etymology:
[latin] from australis = southern
Type Material:
Described from the seas of New Holland, sent by Macleay; Port J ackson, New South Wales, may be selected as the restricted type locality. for Opalia australis (Lamarck, 1822). [Iredale, T., 1936]
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.
Kiener, L. C., & Fischer, P. (1838b).
Plate VI. Fig. 17.
Plate VI. Fig. 17.
pp: 16.
14. Southern Wentletrap -Scalaria australis Lamarck
(Mass collection; Lamarck collection)
Guérin, Magasin de Zoologie, 1830, pl. 40.
(Pl. VI, fig. 17)
Shell elongate, turreted, slender, apex obtuse, white; ribs smooth and very straight, terminating below the last whorl above a keel; sutures scarcely excavated.
Shell elongate, turreted, with a very pointed spire, composed of 9-10 rather narrow, slightly convex whorls united by a shallow suture. The whorls are ornamented longitudinally with nine smooth, obtuse, perpendicular ribs. On the last whorl, the ribs are bounded near their lower extremity by a thick decurrent keel, leaving a smooth space between the keel and the base of the shell; base not umbilicate. Aperture moderate, rounded, with a slightly thickened peristome. Shell entirely white.
Length 1 inch.
Habitat. Seas of New Holland (Australia).
This shell appears most closely related to Scalaria lamellosa Scalaria lamellosa, but differs in having a less deeply impressed suture and ribs that are more rounded and less elevated. In certain individuals the ribs may disappear almost entirely, leaving only faint traces of their former presence. Quoy, in the Voyage de l'Astrolabe (pl. 55, figs. 27-28), established under the name Turritella cerithium Turritella cerithium a specimen of Scalaria australis, although in poor condition.
Sowerby, G. B. II. (1844).
Shown in text as Scalaria australis Lamarck, 1822
Plate xxxv. Fig. 135.
pp: 103-104.
"T. elongated, thick, smooth, imperforate; with 9 contiguous whorls, barely prominent; the last whorl encircled by a strong keel at the front; suture barely excavated; with 10 simple, somewhat straight, thick, smooth, prominent varices terminating at the keel; white in color, or faintly purplish in the spaces between varices."
Sowerby, G. B. II. (1873).
Shown in text as Scalaria australis.
Plate i. Fig. 3.
Scalaria australis. The shell is somewhat small, thick, moderately elevated, greyish between the varices; whorls increasing slowly, contiguous, somewhat compressed, rounded below the shoulder, thickly encircled; varices thick, somewhat spaced, slightly raised, continuous.
Tryon, G.W. (1887).
Shown in text as Scalaria australis Lamarck, 1822
Plate 16. Fig. 990.
pp: 76.
Clessin, S. (1897).
Plate 2. Fig. 5.
pp: 5.
Verco, J.C. (1906).
pp: 146.
Verco, J.C. (1906).
Shown in text as Scalaria australis Lamarck, 1822
pp: 146.
Cotton, B.C. & Godfrey, F.K. (1931).
Plate I. Fig. 4.
pp: 7.
Iredale, T. (1936).
Fig. 26.
Macpherson, J.H. & Gabriel, C.J. (1962).
pp: 116. Fig. 141.
pp: 114.
pp: 115.
Mermod, G, & Binder, E. (1963).
pp: 165. Fig. 230.
Kaicher, S.D. (1980).
Card #: EP1-2370.
Beechey, D. (2008).
