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 [Beechey, 2008ae]. Intercostal spaces with extremely fine spiral striae. Base with a strong basal ridge, costae do not cross the base, terminating at the ridge. 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, New South Wales, southwards around southern Australia to Perth, Western Australia [Wilson, 1993:280]. Cotton & Godfrey [1906:7] additionally recorded the species from Middleton, South Australia, to Yallingup, Western Australia, while Macpherson & Gabriel [1962:114] included Victoria and Tasmania. Clessin [1897:5] also cited the Cape of Good Hope as part of the species' range; however, this record has not been corroborated by subsequent authors.
Habitat:
Under rocks on rocky shores, in association with anemones [Beechey, 2008ae].
Etymology:
[latin] from australis = southern.
Sowerby, G. B. II. (1844). Plate xxxv. Fig. 135.
Distribution
as listed in source literature
Type Material:
Iredale [1936:304] noted the species was "described from the seas of New Holland, sent by Macleay;" and restricted the type locality to Port Jackson, New South Wales. Mermod & Binder [1963:164] note that the Lamarck collection housed in the Museum de Geneve contains 5 specimens from "mers se la Nouvellle-Hollande" with a label by Lamarck reading "Scalaria e nova holl. Macleay" and, on the reverse, "Sc. australis" in the hand of Rosalie de Lamarck. Brown & Neville [2015:42], refering to Mermod and Binder [1963: 164] comment that, as no type is designated, the five specimens must be considered syntypes.
The following list brings together type material and other cited specimens as reported in the sources examined, grouped under the names and designations used in each source. The same specimen may appear in multiple entries drawn from different sources. Some entries concern other species included by authors for comparison; inclusion in this list does not imply synonymy.
Opalia australis (Lamarck, 1822)Typeseas of New Holland; Port Jackson, New South Wales, Australia. Collected by: Macleay. sent by Macleay. [Iredale, 1936: 304].
Scalaria australis Lamarck, 1822SyntypeLamarckian collection. les mers de la Nouvelle-Hollande [the seas of ] per Lamarck (1822: 228), New South Wales, Australia. Iredale (1936: 304) restricted the type locality to Port Jackson. [Brown & Neville, 2015: 42].
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.
pp: 164.
Scalaria australis Lamarck, Animaux sans vertèbres, vol. 6, part 2, p. 228, no. 6; seas of New Holland (M. Macleay); my cabinet; length 1 inch (= 27 mm); manuscript. Eight specimens -Lamarck Collection, Geneva:
Five specimens with a label by Lamarck reading "Scalaria e nova holl. Macleay" and, on the reverse, "Sc. australis" in the hand of Rosalie de Lamarck.
pp: 165.
The apex is truncated in all specimens. The first four specimens show identical characters; only the fifth appears aberrant, with the costulation of the last two whorls much less distinct. The ribs fuse into strictly vertical rows from the apex to the base of the shell. The peri-umbilical region is delimited by a raised spiral cord, as in Scalaria lamellosa Lamarck, so that the space between this cord and the columella forms a distinctly concave spiral zone in which the axial ribs are greatly attenuated. Under the binocular microscope, an extremely fine reticulate pattern can be seen in the intercostal intervals, formed by the perpendicular intersection of two microscopic systems, axial and spiral, producing areolae that resemble pinpricks. This ornamentation extends onto the faces of the ribs but is worn on their summits. The aperture is very regularly oval, externally bordered by the ultimate rib and internally by the columella. The base is slightly notched by the concavity of the peri-umbilical zone. In general, the relief of the ribs is much less pronounced than in Sc. communis and Sc. lamellosa Lamarck.
Beechey, D. (2008).
