Variciscala raricostata
(G. B. Sowerby II, 1844)
Description:
Dimensions range from 20.5 mm - 25 mm high.
Width to height ratio: 00:1 ~ 00:1
Shell: pyramidal, ventricose; solid, thick; moderately small. Exterior colour white. About 5 whorls, rounded, rapidly increasing, convex, distinct. Suture deeply impressed, distinct. Umbilicate: narrow, small, but more or less obstructed by varices that extend inward. Costae are regularly spaced, low, subequal axial cords, with rare, prominent, crenulated, rounded, very few, unequally distant. rounded, crenulated, thick, thin, cord like. There is a single varix on each whorl. The varix is with an occasional thick, crenulated, reflected varix . Costae reflexed. Intercostal spaces numerous radial striae, creating a cancellate appearance where they intersect the costae. Fasciole complete. Aperture large, sub-circular, lip thickened by a weakly nodulose varix; inner lip slightly expanded anteriorly.
Distribution:
Indo-West Pacific; North Queensland, Australia; Sri Lanka, Mauritius. Kiener [1873:8] cites a specimen from Sicily.
Habitat:
not listed in source material
Etymology:
from rarus [latin] = scattered, far apart, seldom, rare or few and costatus = ribbed, in reference to the occasional expanded rib on the shell
Type Material:
Iredale indicates a single specimen; not located, but presumably in the Australian Museum. [as Cirsotrema kelea Iredale, 1930:] - Type Locality: Michaelmas Cay, Queensland, Australia, 9-12 fms [= 16-22 m].. [Brown, L. & Neville, B.D., 2015]
arsint.com (2023).
20.5 mm
North Queensland, Australia. 1991
Distribution
as listed in source literature
Sowerby, G. B. II. (1844).
Plate xxxiv. Fig. 79-80.
pp: 93.
original description
Sowerby, G. B. II. (1873).
Plate ii. Fig. 9.
Plate xiv. Fig. 9b.
Kiener, L. C., & Fischer, P (1873a).
Shown in text as Scalaria raricosta Lamarck, 1822
Plate II. Fig. 6.
Plate II. Fig. 6.
pp: 8.
6. SCALARIA CÔTES BARRÉES, Scalaria raricosta, LaM.
(Collection Mass. LAM.)
Sowerby, Genera, cahier 11, plate 2, fig. 3.
Plate II, fig. 6.
Description (Latin):
Shell turreted, perforated, white, with very fine transverse striae, obsolete longitudinal ribs; varices shaped like ribs, interrupted, rare and densely clustered in particular spots.
Description (French):
Shell oval-conical, somewhat turreted, cyclostome-shaped, with a pointed spire made up of six very convex, rounded whorls, on which some varices appear representing former peristomes; sometimes these varices are opposite one another, sometimes irregularly scattered. The whorls are separated by a rather deep suture. On these whorls, a very large number of small, closely spaced longitudinal striae can be seen, crossed by even finer transverse striae that give the shell a somewhat rough texture and form a rather regular fine mesh. The last whorl is subglobular, ending at its base in a small, narrow, and shallow umbilicus. The aperture is oval, rounded, almost semi-lunar. The peristome is thick, striated, and externally bordered by a convex ridge. The external color of the shell is a dull white.
Length: 9 lignes (about 20.3 mm or 0.8 inches).
Habitat: Mediterranean? Coasts of Sicily (Costa, Catalogue of Sicily).
Remarks:
This very peculiar shell is quite distinct from all other Scalaria species; in terms of external shape, it shows a strong resemblance to our elegant Cyclostome.
Tryon, G.W. (1887).
Shown in text as Scalaria raricostata Lamarck 1822, Scalaria reticulata Helbling, 1779
Plate 16. Fig. 2-3.
pp: 78.
Clessin, S. (1897).
Plate 3. Fig. 6.
pp: 10.
Shell white, thick, cancellated, pyramidal, swollen; whorls convex, distinct, rapidly increasing; varices very few, unevenly spaced, rounded, crenulated, thick; aperture rather large; inner lip slightly expanded at the front; umbilicus minute.
Mermod, G. (1963).
Shown in text as Scalaria raricosta Lamarck, 1822
pp: 16+. Fig. 231.
pp: 166.
pp: 167.
Wilson, B.R. (1993).
pp: 379. Plate 44. Fig. 10.
Variciscala raricostata
arsint.com (2023).
20.5 mm
North Queensland, Australia. 1991
