Cumberlandica wilsoniana, Shea & Colgan & Stanisic, 2012

Shea, M., Colgan, D. J. & Stanisic, J., 2012, 3585, Zootaxa 3585, pp. 1-109 : 32-33

Cumberlandica wilsoniana n. sp.

( Figs 7G; 8G; 9G)

Etymology. For the type locality.

Diagnosis. Shell very small, light brown, biconcave with a strongly depressed spire and tightly coiled whorls, the last considerably expanded. Protoconch sculpture of prominent radial ribs and weak, closely spaced spiral lirae; teleoconch sculpture of numerous, widely spaced radial ribs and cancellate microsculpture. Umbilicus widely open, U-shaped.

Type material examined. Holotype. QMMO42154 , near Cathedral of Ferns picnic area, Blue Mountains National Park at Mt Wilson , northeast of Blackheath, Upper Blue Mountains, NSW (33° 30´S, 150° 23.96´E), 15.x.1992, coll. J. Stanisic, G. Ingram.

Description. Shell very small, light-brown, biconcave with a strongly depressed spire. Whorls 4.25, tightly coiled, the last considerably expanded and descending in front. Sutures impressed. Shell diameter 4.29 mm, height 2.29, H/D 0.53. Protoconch flat, 1.0 whorls, diameter 0.41 mm. Protoconch sculpture consisting of low, spaced, narrow spiral threads and spaced radial ridges, becoming more pronounced toward the protoconch-teleoconch boundary. Teleoconch sculpture of numerous, prominent, quite uniformly spaced, slightly sinuate, orthocline radial ribs. Ribs on body whorl 103, width of interstices on the first teleoconch whorl equal to width of three to less than width of six ribs; on the penultimate whorl equal to width of four to less than six ribs; each rib with two or more overlapping periostracal blades. Interstitial sculpture of low prominent microradial ribs and low, weaker microspiral cords forming beads at their intersection; number of microradials between ribs on the first teleoconch whorl 8–10; on first quarter of body whorl 10–12; microspirals very low. Aperture broadly ovately-lunate. Parietal callus prominent, finely pustulose, transparent. Umbilicus wide U-shaped, diameter 1.22 mm, D/U 3.51. Based on one measured adult.

Anatomy unknown.

Distribution and habitat. Known only from the type locality at Mt Wilson, Blue Mountains, NSW; found in warm temperate rainforest on basaltic soil at altitude c. 900–1,000m, in litter under logs and rocks.

Remarks. The single specimen of Cu. wilsoniana n. sp. was mistakenly thought to be conspecific with Cu. impressa impressa by Stanisic et al. (2010) on the basis of its general resemblance to the type of the species illustrated by Hedley (1924). However, detailed examination has revealed that it does not belong to that species. Cu. wilsoniana n. sp. is included in Cumberlandica on the basis of general shell features, pending further study. The protoconch of Cu. wilsoniana n. sp. has not been examined by SEM but optically it appears to consist of prominent radial ribs which extend over the entire protoconch surface and very insipid, closely spaced spiral lirae. These features combined with the broadly ovate aperture and inflated body whorl make its inclusion here rather tentative. In general shell morphology the species more closely resembles Nautiliropa omicron from far northern NSW and south-eastern Qld. The species has only been collected once in spite of additional searches in the type locality.