Planorbacochlea manningensis, Shea & Colgan & Stanisic, 2012

Shea, M., Colgan, D. J. & Stanisic, J., 2012, 3585, Zootaxa 3585, pp. 1-109 : 56

Planorbacochlea manningensis n. sp.

( Figs 20A; 21A; 22A; 23A; 24A; 25E; 26E; 28C–E)

Etymology. For the Manning Valley, New South Wales.

Diagnosis. Shell very small, orange-brown, biconcave with weekly depressed spire. Protoconch sculpture spiral consisting of 25 to 27 prominent, closely spaced, beaded spiral cords and weak, closely spaced radial ridges becoming more pronounced toward the protoconch-teleoconch boundary. Teleoconch sculpture of numerous, prominent, quite uniformly spaced, slightly sinuate, orthocline to weakly prosocline radial ribs. Ribs on body whorl 129–144. Umbilicus wide cup-shaped. Penis club- or pear-shaped, longitudinal pilasters distally, apically with a fluted vase-shaped verge having a terminal pore and about half the length of penis or longer.

Type material examined. Holotype. AM C.369784, 15 km SW of Taree, via Tinonee, off Possum Brush Rd , New South Wales, (31° 59’ 23” S, 152° 22’ 23" E), 19.iii.1990, coll. I. Loch, P.H. Colman. Paratypes. AM C. 472893, same data as holotype. SW Taree : AM C.163134. NW Taree : AM C.163253. S Wingham: AM C.163268.

Description. Shell very small, orange-brown, biconcave with weakly depressed spire. Whorls 3.5–4.0, tightly coiled, the last inflated and descending in front. Sutures strongly impressed. Shell diameter 3.05–3.37 mm (mean 3.25 mm), height 1.50–1.63 mm (mean 1.57 mm), H/D 0.47–0.51 (mean 0.48). Protoconch flat, of 1.12–1.25 whorls, diameter 0.40–0.54 mm. Protoconch sculpture strongly spiral consisting of 25 to 27 prominent, closely spaced, beaded spiral cords and weak, closely spaced radial ridges becoming more pronounced toward the protoconch-teleoconch boundary. Teleoconch sculpture of numerous, prominent, quite uniformly spaced, slightly sinuate, orthocline to weakly prosocline radial ribs. Ribs on body whorl 129–144 (mean 138), width of interstices on the first teleoconch whorl equal to width of four to less than six ribs; on the penultimate whorl equal to width of four to less than six ribs; each rib with two or more periostracal blades. Interstitial sculpture of low prominent microradial ribs and low, weaker microspiral cords forming weak beads at their intersection; number of microradials between ribs on the first teleoconch whorl 5–7; on first quarter of body whorl 6–7. Aperture broadly ovately-lunate. Parietal callus prominent, transparent. Umbilicus wide cup-shaped, diameter 0.85–1.03 mm (mean 0.95 mm), D/U 3.23–3.61 (mean 3.43). Based on 8 measured adults.

Reproductive organs with ovotestis containing two clumps of alveoli, with more than two alveolar lobes per clump. Hermaphroditic duct narrow to broad crescent-shaped. Spermatheca with a large oval bulb. Penial retractor muscle inserting at the junction of the penis and epiphallus. Epiphallus equal or shorter than penis, entering penis through a verge. Penis club- or pear-shaped, longitudinal pilasters distally, apically with a fluted vase-shaped verge having a terminal pore and about half the length of penis or longer. Vagina shorter than penis. Atrium short.

Distribution and habitat. Lower Manning Valley, NSW; found in wet sclerophyll forest, living under logs.

Remarks. Planorbacochlea manningensis n. sp. superficially resembles P. planorbis from the Port Stephens/ Hunter River area in shell morphology but can be distinguished from that species by the more crowded ribbing on the teleoconch. P. yessabahensis n. sp. from the Macleay Valley has less crowded ribs on the teleoconch and a protoconch which is reticulate (lattice-like) with more widely spaced spiral cords. DNA extraction was unsuccessful for this species.