Richmondaropa prava ( Hedley, 1924 ) Shea & Colgan & Stanisic, 2012

Shea, M., Colgan, D. J. & Stanisic, J., 2012, 3585, Zootaxa 3585, pp. 1-109 : 82-83

Richmondaropa prava ( Hedley, 1924) n. comb.

( Figs 30B, C; 32B. C; 34B, C; 36B, C; 38A, B; 39F, G; 40F; 41E, F)

Gyrocochlea prava Hedley, 1924: 217 .

Gyrocochlea prava: Iredale 1937: 323 ; Iredale 1941a: 268; Smith 1992: 191; Stanisic et al. 2010: 200.

Diagnosis. Shell very small, cinnamon brown, biconcave with weakly depressed spire. Protoconch sculpture primarily spiral consisting of 21 prominent, widely spaced, narrow, continuous spiral cords; vague, very weak, underlying radial ridges present. Teleoconch sculpture of numerous, prominent, quite uniformly spaced, slightly sinuate, strongly prosocline radial ribs. Ribs on body whorl 100–117 (mean 104). Umbilicus wide U-shaped to cupshaped. Epiphallus longer than penis, entering penis through a simple pore (verge absent). Penis tubular with an expanded apical portion, internally with 2–3 longitudinal pilasters.

Type material examined. Holotype. AM C63491, Upper Tweed River , NSW, coll. W. Petterd. Paratypes. AM C.103621, same data as holotype .

Other material examined. NSW-Booyong Nature Reserve: AM C.140225, QMMO 17066. Richmond Range: QMMO 6273, QMMO 10909/ AM C.128499, QMMO 49123. Stotts Island: QMMO 10517, QMMO 78719. Lismore: QMMO 19824, QMMO 77015. Qld-Currumbin Valley: AM C.339711.

Description. Shell very small, cinnamon brown, biconcave with weakly depressed spire. Whorls 3.62–4.5 (mean 4.00), tightly coiled, the last weakly expanding and strongly descending in front. Sutures strongly impressed. Shell diameter 3.59–3.93 mm (mean 3.77 mm), height 1.99–2.17 mm (mean 2.09 mm), H/D 0.48–0.77 (mean 0.55). Protoconch flat, of 1.12 whorls, diameter 0.56–0.67 mm. Protoconch sculpture primarily spiral consisting of 21 prominent, widely spaced, narrow, continuous spiral cords; underlying weak radial ridges present. Teleoconch sculpture of numerous, prominent, quite uniformly spaced, slightly sinuate, strongly prosocline radial ribs. Ribs on body whorl 100–117 (mean 104), width of interstices on the first teleoconch whorl equal to width of four to greater than or equal to width of six ribs; on the penultimate whorl equal to width of four to equal to width of six ribs; each rib with single periostracal blade. 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 5–8; on first quarter of body whorl 9–10. Aperture broadly ovately-lunate. Parietal callus prominent, transparent. Umbilicus wide U shaped to cup-shaped, diameter 0.82–1.32 mm (mean 1.04 mm), D/U 2.65–4.40 (mean 3.56). Based on 25 measured adults.

Reproductive tract with ovotestis containing two clumps of alveoli, with more than two alveolar lobes per clump. Hermaphroditic duct corrugated, crescent-shaped. Spermatheca with a medium-sized circular bulb. Penial retractor muscle inserting on top of penis at the junction of the penis and epiphallus. Epiphallus longer than penis, entering penis through a simple pore (i.e. verge absent). Penis tubular with an expanded apical portion, internally with 2–3 longitudinal pilasters. Vagina shorter than penis. Atrium short.

Distribution and habitat. Richmond River to the Border Ranges, north-eastern NSW; found in lowland to mid-altitude rainforest and vine thicket, living under logs.

Remarks: Richmondaropa prava ( Hedley, 1924) n. comb. is distinguished from the more coastal and parapatric Richmondaropa conjuncta (Iredale, 1941) n. comb. by its larger size, less tightly coiled whorls and more crowded and numerous radial ribs on the teleoconch. R. prava differs from the broadly sympatric Dictyoropa eurythma chiefly by the protoconch sculpture which in R. prava primarily consists of widely spaced, narrow spiral cords in contrast to the broadly reticulate pattern of D. eurythma . Radial elements are present on the protoconch of R. prava but these take the form of weak underlying growth ridges.