Edgbastonia (Barcaldinia) pagoda Zhang 2019, n. sp.

Edgbastonia (Barcaldinia) pagoda n. sp.

Material examined. Holotype: Queensland, Myross Station, small spring, 22° 46' 32" S, 145° 26' 17" E, under two large gum trees, W.F. Ponder, R. Fairfax & R. Fensham, 17 Sep 2006, C.479948. Paratypes: Same data, C.457756, 49, QM MO85767, 5. Other material examined: Queensland, Myross Station, small spring 22° 47' 42" S, 145° 26' 26" E, R.J. Fensham & R. Fairfax, 1 Jul 2008, C.483021 20+, (=462095) same locality.

Shell (Fig. 13E). Elongate-conic, spire outline straight, normally coiled, opaque. Length 1.8–2.7 mm (mean 2.3 mm), width 1.0– 1.3 mm (mean 1.2 mm). Protoconch about 1.3 whorls, minutely pitted. Teleoconch whorls moderately convex, shouldered to strongly keeled in middle, total number 4.5–5.5 (mean 5.0). Umbilicus represented by chink only. Aperture ovate, inner lip narrow, thin or medium, slightly separated along whole length of parietal wall, outer lip medium. Periostracum moderately developed, white or yellow-brown.

Operculum (Fig. 14F, G). Transparent, pale yellow, slightly concave. Inner side simple, lacking white smear or protuberance.

Head-foot and external body. Snout, tentacles, neck, dorsal and lateral foot and opercular lobes pigmented, mantle roof black, visceral coil densely pigmented or black.

Mantle cavity. Ctenidium well-developed, filaments 22–29, broadly triangular, apex right edge. Osphradium narrowly oval, towards posterior end of ctenidium, length relative to gill 0.29–0.31. Hypobranchial gland welldeveloped (thick), or moderately developed. Rectum with U-shaped bend, anus behind mantle collar. Kidney extends for about third of length into mantle cavity roof, or half or more in roof of mantle cavity. Renal gland transverse. Pericardium extends for about third of length into mantle cavity roof, with moderate separation from posterior end of ctenidium.

Radula (Fig. 15 G–I). Central teeth with cusp formula 5–6+1+5–6, basal cusps 1–2+1–2; median cusp sharp, slightly less than twice as long as adjacent cusps. Lateral teeth with cusp formula 3–4+1+3–5; main cusp sharp to blunt, about 1.5 times length of adjacent cusps. Inner marginal teeth with 22–25 cusps. Outer marginal teeth with 22–26 cusps.

Female reproductive system (Fig. 16G, H). Ovary simple sac. Renal oviduct with vertical U-shaped arch, dorsal part may be twisted to right (as in figured specimen). Seminal receptacle near anterior edge of bursa, oval, duct very short; orientated sperm also in renal oviduct and/or bursal duct. Bursa copulatrix behind albumen gland, round or triangular, shorter than albumen gland, bursal duct enters bursa antero-ventrally, bursal duct joins coiled oviduct at posterior mantle cavity wall. Albumen gland behind posterior mantle cavity wall. Capsule gland with no glandular zones discernible or two distinct glandular zones, medium thickness in cross section, markedly indented by rectum. Anterior vestibule large, opening terminal, short, cowl and/or gutter associated with oviduct opening absent.

Male reproductive system (Fig. 17D, 18E). Prostate gland less than half in mantle roof, oval, medium in cross section. Posterior pallial vas deferens slightly undulating, anteriorly slightly undulating. Penis towards middle of head, well down neck, distal part lacking lobes, terminal papilla small.

Etymology. Pagoda: resembling a Buddhist tower.

Distribution and habitat. Known only from one small, shallow spring on Myross Station (Fig. 1). Lives sympatrically with E (B.) cf. pallida and the species described below.

Remarks. This species is similar in shell size and shape to Ed. (B.) acuminata and Ed. (B.) zeidlerorum but differs from these and all other species in the Jardinella group in having a pagodiform shell. The female oviduct is somewhat similar to that of Ed. (B.) jesswiseae in having a very expanded vestibule, while those of Ed. (B.) acuminata, Ed. (B.) zeidlerorum and Ed. (B.) rugosa n. sp. are not markedly expanded. The penis is not expanded distally as it is in Ed. (B.) jesswiseae but in marked contrast to the other species in this subgroup, both species have an uncoiled vas deferens near the base of the penis.

The spring in which this species and the next were found is a small pool on flat ground and is not fenced or otherwise protected. While a detailed survey of this property has not been conducted, sampling so far has failed to find either this species or the next in other locations.