Amplirhagada descartesana Köhler 2010, n.sp.
Creators: name: Köhler, Frank
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Camaenidae
Amplirhagada
Amplirhagada descartesana

description: <i>Amplirhagada descartesana</i> n.sp. <b>Type locality</b> (Fig. 1). Western Australia, northwestern Kimberley, Admiralty Gulf, Institute Islands, Descartes Island, 14°10'26"S 125°40'38"E; KC-071 (leg. V. Kessner &amp; A. Longbottom, 19 July 1988). <b>Type material</b>. Holotype WAM S34607 (Pl. 1.12). Paratypes WAM S41491 (4 preserved specimens, as holotype), FMNH 219276 (5 preserved specimens, as holotype), FMNH 219272 (16 preserved specimens, unnamed island SW of Descartes Island, 14°10'45"S 125°40'00"E, KC/070), WAM S41490 (10 preserved specimens, same as FMNH 219272), AMS C463749 (7 preserved specimens, same as FMNH 219272). <b>Additional, non-type material</b>. WAM S41452 (Descartes Island, 125°40'47"E 14°09'50"S). <b>Etymology</b>. In reference to Descartes Island, where this species occurs. <b>Shell</b> (Fig. 24A–D, Pl. 1.12). Semi-globose to broadly conical with medium high spire; thin (translucent) to solid. Periphery evenly rounded to slightly angulate; upper and basal sectors of whorls rounded. Umbilicus forming a chink to narrowly winding opening, 30–100 percent concealed by columellar reflection. Background colour brownish horn; uniform or banded; if present sub-sutural and mid-whorl bands diffuse, thin, brown, on last whorl(s) only; ventral colour, outer and inner lip colour whitish to cream. Protoconch c. 2.8 mm in diameter with 1.7 whorls, almost smooth, sculptured by faint axial lirae. Teleoconch sculptured by coarse lirae, rounded in cross-section, regularly spaced, spaces equal to thickness of lirae, evenly distributed across shell and whorl diameter even, reduced underneath suture.Angle of aperture 45°, outer lip rounded, moderately thick, slightly expanded, slightly reflected; basal node absent or weak, palatal node absent. Parietal wall of inner lip inconspicuous. <b>Pallial morphology</b>. Pallial cavity moderately deep, extending <b> 3</b> ⁄ <b> 4</b> whorl. Mottled pigmentation on mantle dark grey. Kidney extending about half of pallial cavity. <b>Genital morphology</b> (Figs. 25–26). Penis straight to slightly curved, longer than anterior part of oviduct. Vas deferens forms simple loop before entering penis. Penial retractor muscle shorter than penis. Penial verge short (&lt; <b> 1</b> ⁄ <b> 4</b> penial chamber), slender to spatulate, with pointed tip. Penial wall pustules present, of average size, slightly elongated, arranged in rows across entire length of inner penial wall. Main stimulatory pilaster well-differentiated, large, cone-shaped, sculptured by smooth horizontal ridges, comprising entire length of penial chamber. Vas deferens entering penial sheath in upper third. Vagina comparatively short to moderately long, posteriorly inflated. Inner vaginal wall with smooth longitudinal pilasters. Spermathecal duct comparatively wide, internally with smooth longitudinal pilasters. Spermathecal head elongately inflated, connected with oviduct by connective tissue, internally smooth, with delicate wall. Free oviduct comprising about half of anterior part of oviduct, rather straight. Spermoviduct clearly longer than anterior part of oviduct. Talon embedded in albumen gland close to anterior end. <b>Radular morphology</b> (Fig. 24E–G). Rectangular. Tooth formula C+16–17+3–4+18–20. In average with 139±5.5 rows of teeth, 31.4±0.2 rows per mm (n = 2). Central teeth with bluntly pointed, triangular mesocones, shorter than base of tooth; ectocones small. Lateral teeth with bluntly pointed, triangular mesocones, length equal to base of tooth; ectocones small, endocones vestigial. Marginal teeth with elongate mesocones; ectocones shorter and narrower than mesocones, divided into two denticles; endocones smaller than ectocones. <b>Comparative remarks</b>. The present material has been labelled as “ <i>Amplirhagada</i> sp. 74” by Solem. The species is most readily distinguished from other species from the Montesquieu Islands by its more turreted shell. Similar to <i>A. montesquieuana</i>, its axial sculpture is more regular than that of <i>A. combeana</i> and <i>A. mckenziei</i>. From <i>A. montesquieuana</i> it differs by its larger size and more conical shape. The main stimulatory pilaster is similar to that in <i>A. montesquieuana</i> in shape but lacks “hooked toes”; broader than pilaster in <i>A. ponderi</i> and <i>A. mckenziei</i>; penial wall pustulation differs markedly from that in <i>A. montesquieuana</i>.
description: Published as part of <i>Köhler, Frank, 2010, Uncovering Local Endemism in the Kimberley, Western Australia: Description of New Species of the Genus Amplirhagada Iredale, 1933 (Pulmonata: Camaenidae), pp. 217-284 in Records of the Australian Museum 62 (2)</i> on pages 234-236, DOI: 10.3853/j.0067-1975.62.2010.1554, http://zenodo.org/record/5239086