Amplirhagada montesquieuana, Köhler, 2010

Köhler, Frank, 2010, Uncovering Local Endemism in the Kimberley, Western Australia: Description of New Species of the Genus Amplirhagada Iredale, 1933 (Pulmonata: Camaenidae), Records of the Australian Museum 62 (2), pp. 217-284 : 232-233

publication ID	https://doi.org/ 10.3853/j.0067-1975.62.2010.1554
publication LSID	lsid:zoobank.org:pub:749A271A-6942-4D4C-B0DF-B968462BFF0C
persistent identifier	https://treatment.plazi.org/id/AE449D6D-B9AE-44E6-905B-A6258CB686E0
taxon LSID	lsid:zoobank.org:act:AE449D6D-B9AE-44E6-905B-A6258CB686E0
treatment provided by	Felipe
scientific name	Amplirhagada montesquieuana
status	sp. nov.

Treatment

Amplirhagada montesquieuana View in CoL n.sp.

Type locality ( Fig. 1 View Figure 1 ). Western Australia, northwestern Kimberley, Bonaparte Archipelago, Admiralty Gulf , Fenelon Island , 14°08'16"S 125°41'55"E; FERT 04 (leg. Harvey, 28.08.2002) GoogleMaps .

Type material. Holotype WAM S34606 View Materials (Pl. 1.11) . Paratypes AMS C463748 (9 preserved specimens), WAM S41453 View Materials (15 preserved specimens) .

Etymology. In reference to Montesquieu Islands, to which Fenelon Island belongs.

Sealing strategy. Rock sealer.

Shell ( Fig. 21A–B View Figure 21 , Pl. 1.11). Broadly conical with low spire; thin (translucent). Whorls evenly rounded in cross-section. Umbilicus open, forming a chink to narrowly winding opening, 80–95 percent concealed by columellar reflection. Background colour whitish or yellowish to golden brown; with diffuse, thin, brown sub-sutural and mid-whorl bands most conspicuous on last whorl; ventral colour whitish; outer lip colour same as shell or lighter; inner lip whitish and translucent. Protoconch c. 2 mm in diameter with 1.5 whorls, sculptured by fine but distinct axial lirae. Teleoconch with coarse axial lirae, rounded in cross-section with regular spacing, spaces equal to thickness of lirae. Sculpture evenly distributed across shell and whorl diameter, height reduced underneath suture. Angle of aperture 30°, outer lip rounded, sharp to moderately thick, slightly expanded and reflected; basal node of lip weak, palatal node absent. Parietal wall of inner lip inconspicuous.

Pallial morphology. Pallial cavity moderately deep, extending 3 ⁄ 4 whorl. Mantle with mottled, black pigmentation. Kidney extending about half of pallial cavity.

Genital morphology ( Figs. 22–23 View Figure 22 View Figure 23 ). Penis straight, of more or less same length as anterior part of oviduct to slightly longer. Vas deferens coils once before entering penis. Penial retractor muscle clearly shorter than penis. Penial verge very short, slender to spatulate, with pointed tip. Penial wall pustules of normal size, slightly elongated, arranged in sparsely distributed, distinct rows over entire length of inner penial wall. Towards base of penial chamber, pustules fuse to form corrugated, narrow pilasters. Main stimulatory pilaster differentiated, forming cone-shaped, prominent ridge covered by enlarged pustules at apical to median portion of penial chamber. Pilaster ridges carry little toe-shaped extensions that support hooks. Vas deferens entering penial sheath in upper third. Vagina moderately long, tubular. Inner vaginal wall with smooth longitudinal pilasters. Spermathecal duct wide; inner wall with transversely structured, longitudinal pilasters. Spermathecal head globular to elongate, connected with oviduct by connective tissue; wall delicate. Free oviduct comprising±half of anterior part of oviduct, rather straight. Spermoviduct longer than anterior part of oviduct. Talon embedded in albumen gland at junction with spermoviduct.

Radular morphology ( Fig. 21C–F View Figure 21 ). Rectangular. Tooth formula C+11+4+14. Average number of rows of teeth 150±32.5 with 38.1±0.3 rows per mm (n = 2). Central teeth with sharply pointed, triangular mesocones, shorter than base of tooth; ectocones small. Lateral teeth with bluntly pointed, triangular mesocones, length equal to base of tooth; ectocones well developed, endocones vestigial. Marginal teeth with elongate mesocones; ectocones shorter and narrower than mesocones, split into two denticles; endocones reduced in size. Comparative remarks. The shell of this species is smaller than that of other species from the Montesquieu Islands but otherwise difficult to differentiate by means of colour, sculpture and shape ( Table 1). Its axial sculpture is more regular than that of A. combeana and A. mckenziei . From A. mckenziei it also differs by a smaller and comparatively flatter shell; a one-way ANOVA revealed that both species differ significantly in the shell parameters H, D, FW and H/D. The inner penial wall is characteristic by its rather sparsely distributed rows of pustules that give rise to corrugated, narrow, longitudinal pilasters towards the base of the penial chamber, and the shape and development of the main stimulatory pilaster being shorter and broader than in A. ponderi and larger than in A. mckenziei . The possession of well-developed “toe-shaped” extensions of the pilaster ridges is unique amongst species from Montesquieu Islands.