Amphidromus (Syndromus) areolatus
Creators: name: Inkhavilay, Khamla
name: Sutcharit, Chirasak
name: Panha, Somsak
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Camaenidae
Amphidromus
Amphidromus areolatus

description: Amphidromus (Syndromus) areolatus (Pfeiffer, 1861)
Figs 1, 7 G−I, 9A, 10A−C, 11A–B; Table 1
Bulimus areolatus Pfeiffer, 1861a: 194. Type locality: Siam [Thailand]. Pfeiffer 1861b: 172, pl. 46, figs 11–12.
Amphidromus areolatus – Fulton 1896: 81. — Pilsbry 1900: 198–199, pl. 63, figs 85–86. — Laidlaw & Solem 1961: 564. — Solem 1965: 624–625, pl. 1, figs 4–7. — Sutcharit et al. 2015: 58, fig. 3j–k.
Material examined
Type material
THAILAND: Lectotype NHMUK 19601430 (Sutcharit et al. 2015: fig. 3j); paralectotype NHMUK 19601431 (1 shell).
Other material
LAOS: 20 shells (Fig. 10 A−C, CUMZ 7022), 17 specimens in freezer (Figs 7 G−I, 9 A, 11A–B, CUMZ 7023), Thad Fek, Sammakeexay District, Attapeu; 8 shells, Thad Phasoam, Paksong District, Champasak (CUMZ 7024).
Description
Shell sinistral, elongate conical, rather small, thin and glossy. Spire conical; apex acute, with black spot on tip. Whorls 5 to 6 slightly convex; suture depressed; last whorl rounded. Periostracum transparent to thin corneous. Last whorl process, with yellow to absent Band 1; Bands 2 to 4 (sometimes Bands 2 to 5) usually merge and become brownish slanted blotches with flame shape; Band 6 yellowish or roseate. Parietal callus thin and transparent. Aperture auriform; peristome expanded to weakly expanded; lip white to transparent. Columella straight and white. Umbilicus narrowly opened.
Radula
Teeth arranged in V-shaped rows, each row contains about 126 (62-(13-9)-1-(9-13)-63) teeth. Central tooth tricuspid, with triangular shaped mesocone, ectocones very small, with pointed cusp. Lateral teeth bicuspid, endocone small, with curved cusp; ectocone large, with truncate or curved cusps, gradually transformed to tricuspid marginal teeth. Tricuspid marginal teeth start around tooth number 9 to 13 outwards; endocone curve shaped; mesocone of largest size, with long and obtuse cusp; ectocone smallest, with pointed cusp. Outermost teeth with small serrated endocone and extocone; mesocone large, with curved cusps (Fig. 7 G–I).
Genital organs
Atrium (at) rather long (n = 10). Penis (p) long, cylindrical and enlarged. Epiphallus (e) short, of about same length as penis; flagellum (fl) short and terminated in pointed tip. Appendix absent. Penial retractor muscle (pr) thin and relatively long. Vas deferens (vd) narrow tube connecting epiphallus and free oviduct (Fig. 11A).
Internal penial wall nearly smooth and corrugated into thin penial pilasters, which form fringe around penial verge. Penial verge rather small, conical, with smooth surface (Fig. 11B).
Vagina cylindrical, of about same length as penis. Gametolytic duct long, proximal to genital orifice, of larger diameter than vagina and coiled; distal to genital orifice tapering to small tube of about same length as proximal part and connected to gametolytic sac. Oviduct and albumin gland very small (Fig. 11A).
Internal wall of vagina shows longitudinal vaginal pilasters (vp); proximal to genital orifice with nearly smooth surface for about half of its length, distally pilasters become corrugated ridges (Fig. 11B).
Distribution
The species is known from southern Laos, where the specimens were collected at Thad Fek, Sammakeexay District, Attapue and Thad Phasoam, Paksong District, Champasak in a dry dipterocarp forest.
Remarks
This species can be distinguished from A. zebrinus (Pfeiffer, 1861) and A. begini (Morlet, 1886) by its having a smooth shell surface and brownish spiral Bands 4 and 5 present, with white lip. In contrast, A. zebrinus (see Sutcharit et al. 2015: fig. 15k) has an elongate conical shell shape, Band 1 absent, Bands 2 to 5 merged and developing slanted radial streaks, as well as a reddish band between Bands 5 and 6. Amphidromus begini exhibits strong radial ridges, Bands 2 to 6 merged and developing slanted brownish radial streaks, and brownish ribs (Fig. 10D, syntype MNHN-IM-2000-1832).
description: Published as part of Inkhavilay, Khamla, Sutcharit, Chirasak & Panha, Somsak, 2017, Taxonomic review of the tree snail genus Amphidromus Albers, 1850 (Pulmonata: Camaenidae) in Laos, with the description of two new species, pp. 1-40 in European Journal of Taxonomy 330 on pages 20-24, DOI: 10.5852/ejt.2017.330, http://zenodo.org/record/3829744