Amphidromus (Syndromus) globonevilli Sutcharit & Panha

Sutcharit, Chirasak, Ablett, Jonathan, Tongkerd, Piyoros, Naggs, Fred & Panha, Somsak, 2015, Illustrated type catalogue of Amphidromus Albers, 1850 in the Natural History Museum, London, and descriptions of two new species, ZooKeys 492, pp. 49-105 : 82

Taxon classification Animalia Stylommatophora Camaenidae

Amphidromus (Syndromus) globonevilli Sutcharit & Panha sp. n. Figs 16A, C–F, 17A, B

Amphidromus sinensis var. globosa Nevill, 1878: 126. [nomen nudum]. Type locality: Chittagong [Bangladesh]. Pilsbry 1900: 191. Richardson 1985: 44.

Type material.

Holotype CUMZ 4925 (height 21.9 mm, width 14.2 mm, whorls 5¾; Fig. 16C), paratypes CUMZ 4926 (13 shells), CUMZ 4927 (6 shells; Fig. 16 D–F), CUMZ 4928 (12 shells), CUMZ 4929 (4 shells), NHMUK 20140707 (2 shells), SMF (2 shells).

Measurement of 37 paratypes; height range 18.3-23.3 mm, mean 21.08 ± 1.18; width range 11.9-15.3 mm, mean 13.59 ± 0.69; height/width ratio 1.46-1.62, mean 1.55 ± 0.04; whorls 5-6.

Other material.

Chittagong [now in Bangladesh] original specimen of " globosa Nevill, 1878" NHMUK 1903.7.1.1921.

Type locality.

Wat Phothikhun, Maesod, Tak, Thailand (16°45'42.2"N, 98°38'49"E).

Diagnosis.

This new species can be distinguished from Amphidromus sinensis (Benson, 1851) by having a smaller, more ovate conic shell (Fig. 16 G–I). It differs from Amphidromus flavus (Pfeiffer, 1861) which exhibits an elongated conic shell a faint yellowish spiral band below the periphery, and an elongated aperture (Fig. 7I, J). It differs from Amphidromus lepidus (Gould, 1856) and Amphidromus roemeri (Pfeiffer, 1863) by having a yellowish shell colour with two dark brown spiral bands below the periphery, while Amphidromus roemeri have a more ovate to stout shell, whitish in colour with reddish-brown spiral bands below the periphery (Fig. 13E, F) and Amphidromus lepidus has a monochrome whitish shell (Fig. 10C).

Description.

Shell. Shell small, sinistral, ovate conic, rather thin; umbilicus perforate. Apex acute without black spot; spire short; suture depressed and wide. Whorls slightly convex; last whorl round to ovate. Periostracum thin and transparent. Shell colour yellowish, paler near apex; subsutural band white and with darker yellow band below. Last whorl with two brown spiral bands below periphery. Aperture wide and ovate; columella straight; lip white and little expanded; parietal callus thin and transparent.

Genital organs.

Atrium (at) short (n = 5). Penis (p) long, cylindrical and enlarged near penial retractor muscle. Epiphallus (e) smaller than penis and almost similar to penis length; flagellum (fl) similar length to epiphallus; appendix absent. Penial retractor muscle (pr) short and relatively thin. Vas deferens (vd) narrow tube extending from free oviduct (fo) and connected to epiphallus (Fig. 17A).

Internal wall of penis almost smooth surfaced, corrugated into a series of thickened; proximal to genital orifice, with swollen longitudinal penial pilasters (pp). Penial verge (pv) large, elongated conical shape, about two-thirds of penis length and with smooth surface (Fig. 17B).

Vagina (v) cylindrical, longer than penis, held in position with series of thin muscles originating from foot floor. Vaginal pouch and stimulator pilaster absent. Gametolytic duct (gd) long, slender; proximal to genital orifice enlarged same diameter as vagina, and distal to genital orifice tapering to small tube connected to gametolytic sac (gs). Oviduct (ov) and albumen gland (ag) enlarged; hermaphroditic gland (hg) multilobed and connected with hermaphroditic duct (hd) (Fig. 17A).

Internally, vaginal wall sculptured with longitudinal vaginal pilasters (vp); proximal to genital orifice with smooth and continuous ridges about two-third of its length, and pilasters at distal to genital orifice interrupted by transverse divisions (Fig. 17B).

Etymology.

The specific name comes from the Latin word " globous " meaning "ball or sphere" and the name of Dr. Geoffroy Nevill, who first recognized this as a new species and introduce the name " globosa " but was unavailable (see Remark of " globosa ").

Distribution.

This new species is known from the type locality in Tak Province, western Thailand. In addition, NHM specimens indicate that this species is also found from Chittagong, Bangladesh.

Remarks.

The type speceimen of Amphidromus sinensis s.s. was presumed to be lost ( Pilsbry 1900, Laidlaw and Solem 1961). Recently, we have located one lot of three shells in Benson’s collection at UMZC with the collection locality of “China”, which we consider to be possible syntypes. Photographs of these three shells (Fig. 16G-I) are shown here for further comparison. The shell that most closely matches the original description of Benson’s (1851: 264) and Benson’s specimen figured in Küster and Pfeiffer (1853: pl. 20, figs 1, 2) is illustrated inFigure 16G.