Anceyoconcha chaudoensis (Rochebrune, 1881)

Sutcharit, Chirasak, Thach, Phanara, Chhuoy, Samol, Ngor, Peng Bun, Jeratthitikul, Ekgachai, Siriwut, Warut, Srisonchai, Ruttapon, Ng, Ting Hui, Pholyotha, Arthit, Jirapatrasilp, Parin & Panha, Somsak, 2020, Annotated checklist of the land snail fauna from southern Cambodia (Mollusca, Gastropoda), ZooKeys 948, pp. 1-46 : 1

Anceyoconcha chaudoensis (Rochebrune, 1881) Figs 5F , 12E, F

Petraeus chaudoensis Rochebrune, 1881a: 70. Type locality: Montagnes de Chaudoe Cambodge [Chau Doc, An Giang Province, Vietnam].

Ena chaudocensis [sic]: Fischer 1973b: 90.

Material examined.

Locality no. 1: CUMZ-CM003 (20 shells; Fig. 12E, F ), CUMZ-CM005 (1 specimen in ethanol; Fig. 5F ). Locality no. 2: CUMZ-CM007 (9 shells). Locality no. 3: CUMZ-CM010 (1 specimen in ethanol). The snails were found to live on tree trunks and leaves.

Distribution.

Cambodia ( Fischer 1973b).

Remarks.

This species was originally described from "Montagnes de Chaudoe Cambodge" [Chau Doc, An Giang Province, Vietnam] probably in the area bordering Cambodia and Vietnam. The original description of this species was brief and without illustration. This species has a sinistral elongate conic to slightly ovate conic shell, with 7 to 9 whorls, which increase regularly; cylindrical, having convex whorl and wide and impressed suture. The shell surface possesses fine growth lines, and the periostracum is thin and brownish. The last whorl is well rounded and without keel near aperture and has a similar diameter to the penultimate whorl. The shell colour is light brownish and translucent (becoming whitish when worn). The aperture is semi-ovate, with expanded and whitish lip and thin or thickened with whitish parietal callus. The columella is straight and dilated, with a rimate umbilicus.

Based on the original description, A. chaudoensis can be distinguished from A. siamensis obesula in having an elongate cylindrical shell and higher number of whorls, while the latter species has an ovate conic shell and a smaller number of whorls.

Figures

Figure 5. Living snails of A Amphidromus leucoxanthus (Martens, 1864) B Trichochloritis norodomiana (Morlet, 1883) C Ganesella perakensis (Crosse, 1879) D, E Anceyoconcha rhombostoma (Pfeiffer, 1861) D brownish morph and E dark brown morph and F Anceyoconcha chaudoensis (Rochebrune, 1881) comb. nov. All not to scale.

Figure 12. A Ganesella perakensis (Crosse, 1879) B Anceyoconcha siamensis obesula (Ancey, 1888) comb. nov. C, D Anceyoconcha rhombostoma (Pfeiffer, 1861). A white arrowhead indicates strong peripheral keel on the last whorl, the distinguished character of this species and E, F Anceyoconcha chaudoensis (Rochebrune, 1881) comb. nov.