Georissa carinata Sutcharit & Jirapatrasilp, 2020

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

Georissa carinata Sutcharit & Jirapatrasilp sp. nov. Fig. 6B

Type material.

Holotype CUMZ-CM094/1 (Fig. 6B ) from locality no. 11. Measurement: shell height 2.1 mm, shell width 1.5 mm and 4¼ whorls. Paratypes CUMZ-CM094/2 (9 shells) from locality no. 11; CUMZ-CM042 (21 shells), IFReDI (10 shells), ZRC (10 shells) and NHMUK (10 shells) from locality no. 9.

Type locality.

Phnom Kampong Trach Cave Temple, Kampong Trach District, Kampot Province, Cambodia, Locality no. 11 (10°34'1.77"N, 104°28'6.13"E).

Other material examined.

Locality no. 12: CUMZ-CM086 (23 shells). Locality no. 17: CUMZ-CM102 (18 shells).

Description.

Shell minute (shell height up to 2.1 mm, shell width up to 1.5 mm), conic, solid, translucent, yellowish to pale orange with darker colour on apex. Whorls 4¼, last whorl large ca. two-thirds of shell height. Protoconch ca. one whorl; sculpture nearly smooth and discontinuous spiral appearing immediately after protoconch. Following whorls slightly keeled, sculptured with thin and uneven growth lines; upper periphery with irregular and strong sculpture; below periphery with discontinuous spiral ribs. Sutures angular and impressed. Aperture round to slightly ovate. Umbilicus closed. Operculum unknown.

Etymology.

The Latin specific name carinata represents its keeled whorls of this new species.

Distribution.

This new species is found from Kampot and Kep Provinces. The snails were found to live on limestone wall syntopically with other Hypselostoma spp.

Remarks.

This new species differs from G. bocourti (Rochebrune, 1881) described from "Eaux douces de Preck-Scholl. Haut Mékong” [Chhloung District, Kratié Province, Cambodia], by having a conic shell with 4¼ whorls, which are slightly keeled and sculptured with thin and uneven growth lines without conspicuous spiral ribs. However, G. bocourti has a turriform shell with 6-7 whorls and sculptured with conspicuous spiral ribs (Rochebrune 1881a). Georissa carinata sp. nov. differs from G. poirieri Mabille, 1887 and G. conspicua Mabille, 1887 described from “Tonkin” [Vietnam] in that the latter two species are larger (shell height 3-5 mm, shell width 2½ -3 mm) and has a turriform shell. In addition, G. poirieri has very thin, tight, wavy spiral ribs, while G. conspicua has uneven spiral ribs with additional protuberances unequally arranged along the longitudinal rows ( Mabille 1887a, b).

Figures

Figure 6. A Georissa monterosatiana Godwin-Austen & Neville, 1879 B Georissa carinata Sutcharit & Jirapatrasilp, sp. nov. C Cyclophorus amoenus (Pfeiffer, 1854) D Cyclophorus paviei Morlet, 1885 E Opisthoporus bernardii (Pfeiffer, 1862) and F Lagocheilus landesi (Morlet, 1885).