Tortulosa Gray, 1847

Jirapatrasilp, Parin, Sutcharit, Chirasak & Panha, Somsak, 2022, Annotated checklist of the operculated land snails from Thailand (Mollusca, Gastropoda, Caenogastropoda): the family Pupinidae, with descriptions of several new species and subspecies, and notes on classification of Pupina Vignard, 1829 and Pupinella Gray, 1850 from mainland Southeast Asia, ZooKeys 1119, pp. 1-115 : 1

6. Genus Tortulosa Gray, 1847

Tortulosa Gray, 1847: 177. Kobelt 1902: 281. Egorov 2013: 14.

Type species.

Turbo tortuosus Férussac, 1821, by original designation.

Diagnosis.

Shell elongated ovate. Periumbilical keel present. Aperture almost round; basal edge of peristome with a canal or indentation extending below into periumbilical keel. Operculum moderately thick to thick, corneous, circular, flat or cylindrical, closely coiled, multi-layer.

Differential diagnosis.

Tortulosa can be distinguished from all other genera in this subfamily, especially Coptocheilus which has a similar shell size and matt surface, by a canal or indentation at a basal edge of peristome extending below into a periumbilical keel, and a thick, multi-layer operculum ( Kobelt 1902; Raheem et al. 2014).

Remarks.

This genus comprises two subgenera: the nominotypical subgenus and Eucataulus Kobelt, 1902. The subgenus Tortulosa possesses a detached last whorl and contains only one species, Tortulosa tortuosa . At present, the subgenus Eucataulus contains 29 species, all of which are distributed in Western Ghats, India, and Sri Lanka ( Kobelt 1902; Raheem et al. 2014, 2018).