GENUS SERMYLA ADAMS & ADAMS, 1854

Sermyla Adams & Adams, 1854: 296 [non Sermyla Walker, 1854 (Lepidoptera), non Sermyla Chapuis, 1875 (Coleoptera)].

Type species: Melania mitra Dunker, 1844 by subsequent designation by Brot (1874).

Sermylasma Iredale, 1943: 208.

Type species: Melania venustula Brot, 1877 by original designation.

Diagnosis: Smallthiarids(usually<30mm,exceptionally up to 41 mm) with slender, turreted to high-turreted shells, with up to ten whorls; spire whorls flattened; last whorl evenly rounded. Shell sculptured with widely spaced axial, usually pronouncedly opisthocyrt ribs on the upper part of all whorls; basal part of body whorl with prominent spiral grooves and ridges.

Distribution: Species of the genus are recorded from India and Sri Lanka and are distributed widely in mainland and the insular regions of Southeast Asia, the Indo-Malay Archipelago ranging far into the Pacific region, as well as to Australia (for details see Fig. 2 and material list under the respective species).

Remarks

Sermyla was originally proposed as a subgenus of Melanella Swainson, 1840 by Adams & Adams (1854) to include five nominal species: Melania harpula Dunker, 1844, Melania mitra Dunker, 1844, Melania nana Lea & Lea, 1851, Melania semicostata Philippi, 1847 and Melania tornatella Lea & Lea, 1851. Brot (1874: 7) designated M. mitra as the type species of Sermyla. The selection of M. harpula by Cossmann (1909: 208) as type species of Sermyla or the mentioning of M. tornatella as typical representative of the taxon by Thiele (1928: 401) are therefore invalid. At least eight nominal species can be attributed as synonyms in addition to the two species S. riquetii and S. carbonata that are currently accepted as biologically valid, resulting in a taxonomic redundancy of 4:1 (i.e. four times more names than evolutionary entities).