Amphidromus (Syndromus), Pilsbry

Inkhavilay, Khamla, Sutcharit, Chirasak & Panha, Somsak, 2017, Taxonomic review of the tree snail genus Amphidromus Albers, 1850 (Pulmonata: Camaenidae) in Laos, with the description of two new species, European Journal of Taxonomy 330, pp. 1-40 : 17

Subgenus Syndromus Pilsbry, 1900

Amphidromus (Syndromus) Pilsbry, 1900: 184 .

Type species

Helix contraria Müller, 1774 by subsequent designation in Zilch (1960: 623).

Diagnosis

Shells mostly sinistral, conical to elongate conical and rather small (height 25 to 40 mm), varices absent and varying in color pattern. Genital characteristics show camaenid type with short epiphallus and flagellum, appendix absent, vaginal pouch and vaginal stimulator pilaster sometimes present. Radula teeth with spatulate shape.

The subgenus Syndromus was first nominated as “Sinistral Division” for Amphidromus with a relatively smaller sinistral coiling shell ( Pilsbry 1900). Until onw, the genital characters of the type species have never been examined; only Wiegmann (1894) briefly reported on the radular and jaw structures of the type species. To clarify the genitalia and radula characters of the subgenus, spirit preserved specimens in the Zoological Museum of Amsterdam (ZMA) collection were examined and are described below.