Subfamily Caspiinae Dybowski, 1913

Remarks. The distinction of the genera Caspia, Ulskia, and Clathrocaspia follows Neubauer et al. (2018). The three taxa are differentiated based on details of the protoconch and the expression of teleoconch sculpture. Caspia s. s. is characterised by a single distinct but fine spiral keel below the suture. It is usually smooth, yet within the type species some reticulate ornament can be found. Species of Clathrocaspia expose a distinctive, reticulate pattern on the teleoconch and a malleate protoconch with faint spiral threads. The aperture of Clathrocaspia often develops a distinct flat base. The discinction of the two genera is subject of current research. Ulskia also has a malleate protoconch but with more distinct spiral threads; teleoconch sculpture is occasionally present as minute elongate nodules.