Family HEMISPEIRIDAE König, 1894

Body often small, with somatic ciliature in reduced number of spiraled rows in many species (becoming oblique and even almost horizontal in some); distinct thigmotactic area of reduced dorsal kineties enclosed in a système sécant, very pronounced in certain genera; arrangements of buccal ciliature parallel those seen in the Ancistridae, but the ciliature is often reduced when at the posterior pole and forms an arc of < 180°; in mantle cavity of marine and fresh-water molluscs or on integument of certain echinoderms.

[Does Nucleocorbula (see separate family, below) more appropriately belong here?]

Ancistrospira Chatton & Lwoff, 1926. Single species.
Cheissinia Chatton & Lwoff, 1949 (for Tiarella). Single species.
Hemispeira Fabre-Domergue, 1888 (syn. Hemispeiropsis). Few spp.
Plagiospira Issel, 1903. Single species.
Protospira Raabe, 1968. Single species.