Parthenina is a genus of very small sea snails, pyramidellid gastropod mollusks or micromollusks.
In the original description Bucquoy, Dautzenberg & Dollfus (1833)[1] states (in English translation) that Partnenina is a type of Odostomia with a mesh-like surface or with longitudinal ridges.
The type species of Besla has a protoconch axis at 90° with that of teleoconch ("type A protoconch") whereas that of Parthenina is tilted nearly 180° ("type C"); this important character suggests that they are unrelated and that their teleoconch sculpture may be convergent [5] The Eastern Atlantic and Mediterranean species of the family Pyramidellidae, here listed under the genus Parthenina Bucquoy, Dautzenberg & Dollfus, 1883, have been included by most 20th-century European authors in the genus Chrysallida Carpenter, 1856, following a lead by Winckworth (1932).
The first explicit statement that this is incorrect was voiced by van Aartsen, Gittenberger & Goud (2000: 21) "None of the many species from European Atlantic and Mediterranean waters currently included in Chrysallida conforms exactly to the description of the genus sensu stricto", but they still used Chrysallida as a genus and used Parthenina and other names as subgenera.
Micali, Nofroni & Perna (2012) formally raised Parthenina to the rank of genus and included a number of European species, whereas other congeners not treated in that paper were still listed in WoRMS and elsewhere as Chrysallida.