Tethydidae

Tethydidae is a family of dendronotid nudibranch gastropod molluscs in the superfamily Dendronotoidea.

The original spelling (subfamily) is Tethydia. It was placed on the Official List by Opinion 1182 of ICZN (1981: 174), which also ruled that the name should be corrected to Tethydidae (Bouchet & Rocroi, 2005).

Taxonomy
This family is within the clade Cladobranchia and has no subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).

Genera
There are two genera within the family Tethydidae:
 * Melibe Rang, 1829
 * Tethys Linnaeus, 1767 - the type genus,
 * Genera brought into synonymy :
 * Chioraera Gould, 1852 accepted as Melibe Rang, 1829
 * Fimbria O'Donoghue, 1926 : synonym of Tethys Linnaeus, 1767 (invalid: junior homonym of Fimbria Megerle, 1811.)
 * Jacunia de Filippi, 1867 accepted as Melibe Rang, 1829
 * Melibaea synonym of Melibe Rang, 1829
 * Meliboea [sic] : Melibe Rang, 1829 (incorrect subsequent spelling [by Forbes, 1838] of Melibe Rang, 1829)
 * Propemelibe Allan, 1932 accepted as Melibe Rang, 1829

Description
Species in this family do not possess a radula.