''Cythnia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

s, marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

s in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Rissoellidae Rissoellidae are a family (biology), family of small sea snails, marine (ocean), marine gastropod molluscs in the subclass Heterobranchia. Rissoellidae is the only family within the superfamily Rissoelloidea in the Taxonomy of the Gastropoda (Bo ...

Species

There are only two known species to exist within this genus, these include the following: * '' Cythnia albida'' (Carpenter, 1864) * '' Cythnia asteriaphila'' (Carpenter, 1864)

References

Rissoellidae {{Heterobranchia-stub