Genus is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.
The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the International Commission on Zoological Nomenclature. The rules principally regulate:
Aplysiidae is the only family in the superfamily Aplysioidea, within the clade Anaspidea. These animals are commonly called sea hares because, unlike most sea slugs, they are often quite large, and when they are underwater, their rounded body shape and the long rhinophores on their heads mean that their overall shape resembles that of a sitting rabbit or hare. Sea hares are however sea snails with shells reduced to a small plate hidden between the parapodia, and some species are extremely large. The Californian black sea hare, Aplysia vaccaria is arguably the largest living gastropod species, and is certainly the largest living heterobranch gastropod.
The Limacinidae are a family of small sea snails, pteropods, pelagic marine gastropod mollusks in the clade Thecosomata.
The superfamily Cavolinioidea is the most speciose group of sea butterflies. They belong to the suborder Euthecosomata.
The Clionidae are a family of sea angels, which are a group of pelagic marine gastropods.
Tiberia is a genus of minute parasitic sea snails, marine gastropod molluscs in the family Pyramidellidae, the pyrams and their allies. Tiberia is the only genus in the tribe Tiberiini.
Neritidae, common name the nerites, is a taxonomic family of small to medium-sized saltwater and freshwater snails which have a gill and a distinctive operculum. The family Neritidae includes marine genera such as Nerita, marine and freshwater genera such as Neritina, and freshwater and brackish water genera such as Theodoxus.
Paludinella is a genus of minute salt marsh snails with an operculum, aquatic gastropod mollusks or micromollusks, in the family Assimineidae.
Neverita is a genus of medium-sized to large sea snails, marine gastropod molluscs in the subfamily Polinicinae of the family Naticidae, the moon snails
Cylindrobulla is a genus of sea snails or bubble snails, marine gastropod mollusks in the clade Sacoglossa.
The family Cavoliniidae is a taxonomic group of small floating sea snails, pelagic marine opisthobranch gastropod mollusks.
Fusus is a genus of small to large sea snails, marine gastropod molluscs in the family Fasciolariidae, the spindle snails and tulip snails.
Leptothyra is a genus of sea snails, marine gastropod mollusks in the family Colloniidae.
Pterygia is a genus of sea snails, marine gastropod mollusks in the subfamily Cylindromitrinae of the family Mitridae.
Eburna is a genus of sea snails, marine gastropod mollusks in the family Ancillariidae.
Benthonella is a genus of minute sea snails, marine gastropod mollusks or micromollusks in the family Rissoidae.
Tethys is a genus of sea slugs, nudibranchs, marine gastropod mollusks in the family Tethydidae.
Clio pyramidata is a species of sea butterfly, a floating and swimming sea snail, a pelagic marine gastropod mollusk in the family Cliidae.
The genus Clio is a taxonomic group of small floating sea snails, pelagic marine opisthobranch gastropod mollusks, the sole genus belonging to the family Cliidae
