Parateuthis tunicata, the only known member of the genus Parateuthis, is the scientific name currently given to a species of squid based on a single specimen. The validity of Parateuthis and of P. tunicata is uncertain. The sole specimen was found in the Antarctic Ocean, and is held in the repository at the Museum für Naturkunde in Berlin, Germany.
Idiosepiidae, also known as the pygmy squids, is a family of squids in the superorder Decapodiformes. They are the smallest known squids.
Pterygioteuthis is a genus of squid in the family Pyroteuthidae. Members are differentiated from the genus Pyroteuthis due to size and head shape. The genus is characterised by the presence of a lidded photophore over each eye.
Dilemma inexpectatum is a minute species of deepwater cockle, a marine bivalve mollusc in the family Cardiidae.
Bactrocythara agachada is a species of sea snail, a marine gastropod mollusk in the family Mangeliidae.
Amphidromus coeruleus is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Camaenidae.
Euvola marensis, or the paper scallop, is a species of bivalve mollusc in the family Pectinidae. It can be found in the Gulf of Mexico, ranging from the West Indies to Brazil.
Chama congregata, commonly known as the corrugated jewel box clam, is a species of bivalve mollusc in the family Chamidae. It can be found along the Atlantic coast of North America, ranging from North Carolina to the West Indies and Bermuda.
Occidenthella is a genus of sea slugs, specifically aeolid nudibranchs, in the family Flabellinidae. The only described species is Occidenthella athadona, a combination named in 2017. It was originally described as Coryphella athadona in 1875. The genus name Occidenthella, from occidens, meaning "west" in Latin, refers to its distribution in the Western Pacific Ocean.
After excluding groups not related, the informal group Sigmurethra has become the suborder Helicina, with the following infraorders and a collection of families with no superfamily：
Rokopella capulus is a species of monoplacophoran, a superficially limpet-like marine mollusc.
Rokopella euglypta is a species of monoplacophoran, a superficially limpet-like marine mollusc.
Rokopella goesi is a species of monoplacophoran, a superficially limpet-like marine mollusc.
Rokopella oligotropha is a species of monoplacophoran, a superficially limpet-like marine mollusc. It is known from only one specimen and a shell fragment collected in the north-central Pacific Ocean.
Rokopella segonzaci is a species of monoplacophoran, a superficially limpet-like marine mollusc.
Vema occidua is a species of monoplacophoran, a superficially limpet-like marine mollusc.
Amonovula is a monotypic genus of marine gastropod molluscs in the family Ovulidae, the ovulids, cowry allies or false cowries
Calliodentalium is a genus of scaphopodan molluscs. It is monotypic within the family Calliodentaliidae. It is known from the Atlantic, Indian, and Pacific Oceans.
Hyalocylis is a genus of gastropods belonging to the family Hyalocylidae. The genus has almost cosmopolitan distribution.
Euthrenopsis is a genus of sea snails, marine gastropod mollusks in the family Buccinidae, the true whelks. All species in the family are endemic to the waters of New Zealand.
