Thysanoteuthis is a genus of large squid comprising one well-known species, the diamond squid, and two dubious taxa.
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.
Dentaliida is one of the two orders of scaphopod mollusks, commonly known as elephant's tusk shells. The order Dentaliida contains most of the larger scaphopods, and is distinguished from the other order by the shape of its shell, the shape of the foot, and the arrangement of some of their internal organs.
Exquisitiropa is a monotypic genus of small land snails in the family Charopidae. The sole species is Exquisitiropa agnewi, also known as silky snail or silky pinwheel snail. It is endemic to Tasmania.
Roblinella is a monotypic genus of small land snails in the family Charopidae. The sole species is Roblinella roblini, also known as Roblin's pinwheel snail. It is endemic to Tasmania.
Notonykia is a genus of squid in the family Onychoteuthidae. The type species is Notonykia africanae.
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.
Euvola is a genus of marine bivalve mollusks in the family Pectinidae, the scallops. In shells of this genus, one valve is flat, and the other is deeply cupped.
Calliostoma tsuchiyai is a species of sea snail, a marine gastropod mollusk in the family Calliostomatidae.
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 goesi is a species of monoplacophoran, a superficially limpet-like marine mollusc.
Rokopella segonzaci is a species of monoplacophoran, a superficially limpet-like marine mollusc.
Vema levinae 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.
