''Notomenia'' 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 ...
of
solenogaster
The Solenogastres (less often referred to as Neomeniomorpha), commonly known as solenogasters, are a class of small, worm-like, shell-less molluscs ( Aplacophora), the other class being the Caudofoveata ( Chaetodermomorpha).MolluscaBase eds. (20 ...
s, shell-less, worm-like,
marinemollusk
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 this genus the animal bears non-mineralized
sclerite
A sclerite (Greek language, Greek , ', meaning "hardness, hard") is a hardened body part. In various branches of biology the term is applied to various structures, but not as a rule to vertebrate anatomical features such as bones and teeth. Instea ...
s.
This genus is the sole representative of the family Notomeniidae, and has secondarily reduced its
radula
The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...
, which is
vestigial
Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on co ...
.
References
Solenogastres
{{Solenogaster-stub