![banner3 Molluscs of Tasmania](https://molluscsoftasmania.org.au/wp-content/uploads/2017/07/banner3.jpg)
Rissoidae: Onoba (Onoba) demessa (Tate & May, 1900) (‘mown rice-shell’)
Synonym(s): demessa Tate & May, 1900.
Typical shell-length 3.5 mm. Lives subtidally and offshore. Native. Endemic to southeastern Australia (TAS only).
Classification
Class: Gastropoda
Subclass: Caenogastropoda – Sorbeoconcha
Order: Hypsogastropoda – Littorinimorpha
Superfamily: Rissooidea
Family: Rissoidae
Genus: Onoba
![species image](https://molluscsoftasmania.org.au/wp-content/uploads/2017/07/no_image.jpg)
![locality map](https://molluscsoftasmania.org.au/wp-content/uploads/2017/09/Onoba-demessa.jpg)