Historical reference: Do not rely on this information. It is very old. About this collection
Holostomata, the division of Gastropoda (q.v.) which includes all those with a rounded, unnotched mouth. They belong to the Streptoneura and the subdivision Azygobranchia. [Gastropoda.] They are all vegetable-feeders, whereas' those with a notched mouth (e.g. the Whelks) are mostly carnivorous. The Top-shell (Trochus), the Winkle (Littorina), the Pondsnail (Paludina) are wellknown representatives. In order to base the nomenclature on the anatomy of the soft parts instead of the shell, it has been proposed to call the group "Holochlamyda."