Ceratostoma

{{Short description|Genus of gastropods}}

{{More footnotes|date=May 2021}}

{{Automatic Taxobox

|taxon = Ceratostoma

|image = Ceratostoma foliatum.jpg

|image_caption = A live individual of Ceratostoma foliatum, in situ on a rock

|authority = Herrmannsen, 1846

|synonyms_ref=

|synonyms=

• Cerostoma Conrad, 1837 (invalid: junior homonym of Cerostoma Latreille, 1802 [Lepidoptera]; Ceratostoma is an emendation )
• Microrhytis Emerson, 1959
• Pteropurpura (Ceratostoma) Herrmannsen, 1846
• Spinostoma Coen, 1943

|display_parents= 3

}}

Ceratostoma, common name the "hornmouth" snails, is a genus of medium to large predatory sea snails, marine gastropod mollusks in the family Muricidae, the rock snails. MolluscaBase eds. (2020). MolluscaBase. Ceratostoma Herrmannsen, 1846. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=240766 on 2020-07-31

This genus should not be confused with the nudibranch genus Ceratosoma, meaning "thorn body". Ceratostoma means "thorn mouth" because of the thornlike projection on the edge of the aperture, used as a tool in predation to prop open the shells of bivalves and barnacles.