The conchis is found in some medieval encyclopedias. It is a shellfish which has a keel and bow like a ship; it can spread its shells to use like sails. It invites the nauplius (a kind of cuttlefish) to take up residence in its shell, so that togther they can play at being a ship.

Conchis (conche, concha) in Latin is a generic name for shellfish, but Thomas of Cantimpré and others use it as the name of of a particular (not otherwise named) shellfish.