Note: Do not rely on this information. It is very old.
Calceola
Calceola, a genus of corals from the Devonian rocks of Europe and America. Its position was not well known until recently, as owing to the possession of an operculum it was regarded as one of the Brachiopoda. Several genera of operculate corals, however, are now known. It is most common in the limestone of the Eifel in Germany, but is found in Devonshire.