The littoral Trochoidea (Mollusca: Gastropoda) of the Azores

A revision of the Azorean littoral Trochoidea is conducted and a description of the shell, animal and radula is provided. The endemic Calliostoma lividum (Dautzenberg :1927), originally proposed as a variety of C. conulus, is herein elevated to specific status and re-described. Of the remaining littoral trochid species reported from the Azores, two are dubious records, two are endemic (Jujubinus pseudogravinae and Gibbula delgadensis) and one has a wide geographical distribution in the North Atlantic (Gibbula magus). A note on the Pleistocene fossil record from Santa Maria is added and the dispersal abilities of the littoral trochids are commented.