The species belonging to the genus Ceratostoma are listed and some are figured, as are forms that closely resemble the genus. The genus is characterized by 3 varices, foliations on the varices, and a tooth on the anterior portion of the outer lip. The genus Ceratostoma lives in a littoral marine environment with water temperatures ranging from 2 degrees to 27 degrees C. Known time range of the genus is from the middle Miocene to the Recent
