Cerithiidae, common name the cerithiids or ceriths, is a large family of medium-sized marine gastropods in the clade Sorbeoconcha. Distribution Ceriths are found worldwide on sandy bottoms, reef flats or coral reef rock covered with sand and algae in the sublittoral zone of warm or temperate waters. Most are found in tropical areas. A few occur along the European coastline and about 30 species in two genera are found along the American coast. A few species occur in estuarine areas of mangrove forests close to the sea. Only a few species of the subfamily Bittiinae are found in deep water. Diet Ceriths are herbivores and detritivores that graze the sea bed. Description Their slender shell is elongated with a pointed spire. They vary in size from 3 mm (Bittium alternatum) to 150 mm (Cerithium nodulosum). The smallest shells are found in the subfamily Bittiinae. The many whorls have radial sculpture with axial ridges and nodules. The aperture shows at its base a vague curve or a distinct siphonal canal. The aperture is closed off by a thin oval brown operculum that is corneous and paucispiral. The palatal wall of the aperture is somewhat enlarged and often shows a varix. The taenioglossan radula has seven teeth in each row. The single rachidian tooth is flanked on each side by one rhomboidal lateral tooth and two long, hook-like marginal teeth. Subfamilies The following three subfamilies have been recognized in the taxonomy of Bouchet & Rocroi (2005): Alabininae Dall, 1927 Bittiinae Cossmann, 1906 Cerithiinae Fleming, 1822 - synonyms: Rhinoclavinae Gründel, 1982; Colininae Golikov & Starobogatov, 1987 Bandel (2006) used different classification: Bittiinae on its own family level named Diastomatidae (overview of WoRMS). Some authors classify Argyropezinae Bandel, 2006 as a synonym of Bittiinae. Genera Genera within the family Cerithiidae include: Alabininae Dall, 1927 Alabina Dall, 1902 - type genus of the subfamily Alabininae, the type species of the genus Alabina is extinct Bittiinae Cossmann, 1906 Bandel (2006) recognized a family Bittiidae Cossmann, 1906 [which should then be named Diastomatidae Cossmann, 1894 on the grounds of priority] with five subfamilies Bittiinae Cossmann, 1906 (usually placed in Cerithiidae following Houbrick, 1993), Finellinae Thiele, 1931, Alabininae Dall, 1927, Dialinae Kay, 1979 and Diastomatinae Cossmann, 1894. This contradicts Ponder (1994) who grouped Finella with Scaliola A. Adams, 1860 in a separate family Scaliolidae Jousseaume, 1912 [Scaliolidae is nevertheless kept distinct by Bandel (2006: 76) on the basis