Cerithiform gastropods possess high-spired shells with small apertures, anterior canals or sinuses, and usually one or more spiral rows of tubercles, spines or nodes. This shell morphology occurs mostly within the superfamily Cerithioidea. Several morphologic characters of cerithiform shells are adaptive within five broad functional areas: (1) defence from shell-peeling predators (external sculpture, pre-adult internal barriers, preadult varices, adult aperture) (2) burrowing and infaunal life (burrowing sculptures, bent and elongated inhalant adult siphon, plough-like adult outer lip, flattened dorsal region of last whorl), (3) clamping of the aperture onto a solid substrate (broad tangential adult aperture), (4) stabilisation of the shell when epifaunal (broad adult outer lip and at least three types of swellings located on the left ventrolateral side of the last whorl in the adult stage), and (5) righting after accidental overturning (projecting dorsal tubercles or varix on the last or penultimate whorl, in one instance accompanied by hollow ventral tubercles that are removed by abrasion against the substrate in the adult stage). Most of these characters are made feasible by determinate growth and a countdown ontogenetic programme. These varied adaptations often have evolved independently among different taxonomic groups of cerithiforms, and multiple times within the same group.