[Mollusca] The chitinous, ribbon-like band in the mouth of molluscs containing numerous transverse rows of teeth.
— ctenodont: a radula in which the rachidian (central) and lateral teeth are similar in appearance; each has multiple cusps (more than three). The central cusp (mesocone) on the rachidian tooth may be inconspicuous
— heterodont: a radula in which the teeth on each side are different from one another in appearance; the rachidian tooth has one or two cusps on either side of a distinct central cusp (mesocone), and each lateral tooth bears one or two cusps.
— homodont: a radula in which all teeth appear similar in size and shape; each rachidian and lateral tooth has one simple cusp.

Alternative forms for radula : ctenodont, heterodont, homodont.