The coffee bean snail, Melampus coffeus, is a small intertidal snail. The shell is ovate, tapering toward the base. Most snails are brown with three horizontal light bands (Kaplan 1988), but the background color in some individuals may range from shades of gray or tan to yellowish brown. The aperture is narrow and long, with a sharp outer lip and an inner margin bearing two teeth (Kaplan 1988). The pale brown inner lip is turned slightly backwards, and the spire is conical. Unlike many other snails, M. coffeus lacks an operculum (Ruppert & Barnes 1994).