The whorls of the shell of species of "Amphidromus" are moderately convex and, with only a few exceptions, are smooth or have a faint sculpture of growth lines. However, a sculpture of moderately heavy oblique radial ribs has appeared at least four separate times in the genus, and can be seen in the following species: "Amphidromus costifer" Smith from Binh Dinh Province in Vietnam; "A. begini" Morlet from Cambodia; "A. heccarii" Tapparone-Canefri from Celebes; and the "A. palaceus"-"A. winteri" complex from Java and Sumatra. Correlated with the ribbing is a light, monochrome coloration, and a thin shell with a large aperture and a flaring lip. Many solid shells in other species do show a slight roughening of the surface, but this is very different from the ribbed sculpture mentioned above.