Amphicyclotulus amethystinus is a species of tropical land snail with a gill and an operculum, a terrestrial gastropod mollusc in the family Neocyclotidae.

The shell is smooth, shining, not striate spirally, generally somewhat more depressed, deep chestnut or reddish brown.

[1] The species may have subtle spiral striation, although there exists considerable variation; axial growth lines are clearly visible.

[2] The operculum is horny, diaphanous, concave externally, cartilaginous within, the nucleus projecting internally; with from ten to fourteen very narrow whorls, their rather lamellar outer edges slightly free.

George French Angas (1884)[3] subsequently recorded "Cyclophorus amethystinus" from altitudes above 1200 m. Paul Bartsch (1942)[4] restricted the name amesthystinus to Guppy’s var.