- paper nautilus: Argonauta argo (Argonautidae), a mollusk, a member of the super-family of octopus-like cephalopods that lives in pelagic habitats of the tropical and subtropical seas. It is not a nautilus, but its shell superficially resembles that of a nautilus in that it is spiral shaped
- however, it is not chambered like a nautilus. The female produces a spiral shell of increasing diameter that serves as an egg case, up to 20 cm. in diameter. The male produces no shell and is much smaller and shorter-lived. Lungsir shells are sometimes found in the stomachs of fish. The shell and dead animal are put in lengis and kept for use as a medicine to induce vomiting. Usually only a drop of the oil on the tongue is sufficient. Some balians use lengis lungsir to induce vomiting in cases of cetik poisoning.