Worldwide warm seas; more common in the atlantic area than in the indo-pacific. Epipelagic, it lives in free waters down to circa 200m deep. Predator on mobile preys. Local synonym: mediterranea. Beached in the Faro, Messina, NE. Sicily. 10mm.

When swimming, unlike what shows the drawing, the animal is upside down: the dorsal shell below, the ventral side, with its undulating fin, on top.

« Corpore crystalino, muricato; cauda acutissima, superne cristata; ventre pinna orbiculari, reticulato-fibrosa, acetabuloque insignita; dorso testa geleaeformi, fragili, vitrea, viscera tegente communita, branchiis pinnatis, extra concham pendulis. » – vol. II, pp. 199-202.

« Fragile and prized by collectors, this shell has at the base of its dextral winding a small spiral that served as shelter to the juvenile form of the individual. » (DORIS). – Above, this shell of a juvenile from Capo Teulada, Cagliari, S. Sardinia. 1mm.