Dicathais orbita (formerly Thais orbita) is a predatory marine gastropod in the family Muricidae. Commonly known as the cart-rut shell, Australian dogwhelk, or white rock shell, it is endemic to southern Australia and New Zealand. It lives on intertidal rocky reefs and plays a vital role in controlling mussel and barnacle populations.Collected out from Mandurah, WA MUR O18