The Crucibulum umbrella (Crucibulum umbrella), also known as the umbrella slipper shell, is a distinctive marine snail found along rocky shores and reefs of the eastern Pacific. It is easily recognized by its low, cap-shaped shell with a broad, flared margin and a characteristic internal “cup” or shelf that resembles a small umbrella, which gives the species its common name. The shell is usually white to pale cream and often encrusted with algae or other organisms, helping it blend into its surroundings. This sedentary gastropod typically attaches firmly to rocks or other hard surfaces and feeds by filter-feeding, drawing in plankton and organic particles from the surrounding water.