The bat star gets its name from the webbing between its arms, which is said to resemble a bat's wings. It typically has five arms, with the center disk of the animal being much wider than the stubby arms are in length. Although the bat star usually has five arms, it sometimes has as many as nine. Its range extends from Sitka, Alaska to Baja California in the Pacific Ocean. It is most abundant along the coast of Central California and the Monterey Bay.