The cannonball jellyfish (Stomolophus meleagris), also known as the cabbage head jellyfish, is a species of jellyfish in the family Stomolophidae. Its common name derives from its similarity to a cannonball in shape and size. Its dome-shaped bell can reach 25 cm (10 in) in diameter and the rim is sometimes colored with brown pigment. Underneath of the body is a cluster of oral arms that extend out around the mouth. These arms function as a way of propulsion and aid in catching prey. Cannonballs are prominent from North America's eastern seaboard all the way to Brazil, but are also found in parts of the Pacific.