Cannonball jellyfish

The cannonball jelly is a firm, round dome somewhere between a softball and a volleyball in size, usually white with a reddish-brown lower edge. It has no tentacles around the outside of the bell, which gives it its smooth, ball-like look as it pulses along. Its sting is mild if felt at all, so this is one of the jellies a beachgoer can relax about when one drifts past. In the Chesapeake Bay it is only an uncommon winter visitor.