We have already discussed the head and neck domains that are responsible for the motor properties of myosins. We now come to the tail domains, which define the cargoes that myosins move. The functions of many of the newly discovered classes of myosins found in metazoans are not yet known. In this section, we give just two examples for which we have a good idea of specific myosin functions. Our first example is skeletal muscle, in which myosin II was discovered. In muscle, many myosin II heads, each with a low duty ratio, are bundled into bipolar filaments, in which they work together to bring about contraction. Similarly organized contractile machineries function in the contraction of smooth muscle, in stress fibers, and in the contractile ring during cytokinesis. We then turn to the myosin V class, whose higher duty ratio allows these myosins to transport cargoes over relatively long distances without dissociating from actin filaments.