<P> The lateral arch is composed of the calcaneus, the cuboid, and the fourth and fifth metatarsals . </P> <P> Two notable features of this arch are its solidity and its slight elevation . Two strong ligaments, the long plantar and the plantar calcaneocuboid, together with the Extensor tendons and the short muscles of the little toe, preserve its integrity . </P> <P> While these medial and lateral arches may be readily demonstrated as the component antero - posterior arches of the foot, the fundamental longitudinal arch is contributed to by both, and consists of the calcaneus, cuboid, third cuneiform, and third metatarsal: all the other bones of the foot may be removed without destroying this arch . </P> <P> In addition to the longitudinal arches the foot presents a series of transverse arches . </P>

Which is not one of the five bones that form the medial longitudinal arch