There is a pair of large nodular sesamoids behind the metacarpo-phalangeal articulation, and a single large transversely-extended sesamoid behind the joint between the second and third phalanx, called the " navicular bone."
A strong ligamentous band behind the metapodium, arising from near the upper extremity of its posterior surface, divides into two at its lower end, and each division, being first connected with one of the paired upper sesamoid bones, passes by the side of the first phalanx to join the extensor tendon of the phalanges.
Inferior or short sesamoid s, Third or ungual phalanx (os ligament.
12, Derma or skin of the foot, 5, One of the upper sesamoid covered with hair, and continued into bones.
6, Lower sesamoid or navicular 13, The coronary cushion, bone.