_a_, calcaneus; _b_, astragalus; _c_, cuboid; _d_, scaphoid; _e_, lateral cuneiform; _g_, medial cuneiform; _h_, peroneal groove, for the tendon of the peroneus longus muscle; _i_, proximal phalanges; _j_, second row of phalanges; _k_, distal phalanges; _l_, sesamoid bones. 1, rudimentary first (medial) metatarsal; 2, 3, 4, 5, the other metatarsals.] [Illustration: FIG. 59.--CALCANEUS OF RIGHT FOOT, DORSAL VIEW. _a_, distal facet for cuboid; _b_, proximal end with groove for tendon of Achilles; _c_, sustentaculum tali; _d_, peroneal tubercle.] _Cuboid._ _Os cuboideum_ (Fig. 58, _c_).--The cuboid has somewhat the form of a cube and articulates by its proximal end with the calcaneus (_a_), and by its distal end with the fourth and fifth metatarsals. Its medial surface articulates with the scaphoid (_d_) and lateral cuneiform (_e_). The ventral surface is marked near its distal end by an oblique ridge, distad of which is a deep groove, the peroneal groove (_h_), for the tendon of the peroneus longus muscle. _Scaphoid._ (_Os naviculare pedis BNA_) (Fig. 58, _d_).--The scaphoid is a boat-shaped bone. Its proximal surface is marked by a concave facet for the head of the astragalus (_b_), and its distal surface has three facets for the lateral (_e_), intermediate and medial (_g_) cuneiform bones. At the junction of the ventral with the medial surface is a prominent tubercle. The lateral surface bears two linear facets for articulation with the calcaneus (_a_) and cuboid (_c_). _Lateral Cuneiform._ _Ectocuneiform._ _Os cuneiforme tertium BNA_ (Fig. 58, _e_).--The lateral cuneiform is a wedge-shaped bone with a hooked process extending from the ventral sharp angle of the bone. It articulates by its proximal end with the scaphoid (_d_), and by its distal end with the third metatarsal. The medial surface bears near its distal end two facets for the second metatarsal, and on its proximal end a facet for the intermediate cuneiform. The caudal surface has a facet on its proximal end for the cuboid (_c_). _Intermediate Cuneiform._ _Mesocuneiform._ _Os cuneiforme secundum BNA._--The intermediate cuneiform is small and wedge-shaped, with the base of the wedge dorsad. It lies between the lateral cuneiform and the medial cuneiform, articulates by its proximal end with the middle facet of the scaphoid, and bears on its distal end the second metatarsal. It is not visible in ventral view.