104 ATLAS AND TEXT-BOOK OF HUMAN ANATOMY. 



Fig. 158. — The right calcaneus seen from the inner surface (f). 



Fig. 159. — The right calcaneus seen from the outer surface (-f). 



Fig. 160. — The right calcaneus seen from above (i). 



Fig. 161. — The right navicular bone seen from behind (\). 



Fig. 162. — The right navicular bone seen from in front (\). 



Fig. 163. — The right cuboid bone from the inner surface (\). 



Fig. 164. — The right internal cuneiform bone seen from in front (\). 



Fig. 165. — The right middle cuneiform bone seen from behind (-f-). 



Fig. 166. — The right external cuneiform bone seen from behind (\). 



THE CUBOID BONE. 

 The cuboid bone (Fig. 163) is situated on the outer side of the foot, in front of the anterior 

 extremity of the calcaneus and behind the bases of the fourth and fifth metatarsal bones (Figs. 

 153 and 154). It is irregularly cuboid in form and its inner border is longer than the outer one. 

 Its dorsal surface is convex, its anterior surface presents two articular facets for the bases of the 

 fourth and fifth metatarsal bones, and its posterior surface is saddle-shaped and articulates with 

 the calcaneus. The internal surface (Fig. 163) presents a flat articular facet for connection 

 with the external cuneiform bone, and a small inconstant one for the navicular, and the external 

 surface is narrow and forms a part of the outer border of the foot. The plantar surface presents 

 a flattened tuberosity (Fig. 153), in front of which is situated a broad groove, the peroneal groove, 

 which is lined with cartilage and accommodates the tendon of the peroneus longus muscle. 



THE CUNEIFORM BONES. 



The three cuneiform bones (Figs. 164 to 166) are situated between the navicular and the 

 bases of the first three metatarsal bones, and, as their name indicates, are more or less wedge- 

 shaped. 



The internal or first cuneiform bone (Fig. 164) is by far the largest and also the longest 

 of the three, and it has the narrow edge of its wedge directed dorsally, so that its plantar surface 

 is much broader than the dorsal surface. Its internal surface is directly continuous with the 

 narrow dorsal one; the anterior semilunar surface articulates with the base of the metatarsal 

 bone of the great toe; the posterior triangular surface articulates with the navicular bone; and 

 the external surface is in contact with the middle cuneiform and with the base of the second 

 metatarsal bone, and exhibits articular facets for both. 



The middle or second cuneiform bone (Fig. 165) is the smallest and the shortest of the 

 three. The thin edge of its wedge is directed downward and is almost concealed between the 

 external and the internal cuneiform bones; its base forms part of the dorsal surface of the foot, 

 and its posterior surface presents a triangular articular facet for the navicular bone. The middle 

 cuneiform also articulates with the second metatarsal, and with the external and internal cuneiform 

 bones. 



The external or third cuneiform bone (Fig. 166) is somewhat larger (especially in length) 

 than the middle one. Its thin edge is likewise directed downward and its broadest surface looks 



