PELyiC LIMBS. 



83 



J 



lateral and medial surfaces by curved 

 facets for articulation with the malleoli 

 of the tibia and fibula. This entire 

 surface for articulation with the bones 

 k, of the leg is known as the trochlea. 

 The lower surface is marked by two 

 facets separated by a groove ; these are 

 for articulation with corresponding 

 t facets on the calcaneus. Distally the 

 '_../ bone contracts to form the neck and 

 enlarges at the end, forming the head, 

 which is smooth on its distal surface for 

 articulation with the navicular or sca- 

 phoid. 



Calcanc7is (Fig. 58, a, and Fig. 59). 

 — The calcaneus (os calcis) is the largest 

 bone of the foot and forms the heel. 

 It is two or three times as long as broad 

 and has six surfaces: dorsal, ventral, 

 medial, lateral, proximal, and distal. 

 The proximal one-half of the dorsal 

 surface (Fig. 59) is smooth, while the 

 distal half is broadened and bears two 

 facets which are separated by a groove. 

 These articulate with the corresponding 

 facets on the astragalus. The medial 



Fig. 58. — Tarsus, Meta- 

 tarsus, AND Phalanges 

 OF Left Foot, Ventral 

 View. 



a, calcaneus; /', astragalus; 

 c, cuboid; d, scaplioid; <-, lat- 

 eral cuneiform; g, medial 

 cuneiform; //, peroneal groove, 

 for the tendon of the peroneus 

 longus muscle; ?', proximal 

 phalanges; j, second row of 

 phalanges; k, distal phalanges; 

 /, sesamoid bones. i, rudi- 

 mentary first (medial) meta- 

 tarsal; 2, 3, 4, 5, the other 

 metatarsals. 



Fig. 59. — Calcaneus of Right 

 Foot, Dorsal View. 



a, distal facet for cuboid; b, 

 proximal end with groove for 

 tendon of Achilles; f, sustentacu- 

 lum tali; (/, peroneal tubercle. 



