OS CUNKIFORMK MAGNUM. 95 



tendon of the flexor perforatus muscle plays ; and anteriorly is a 

 smaller portion, also covered with cartilage, for the gastrocnemius 

 tendon to play over ; and, finally, a roughened depression 

 betsveen the two smooth portions for the insertion of the last 

 named teudon. The calcaneum articulates with the astragalus 

 and cuboid bones. 



OS CUBOIDES. 



(Fie. 22. 5.) 



The cuboid bone is a small irregularly-shaped bone, which 

 occupies the outer part of the hock between the os calcis and 

 the large and outer small metatarsal bones ; it presents four 

 surfaces. 



The external surface is. convex, very rough and irregular, and 

 gives attachment to ligaments ; the internal surface has four 

 articular facets, the two superior of which articulate with the 

 cuneiforme magnum, and the two inferior with the cuneiforme 

 medium ; between the upper and lower facets a large foramen is 

 formed by these three bones, giving passage to the perforating 

 pedal artery. The superior surface is smooth, and possesses 

 two continuous articular facets, one large, to articulate with the 

 os calcis, and the other small, to articulate with the astragalus ; 

 the inferior surface, also smooth, has two continuous articular 

 facets, separated by a ridge, one flat, to articulate with the large 

 metatarsal, and the other bevelled, to articulate with the outer 

 small metatarsal bone. 



The cuboid articulates with six bones viz., the calcaneum and 

 astragalus above, the cuneiforme magnum and medium internally, 

 and the large and external small metatarsal bones below. 



OS CUNEIFORMS MAGNUM. 

 (FiG. 22. 3.) 



The large cuneiform, called also the scaphoid, and sometimes 

 the navicular bone, is the bone on which the astragalus chiefly 

 rests ; it is somewhat flattened and thin, and presents two surfaces 

 and a circumferent border. The superior surface is concave and 

 entirely articulatory, with the exception of a groove which runs 

 from its outer surface to its middle, and gives attachment to a 

 ligament ; this- surface articulates with the astragalus. The 



