THE BONES OF THE TARSUS 69 



for the attachment of the interosseous ligament which unites this bone 

 to the cuneiform magnum. 



The anterior and inner edges are convex and blended with each 

 other. They present a curved, roughened ridge, which gives attach- 

 ment to the astragalo-metatarsal and internal lateral ligaments. The 

 posterior edge is irregular and roughened for the attachment of the 

 tarso-metatarsal ligament. The outer edge is concave, and presents two 

 facets which articulate with like facets on the cuboid. This surface 

 also presents a roughening for the attachment of the cuboido-scaphoid 

 interosseous ligament. 



The Cuneiform Magnum. — This bone is situate below the scaphoid, 

 and rests on the upper extremity of the large metatarsal bone. It is 

 flattened from above to below, and is not unlike the scaphoid. It is, 

 however, a smaller bone, and is somewhat triangular in outline, presenting 

 for description, therefore, two surfaces and three edges. 



Its superior surface is slightly concave and presents two articular 

 facets, separated from one another by a transverse, non-articular groove. 

 The anterior facet is much the larger, and both facets articulate with 

 the scaphoid. To the non-articular groove the scaphoido-cunean 

 interosseous ligament is attached. The inferior surface is somewhat 

 similar, possessing facets for articulation with the large metatarsal bone 

 and a roughened area for ligamentous attachment. This surface is 

 slightly convex. The outer edge is concave, and possesses two facets for 

 articulation with the cuboid. Between the facets the edge is roughened 

 for the attachment of the cuboido-cunean interosseous ligament. The 

 inner edge is also concave, slightly more so than the outer. It presents 

 a single facet for articulation with the small cuneiform bone. The 

 anterior edge forms the base of the triangle. It presents a curved, 

 roughened ridge, which gives attachment to the astragalo-metatarsal 

 and internal lateral ligaments. This ridge is of great surgical 

 importance. It is subject to a considerable degree of variation in 

 size, variations being more frequently met with in the size of this ridge 



