THE FORE FEET. 123 



The Third Metacarpal. (Plate XXXVI, figures 1-6.) 



The third metacarpal resembles the second in general size and shape, 

 but may be readily distinguished from it by the presence, on the proximal 

 «nd, of four, instead of three, articular faces. Like that bone, it is rough 

 and tuberculated, especially near the ends. It bears, also, a rugose surface 

 not far above the middle of its shaft on the ulnar side, best shown in 

 Plate XXXVI, figures 1 and 3. 



Of the four proximal articular faces, the first, beginning on the radial 

 side is almost entirely on the lateral surface of the bone, as represented 

 in figure 2. In life, it moved upon a corresponding face on the adjoining- 

 second metacarpal. It is confluent, along its proximal margin, with the 

 second articular face, which is the largest of the four, and articulated with 

 the principal distal face of the magnum. 



This face, shown in figures 2 and 5, extends with parallel sides across 

 the proximal end of the bone, from before backward. It is concave 

 from side to side, though slightly convex antero-posteriorly, and formed, 

 during life, the principal support of the bone. Its plane is more inclined 

 to the axis of the bone than is that of the third face, which, in life, rested 

 on the unciform. 



The third face, best shown in figure 5, is large and triangular, the 

 apex of the triangle being turned posteriorly, or toward the palmar surface 

 of the manus. This face articulated with the unciform. It is convex in 

 both directions, and, being more nearly perpendicular to the axis of the 

 metacarpal than is the face foi- the magnum, must have contributed, 

 during life, nearly as much to its support. 



The face for the unciform is confluent along its entire outer, or ulnar, 

 margin with a fourth, broad articular face on the side of the bone (figure 4j, 

 which, in life, met a corresponding face on tlie fourth metacarpal. 



The distal end of the bone (figure (!) supports a moderately convex 

 face for the ]lialangeal articulation, placed well upon the upper surface of 

 the bone, and 'scarcely extending as low as the middle of the distal end. 

 Here, it is met by the teoad and shallow^ grooves, in which a pair of 



