. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. Fig. 9. Right scaphoid. Top row: Heptodon posticus, MCZ 17670, in, from left to right, lateral, medial, proximal and distal views. X I'A- Middle row: Protapirus obiiquidens, AMNH 662 (reversed), X ^4- Bottom row: Tapirus pinch- aquc, YPM 204, X 'A- Letters indicate articular contacts. For abbreviations see p. 102. extensor. Tlie anterior edge of tlie medial side of the ulna bears scars just Ix'low the coronoid crest, marking the insertions of the biceps and brachialis. Distally, the shaft of the ulna is excavated to f
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. Fig. 9. Right scaphoid. Top row: Heptodon posticus, MCZ 17670, in, from left to right, lateral, medial, proximal and distal views. X I'A- Middle row: Protapirus obiiquidens, AMNH 662 (reversed), X ^4- Bottom row: Tapirus pinch- aquc, YPM 204, X 'A- Letters indicate articular contacts. For abbreviations see p. 102. extensor. Tlie anterior edge of tlie medial side of the ulna bears scars just Ix'low the coronoid crest, marking the insertions of the biceps and brachialis. Distally, the shaft of the ulna is excavated to fit the swollen distal end of the radius, and there is a small an- teromedial facet for articulation with the radius. The distal end of the ulna bears a roughly square, saddle-shaped facet for articulation with the cuneiform and, poste- rior to it, a slightly smaller, triangular, con- vex, posteromedially-facing facet for the pisiform. The radius and ulna of Tapirus differ from those of Heptodon in the following features: radius and ulna fused together proximally and distally; humeral facet of radius further extended laterally, and lat- eral tuberosity more prominent; distal end of radius wider, with most of the expansion on the lateral side; facet for lunar (at distal end of radius) shorter anteroposteriorly. Carpus: The carpus, seen in anterior view, is relativelv low and \\'ide, with the lunar resting mainly on the unciform. The scaphoid (see Fig. 9) is relatively long (anteroposteriorly) and low, with a large posterior process. The proximal surface is covered by an anteromedially convex, pos- terolaterally concave facet for the radius, and the lateral side bears narrow proximal and distal strips for articulation with the lu- nar. On the distal smface there are two lateral facets, the posterior one steeply in- clined and the anterior one horizontal, for the magnum, and a large medial facet for the trapezoid. There is no evidence of a facet for the trapezium. The lunar (see Fi
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