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PANTODONTA. 
border. The pisiform is an L-shaped bone, the transverse limb proximal, 
and bearing- the long facet for the cuneiform. The long limb equals the 
transverse, and has a neck and oblique tuberous head. 
Of the second row of carpal bones, the unciform is much the largest, 
the magnum is next in size, the trapezium next, and the trapezoides the 
smallest. But, of the exposed anterior surfaces, the magnum displays the 
smallest, and the others in the order named. The unciform is subcrescentic 
in vertical section, and its transverse exceeds its antero-posterior diameter. 
It presents two superior facets, one interior terminal, and three inferior. 
Of the two superior, the inner is antero-posterior, being narrower than the 
other and elevated above it; it is applied to the lunar. The other superior 
facet is the largest in the carpus, is transverse and strongly concave. The 
three inferior facets apply to the external metacarpals, the inner to a portion 
only of the third, and is therefore narrower than the others. The median is 
largest, and the external is oblique. The magnum has very little transverse 
diameter, but the antero-posterior and vertical are considerable, and in some 
of the species subequal. It has but one superior facet, that for the lunar, 
and one of nearly the same width inferiorly, for the internal part of the 
third metacarpal. Alongside of this is a narrower facet, partly lateral, for a 
small part of the second metacarpal. The inferior posterior tuberosity of 
the magnum does not extend much beyond the inferior articular face, while 
a superior posterior tuberosity occupies a corresponding concavity of the 
lunar. From this, the superior facet descends steeply to the anterior face. 
The trapezoides is the smallest bone of the carpus. Its anterior face is a 
vertical wide rhomboid, and is rather shorter than the antero-posteiior 
diameter. Each side is a facet, but the supero-exterior and intero-inferior 
angles are obtuse, while the opposite ones are acute. The proximal facet 
is narrower than the distal. The trapezoides is larger, and would present 
a quadrate anterior face but for the presence of two proximal facets, the 
internal narrower than the external. The external presents a median fossa; 
the distal face is truncate; the internal (free) face presents the usual rough 
surface. 
The lengths of the metacarpals have been already stated. The 
proximal ends present faces which are a little convex antero-posteriorly. 
