354 DESCRIPTION OF A NEW SPECIMEN OF GLYPTODON 
But it is not a little remarkable that whereas in Dasypus it is the 
fifth metacarpal whose proximal end partially articulates with the 
cuneiform, in Glyptodon the corresponding bone articulated wholly 
with the cuneiform, and not with any of the distal row of carpal 
bones. The metacarpal articular end of that bone is, in fact, divided 
into two facets—an inner, larger, which articulates with part of the 
proximal end of the fourth metacarpal, and an outer, smaller, which 
is appropriated by the proximal end of the fifth metacarpal. 
That the cuneiform should articulate with two metacarpal bones, 
and that the unciform should not articulate with the fifth metacarpal 
at all, are very remarkable peculiarities of the wrist of Glyptodon. 
The pisiform is a large curved bone, the proximal end of which 
articulates by a large facet with the ulna, and by a small one with a 
facet on the palmar aspect of the cuneiform. It closely resembles 
the same bone in Armadillos. 
The trapezium and trapezoid, taken together, have a form closely 
resembling that of the single trapezio-trapezoid of Dasypus. The 
trapezium possesses only a very small double articular facet on its 
palmar face. If this gives support to a metacarpal, it must have 
been very small; and as at present neither it nor any of the hallucal 
phalanges have been discovered, it is possible the pollex may have 
been altogether rudimentary. In any case the pollex must have 
been so much smaller and more slender in proportion than that of 
Dasypus, that the animal must have had a practically tetradactyle 
fore foot. 
The second metacarpal is the longest of all which have been 
discovered, but is not quite so thick as the third. Its proximal end 
articulates with the trapezium, trapezoid, and magnum. 
The third metacarpal, an almost cuboidal bone, but broader than 
long, articulates with the magnum, the cuneiform, and the adjacent 
metacarpals. 
The fourth metacarpal, still shorter and broader in proportion, 
articulates with the unciform and cuneiform, and with the adjacent 
metacarpals. 
The fifth metacarpal has not been found. The two proximal or 
first and second phalanges are very short, broad, discoidal bones in 
the second and in the third digits ; and the second, which alone exists 
in the fourth digit, has the same character. The proximal phalanges 
of the fifth digit have not been found. 
The distal or third phalanx is a broad bone, squarely truncated at 
the extremity, and longer than the rest of the digit, in the second, 
third, and fourth, and presumably in the fifth digit. Each of these 
