350 MEMOIRS OF THE CARNEGIE MUSEUM. 
described is located the sixth facet, which is underneath a heavy projecting ledge 
on the ulnar face of the bone. This facet is quite sharply concave antero-posteri- 
orly and articulates with a correspondingly convex facet on the proximo-radial 
angle of Me. III. The head of Me. II has a considerable palmar projection, so 
that the bone assumes a decidedly triangular appearance when seen from the 
proximal end. On the palmar and ulnar faces the bone is quite rugose immediately 
below the head, and on the ulnar face there is a considerable eminence on the 
upper half of the shaft. In general appearance the shaft is rather sub-cylindrical. 
There is, however, a sinuous ridge on the dorso-ulnar angle, which is perhaps 
somewhat too much emphasized in the illustration 
(Fig. 88,2). Near the distal end there is, on the 
dorsal face of the shaft, a prominent and rugose 
swelling for muscular attachment. Distally the 
bone is suddenly expanded, especially in the radial 
and the palmo-ulnar directions.” The trochlea is 
decidedly oblique to the long axis of the shaft, the 
anterior portion being evenly convex in all direc- 
tions, indicating a very flexible joint, as in some 
carnivores, while posteriorly the facets for the sesa- 
moids are divided by a median carina, which is 
rather slightly developed. The facet on the radial 
side of the carina is concave transversely and con- 
i i " = Wy). 
ie aM 
( i) | 
i: 
Wy), 
Wee 
7 hep) 
Fic. 88. Me. II, left manus of M. Vex antero-posteriorly, while the facet on the ulnar 
elatus (No. 1604). Xz. 1, ulnar view; gide is convex both antero-posteriorly and trans- 
poe te versely, less so in the latter direction. As already 
stated the trochlea faces obliquely inward so that the duplex bone (= first and 
second phalanges coéssified) points forward, upward, and slightly outward, when 
in position. The ungual phalanx again, however, points forward and inward, due 
to the peculiar tilt and the slight curve of the duplex bone. (See Pl. LX VIII, 1, 2.) 
In Nestoritherium Me. II is represented by the complete head and proximal 
portion of the shaft. The head in its details is remarkably similar to that in 
Moropus, the facet for the trapezium being smaller and the tuberosity on the 
dorso-ulnar angle thicker though not produced in a projecting flange articulating 
with the dorsal face of Me. III asin Moropus. The shaft appears to be less evenly 
cylindrical than in Moropus. 
The general similarity of Me. II in Macrotherium to that in Moropus elatus 
% The distal end of Me. II is present in the type of Moropus elatus Marsh, and was identified and illus- 
trated (Am. Naturalist, Vol. XLI, p. 735, Fig. 6) by Mr. Peterson in 1907. 
