352 MEMOIRS OF THE CARNEGIE MUSEUM. 
no doubt present, and the tuberosity on the radial angle is identical with that in 
Moropus elatus, as is also the tuberosity on the ulnar angle, which overlaps and 
articulates with Me. III in the same manner. In the latter genus the bone as a 
whole is, however, relatively somewhat heavier and shorter than in Schizotherium. 
In Titanothertum Me. II is flat and broad, the facet for the trapezium is present, 
and in some species, the articular facet for the trapezoid is large, while that for 
the magnum is small and placed laterally. The distal trochlea is not oblique in 
Titanotherium. Me. II in the latter genus, while presenting some general affini- 
ties, cannot be compared with that in the Chalicotheriide. 
MEASUREMENTS OF SECOND METACARPAL. 
No. 2193 Y.M. No. 1604 No. 1700 No. 1424 
(M. elatus), (M. elatus), (M. petersoni), (M. hollandi), 
mm. mm. mm. mm. 
Greatestilength). SQ eeshate nar Pee oe ae ocean ene een 230 158 179 
Greatest transverse diameter of head................. « 92 66 64 
Greatest antero-posterior diameter of head............. .. 60 43 44 
Greatest antero-posterior diameter of distal end........ 55 67 45 38 
Greatest transverse diameter of distal end............. 60 69 53 41 
Metacarpal III (Fig. 89).—The third metacarpal is the longest in the series. 
The proximal end is very little expanded, while distally the bone is of much larger pro 
portions than the shaft both antero-posteriorly and trans- 
versely. When in position in the manus the radial portion 
of the head is hidden by the overlapping flange of Me. II re- 
ferred toabove. On the dorsal face near the radial angle 
is a facet of quite large size, triangular in outline, which ar- 
ticulates with a corresponding facet on the posterior face of 
the large tuberosity on the ulnar angle of Me. II. The 
anterior face of the head of Me. III is otherwise quite ru- 
gose and irregular in outline as is shown in Fig. 89, 2. 
The radial face of the head has no articular facets,” while 
proximally there are three: one for Me. II; one for the 
magnum; and one for the unciform. The first is the 
smallest of the three and is located on the proximal face of 
a projecting ledge on the radial angle and is convex ante- 
ro-posteriorly. The second facet is the largest of the 
three. This facet is quite characteristic; along the ra- 
Cui Ld 
Fic. 89. Me. III, left manus 
of M. elatus (No. 1604).  #. 5: : A 
1, lateral view; 2, dorsal view. ial border being a transversely narrow plane, which 
6 Occasionally there is a minute articular surface for Mc. II on the dorso-radial angle. This is not the 
case in No. 1604. 
