304. MEMOIRS OF THE CARNEGIE MUSEUM. 
to that of Moropus elatus. The facet for Me. II in Macrotherium is more lateral; 
the facet for the magnum is similar and the facet for the unciform is more proximal 
and takes up a greater space on the proximal end than that in Moropus. These 
differences give the head of Me. III in Macrotheriwm a more cuboid appearance, 
especially when viewed from in front. The constriction between the articulation 
for the proximal phalanx and the tuberosities on the lower portion of the shaft in 
Macrotherium is relatively greater than in Moropus, but the shaft itself is quite 
similar in the two genera. 
The distal end and the shaft of Me. III in Schizotherium priscum more closely 
resemble these parts in Macrotherium than in either Moropus elatus or Nestori- 
therium, while the proximal end seems to possess characters which are found in 
both the European and American forms. Thus, the dorso-radial angle bears the 
facet for the overlapping flange for Me. II, while the facet for Me. II on the radial 
face is not as high up (or proximal) as in Moropus or Nestoritherium, nor as low, 
as extensive, and oblique as in Macrotherium. The facet for the magnum is more 
nearly like that in Macrotherium, being oblique transversely, and convex antero- 
posteriorly, while the small facet for the unciform, near the dorsal face and on the 
ulnar side of the prominent superior crest, is extremely suggestive of the facet for 
the same bone in Moropus elatus, and located in the same place on Me. III. The 
overhanging ledge on the ulnar face of the head of Me. III in Schizotherium priscum 
is much less developed than in Macrotherium, Nestoritherium, and Moropus. 
MEASUREMENTS OF THIRD METACARPAL. 
No. 1604 No. 1700 No. 1424 
(M. elatus), (M. petersoni), (M. hollandi), 
mm. mm. mm. 
Greatestilength.s./0% Sh 6 oe hone ee ae ees 274 183 of 
Greatest transverse diameter of head..................-+e.e+ce 54 42 40 
Greatest antero-posterior diameter of head...................6- 55 47 49 
Greatest antero-posterior diameter of distal end................ 56 43 
Greatest transverse diameter of distal end..................00- 58 40 
Metacarpal IV (Fig. 90).—The fourth metacarpal! is considerably shorter than 
the third, the head of the latter occupying a more elevated position in the carpus 
and the distal end extending slightly lower down than any of the series. The 
proximal and distal ends are much expanded. The shaft is trihedral near the 
head and more cylindrical lower down, terminating distally in tuberosities like 
those seen on Me. II and IIJ. When viewed from above the general outline of 
the head is triangular, revealing two articular facets, which are unequally divided 
