362 MEMOIRS OF THE CARNEGIE MUSEUM. 
chanters are of larger size, the trochanteric fossa deeper, and the entire upper end 
of the posterior face of the shaft broader, than in Titanotherium. Peterson (Ann. 
Carnegie Museum, Vol. IV, p. 6; American Naturalist, Vol. XLI, p. 748) has 
called attention to the great development of the third trochanter, which is charac- 
teristic of Moropus, while in Macrotherium it is very feebly, or not at all, developed. 
(Cf. Blainville, Illustrations of Macrotherium, and Zittel, Handbook of Paleontology, 
p. 310.) The third trochanter is not as strongly developed in M. hollandi as in M. 
elatus and M. peterson. The flat broad surface across the shaft opposite the third 
trochanter recalls the same feature in Titanotheriwum. Below this trochanter the 
shaft is greatly constricted, but nevertheless the transverse diameter is considerably 
greater than the antero-posterior diameter. The distal end is suddenly expanded, 
the condyles being of large size, and well separated by a broad and deep inter- 
condylar notch. The rotular trochlea is not very wide, but has approximately the 
same obliquity as in Titanotherium. The pit, or supracondylar fossa, is not very 
deep, or distinctly marked, and is situated unusually low. 
The antero-posterior and transverse diameters of the head of the femur of 
Macrotherium grande as figured by Blainville are approximately like those in 
Moropus, but the distal end of the femur in Macrotherium is broader, the condyles 
being more widely separated by a broader intercondylar notch. The rotular 
trochlea is also seen to be broader and shallower. 
MEASUREMENTS OF FEMUR. 
No. 1706 No. 1701 No. 1424 
(M. elatus), (M. petersoni), (M. hollandi), 
mm. mm. mm. 
Greatest lenethiotstemitn eee erate eee ie Seginuhs §50 430 500% 
Transverse diameter of proximal end..................------ 220 133 170 
iiransyersediametenof headers eee e eer enicecrr 95 66 78 
Antero-posterior diameter of head.................-...----- 93 64 74 
Antero-posterior diameter at distal end...................... 170 102 ae) 
diransverserdiame ter Olaistalucnd mela: ele eee erent: 170 110 125% 
The Patella. 
(Plate LXXI.) 
The trochlear face of the patella strongly recalls that of Titanotherivum, the 
median trochlear ridge being of approximately equal prominence, but the bone as 
a whole has a relatively smaller vertical and a relatively greater antero-posterior 
diameter than in T%tanotherium. 
64 Approximate. 
