t 
RES TS OREN RESET 
112 MEMOIRS OF THE CARNEGIE MUSEUM 
Scapula. —'The scapula of Dinohyus is relatively higher than that of the Prince- 
ton specimen from the Oligocene. Its neck also has a relatively greater transverse 
diameter. In other respects very little difference in the general make-up of this 
bone of the fore limb is shown in the two genera. The pre- and postscapular fossee 
are divided by the spine in very nearly the same way in Dinohyus and Archxothe- 
riwm, while according to Scott (87, p. 298), the John Day form, Bodchawrus hwmer- 
osus Cope, has a much broader blade with the pre- and postscapular fosse of nearly 
equal width. 
MEASUREMENTS. 
Mm. 
Deapulyeg reavostslon Obltestveteietcnteulacelas .e.thsi varie tadcdewessecrscanece neers 560 
ie Ge width ... 885 
us transverse diameter of neck... 93 
iW antero-posterior diameter of glenoid cavity... 86 
ge transverse es ee ge Ow ESI is ROSIE cis Me 67 
Humerus. —The greater tuberosity of the humerus of Dinohyus was unfortu- 
nately lost in the process of collecting, so that its elevation above the head is only 
conjectural.” The bone is otherwise complete and its lengthis relatively less than 
that of Bodcherus humerosus from the John Day formation, and considerably less 
than that of Archxotherium. Indeed the humerus of Dinohyus is even proportion- 
ately somewhat shorter than is the case in Bos and Hqwus caballus, while that of 
Archxotherium is relatively longer than in these two recent genera. The proximal 
end of the humerus in Dinohyus is, as in Archxotheriwm, of great antero-posterior 
diameter; its transverse diameter, though less than the antero-posterior, is also 
great, perhaps relatively greater than that in Archwotheriwm. ‘The head is large and 
takes up a considerable portion of the proximal end. The greater tuberosity is very 
massive and evidently terminated above in a heavy blunt process, as in other represen- 
tatives of the family. The lesser or internal tuberosity is unfortunately also dam- 
aged, but its anterior border indicates a strong margin which bounded the bicipital 
groove. The latter is broad and displays a large, smoothly convex tubercle, over 
which the tendon for the biceps muscle spread. The deltoid ridge is prominent and 
extends well down on the shaft. The distal end is much expanded, especially trans- 
versely, as the supinator ridge and the surfaces for the attachments of the ligaments 
are well developed. ‘The internal epicondyle which is on the point of disappearance 
in Archeotherium is still smaller in Dinohyus. The intercondylar ridge, which is fully 
as prominent as in Archexotheriwm, is shifted even more outwardly than in that genus, 
and the trochlea has a more modernized appearance. The ridge which bounds the 
supratrochlear fossa externally is more prominent than in Archwotheriwm; the differ- 
‘’ From material recently (1908) acquired in the Agate Spring Fossil Quarries, it is very evident that the dotted 
lines in Fig. 68 are too high. 
