Temnocyon and Hypotemnodon. — THyerman. 275 
brachialus anticus or ridge not curving forward to join the 
internal edge of the trochlea as in C. familiaris. The proxi- 
mal end is proportionately not so well developed as the distal ; 
the head is rather more elliptical than spherical and does not 
overlap the shaft, neither is it proportionately so large. The 
external (internal to the body) side does not curve inward 
toward the bicipital groove but conies to a point and forms 
more of a ridge, and, hence, the groove has greater width and 
is not so sharply deepened on the external or tuberosity side; 
the distal end measures 45 mm. across and is of normal de- 
velopment; the transverse diameter of the articular surface 
for the ulna is 13 mm. and for the radius 20 mm; the vertical 
diameters are less and not in proportion to the development 
of the end as a whole; the groove between the trochlea i- 
rather shallow: the external condyle is weakly and the inter- 
nal very strongly developed. The ulna (fig. 7) is considerably 
shortened, for, while the humerus is nearly equal in size to 
that of C . familiaris, the ulna is some 35 mm. shorter than 
that in the same C . familiaris, The shaft is slender and com- 
pressed throughout, especially just below the sigmoid, and 
the transverse diameter at this point is one-third that in the 
living species; neither does it describe that easy curve usually 
developed, but curves sharply backward and upward from the 
sigmoid cavity. The apex of the olecranon is nearly flat and 
from this point to the beak of the bone is considerably 
broader, with less sharp forward inclination; the coronoid 
process is well developed. Directly under the beak the dia- 
meter of the sigmoid cavity is 26 mm. or of more than normal 
development, but in depth not so great as in the living- 
species. The articulation of the humerus is principally upon 
the sigmoid, like that in the smaller species. ('. aureus, a 
second internal articular surface not being developed. The 
transverse diameter of the bone at this point is very narrow. 
In the living species the compression of the upper half of the 
bone is transverse ; in the species under consideration, however, 
it is antero-posterior ; the lower half of the shaft becomes 
more cylindrical as it approaches the distal end. the diameter 
at this point being equal in both species. Furthermore the 
shaft from a point below the cavity, has a very regular curve 
more like that in C. aureus. The distal extremity is less external 
