160 Cincinnats Soctety of Natural History. 
cavity, is.g of an inch. Diameter of smallest portion, near distal 
end, is .5 of an inch. 
There is a strongly marked, longitudinal fossa, half an inch 
wide, on the outer surface, beginning below the middle of the sig- 
moid cavity, and reaching forward to nearly half the length of the 
shaft, as seen in Castor, and less marked in F7éer. 
The radius, minus the epiphysis, is 6.85 inches in length. 
Greater diameter of the distal face, which was joined to the epiphy- 
sis, .95 of aninch. Greater diameter of the head, one inch. As 
in Castor, the radius, 2 sztu, lies directly upon the upper edge of 
the shaft of the ulna, nearly or quite touching it all the way. 
There does not appear to have been so much of an apparent 
approach to the fusion of the two bones as we find in a mature 
skeleton of Castor. ‘The forearm, both bones taken together, is 
relatively more slender as compared with Caséor, and rather more 
bent. When the forearm was extended, as far as the articulation 
at elbow would appear to admit, it still made an angle with the 
humerus of about 135 degrees. The arm, however, could com- 
pletely fold on itself with ease, and that it didso abundantly would 
seem evident from what appears to be a well-marked, abnormal 
fossa, worn into the shaft of the humerus by the anterior border of 
the sigmoid cavity. Said fossa is one-fourth of an inch above the 
trochlea. ; 
The remaining portions of the anterior extremities are, so far, 
entirely wanting. 

Fic. 21.—One-third natural size. Left innominata, anterior epiphysis missing: 
pubie region missing. a, Acetabulum; ¢, tuberosity of ischium; 0, obturator 
foramen. 


