364 



Annals of the Carnegie Museum. 



as tri-radiate. The rays are formed by the posterior anconeal spine, 

 the directly opposite external anterior projection and the widely ex- 



FlG. 4. Front view of right radius, ulna and nianus in position about one-tenth 

 natural size. (No. 5'^3-) 



panded internal portion. The first two of these are subequal and much 

 smaller than the last. All are separated by cbncave surfaces. There 

 is a deep cavity on the posterior surface between the anconeal spine 

 and the internal, lateral margin of the ulna. Distally the radius 

 shows a prominent rugosity on the posterior side near the externa 

 border. This commences about four inches from the distal extremity 

 and continues as a prominent narrow ridge for a distance of nine 

 inches. At about one third the distance from the lower to the upper 



