T 



( 526 ) 

 No. Lxxvr. 



A Defcript'ion of the Bones dcpojited, by the Prejident, in the 

 Mufeum of the Society * and reprefented in the annexed 

 plates. By C. Wis tar, M. D. Adjund: ProfelTor of 

 Anatomy, &c. in the Univerfity of Pennfylvania. 



HE large bones are the ulna and radius of 

 the left leg. And the plate, No. i. contains 

 two views of each. 



The figure A exhibits the ulna with a view of its fur- 

 face for articulation with the os humeri (No. i,) con- 

 nected with another fmooth furface (No. 2j for fupport- 

 ing the upper end of the radius. 



The ulna is remarkably thin for fo broad a bone, being 

 2-8 inches in breadth,-f- and but 1*14 inches thick about the 

 middle. 



At the lower end is an oval furface for articulation with 

 the carpus, about i "8 inches in length, which is not re- 

 prefented in the figure. On the edge next to the radius is 

 a protuberance (A. No. 3. — B. No. 5) which appears cal- 

 culated to be received into that bone, but its furface, as 

 well as the furface of a correfponding depreffion of the ra- 

 dius, has been fo much abraded that they do not now 

 feem calculated for articulation. 



On the other edge of the bone, at the extremity, is a 

 projedion (B. No. 4.) analogous to the ftyloid procefs of 

 the human ulna, but not proportion ably long, with a 

 fmooth furface externally, about eight-tenths of an inch in 

 length, which feems to indicate that one of the carpal 

 bones muft have lapped over, or extended beyond it. 



The upper end of the radius is nearly oval, it is concave 

 on the top for articulation with a condyle of the os hu- 

 meri 



* See page 246. 



\ The difference which may be obferved between this ftatement and that 

 of the Prefidcnt is owing to the different methods of mca'uring — he ufed a 

 flip of paper whereas the dimenfions above were taken witli dividers. 



