On certain BONES, &c. 



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meri (C. No. i.) on one fide of it is the fmooth furface 

 for articulation with the ulna (C. No. i. — D. No. 4.) 

 which is fo fmall that it does not appear calculated to ad- 

 mit much rotation, or pronation and fupination of the paw ; 

 for the oval circumference of the upper end of the bone is 

 7*6 inches and this furface extends upon it but i"j Inches. 

 It is in the fame line of diredtion with the edge of the bone, 

 and not with the flat fide of it — When it is applied to the 

 corrcfponding lurface of the ulna the two edges of the 

 bones are oppoled, and as there is no rotation of the radius 

 upon the ulna, they muft be nearly parallel to each other, 

 without much decuffation, making the fore arm immenfely 

 broad. 



From this arrangment of the bones and their want of ro- 

 tation and decuffation, the palm of the paw would pre- 

 fent inwards, and not downwards or backwards, unlefs 

 the pofition of the os humeri, or the form of its lower 

 extremity, were particularly calculated to prevent it. At 

 the lower extremity of the radius, on the external furface, 

 (C. No. 3), are feveral remarkable foflle or grooves, like 

 thofe on the human radius, for the tendons of the extenfor 

 mufcles — The edge of the bone which prefents, or is op- 

 pofed, to the ulna, becomes gradually broader as it extends 

 to the lower extremity (D. No. 5) and there is a depreffion 

 in it corrcfponding to the protuberance of the ulna, but 

 the furface is fo abraded that no inference can be deduced 

 from it refpedling the connexion of the bones at this 

 place. 



At the lower end of the radius is a deep oblong cavity 

 for receiving the carpal bones, (D. No. 6), its longefl 

 diameter is 3*2 inches, its tranverfe is 2*37 inches, and its 

 depth eight-tenths of an inch. When the ulna is in its natu- 

 ral fituation, the cavity for receiving the carpus, formed 

 by both bones taken together, is very near five inches in ex- 

 tent — the carpus was probably equally broad, and the hand 

 or paw much broader. This breadth is not difproportioned 



to 



