CERTAIN BONES, &c. 529 



The furface No. 2. b. corrcfponds with the lower end of 

 the metacarpal bone, having a deep groove to receive its 

 projecting ridge, and on each fide of the groove a fmooth 

 furface correfponding to the furfaces on each fide of the 

 ridge. 



From thefe furfaces it appears that this bone muft have 

 moved conliderably on the metacarpal bone, and that its 

 motion was from above downwards in a circular diredlion. 



The other furface of the bone No. 2. a. forms two emi- 

 nences with a large depreflion between them, which is well 

 exhibited by the plate, and correfponds with the upper 

 furface of the next bone No. 3. 



1 he form of No. 3 is accurately reprefented in the plate, 

 — the furface articulated with No. 2 has an eminence in the 

 middle, with a depreflion on each fide of it ; correfpond- 

 ing to the eminences and depreflion of that bone, — the 

 other extremity is flat on the fides, and remarkably round, 

 forming two-thirds of a circle — The articulating circular 

 furface is divided by a very deep groove which is extreme- 

 ly narrow at the bottom to receive a fharp ridge of the 

 next bone. 



1 believe the pofition of this bone in the plate is invert- 

 ed and that the upper fide of the figure ought to be down. 



The three figures, marked No. 4, will convey an accu- 

 rate idea of the original ftate of the bone of the lafl phalanx, 

 the two largeft bones are not entire, the bony cafe round 

 the root of the unguis, as well as the point, being broken 

 off", in each of them — in the lowermoft figure both of thefe 

 parts are entire, and from this an idea may be formed of the 

 large claw bones before they were mutilated — The furface 

 for articulating with the end of the other phalanx is beft 

 reprefented in the fecond figure No. 4, the ridge which pene- 

 trates into the groove of that bone being very fharp and deep, 

 no motion but that of fimple flexion and extenfion is prac- 

 ticable. The circular form of the furfaces evinces a great 

 3 Z degree 



