THE ANTEBIOB LIMBS. 79 



In applying to them the names proposed by Liser, we have, in the upper 

 row : "^ 



"rl. The pisiform, or supercarpal bone (trapezium); 



.J 2. The pyramidal (or cuneiform) bone ; 



^3. The semilunar (or lunar e) bone 



} 4. The scaphoid bone ; 



In the inferior row : 



T 1- The hook or unciform bone ; 



4 2. The great bone or capitatum (magnum) ; 



JT 3. The trapezoid bone.^ 



The description of these bones is most simple, and may be made in a 

 general manner for all. Thus, with the exception of the supercarpal bone, 

 they are solids, nearly cubical in form, and exhibit on their periphery : 

 1, Articular surfaces ; 2, Surfaces of insertion. 



The articular surfaces represent small, flat, or slightly-undulating facets, 

 distributed on the superior, inferior, and lateral surfaces ; none are found in 

 front or behind. The superior and inferior faces are entirely occupied by 

 a single facet which responds either to the radius, the metacarpal, or to the 

 bone of the other row. The lateral facets are always multiple and in contact 

 with the bones of the same tier ; they do not exist, of course, on the eccentric 

 side of the first and third bones of the superior or inferior rows. 



The surfaces of insertion are absent on the superior and inferior faces ; 

 they separate, in the form of roughened fossse, the lateral articular facets. 

 Before and behind they are covered by more or less marked rugosities. 



Bones op the Upper or Antibeachial Eow. — Tlae first, or os pisiforme, 

 is without the row ; it is situated above and behind the carpus, from whence 

 its name of supercarpal hone, by which it is usually known in veterinary 

 anatomy. This bone, which merits a special description, represents a disc 

 flattened on both sides, offering for study two faces and a circumference. 

 The external face is convex, roughened, and channeled anteriorly by a 

 groove that traverses it from above to below, and in which glides the 

 inferior tendon of the external flexor of the metacarpus. Its internal face, 

 smooth and concave, concurs to form the external wall of the carpal sheath. 

 The circumference presents, in front, two articular facets : the superior, 

 concave, corresponds to the radius ; the inferior, convex, is in contact with 

 the second bone of the upper row. 



The other three bones of this row increase in volume from without to 

 within. 



The second, or os pyramidalis (or cuneiform), responds to the radius, 

 the first bone of the lower row, the third of the upper, and the supercarpal 

 bone ; it has in all five articular facets. 



The tMrd, or os semilunare (lunare), has six facets, and is united below to 

 the first and second bones of the second row. 



' The analooTie of the trapezitim of Man is not found in the Horse. According to M. 

 Lavocat, we ought to regard as such a small supernumerary bone sometimes seen articu- 

 lating behind the third bone. We are entirely of his opinion. (Leyh is also of this 

 opinion, and states that this supernumerary bone is more frequently iound m large 

 common-bred horses. Stubbs, in his old, but fine ' Anatomy of the Horse, does not refer to 

 it, but describes the seventh bone as the pisiform. Percivall says the supernumerary ^bone 

 is not invariably present, and that sometimes two are found. He designates btubbs and 

 Chauveau's pisiform bone as the trapezium. Girard names the supernumerary bone the 

 " pisiform " or pea-shaped. When one or more of these osseous nodules are present, they 

 represent the poUex and fifth digit of the human hand.) 



