OSTEOLOGY OF THE HORSE. 53 



LUNAR liONE. (OS LUNARE.) 



Cuneiform. — Divided into four surfaces, base, and apex : — 

 1st, Superior surface, triangular, articulating with the arm-bone. 

 2d, Inferior surface, oblong, uniting with the magnum and un- 

 ciform bones. 3d, Interualsuiface, excavated, joining above and 

 below, with the scaphoid. 4th, luternal surface, excavated, ar- 

 ticulating in two places with the cuneiform bone. — Base, broad 

 and rough, presenting forwards. Apex, obtuse and rounded, 

 turned backwards, 



CUNEIFORM BONE. (oS CUNEIFORME.) 



The smallest bone of the superior row. Figure — Pentan- 

 gular. — Divided into five surfaces : — 1st, Superior sufface, small, 

 oval, and cupped, articulating with the arm-bone. 2d, Lferior 

 surface, smooth, resting upon the unciform bone. 3d, luternal 

 suiface, convex and roughened, receives the attachment of the 

 external lateral ligaments. 4th, Internal surface, ']o\w\n^ in two 

 places with the lunar bone. 5th, Posterior surface, ovoid, smooth, 

 and slanting, unites with the trapezium. 



TRAPEZOID BONE, (os TR A P EZO I D ES.) 



Situation — Inner side of the knee. Form — An irregular, 

 curvated, flattened cone. Division — into four surfaces, a base, 

 and an apex: — 1st, Superior snrj'ace, smooth and convex, arti- 

 culating with the scaphoides. 2d, Inferior surface, flattened, 

 articulatory, and divided, the larger part resting upon the inner 

 splint bone. 3d, Internal surface, excavated, presenting three 

 sniooth places for articulation with the os magnum. 4th, Internal 

 surface, convex and roughened. Base, looking forwards and 

 inwards. Apex, turned backwards and outwards. 



THE GREAT BONE. (oS MAGNUM.) 



The largest bone of the knee. Situated in the middle of the 

 inferior row. Figure — Triangular. Divided into two surfaces, 

 two sides, a base, and an apex. 1st, Superior suiface, presentino- 

 two articulary compartments, one, sigmoid and oblono-, for the 

 lunare ; the other, ovoid and flat, for the scaphoides. 2d, Inferior 

 surface, broad and flat, resting upon the cannon bone. 3d, In- 

 ternal side, excavated, presenting three little surfaces for articu- 

 lation with the trapezoides. 4th, External side, having two smooth 

 places, with a pit between them, for articulation with the next 

 bone. 



UNCIFORM BONE. (OS UNCIFORME.) 



Situated outwardly. Form — irregularly conoid. 

 Division into four surfaces, a base, and an apex. 1st, Su- 

 perior sinfncr. convex, and oxtondcH outward -ind backward, 



