DISTAL PHALANX. 81 



the reception of the supensory ligament. The inferior surface 

 or base is also roughened, to afford attachment for the ligaments 

 by which these bones are attached to the phalanges below. 



MEDIAN PHALANX. 



(Fig. 19. B.) 



The second phalanx, os coronse, or small pastern bone, has no 

 medullary canal, and belongs to the class of irregular bones. 

 It is inclined, like the os suffraginis, obliquely downwards 

 and forwards, and is partly covered by the hoof. The sujDerior 

 surface is smooth, and divided by an eminence into two 

 glenoid cavities for the condyles of the os suffraginis, and havino- 

 in the centre two slight eminences, one in front and one behind, 

 which, by limiting its motion, make the joint more secure ; a 

 portion of the tendon of the extensor pedis muscle is attached 

 to the anterior, and a ligament to the posterior of these 

 eminences. The inferior surface of the bone is smooth and 

 convex, and divided by a central depression into two condyles, 

 which articulate with the os pedis and os naviculare. The 

 anterior surface is convex, very rough, and widest superiorly ; 

 it affords attachment to part of the tendon of the extensor pedis 

 muscle. The posterior surface, slightly excavated and not very 

 rough, has on its upper part a prominent eminence covered by 

 fibro-cartilage, over which plays the tendon of the flexor perforans, 

 while on either side of this eminence is inserted part of the 

 tendon of the flexor perforatus muscle. 



DISTAL PHALANX, 

 (Fig. 19. C.) 



The third, or ungual phalanx, os pedis, or coffin bone, is an 

 irregular bone situated within the hoof, and, when in a healthy 

 state, corresponding somewhat to it in shape, being semilunar in 

 form, with the convexity to the front. It is a very hard but 

 porous bone, having many excavations and foramina for the 

 transmission of arteries and veins. In this bone we notice the 

 wall, the sole, the tendinous surface, the articular surface, and 

 the alas or wings. 



The wall, or anterior surface, is the semicircular part in front 



G 



