POSTERIOR AXTIBRACHIAL GROUP. 





capsule of the navicular bone, termed the navicular sheath, forms 

 two cul-de-sacs, one stretching upwards almost to the inferior 

 cul-ile-sac of the sesamoid sheath, the other being situated under 

 the inferior navicular ligament. A broad strengthening sheath of 

 fibrous tissue covers the plantar aponeurosis and blends with it 

 inferiorlv, beinsr attached above by two bands to the sides of 



w * O / 



the first phalanx. 



Action It flexes the joints below the carpus, and assists in 

 flexing the latter. 



FIG. 



Longitudinal section through the digit of a Horse. 

 1, The skin ; 2, Extensor pedis tendon ; 3, Synovial cap- 

 sule of pastern joint ; 4, Metacarpus ; 5, Perforatus 

 tendon ; 6 (omitted in cut), Perforans tendon : 7, Synovial 

 sheath ; 8, Projecting synovial cut-de-sac; 9, Inner aspect 

 of sesamoid bone; 10, The fetlock; 11, The y-ligament ; 

 12, The v-ligament ; 13, Proximal phalanx ; 14, Terminal 

 portion of extensor tendon ; 15, Median phalanx ; 16, 

 Third sesamoid or navicular bone ; 17, The sensitive frog ; 

 18, Distal phalanx ; 19. The hoof ; 20, Sensitive laminae. 



ULNARIS ACCESSORIUS. 



(Flexor Accessories Sublimis.) 



(FiG. SI. c".) 



Situated on the posterior part of the fore-arm, between the 

 external and middle flexors of the metacarpus, it is triangular, 



