THE PELVIS. 



143 



spring from the imprints on the lateral aspect of the os coronae, 

 and are inserted into two depressions at the superior border of 

 the OS pedis, partly covered by the lateral cartilages. 



The postero-lateral ar3 continuations of the 

 lateral ligaments of the pastern joint, which, 

 after reaching the os coronse, form an elastic 

 fibrous cord, attached to the upper border of 

 the navicular bone, the two uniting to form 

 the superior or hroad ligament. They give 

 off short lateral bundles to the retrossal pro- 

 cesses and inner surfaces of the lateral carti- 

 lages. The lateral navicular ligaments con- 

 sist of strong w^hite fibres, which join the angles 

 of the navicular bone to the inner aspect of 

 the lateral cartilages, and the wings of the os 

 pedis. Tho inferior ligament is an inter- 

 osseous one, which is attached to a roughened 

 groove on the anterior border of 'the navicular 

 bone and to the semilunar ridge of the os 

 pedis. The synovial laemhrane lines the 

 cavity of the joint, and sends upwards a very 

 large sac along the posterior surface of the 

 median phalanx. Smaller projections are found bet7/een the 

 anterior and posterior lateral ligaments. The motion of the joint 

 is that of flexion and extension. 



Fig. 58. 

 Navicular ligaments. 

 a a, Superior, or broad ; 

 6, Inferior ; andc c, Late- 

 ral ligaments. 



Articulations of the Pelvic Limb. 



THE PELVIS. 



Sacro-iliac Articulation. — This is the articular connection 

 between the axial skeleton and the pelvic limb ; it is described 

 both as a diarthrosis and an amphiarthrosis ; it is capable of little 

 motion, and the synovia is small in quantity, if present at all ; the 

 joint is formed by the venter of the ilium, and the supero-lateral 

 surface of the sacrum, which articular surfaces are clothed with 

 cartilage, and the union completed by the three sacro-iliac liga- 

 ments, inferior, lateral and superior. The inferior consists of 

 strong bundles of fibres, v^hich envelop the articulation like a 

 strong and irregular capsular ligament, and are attached below to 

 the transverse process of the sacrum, and above to the venter 

 iln. The superior sacro-iliac, short and strong, stretches from: 



