76 



Bones of the Spine. 



Cornua coccygea 



Cornua coccygea 



Processus 

 transversus 



94 and 95. Coccyx, os coccygis. 



From in front. From behind. 



The OS COCCygis (see also Fig. 93) lies as a small, triangular bone at the 

 lower end of the vertebral column below the sacrum. It consists of from four to five 

 rudimentary vertebrae coccygeae, of each of which the body only, as a rule, is present. 

 The first possesses still two small y transversely directed processus transversi and in 

 place of the processus articulares superiores two flat processes, cornua coccygea, directed 

 upward. The succeeding vertebrae diminish in size from above downward and represent 

 actually only small oblong or spherical pieces of bone. 



The upper surface of the coccyx is united with the tip of the sacrum by the 

 symphysis sacrococcygea (see p. 162). The first, second and third coccygeal vertebra 

 are usually united with one another by a layer of fibro-cartilage, the third, fourth and 

 fifth by bony substance. Deviations occur very often in that the connections between 

 the first three or that between the coccyx and sacrum ossify. 



