AXIAL SKELETON OF THE OSTEICH. 451 



pophyses, as also in the posterior caudal vertebri3e, though in the latter a tendency to 

 diverge is shown by the projecting extremities of each transverse process. 



Parapophyses. 



These are very constant structures, existing either as lower transverse processes or as 

 articular surfaces for the capitula of the ribs. 



In the lumbar region their place of development singularly descends, being there 

 placed quite at the ventral edge of the sides of the centra. 



They ascend through the three true sacral vertebrae, till in the most anterior caudal 

 (or anterior sacro-caudal) vertebrae they reassume the same position they occupied in 

 the posterior dorsal region. In the more postaxial vertebrae their place of origin again 

 descends, and occupies the side of quite the ventral surface of each centrum. 



The parapophysis of the thirty-first vertebra is almost entirely formed by the neural 

 arch ; but in the three succeeding vertebrae each parapophysial prominence is produced 

 by the concurrence of processes from the centra of adjoining vertebrae, the thirty-second, 

 thirty- third, and thirty-fourth vertebrae having each such a projection from each end 

 of each side of each centrum. 



These low complex parapophysial projections abut against the ischium and ventral 

 margin of the acetabulum. 



Pleurapophyses. 



By pleurapophyses I mean ribs and all elements of the paraxial system which are 

 serially homologous with ribs, including their capitula and tubercula. 



Consequently when the diapophyses and parapophyses are respectively connected by 

 an osseous bridge, such bridge is plem-apophysial. 



To the thirty-sixth, thirty-seventh, and thirty-eighth vertebrae three capitula of large 

 size are attached ; they expand as they extend postaxiad and dorsad to abut against the 

 ilium. 



Hypapophyses. 

 These are developed as twofold or azygos processes from beneath certain vertebi-se, 

 generally from the seventeenth to the twenty-first inclusive, as already described. 



Catapopkyses. 

 These have been already noticed as developed from the more postaxial of the true 

 cervical vertebrae, generally anterior to the seventeenth vertebra. 



