926 THE OSTEOLOGY AND MYOLOGY OF THE DEATH ADDER, 



" There can be no doubt, but that an autogenous process of one 

 vertebra of an animal may be serially represented by an exogenous 

 process in another vertebra of the same animal ; and likewise that 

 the corresponding processes of the same vertebra may be developed 

 exogenously in one animal and autogenously in another." 



In dealing with the prezygapophysis above, we suggested that 

 the process connected with it might represent a metapophysis, and 

 we now suggest that the superior of the two processes may be 

 an anapophysis, while the inferior may represent the lumbar 

 transverse process of higher animals. 



From the 133rd vertebra to the end we have considerable alter- 

 ations. The elements of the vertebrae begin to diminish in size, 

 and at the same time the hypapophysis becomes bifid. Kapidly 

 the processes become less conspicuous, so that when we reach the 

 last fifteen vertebrae we find a neural arch formed by the diminu- 

 tive laminae supporting a thin perpendicular spine, while inferiorly 

 the hypapophjsis is represented by two small spicules of bone only. 



In comparing the vertebral column of Acanthophis with that of 

 Pseudechis and Diemenia, we see no very marked difierence. The 

 processes from the prezygapophysis are more conspicuous, and the 

 neural spines are not so high in these two forms. The greatest 

 dissimilarity exists in regard to the tail vertebrge which are more 

 stoutly made, and exhibit the same processes as the anterior, only 

 less well developed. As compared with 2Iorelia the zygantrum of 

 the latter is much more excavated, the articular surfaces on either 

 side being separated anteriorly only by a slight ridge of bone in 

 the mid-line. In the second place there are no processes (meta- 

 pophysis'?) springing from the prezygapophysis, a slight ridge* 

 below the articular head being the only representative ; neither 

 are there any inferior processes from the lower portion of the 

 transverse processes. 



Perhaps the most striking difierence arises in the connection 

 with the hypapophysis. In all venomous snakes that we have 

 examined there is a well-developed hypapophysis on all the 

 vertebrae that bear ribs, but in non-venomous forms the 



