SKELETON OF AKTIODACTYLA. 461 



process equals or exceeds the length of the vertebra, and those 

 parts are arranged so as to overlap each other. There is a dis- 

 tinct, but less extensive diapophysial portion projecting external 

 to the vertebrarterial canal : this part alone represents the trans- 

 verse process in the seventh cervical. The spines of the third 

 and seventh cervical vertebras are vertical, those of the inter- 

 mediate ones incline forward. The spines of the anterior dorsal 

 vertebra) are remarkable for their height, those of the posterior 

 dorsal and of the lumbar vertebrte for their antero-posterior 

 extent, the anterior angle being produced forward and overlapping 

 the spine in advance. A distinct metapophysis begins to be 

 developed from the second dorsal, and attains its greatest length 

 on the twelfth. There are no anapophyses. The notches for 

 the nerves increase in depth as the vertebrae recede in position, 



309 



and in the last dorsal the neural arch is completely perforated by 

 these, which is likewise the case in most of the lumbar vertebra;. 

 Eight pairs of ribs directly articulate with the sternum, which 

 consists of seven bones. The tubercle disappears from the penul- 

 timate pair of ribs, and the diapophysis is reduced to a short 

 rough tuberosity ; but in the last pair the costal tubercle with its 

 articular surface reappears, and the diapophysis resumes its 

 normal size and articulation with the rib. In the first lumbar 

 vertebra the diapophysis suddenly increases in length and breadth, 

 and is probably augmented by the ossified and coalesced beginning 

 of a rib. 



In the common Ox (^Bos Taurus, fig. 309), the vertebral for- 



