232 A BOOK OF- WHALES 



slenderness of the neural spines, as well as their 

 greater inclination backwards. Of the ten dorsal 

 vertebrae zygapophyses are only developed until 

 between the eighth and ninth ; there are none between 

 the ninth and tenth. The lumbar vertebrae have 

 their transverse processes (continuous with the lower 

 transverse processes of the ninth and tenth dorsals, 

 which bear the last two ribs) in a perfectly straight 

 line from beginning to end of the series as in Meso- 

 plodon. The lumbar vertebras are distinctly keeled on 

 the under surface. The first of the nineteen caudal 

 vertebra is to be distinguished from the last of the 

 lumbar series not only by the pair of facets on the 

 hinder lower surface of the centrum for the chevron 

 bones, but also by the absence of the keel spoken of 

 as characteristic of the lumbars. There appear to be 

 nine chevron bones. Of the ten pairs of ribs the 

 first articulates with the transverse process of the first 

 dorsal vertebrae, and with the centrum of the last 

 cervical. As in most other Ziphioids (cf., however, 

 Hyperoodon) there is a sudden break at the end of 

 the series of ribs ; the ninth and tenth have only the 

 capitular head, which is attached to a lower transverse 

 process springing from the centrum of the vertebrae, 

 and not existing, even in rudiment, in the vertebrae in 

 front 



The sternum consists of five elements not connected 

 by bone. Between the first four of these are spacious 

 foramina in the dried skeleton, the edges of which 

 are bevelled and smooth, "so that it does not appear 

 that ossification would have advanced further in this 



