PHOCAENA DIOPTRICA 



231 



The transverse processes have an anterior inchnation from the sixth (Plate VI, 

 figs. 7, 8). 



Caudal vertebrae, 32. The neural arch ceases to exist after the sixteenth, but the 

 seventeenth has a groove betw^een tv^^o small lateral tubercles, a last trace of the arch. 

 The transverse processes are gradually reduced until on the eleventh vertebra there are 

 the merest traces, and even they are absent after this. 



Table I. Body measurements 



* Approximate. 



Ribs. Thirteen pairs, all remarkable for their stoutness in comparison with P. 

 phocaena. Nine of them are double-headed. The four pairs of floating ribs are pro- 

 gressively and markedly flattened in a manner reminiscent of Neobalaena (Plate VI, 

 figs. 5, 6). 



