256 



THE WHALEBOKE WHALES OF THE AVESTERN NORTH ATLANTIC. 



The points in the vertebral columu at which the several pi'ocesses and fora- 

 mina appear or disappear furnish data of considerable inipoi'tance in the compari- 

 son of species. These data are brought together in the following table ; 



balje:sa olacialis bonnaterre. American and European, vertebral characters. 



It is much to be regretted that so few data I'elative to European specimens 

 have been recorded. In so far as they are available for comparison, the agreement 

 with corj'esponding data from American speciinens is very close. 



CHEVRON BONES. 



The chevron bones are tigui'ed or described in the case of one or two European 

 skeletons only. Graells's figure of the Guetai-ia skeleton {52^ shows 12 chevrons, 

 the first smaller than the second and somewhat pointed. Gasco states that the 

 Taranto skeleton has 10 chevi'ons, but that some were probably lost. 



Of the American skeletons, those in the Field Columbian Museum and in the 

 Museum of Comparative Zoology, have 9 chevrons eacli. In both cases the first is 

 attached to the posterior end of what is really the second caudal vertebra, so that 

 the skeletons appear to have one more lumbar vertebra than they should. In the 

 skeleton in the former museum the first chevron in position is small, but in the 

 skeleton in Cambridge it is the largest of the series. In this case it is therefore 

 probably the second chevron. The Charleston skeleton has 10 chevrons, but there 

 were probably more oi'igiually. 



RIBS. 



The number of pairs of ribs is 14 in all European and American specimens, 

 except the San Sebastian skeleton of 1854, and in this also, although 13 j^airs are 



Right side only. 



Left side only. 



'Or 42d. 



