256 



THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



The points in the vertebral column at which the several processes and fora- 

 mina appeal- or disappear furnish data of considerable importance in the compari- 

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



BALMNA OLACIALIS BONNATERRE. AMERICAN AND EUROPEAN. VERTEBRAL CHARACTERS. 



It is much to be regretted that so few data relative to European specimens 

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

 with corresponding data from American specimens is very close. 



CHEVRON BONES. 



The chevron bones are figured or described in the case of one or two European 

 skeletons only. Graells's figure of the Guetaria skeleton (52~) shows 12 chevrons, 

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

 Taranto skeleton has 10 chevrons, 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 each. 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 originally. 



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 pairs are 



1 Right side only. 



2 Left side only. 



3 Or 4 2d. 



