THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



137 



It appears, therefore, that in European specimens the number of ribs varies from 14 

 to 16 pairs, and in American specimens, 15 to 16 pairs. 



With the modifications indicated above, the various European and American 

 formula} will stand as follows : 



BAL^NOPTEBA PHTSALUS (L.). EUROPEAN AND AMERICAN. VERTEBRAL FORMULA, REVISED. 



EUROPEAN. 



The most frequent formula? for the cervical, dorsal, and lumbar vertebrae of 

 European specimens shown by this revised table are: 7, 15, 14, and 7, 15, 15. A 

 comparison with American specimens can scarcely be made with advantage as 

 there are but six of these with complete formulae as against eleven European speci- 

 mens. The formulae of two of the American specimens, however, agree with one of the 

 two most frequent European formula? above cited. In two other cases the Ameri- 

 can formula is 7, 16, 14. This might be considered as of some importance were it 

 not that sixteen dorsals are indicated in two European specimens, as already noted 

 on p. 136. A fifth American formula 7, 15, 13 is repeated in the Vlieland 

 Id. skeleton, according to the interpretation of Flower. 



On the whole, the facts regarding the vertebral formula do not appear to 

 point to specific distinctness between European and American specimens, but the 

 matter cannot be pronounced upon with entire satisfaction until more American 

 specimens have been examined. 



In Struthers's Nairn (Scotland) specimen the 2d and 3d pairs of ribs had 

 capitular processes, or beaks ; in Van Beneden's Borselaer specimen, the 1st and 

 2d pairs; in Heddle's Laman Id. specimen, the 2d, 3d, and 4th pairs. Other Euro- 

 pean specimens present still different combinations. In the American specimen in 



