RIGHT WHALES 123 



limb points to a less modified condition than that 

 which is exhibited by Bal&noptera, where the limb 

 is still further reduced. 



And furthermore, the ribs point to a more primitive 

 stage in Bal&na. In the Rorquals and in Neobalccna 

 very few have capitular processes. In a specimen of 

 Balccna biscayensis at the British Museum, of the 

 fourteen ribs present the first two had no capitulum ; 

 but the ten following on each side were provided with 

 capitular processes. 



There would seem to be some little vagueness 

 about the number of ribs in this genus. Vagueness 

 is, however, readily produced by deficient specimens ; 

 and this fact may easily account for some of the 

 discrepancies. But there would not seern to be any 

 method by which a less number of ribs should be 

 converted into a greater. The Greenland whale is 

 characterised by Mr. Lydekker as possessing but 

 twelve ribs, and thus distinguished from its southern 

 cono-ener, which has fifteen. The skeleton of Balcena 



o 



mysticelus at Brussels is described by Sir W. Flower 

 as having fourteen pairs of ribs, though the "usual" 

 number is stated at thirteen. 



The sternum of Bal&na is not cross-shaped as in 

 Rorquals ; it is oval, decreasing in diameter behind, 

 or somewhat heart-shaped in contour. The scapula 

 is high, thus contrasting with the more elongated 

 scapula of the Rorquals. 



It is, or perhaps rather has been, a matter of 

 dispute as to how many species of whale are em- 

 braced in the general expression " Right whale." It 



