RORQUALS 145 



the prevailing opinion at present, though many 

 naturalists even Sir William Flower in his earlier 

 memoirs have divided the existing Rorquals into 

 three or even more genera. We shall clear the 

 ground by defining this genus, of which of course 

 the definition will be, in the opinion of some, 

 applicable to a sub-family. 



GENUS, BAL^ENOPTERA 



Dorsal fin present and falcate. Throat plaits 

 numerous. Scapula low and broad, with long 

 acromion and coracoid process. 



In considering whether or not it is advisable to 

 divide the only four really definable species into 

 different genera we may at once discard Benedenia, 

 founded upon an immature specimen, Rudolphius, 

 which is the same as Sibbaldius, the two names 

 having been given to identical species. 



Sibbaldius and Flowerius again have both been 

 applied to what we term here Balanoptera borealis ; 

 so that one of them at least may be discarded, and 

 that one must obviously be Flowerius, as it is the 

 newer name. Balana is clearly to be left out of 

 consideration, as it is or rather has been in the hands 

 of older authors of wide applicability, embracing all 

 the whalebone whales. Physalus is an older name 

 than Pterobalcsna for the same species, and the same 

 applies to Ogmobalana. So we may in this way 

 weed down the generic names of the Rorquals to 

 Balcrnoptera, Sibbaldius, and Physalus. These three 



