1918.] il. C. Andeews : Balaenoptera edeni. 107 



the first left rib of the type of B. edeni was preserved and that it was 

 " single-headed." The Sidhi Island skeleton exhibits a bifurcated first 

 rib exactly as in B. horcalis as may be seen from the accompanying 

 figures (figs. 3, 4). While the presence or absence of a cervical rib has 

 no specific value, nevertheless it is interesting since in B. borealis its 

 presence is almost universal (see Andrews, I. c, pp. 367-368). 



The Sidhi Island skeleton, so far as I was able to examine it, appears 

 to substantiate the characters pointed out by Dr. Anderson in the type 

 specimen of B. edeni. While in almost any other group of mammals 

 these would be deemed sufficient reason for separation from even closely 

 allied forms, yet any naturalist who is familiar with the extraordinary 

 individual variation among cetaceans will realize that it is unwise to 

 make positive statements based upon a limited amount of material. 



It is difficult for me to believe that the differences exhibited by these 

 skeletons can be individual, and yet they must be strengthened by a 

 knowledge of the external anatomy before the species can be said to rest 

 upon a firm foundation. There is no doubt that it is a form very closely 

 allied to B. borealis and it may possibly prove to be identical with the 

 recently described Balaenoptera brydei from South Africa of which only 

 the external characters are known. 



