BLUE WHALE. 245 



Vernacular Names. 



This, the largest of living mammals, is often spoken of as Sibbald's Whale or Sibbald's 

 Rorqual after the Scotch naturalist of that name who first brought it to the notice of scientists 

 in his work on whales of the Scottish coasts, published in 1692. From its size and habitat, it 

 is also called the Great Northern Rorqual, but more commonly Sulphurbottom Whale, or 

 Sulphurbottom (shortened by the Newfoundland whalers to 'Sulphur'), notwithstanding 

 that the latter term is a gross misnomer. How this name arose is not altogether clear, though 

 Scammon, in writing of the representative of this whale in the Pacific Ocean, supposes it is 

 descriptive of "a yellowish cast or sulphur color," which he says, is in some instances to be 

 noted on the under surfaces. It seems better to use the more descriptive epithet of Blue Whale, 

 which indicates the slaty-gray of its color. This is merely following Norwegian usage, how- 

 ever, since Blue Whale is but a translation of ' Blaahval,' first applied to it by the Norwegian 

 whaler, Capt. Svend Foyn, and formally adopted by Sars (1875). It has brevity to recommend 

 it as well. The German word is 'Blauwal,' after the Norwegian. In Icelandic it is called 

 'Steypiredyr,' meaning a great whale. 



Description. 



Form. — Compared with the Common Finback, the Blue Whale is longer of l)ody but 

 the head is differently shaped, with a broader muzzle, the sides of which are bowed outward 

 instead of loeing nearly straight. A prominent ridge runs forward from the blowholes on the 

 center of the snout. The pectoral fin is slightly longer in proportion and its outhne charac- 

 teristically different. Its outer margin is more convex, and its inner margin a long sigmoid 

 curve, with more of a concavity near the tip. Frequently the tip is serrated as if the ends of the 

 four fingers projected sUghtly at the margin of the paddle. This was seen in several cases at 

 Newfoundland by Ti'ue and by myself (see text-figs. 8, 9) . Sars also mentions it. Sometimes 

 this appearance may be present on but one side only. True lielieved that this irregular margin 

 of the end of the pectorals was "due in most cases to external injury." Certainly, however, 

 it may be a perfectly normal occurrence, since a foetus from Newfoundland which I dissected, 

 had a small notch at the tip of each pectoral, forming an emargination between the two longest 

 digits (II and IV), as shown in outline in text-fig. 8. 



The adipose fin at the lower part of the back is generally much smaller in proportion, than 

 in the other Balaenopterae, nearly an equal-sided triangle in outline with a concave hinder 

 margin. 



As in the Common Finback, the eye is behind and a little above the angle of the mouth. 

 The eyeball itself in a 71-foot animal was 5 inches in antero-posterior length and 4.5 inches in 



