8 CETACEANS. 



different species. In colour it may vary from black to creamy white ; while in 

 some cases it is ornamented with stripes of dark and light. The object of the 

 baleen, as already said, is to strain the water from the small animals on which the 

 whale feeds ; and its mode of action is described by Sir W. H. Flower as follows : 

 " In feeding, the immense mouth is filled with water containing shoals of these 

 small creatures, and then, on the whale closing the jaws and raising the tongue, so 

 as to diminish the cavity of the mouth, the water streams out through the narrow 



MEDIAN SECTION, SHOWING THE LEFT SIDE OP THE SKULL OF THE GREENLAND WHALE, 



WITH THE WHALEBONE. 



Br, brain-cavity ; J,J* upper and lower jaws ; bo, bones of roof of skull ; s, blow-hole, 

 with arrows leading from the cavity of the nostrils ; iv, whalebone : t, contour of tongue ; 

 n, aperture of nerve canal in lower jaw. (From Southwell's British Seals and Whales. 

 After Eschricht.) 



intervals between the hairy fringe of the whalebone blades, and escapes through 

 the lips, leaving the living prey to be swallowed." 



The whalebone whales are commonly divided into right- whales, 

 humpbacks, and rorquals or finners, severally representing as many 

 genera, in addition to which there are two less well-known forms, each of which is 

 entitled to generic distinction. 



Various Kinds. 



RIGHT-WHALES. 

 Genus Balcena. 



The right-whales, of which the Greenland whale is the best known repre- 

 sentative, are characterised by the absence of any fin on the back, and of any 

 furrows in the skin of the throat ; and likewise by the proportionately large size 

 of the head, and the arched form of the sides of the mouth, which ascends in the 

 middle far above the level of the eye. The flipper is relatively short, and contains 

 five distinct digits ; and the whole of the seven vertebrae of the neck are welded 

 together into a solid mass. The baleen is long, narrow, very elastic, and black 

 in colour. 



