42 BRITISH MAMMALS 



Mesoplodon bidens. SOWERBY'S WHALE 



In this animal (about 15 ft. long) there are two functional 

 (and rather large) teeth growing out of the middle portion of the 

 lower jaw. In the males these teeth are sometimes considerably 

 developed, and always show like the tusks of a boar when the 

 mouth is closed, as they diverge from the edge and project 

 outwards. Under the throat are two diverging furrows somewhat 

 in the shape of a V, with a point directed forwards. The opening 

 of the ear in this animal is so small as to admit only a fine bristle 

 being passed through it. Sowerby's Whale is dark blackish-gray, 

 or sometimes a bluish-slate, with the under parts of the body 

 much lighter, and the surface of the body is also diversified with 

 small whitish spots and streaks. The nostrils open not at the 

 bottom of a deep hole just above the base of the beak, but 

 directly on the top of the skull, in a slight depression. This 

 Ziphioid was first made known to science by a specimen cast 

 ashore on the coast of Elginshire (Scotland). Since that time a 

 number of other specimens have been stranded on the Scotch or 

 English coasts, or have been captured at sea close to the coast-line. 

 This whale would appear mainly to frequent the Atlantic, and to 

 range perhaps as far south as the Equator. In the southern seas 

 it is represented by closely allied species. In a very distinct form 

 of this genus in South African waters, the teeth in the lower jaw 

 appear to grow out into long, grooved tusks, which arch over the 

 upper jaw and prevent the animal from opening its mouth more 

 than a few inches. 



SUB-ORDER : MYSTACOCETL WHALEBONE WHALES 



The Whalebone Whales, whose distinction from the existing 

 toothed whales has already been described, are divided at the 

 present day into two well-marked families : the Right Whales * 

 and the Rorquals. 



1 Called by whalers the " Right " whales because the other whalebone 

 whales were wrong, that is to say, far less valuable, both for the whalebone 

 and oil. 



