34 



CETACEANS. 



but has no sign of the longitudinal crests. Usually only the first two or three 

 of the vertebrae are united together. The massive rostrum of the skull is not 

 imfrequently picked up on the shores of regions -where these whales are common ; 

 and similar rostra are among the commonest of Cetacean remains found in the 

 Pliocene crag deposits of the Sussex and Essex coasts, thus indicating that beaked 

 whales formerly abounded in the English seas. These rostra are, perhaps, the 

 most solid bones found among the Vertebrates, their material being as dense as 

 ivory. In some cases a row of minute functionless teeth are present in the upper 

 jaw, and thus serve to show that the whales of this group are descended from 

 ancestors possessing a full set of teeth in both the upper and lower jaws. In 

 the Crag period seven species are recognisable ; in these days the beaked whales 

 are represented by at least two species ; and they range over most seas, although 

 they appear more common in the Southern than in the Northern Hemisphere. 

 Nothing is known as to their habits. 



The best-known species of the genus is Sowerby's whale (Mes- 

 oplodon bideas), of which, according to Sir W. Turner, eighteen 



SKXIX OF SOWERBYS WHALE. 



specimens have been taken between the years 1800 and 1889 in the North Atlantic 

 and its inlets, all but two of which occurred on the coasts of Europe. Seven of 

 these were captured between 1880 and 1888: the one taken in 1885 having been 

 stranded at the mouth of the Humber, and being the only known English 

 example. The first specimen known to science was captured oft' the coast of Elgin 

 in 1800. By its describer, after whom it is now named, it was then called the two- 

 toothed cachalot, on account of the feature so well shown in our illustration. 



This whale usually attains a length of about 15 feet, and its teeth are of 

 comparatively small size, and sometimes only project slightly from the sides of 

 the mouth when the jaws are closed. Above the nearly straight beak the head 

 rises gently into a marked prominence in front of the blowhole, behind which 

 is another prominence, with the level of its summit continued backwards into the 

 line of the back. The opening of the ear is so small as to admit only of the 

 passage of a fine bristle. In a specimen stranded in 1888 on the shores of the 

 Firth of Forth the colour of the upper-parts was bluish slate, while that of the 



