I2O6 



THE CETACEANS 



Each of these teeth is pointed and much flattened, sometimes being elongated 

 into a strap-like form, so as to overhang the beak of the skull; their position is 

 variable, but generally some distance behind the extremity of the jaw. The skull 

 has the same curving crests over the aperture of the nostrils as in the bottle-nose, 

 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 unfre- 

 quently 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 possess- 

 ing a full set of teeth in both the upper and lower jaws. In the Crag period seven 

 species are recognizable; in these days the beaked whales are represented by at 



SKITI.I, OF SOWERBY'S WHALE. 



least two species; and they range over most seas, although they appear more com- 

 mon 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 (Mesoplo- 

 don bidens), of which, according to Sir W. Turner, eighteen specimens 

 have been taken between the years 1800 and 1889 in the North Atlan- 

 tic and its inlets, all but two of which occcurred 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 off 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 fifteen 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 



