•±00 PALAEONTOLOGY 



the latest instance of this kind. But this cause avails not in 

 the question of the extinction of species at periods prior to 

 any evidence of human existence; it does not help us in the 

 explanation of the majority of extinctions, as of the races of 

 aquatic Invertebrata and Vertebrata which have successively 

 passed away. 



The Great Auk (A lea impennis, L.) seems to be rapidly 

 verging to extinction. It has not been specially hunted down, 

 like the doclo and dinornis, but by degrees has become more 

 scarce. Some of the geological changes affecting circum- 

 stances favourable to the well-being of the A lea impennis, 

 have been matters of observation. The last great auks, known 

 with anything like certainty to have been seen living, were 

 two which were taken in 1844 during a visit made to the high 

 rock, called " Eldey," or " Meelsoekten," lying off Cape Eeyki- 

 anes, the S. W. point of Iceland. This is one of three principal 

 rocky islets formerly existing in that direction, of which the 

 one specially named from this rare bird " Geirfugla Sker " sank 

 to the level of the surface of the sea during a volcanic disturb- 

 ance in or about the year 1830. Such disappearance of the 

 fit and favourable breeding-places of the Alca impennis must 

 form an important element in its decline towards extinct ion. 

 The numbers of the bones of Alca impennis on the shores of 

 Iceland, Greenland, and Denmark, attest the abundance of the 

 bird in former times. 



Within the last century, academicians of Petersburg and 

 good naturalists described and gave figures of the bony and the 

 perishable parts, including the alimentary canal, of a large and 

 peculiar fucivorous Sirenian — an amphibious animal like the 

 Manatee, which Cuvier classified with his herbivorous Cetacea, 

 and called Rytina Stelleri, after its discoverer. This animal 

 inhabited the Siberian shores and the mouths of the great 

 rivers there disemboguing. It is now believed to be extinct, 

 and this extinction appears nol to have been due In any special 



