1859.] on Recent and Fossil Mammalia. 1 1 1 



bably, or possibly, due to the direct agency of man ; but tliis cause 

 avails not in the question of the extinction of species at periods 

 prior to any evidence of liunian 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. 



Within the last century academicians of St. Petersburg and good 

 naturalists have described and given 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 Stelleria 

 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 seems not to have been due to any special 

 quest and persecution by man. We may discern, in this fact, the 

 operation of changes in physical geography which have, at length, so 

 affected the conditions of existence of the Stelleria as to have caused 

 its extinction. Such changes had operated, at an earlier period, to the 

 extinction of the Siberian elephant and rhinoceros of the same regions 

 and latitudes. A future generation of zoologists may have to record 

 tlie final disappearance of the Arctic buffalo (Ovibos moschattis). 

 Fossil remains of Ovibos and Stelleria show that they were contem-^ 

 poraries of Elephas primigenius and Rhinoceros tichorrhinus. 



The Great Auk {Alca impennis, L.) seems to be rapidly verging 

 to extinction. It has not been specially hunted down, like the dodo 

 and dinornis, but by degrees has become more scarce. Some of the 

 geological changes affecting circumstances favourable to the well- 

 being of the Alca impennis, have been matters of observation. A 

 friend,* who last year visited Iceland, informs me that the last great 

 auks, known with anything like certainty to have been there seen, 

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

 rock called "Eldey," or *' Meelsoekten," lying off Cape Eeykianes, 

 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 disturbance in or about the year 18S0. Such 

 disappearance of the fit and favourable breeding -places of the A/ca 

 impennis must form an important element in its decline towards extinc- 

 tion. 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. A consideration of such instances of modern partial or 

 total extinctions may best throw light, and suggest the truest notions, 

 of the causes of ancient extinctions. 



As to the successions, or coming in, of new species, one 

 might speculate on the gradual modifiability of the individual; 

 on the tendency of certain varieties to survive local changes, and thus 

 progressively diverge from an older type ; on the production and 



♦John Wolley, junr., Esq., F.Z.S. 



