S52 E. J. Pictet on the Diluvian Period. 
I will not add the Bos primigenius because it was seen alive by 
Julius Ceesar. 
I have not found among birds or reptiles any species to add 
with certainty to this list. 
We shall find only a few in this category among the terrestrial 
invertebrata. 'The marine deposits on the borders of the Med- 
iterranean contain some mollusks of lost species, but their num- 
bers are small compared with species still living. 
have said, it is the very limited number of species of small size, 
or little connected with the wants of man, among those which 
have disappeared. 
Such is the opinion which has been formed in regard to the 
causes of this extinction. Irepeat therefore that these causes can. 
* Bibl. Univ. (new series), tome vii, p. 871, March, 1860. 
’ 
Ses 
