EVOLUTION AND DISTRIBUTION OF TERTIARY FAUNAS 221 



cation every living thing along many miles of coast. This has 

 happened on the coast of Florida several times within my recollection. 

 The repopulation of the devastated area is slow and can rarely 

 reproduce exactly the same assemblage of animals which previously 

 occupied that area. 



Another mode in which widespread extermination of a sedentary 

 population of invertebrates may be brought about is by the sudden 

 appearance of vast multitudes of minute organisms like Peredinia. 

 Within the last few years, both on the coasts of Japan and of Cali- 

 fornia, the sea at times has been covered for miles with reddish clouds 

 of these submicroscopic creatures. On their advent near the shore, 

 driven by wind or currents, the shellfish, corals, and fishes are rapidly 

 suffocated, and, if the pest continues, everything within the area it 

 occupies will succumb. I have heard that, within two years, the 

 Japanese pearlshell preserves on the seashore of that country have 

 been almost wholly ruined by the organisms referred to, with the loss 

 of hundreds of thousands of dollars, to say nothing of years of labor 

 rendered fruitless. 



