502 W. H. DALL 
In some regions, as the west coast of the Floridian peninsula, the 
strata may be slightly inclined so that the beds between which sub- 
terranean waters move have their edges beneath the sea. Torrential 
rains in the interior of the peninsula carry vegetable matter into the 
interstices of the soft limestone rocks, where it decays with the accom- 
panying production of carbon dioxide and sulphuretted hydrogen gas. 
This accumulates and under the hydrostatic pressure of an excep- 
tionally heavy rainfall is sometimes forced out beneath the sea from 
the edges of the submerged strata in sufficient volume to kill by suffo- 
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. 
