THE GEOLOGIST. 
117 
LioM 7. Shell* imbedded ia a stratum of mud, all on one lerel, shewing the destruction of the 
Diolluacs by a catastrophe. 
that narrow line at once speaks of the catastrophe — it is the 
mausoleum of young and old alike. A storm, a poisonous influ- 
ence, an inundation of mud or oose may equally have effected this ; 
but whatever was the cause the myriads were cut oif at once and 
suddenly. 
One bed of rock may immediately overlie another, and 
yet a great interval may have occurred between them. The dis- 
tance of one bed from the other in time, may be a thousand years 
— or more. It may be ages, — or it may be but a day. The intimate 
particles of which they are composed may be sUent upon this, the 
one may present a harder face or more consolidated constitution 
than the other, but of time they tell us nothing. What are days or 
years, minutes or hours, to the senseless particles drifted about by 
the changeful seas ? Time was, however, to the perished shell- 
fish ; they might not have measured it by months or years, by 
days or nights, but timed were their lives, and their species. 
They were not in their generations from the beginning until now, 
but they appeared and disappeared as the succession of the beds 
continued, and thus each great period of Geology had its creation 
of animated beings and vegetation, its fauna and flora distinct 
and appropriate — even as ours are now. One after another have 
these creations passed away, and in consequence of the suc- 
cessive upheavals and depressions of the land, the lines of 
level of different shells in a quarry may, nay, often do, 
note the demarcation of enormous periods — periods of mar- 
vellous ages — from each other. Nor do sheU-fish only tell 
their tales of those remote times. The bright and scaly 
fish, decomposing on the ocean's bed, has left a few and scattered 
scales, to mark its existence and decay ; or a few isolated teeth, 
may be of sharks, or other predaceous fish, torn from their jaws by 
the struggling prey, are sufficient to record the ferocious instincts 
