58 
RULES RESPECTING THE FOSSILS. 
the doctrine of those, who could see no animal re¬ 
mains in it. But, surprising as its amplitude may 
seem, this fact is of trifling interest when compared 
to the much more astonishing circumstance, that it 
contains genera preserved through all the changes 
of the earth, up to the present period. Indeed, a 
mere glance at it will shew, that the type of structure 
has been preserved nine cases in ten, and, though 
many species are peculiar to these rocks, very few of 
the genera (save of course certain modern names 
adopted for the classification of fossils) are so,— 
they are continued into more recent groups.* That 
some of those kinds which from their obscurity 
cannot as yet be spoken of w r ith confidence, are 
peculiar genera in the grauw r acke rocks, is indeed 
far from improbable. Some of these anomalous 
fossils I have had represented ; they occur princi¬ 
pally in the slate rock, but in all likelihood, many 
of those unintelligible forms observed in the lime, 
are likewise the remains or fragments of beings 
equally strange and peculiar. There are some 
also in the sandstone to which the same remarks 
apply. 
The limestone obviously includes the largest 
amount and variety of fossils, and the sandstone, a 
much less quantity than the slate, but, though the 
general prevalence of some genera, (and same species 
probably in some cases) through these three incon¬ 
gruous depositions cannot be overlooked, it is to be 
apprehended as above said, that the slate and sand¬ 
stone, and more especially the former, contain animal 
remains, not discoverable in the lime,—some which 
are ipso facto characteristic of those strata. 
* The fossils which I collected in Oxfordshire from a soil 
totally different in age from our rocks, are yet in great measure, 
similar to those in the limestone of South Devon.—Many fossils 
of the chalk are also very similar to those of our limestone. 
