SLATE FOSSILS. 49 
profusely. ‘The same circumstance of identity in the 
fossils of the two rocks, seems to occur with respect 
to some other kinds. Between Elburton and Brixton 
in particular. | have observed that at the junction of 
lime and slate the two strata intermix, and alter- 
nate in narrow layers of two, or three inches thick, 
the encrinites here, being common to both kinds of 
matrix. Herns are reported to have been found in 
our slate, but I think the fact questionable. 
It has been laid down as an axiom, that the fossils 
of laminated rocks, suchas slate, are situated parallel 
to those laminz ; this however is not invariably the 
case; I have a fossil from my neighbourhod, a repre- 
sentation of which appears among the engravings, 
_- which was found to be placed in the stratum, without 
regard to its lamination, and the same observation 
’ may apply to thee yathophylla, and some other relics 
of the slate. 
There is yet one other remark belonging to this - 
portion of the subject, and which requires to be 
taken into account, by those who would advance 
our present acquaintance with the slate fossils to a 
higher standing than it now assumes. A large pro- 
portion of these remains consist in their present 
form, of lines arranged in a parallel manner, being 
in fact the impressions of animals, whose organiza- 
tions like those in the same class now living, 
involved that parallelism of their component parts. 
This fact is important, because it prepares us to 
admit specific, and even generic (perhaps I might 
be safe in adding ordinal) differences between the 
specimens, which otherwise the mind through over- 
caution, might reject. Certain it is, that a great 
variety of our specimens, from assuming this almost 
universal aspect of parallel lines, might seem to 
have had one common specific origin, whilst, on 
more deliberate inspection, they may more correctly 
be referred to several species, belonging even to 
more than one genus. 
