74 Geology, &§c. of the Connecticut. 
to describe these remains. Butin other countries ‘‘these 
fossil remains of fishes are found only in strata of very re- 
cent origin.” (Rees. Cyc. Art. Icthyolites.) 
The great dip of many of these rocks may be thought to 
afford evidence of their being older than the old red sand- 
stone, or the independent coal formation. But to show 
that the dip of rocks is a very equivocal criterion of their 
age, I need only to refer to the recent work of Greenough 
on the first principles of geology. And besides, it is no un- 
common thing in real coal fields for rocks to be highly in- 
clined. ‘This inclination or dip of the (coal) strata is found 
every where; in some places it varies very little from the 
level; in others considetably, even so much as to be nearly 
erpendicular direction;” (Rees Cyclopedia, Art. 
Coal,) and still farther, as already hinted, there is rea- 
son to believe that Mount Toby, the strata of whic 
are almost horizontal, exhibits the original dip of these 
rocks, and that those cases in which they are more 
highly inclined are the result of some Plutonian convul- 
sion, Such irregularity in the dip of coal fields is no 
uncommon occurrence. “In some coal fields,” says Mr. 
Williams, (Nat. Hist. Min. Kingd. vol. 1, p. 93,) ‘the stra- 
ta acquire this horizontal and waving position, and afterward, 
towards the south-west or toward the north-east, the decliv- 
ity becomes again so steep as to form an angle of 45°, and 
in some particular instances to approach still nearer to the 
vertical position.” Upon the whole, I think there are insu- 
perable objections against referring the rocks of our coal for- 
mation to grey wacke and grey wacke slate. 
Another opinion already advanced on the subject is more 
probable. Itis that of Mr. Brongniart, who gave it after | 
having seen only the rocks containing the Westfield fish 
impressions. ‘This formation,” says he, “appears to me 
to have the strongest resemblance to that of the bituminous 
marl slates of the copper-mines in the country of Mansfield 
ge 
and Hesse.” (Journal of Science, vol. 3, . 220.) 
arguments in favor of such an opinion are, 1. The great sim- 
ilarity in the appearance of the German and American rocks 
on which the fish are found—one species, at least, being 
the same in both. 2. The occurrences of copper ores, and 
similar ones too, along with native copper in both rocks. 
3. The fact that both these varieties of rocks lie immedi- 
ately above the old red sandstone. Perhaps there are oth- 
