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species of Orthis, a large winged Delthyris, &c.), confirmed this 
view. Hence also the chain of the Taunus, which is the physical 
prolongation of the Hundsruck, must be referred to a similar place 
in the general series; a conclusion at which the authors also arrived 
from an examination of the sections on the right bank of the Rhine, 
though obscured by the enormous development of masses of con- 
temporaneous trap ( Schaalstein). 
The authors then give some details respecting the trappean and 
voleanic rocks on both banks of the Rhine, and conclude, that the 
quartzite and chlorite slates, &c. of the Hundsruck and Taunus are 
but altered forms of a great Silurian group under the Eifel lime- 
stone; and that the causes which at an ancient epoch dislocated, 
contorted, and mineralized the strata, have perhaps not yet entirely 
ceased, and that the hot springs of Wisbaden and bubbling fountains 
of Nassau, may be referred to their last expiring efforts. 
On a review of all the facts stated in this and the preceding Part 
of their communication, the authors conclude, (1.) That from the 
carboniferous deposits of Westphalia and Belgium, to the lowest 
fossiliferous deposits of the Rhenish provinces, there is a great and 
uninterrupted series of formations, which are in general accordance 
with the British series, though the subordinate groups do not admit 
of direct comparison; (2.) That, considered in a broad point of 
view, the natural successive groups of strata and the natural suc- 
cessive groups of fossils, are in general accordance; but as the 
boundaries of the physical groups are ill defined, so also the bound- 
aries of the fossil groups are ill defined, and pass into or overlap one 
another; (3.) That as there are no great mineralogical interruptions, 
producing a discontinuity and a want of conformity among the de- 
posits, so also there seems to be no want of continuity among the 
groups of the great paleozoic series of animal forms. If the ex- 
treme terms be compared together, all the objects are dissimilar ; 
but if the proximate fossil groups be put side by side, there are 
many points of resemblance, and many of specific agreement ; (4.) 
That the Devonian system is, therefore, a natural system, not merely 
made out, as in England, by a plausible interpretation of fossil evi- 
dence, but defined, in the Rhenish provinces, both by its group of 
fossils and its place in a true descending section. And as the old 
red sandstone of Herefordshire passes on the one hand into the car- 
boniferous limestone, and on the other into the upper Silurian rocks, 
without interruption, it follows, that the Devonian system, as above 
defined, is contemporaneous with, and the representative of, this old 
red sandstone. 
§ 3. Chain of the Hartz —Fichtelgebirge, §c.—The general strike 
of this chain is nearly the same as in the provinces before described 
(4. e. east-north-east), and therefore almost at right angles to the 
prevailing direction of the chain, as laid down on a geological map. 
The mineral structure and the fossils are also nearly the same, and 
the numerous contortions throw the same difficulties in the way of 
determining the true order of superposition ; and these difficulties 
are greatly increased by protruding masses of granite, which have 
VOL. III. 2B 
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