1848,. MURCHISON ON THE STRUCTURE OF THE ALPS. 191
remarkably bold and highly dislocated mountain. From a spot near
the Esel summit, where I observed nummulites*, I perceived that
there was an ascending section, with a rapid dip to the S.S.E., through
beds of impure limestone into highly ferruginous strata, which in parts
became a strikingly green calcareous grit (in parts small pisolitic), in
which were casts of Pectens and other shells, similar to those associated
with nummulites in many other parts of Switzerland. These green
sandstones and calc grits there dipped rapidly under a vast thickness
of schists, micaceous sandstones and bastard limestones ; in short,
imder the *'flysch." It was thus clear that the nummulitic and
flysch rocks, though perfectly united and conformable within them-
selves, and clearly forming one natural division, were at this high
gorge unconformably enclosed between two walls of the older neo-
comian limestone, as exhibited in this diagram. In my rapid survey
Fig. 8.
Gorge east of Mt. Pilatus.
g. Flysch of great thickness.
/. Ferruginous greensand with Pectens (part of the nummulitic group).
b. Neocomian limestone (upper).
I did not visit the adjacent flanks of the mountain in which a sequence
might be found ; and I have only to observe, that in the great masses
of finely laminated marly and sandy schists which descend rapidly on
the face of the older limestones into the lake, I found some of the
same small foraminifera which MM. Briinner and Riittimeyer have
recognized in the environs of Thun.
On the whole, however, the nummulitic and flysch rocks of the
Pilatus have the appearance of having been upheaved in a highly
broken and elevated trough, the sides of which rest on the edges of
the neocomian limestone, which latter presents to the north one of
the finest mural precipices along the whole outer edge of the Alps, to
the lower and undulating country of molasse and nagelflue, which
here range over the canton of Lucerne.
The eastern end of the lake of Alpnach is almost barred in by a
tongue of land, composed of subcorneal and undulating hills, which

• The species of nummulite I found in the Pilatus was small, but it is well known
  

that large forms of this genus are there also present. In reference to these
organic remains, I ascertained, when in the company of Professor Briinner, how
much the species of Nummulites and other Foraminifera differ in the same region
at different localities, and yet, as will hereafter be seen, the very same character-
istic species reappear at spots very widely distant from each other.