148 OBSERVATIONS ON THE 
known as the Coniston Flags. All the Sandy Series, from the 
top of the Tebay Mudstones to the base of the Helm Knot 
Sandstones, being known as the Coniston Grit. 
At the base of the Coniston Flags in the Lake District, there 
is a very variable series consisting of red shales, pale paste- 
coloured rock, and black bituminous shales, so full of graptolites, 
as to have been named by Professors HARKNESS and NICHOLSON, 
who first observed them, the Graptolithic Mudstones.* At the 
base of the Graptolithic Mudstones, there is often a strong 
conglomerate. In the typical Sections behind the Low Wood 
Hotel, on Windermere, this can hardly be called a conglomerate, 
but in the tributaries of the Rawthey, above Sedbergh, 
the conglomerate is well developed. In the S.W. corner of 
the Howgill Fells, near Ravenstonedale, there is a valley 
called Westerdale, in which, at the junction of Spengill and 
Stockless Gill, a very instructive section through the basement 
beds is exposed. The lower Coniston Flags, with Monograpius 
priodon, pass rapidly down into red flaggy shale, and this into 
blocky grey and red mudstone, which with the interruption of 
some crushed rock and an intruded felspathic mass, passes down 
into banded and striped pale paste-coloured rock with darker or 
lighter grey shaley partings. At this horizon there are 
sandy beds and thin lenticular bands of limestone with fossils 
distinct from those in the beds above or below. Underneath 
these are some 210 feet of shales breaking up into prismatic 
fragments, and having at their base a calcareous gritty 
band with MMeris/ella crassa, &c. Here we have the May 
Hill basement series with its characteristic fossils, and above it 
the Graptolithic Mudstones, many of the various zones in which 
have been identified by the graptolites, and correlated with those 
of Scotland ; and above these again, the Pale Slates passing up 
into the Lower Coniston Flags (Austwick Flags.) 
In the calcareous gritty basement bed the following fossils 
occur :— 
Favosites fibrosa O. crispa (?) 
Strophomena ungula (?) O. sp., a turgid form 
Orthis hirnantensis Pentamerus liratus (?) 
O. protensa Meristella crassa 
This bed occurs exactly where the mountain path crosses the 
stream, and must not be confounded with another somewhat 
similar gritty bed a little lower down the stream in the Bala 
Series. 
In this section the conglomerate of the Sedbergh basement 
beds is hardly represented, but the A/erzs/e//a is common to the 
lower beds in both areas. On Windermere there is only a 
thin pasty band at the base of the Graptolithic Mudstones, 
resting on the Coniston Limestone Series; but at Ashgill, near 
* The true equivalency of the sub-divisions of the lower part of the Silurian of the Lake 
District has more recently been worked out by Mr. Marr. Geod. Mag., 1887, p. 35- 
