398 MARR t SECTIONS IN LOWER PALAEOZOIC ROCKS. 
At Austwick Beck, (Fig. 1.) the Bala beds (1) are seen m a 
tributary stream, to be unconformably overlain by a coarse con- 
glomerate, (2) as described by Prof. Hughes, interbedded with 
thin, black, apparently unfossiliferous shales ; the whole reaching 
a thickness of several feet. Above these is a gradual passage, 
into black shales, (3) which are also seen in the main stream. 
They are there overlaid by a thin band of hard blue mudstone, a 
few inches thick, with calcareous nodules, and containing numerous 
fossils, among which are : — 
Petraia. 
Illamus. 
Phacops elegans, Boeck and Sara. 
Leptsena quinquecostata, McCoy. 
Above these are pale green shales, a few feet in thickness, appa- 
rently unfossiliferous. They are surmounted by pale blue flags, 
(6) containing Monograptus priodon and Monograptus vomerinus, 
and these by the Austwick grits (7) above which are various alter- 
nations of grits and flags. 
At Crummack Beck Head, near the last described section, the 
Bala beds are seen overlain by a similar conglomerate, again with 
an unconformable junction. Both this conglomerate and that at 
Austwick Beck consist of a crystalline matrix, with pebbles of 
various sizes, up to some inches in diameter. Above the conglo- 
merate of Crummack Beck Head are black shales, (Fig. 2, Bed 3.) 
the top of which is not seen, being covered by vegetation. 
On comparing these beds with those of the neighbouring 
Lake District, and those of the Sedbergh District, we find no diffi- 
culty whatever in correlating them. 
The conglomerate of Austwick Beck is replaced by calcareous 
grits and conglomerates near Sedbergh, and by a thin calcareous 
bed, sometimes containing included fragments in the Lake District. 
In Spengill near Sedbergh, and in Torver Beck, near Conis- 
ton, a thin blue band occurs between the black graptolitic mud- 
stones, and the pale slates. This band in every respect resembles 
