TAYLOR — aEOLOaT OF CASTLETON, DERBYSHIRE. 
87 
in the richer pastures. The number of mosses is exceedingly great. 
The beautiful Bryum dendroides and others abound in the moister 
spots of the Cave Dale. In fact, the botanical character of the vege- 
tation hereabout is so peculiar to the three formations which are 
found as to form a geological map to the underlying rocks, coloured 
by nature herself! The limestone clothed with its short and beautiful 
carpet of green ; the black shales of the Yoredale rocks covered by 
their stunted and brown vegetation ; and the millstone-grit in the 
glowiug summer-time quite purple with the flowers of the heather. 
And for land shells no other locality can compete with it. Trom the 
robust Helix as'pe7^sa to the diminutive Pupa numerous species in- 
terveue; some of them, such as Glcmsilia and Fupa, being more nu- 
merous in individuals than any other place that I have visited. 
But to the geologist the rocks present treasures of fossils most 
beautifully preserved. 1 have found the Terebratiila hastata retaining 
its purple colour-bands as beautifully as when alive in the carboni- 
ferous seas ; and in some places every slab that is turned up is 
matted with Eetepora and Fenestrella. Coming here from Manchester, 
along the new^ road from Chapel-en-le-Frith, the first place where we 
meet with the limestone is about a mile and a half distant from the 
town. This hill, Trecliff, is about six hundred feet in heiglit, and the 
dip of the beds is about 25° in a direction N.N.E. It is in this hill 
that the " Blue John " mines are situated ; and is the only locality 
in the country where this peculiar mineral is met with. It lies in 
"pipe-veins," having the same inclination as the rocks which the 
veins traverse. One of these veins lies in a sort of clayey stratum, 
and another seems to be imbedded in the nodule state in a mass 
of indurated debris. Besides tliese, the Avhole of the limestone 
masses are fractured and cracked, and, in addition to the pipes, the 
sides of the cavities are lined with the most perfect and beautiful sky- 
blue cubes of fluor, and the rhombic crystals of calcite. I remember 
scarcely anything with greater pleasure then an adventure in search 
of minerals a year or two ago, in one of these caverns, which was 
richly rewarded. AVitherite, fluor-spar, varying in colour from trans- 
parency to rose, blue, violet and other colours, selenite, and occa- 
sionally phosphate of lead, are all found in the lead-mines of the neighs 
bourhood. Some varieties of calcspar have the property of double 
refraction, like Iceland spar. 
Nearly all the characteristic fossils of the carboniferous limestone 
abound, as m.ay be seen by glancing at the names of the localities 
given in Professor Phillips's ' Geology of Yorkshire.' The richest 
localities for obtaining them is just below the "Blue John cavern," and 
in the gorge at the back of the town, which goes by the name of 
the Cave Dale. In geologizing along the side of Trecliff" hill, one 
cannot but be struck with the various groups of fossils which the 
diff"erent beds present. The loive^' beds contain great quantities of 
Pliillipsia — heads, carapaces, etc., being very frequently met with, and 
occasionally they are found whole. Just as we should have expected 
from knowing that the family of Trilobites died out with the mouu-* 
