Reports and Proceedings. 135 
nection with the MaNncuEsSTER and LivERPOOL GEOLOGICAL SOCIE- 
ries. Shortly after twelve o’clock the party commenced their examin- 
ation of the geological features of the northern side of the valley. The 
route lay along the banks of the Dee for upwards of a mile, and the 
first halt was made at the slate-works, near Llantysilio, where the 
huge slabs brought down from the quarries near the summit of the 
adjoining hills are prepared for industrial purposes. As roofing mate- 
rial these slabs appear somewhat coarse, though they are said to be 
durable. They are not in such demand as the thicker slabs, which are 
used for cisterns, chimney-pieces, &c. The next point of interest was 
the venerable pile of ruins, all that now remains of Valle Crucis 
Abbey, which was at one period a famous monastic establishment in 
the Valley of the Cross, one of the most secluded and picturesque 
dells which could have been selected for a religious community. The 
Abbey appears to have been built a.p. 1200. From this point the 
party divided, one portion, including several well-known botanists of 
Llangolien, taking the road for the World’s End, a division of the 
Mountain-limestone ridge of Eglewseg, while the remainder took a 
pathway across the hills, and came upon the remarkable exposure of 
limestone further south. This bold and terraced escarpment extends 
from near Trevor in a north-western line for many miles, and affords 
to the geologist many characteristic fossils of the Carboniferous for- 
mation. The lower measures consist of light-coloured beds, which 
are extensively quarried for use in the ironworks of Staffordshire and 
Lancashire. ‘The upper layers are of a darker colour, and of less in- 
dustrial value. The organic remains are principally Productus 
(P. Llangollensis being the most characteristic), Syringopora, Eu- 
omphalus, Pleurotomaria, Spirifera, Rhynchonella, &c. At the base 
of these rocks a small exposure of the Old Red Sandstone gives its pe- 
culiar colour to the slope, and in several places has been penetrated, 
apparently in search of mineral veins, of which the range contains 
many examples, though they are not productive in this locality. 
After spending some time in skirting the Eglewseg Rocks, and with 
many a halt to admire the ever-changing scenery, the summit of 
Dinas Bran was at length attained. From this point the sea of hills 
piled up in tumultuous succession towards the west, the blue outlines of 
the more distant mountains, and the. varied features of the adjoining 
vale, almost entirely diverted attention from the ruined fortress which 
crowns the eminence, and dates its origin from the early times when 
the Britons were retreating before the invading and conquering 
Saxon race. At five o’clock the various sections assembled at the 
Hand Hotel, where a cold collation was provided. 
In the evening Mr. Edward Wood presided, and Mr. Plant (Sal- 
ford Museum) gave an account of the geological features of the 
district inspected during the day. He described the Upper Silurian 
rocks, which are supposed to be the equivalents of the Wenlock 
Shale and Limestone. These measures form the hills in the immediate 
neighbourhood of Llangollen, and also those from which the slates are 
obtained. These vast layers of rock, he said, must have been formed in 
-a deep sea, and hence they are not rich in fossil remains ; but the few 
