THE WEST OF ENGLAND AND EAST OF WALES. 435 
stone 2; Silurian grit 2=80. But this survey probably did not 
include nearly all the large boulders, though I have no doubt of its 
being approximately correct as regards the great preponderance of 
Criffel over Eskdale granite, and the preponderance of felspathic 
boulders over both. South of Chester, on a line with the great high- 
way of boulder-transportation, Criffel-granite boulders become com- 
paratively rare, and this rarity (so far as I have seen) continues until 
the great terminal concentration is reached. The partial exhaustion 
of the Criffel dispersion south of Chester may be explained by sup- 
posing that while the sea continued shallow the rising ground of 
the peninsula of Wirral intercepted the boulder-laden ice, and that 
afterwards as the sea deepened, the ice met with few obstructions 
or accidents until it reached the border of the warm current south- 
west and north of Wolverhampton, West of the river Dee a few 
Criffel-granite boulders may be found, the furthest west (a mere 
straggler) being about a mile west of Mold. Several may be seen 
south of Caergwrle and Wrexham. I did not see any in Oswestry 
large gravel-pit, or further west than between Welsh Frankton and 
Whittington. The Criffel boundary then runs south to the neigh- 
bourhood of Cardington, near Church Stretton (where I saw a small 
Criffel-granite boulder); but I have not had time to trace its precise 
course. I haye not seen any Criffel boulders at any considerable 
height along the western boundary; but, from what I can learn 
from Prof. Hughes, it is probable that they might be found quite 
700 feet above the sea between St. Asaph and Halkin mountain. 
6. Dispersion over Delamere and Peckforton Hills—Among the 
numerous large boulders found about Helsby, Frodsham, Overton, 
and other towns or villages on the north and north-east sides of the 
Delamere hills, as far south as Delamere church, a few large Criffel- 
granite boulders may be seen, but Scottish “ greenstone” (with a few 
exceptions *) is absent. On the Peckforton hills, so far as I could see 
before the late removal of most of the boulders, Criffel-granite boulders 
were likewise rather scarce, though one of moderate dimensions may 
still be seen near the tower on Mr. Lee’s farm, about 650 feet above 
the sea, There is a very large Criffel boulder at Barrow (west of 
the Delamere hills) and a considerable number at Tattenhall, north- 
west of the Peckforton hills, one being 6x3~x3 feet. In Rock- 
Savage railway-cutting (near Runcorn, north of the Delamere hills), 
when first made, two large Criffel-granite boulders, and one large 
Scottish-‘‘ greenstone” boulder might be seen at the base of the lower 
clay 7 (along with Eskdale-granite boulders). These Criffel granites 
may possibly lie in the course of the boulder-stream which dropped 
large blocks at Stafford, Market Drayton, and Bushbury. 
7. Criffel Boulders at Market Drayton, §c.—Around Market 
Drayton the Upper Boulder-clay, which covers the greater part of 
Cheshire like a pall, begins to thin out south-eastward. In a clay- 
* One about 3x3X2 feet may be seen at the corner of a ladies’ boarding- 
school in Overton, 
+ Several of these boulders had evidently crushed down the Triassic marl on 
which the Boulder-clay rested, as if they had fallen from a considerable height, 
