Page:A Treatise on Geology, volume 1.djvu/171

 CHAP. VI.

and clay with calcareous nodules constitute a fish-bed. Thick masses of conglomerate; the basis red sandstone, the imbedded pebbles of various, often great size, derived from the neighbouring mountains.

On the borders of the English Lake district we have this combination reduced to a small thickness, and deprived of its upper term. The best sections are seen about the foot of Ulswater, in valleys near Kendal, and at Kirkby Lonsdale. At this latter place we have

A little further to the S.S.E. the old red series is totally deficient (Craven), and nearly so in Flintshire.

A second combination of the similar elements appears on the border of Wales, and acquires distinctness in the region south of Shrewsbury. An excellent general section is obtained in the country between Dean Forest and the Silurian Vale of Usk. It may be thus expressed :—

In all the strata enumerated, and in all their localities, the rarity of in vertebral remains and of vegetable fragments is remarkable. Only a small number of bivalves (not brachiopoda, possibly freshwater shells,) has occurred to Mr. Miller in Scotland. Fishes have