Fossils of the Drift beds

Abstract

In examining the Ayrshire drifts my object was not so much to collect fossils as to trace out the extent of the beds which contain them, and I have therefore made no exhaustive examination of any one section. 211. Frequent Occurrence of Certain Fossil Shells. One remarkable feature is that certain shells turn up in nearly every fossiliferous exposure. These are:— Astarte compressa, A. sulcata, Leda pernula , and Cyprina Islandica . Had it not been for the Leda it might be thought that the strength of the shells had prevented them from being broken, but complete valves of this delicate little fossil are got nearly as often as those of any of the stronger ones. The small shells appear to have fared best, probably because, lying between stones on the sea-bottom, they were more easily sheltered from the stones falling from floating-ice than the larger shells. I should state that I have not met with a complete valve of Cyprina Islandica under boulders, except at the Misk (par. 1), where they were got with the valves united, under boulder-sand. 212. Fossils Shells which have been Identified. The determinable fossils which have been met with in the Ayrshire drift-beds are:— The remarkable feature about the shells is that they are nearly all bivalves, as amongst hundreds of specimens collected I have only got some half a dozen univalves, two being Littorina littorea much worn but not scratched , and these, evidently brought from a shore-line, occurring as pebbles This 250-word extract was created in the absence of an abstract