At Capellbacken, near Udevalla, in Sweden, there is an extensive bed of shells 20 to 30 feet in thickness. This formation has been described by Mr. Gwyn Jeffreys.[123] It consists of several distinct layers, apparently representing many epochs and conditions. Its shells are of a highly arctic character, and several of the species have not been found living south of the arctic circle. But the remarkable circumstance is that it contains _Cypræa lurida_, a Mediterranean shell, which Mr. Jeffreys, after some hesitation, believed to belong to the bed. Again, at Lilleherstehagen, a short distance from Capellbacken, another extensive deposit is exposed. “Here the upper layer,” says Mr. Jeffreys, “gives a singular result. Mixed with the universal _Trophon clathratus_ (which is a high northern species, and found living only within the arctic circle) are many shells of a southern type, such are _Ostrea edulis_, _Tapes pullastra_, _Corbula gibba_, and _Aporrhais pes-pelicani_.” At Kempsey, near Worcester, a shell bed is described by Sir R. Murchison in his “Silurian System” (p. 533), in which _Bulla ampulla_ and a species of _Oliva_, shells of a southern type, have been found. A case somewhat similar to the above is recorded by the Rev. Mr. Crosskey as having been met with in Scotland at the Kyles of Bute. “Among the Clyde beds, I have found,” he says, “a layer containing shells, in which those of a more southern type appear to exist in greater profusion and perfection than even in our present seas. It is an open question,” he continues, “whether our climate was not slightly warmer than it is now between the glacial epoch and the present day.”[124] In a glacial bed near Greenock, Mr. A. Bell found the fry of living Mediterranean forms, viz., _Conus Mediterraneus_ and _Cardita trapezia_. Although deposits containing shells of a temperate or of a southern type in glacial beds have not been often recorded, it by no means follows that such deposits are actually of rare occurrence. That glacial beds should contain deposits indicating a temperate or a warm condition of climate is a thing so contrary to all preconceived opinions regarding the sequence of events during the glacial epoch, that most geologists, were they to meet with a shell of a southern type in one of those beds, would instantly come to the conclusion that its occurrence there was purely accidental, and would pay no special attention to the matter.