Geological Society of London. 237 



describes a limestone exposed in one place beneath the basalts, and 

 referred to the Upper Miocene, and a plant-bearing bed associated 

 with them, containing fossils of species still living in the island, 

 some of which have been wrongly referred to extinct forms. In 

 conclusion the author remarked upon the almost infinite variability 

 of the genus Eiibiis and the difficulty of distinguishing its sjoecies. 



3. " On the Crag Shells of Aberdeenshire and the Gravel Beds 

 containing them." By Thomas F. Jamieson, Esq., F.G.S. 



The author, in 1860, described beds of sand and gravel on the 

 coast of Aberdeenshire, containing numerous fragments of Crag 

 shells. His subsequent studies have enabled him to throw much 

 further light on these shells and their mode of occurrence. The 

 deposits containing the shells are almost wholly confined to the 

 districts of Slains and Cruden, and extend up to heights of 225 feet 

 above the present sea-level. They genei-ally consist of coarse gravel 

 with large subangular stones up to 2^ feet in length, intermixed 

 with sand and muddy materials ; the whole form ridges, like eskers 

 or moraines, though glacially striated blocks are rare in them. 

 The author describes the coast-section in detail, and shows that the 

 shell-bearing gravels rest on materials that appear to be formed by 

 glacial action and are covered by the Red Clay, which he regards as 

 having been formed during the period of great submergence. The 

 few entire shells are filled with a calcareous matrix, and fragments 

 of the same material are found scattered in the gravel and sand. 

 This lends support to the conclusion adopted by the author that the 

 sand and gravel have been accumulated by a glacier moving over 

 pre-existent Crag deposits. Among the shells found, 21 could be 

 specifically determined, and of these 67 per cent, occur in the 

 Coralline Crag, 95 per cent, in the Red Crag, and 57 per cent, 

 are living species. Only one species, Tellina halthica, occurring in 

 the Aberdeenshire deposits, is not found in the English Crags. 



4. " On the Red Clay of the Aberdeenshire Coast, and the Direction 

 of Ice-movement in that Quarter." By T. E. Jamieson, Esq., F.G.S. 



The author describes a red clay occurring in the eastern part of 

 Aberdeenshire, which difi^ers in many important respects from the 

 ordinary grey Boulder-clay of the district. Its contents appear to 

 show that it has not been derived from the Jurassic and granitic 

 rocks of Aberdeenshire, but from masses of Old Red Sandstone, now 

 perhaps removed by denudation. Only few and imperfect molluscan 

 remains, with bones of fish, aquatic birds, and seals have been 

 found in this red clay. He regards it as having been formed 

 during a period of great submergence which followed the period of 

 maximum glaciation. He finds at Cove proof of a remarkable 

 change in direction of the flow of the glacial ice. Additional proofs 

 of the submergence are found in the old beaches with shells, extend- 

 ing to heights of from 380 to 470, and even up to 560 feet above 

 the sea-level. The Mollusca occurring in these raised beaches are 

 all of living species, but now occur in arctic seas. He differs from 

 Mr. J. Geikie, who regards these deposits as of post-Glacial age and 

 of estuarine character. He concludes by describing in detail the 

 remarkable section exhibited in the Bay of Nigg. 



