Searles V. Wood,jun. — Sequence of Glacial Beds. 411 



striatula '■-' {gallina), Astarte borealis, Artemis {exoletal^"') Mactra 

 subtruncata, M. solida, Cardium edule, C. tuberculatum ?* C. aculea- 

 tum?^^ Corbula nucleus (inequivalvis), Tellina BdltMca, Psammobia 

 Ferroensis, Ostrea edulis and Mytilus edidis. All of these shells 

 inhabit common ordinary depths of British or contiguous Arctic seas, 

 and those which have an asterisk placed against them have not 

 occurred in the Crag. 



I have not included the shells from the Moel Tryfaen or Maccles- 

 field sands (see Mr. Darbyshire's Article in Vol. II. of this Mag., 

 p. 293) in the above list, because it has not been satisfactorily shown 

 that these sands are identical with the Middle Sands of the Lanca- 

 shire Coast; but however that may prove, these shells, like tlie 

 others, all inhabit ordinary depths of British or contiguous Arctic 

 sea's. 



1 have also carefully compiled from the best authorities I can 

 find, including papers of Prof. Jamieson, with lists of shells 

 identified by Mr. Jeffreys, and papers by Messrs. Crosskey and 

 Eobertson' and by Mr. Peach, a list of the moUusca from all the 

 Glacial or so-called G-lacial beds of Scotland, including the localities 

 of Invernettie, Ellishill, Ednie, Annochil, Auchleucries, Belhelvie 

 (all in Aberdeenshire), King Edward, and Gamrie (both in Banff- 

 shire), Montrose (in Forfarshire), Errol, Tyrie, and Elie (in Fife- 

 shire), Fort William (in Inverness-shire), the Kyles of Bute, Dalmuir, 

 Loch Gilp, Cumbrae, Paisley, and other localities on or near the 

 Clyde, and the Boulder- clay of Caithness. This list comprises about 

 130 species of mollusca, and the whole of them are still living at 

 ordinary detpths in that part of the ocean which, lying North of the 

 60th parallel of North latitude, is bounded by the East coast of 

 America on the one side, and the North-west coast of Europe on the 

 other; while about one-fifth of them are not found in any part of the 

 Crag. How much this fauna of 130 species contrasts with the East 

 Anglian Mid-glacial one of 80, especially if the Scotch species (the 

 names of which I have not set out) be considered with the Mid-glacial 

 ones above named; and how much it negatives the probability of any 

 of the Scotch beds which yield molluscan remains (inclusive of the 

 Caithness Boulder-clay) * belonging to a period as remote as the East 

 Anglian Mid-glacial, with its Crag-like fauna, those familiar with the 

 mollusca of the Newer Tertiaries and (so-called) Post-tertiaries of 

 Britain will, I think, appreciate. 



I have made efforts in various quarters to get at the mollusca of 

 the Wexford gravels, and so far as I can learn there is nothing from 

 these gravels to point to any period so ancient as the East Anglian 

 Mid-glacial, or even as the Bridlington bed, with the exception of a 



' The lists of tlie late James Smith, of Jordan Hill, axe not, except so far as they 

 have been confirmed by Messrs. Crosskey and Eobertson, altogether reliable. 



2 Those who (unlike myself) believe in Mr. Croll's ice-filled North Sea, and in its 

 having brought the shells of the Caithness Boidder-clay from some anterior sea- 

 bottom into that clay, will perceive that any such sea-bottom, as well as the Caithness 

 clay, must, from these Caithness shells belonging to the category mentioned in the 

 body of the paper, be, according to palseontological probabilities, newer than the East 

 Anglian Middle Glacial. 



