H. E. Hoicorth — Traces of a Great Post-Olacial Flood. 557 



Forbes and his successors. Do they mean a sea choked with ice, 

 where all the fiords and coasts were lined with ice ; or do they mean 

 merely an open sea, where the climate was generally colder than 

 that in St. George's Channel and the North Sea at this moment, and 

 corresponding rather to the seas on the coasts of Northern America 

 and Scandinavia? If the former, — and certainly the former is the 

 meaning of the term Glacial Sea in the mouths of several of his 

 followers, — it seems to me that the facts are overwhelming against 

 the position. If the latter, there is no quarrel of any kind ; for the 

 position is apparently impregnable. 



Forbes professes to tabulate the results of the examination of the so- 

 called Glacial mai-ine drifts up to the moment when he wrote, as they 

 occur in North Wales, Cheshire, Lancashire, the Isle of Man, the Valley 

 of the Clyde, and Caithness, and he tells us the number of shells 

 known up to that time was about 124. " With few exceptions," lie 

 adds, " they are all forms now existing in the British seas." It is 

 most pertinent and interesting to quote his tabulated results of the 

 examination of these shells. He divides them into six classes. 



First, species now living throughout the Celtic region in common 

 with the Northern seas, and scarcely ranging south of the British 

 seas. Of these he enumerates twenty-five species. Secondly, species 

 which range far south into the Lusitanian and Mediterranean 

 regions, but which are most prolific in the Celtic and Northern seas. 

 Of these he enumerates twenty-four kinds. Thirdly, species still 

 existing in the British seas, but confined to the northern portion of 

 them, and mostly increasing in abundance of individuals as they 

 approach the Arctic circle. Of these he gives fourteen. Fourthly, 

 species now known, living, only in European seas north of Britain, 

 or in the seas of Greenland or Boreal America. Of these he gives 

 sixteen species. Fifthly, species not now known existing, and 

 unknown fossil in previous deposits, six species. Sixthly, species, 

 fossil in the Coralline or Eed Crag, but still existing in the South- 

 European, though not in the British seas. Seventhly, extinct species, 

 fossil also in the Crag. 



If we exclude classes 5, 6, and 7, as containing unknown factors, 

 what is the result of this tabulation ? That sixty-three species are 

 found still living in the British Seas in our very temperate climate, 

 and only sixteen are confined to the European Seas north of Britain, 

 or the seas of Greenland and Boreal America. Surely this is suspicious 

 evidence upon which to found a postulate that these shells lived 

 under glacial conditions only. But let us examine these 16 species 

 somewhat more closely. 



I. Mr. J. Gwyn Jefi'reys gives Astarte multi-costata as a mere 

 synonym for Astarte compressa, which shell in its typical form, 

 he tells us occurs off Scarborough and off Mull, while of its 

 three varieties, A. globosa is common off Skye, and the coasts of 

 Argyle and Eoss and East of Shetland ; A. striata is plentiful on 

 the coasts of Yorkshire, Northumberland and Durham, the Firth of 

 Forth, the West of Scotland, and the outer Hebrides ; while A. nana 

 is found 15 miles N.W. of Mull. And of the species in general he 



