ANNIVERSARY ADDRESS. OF THE PRESIDENT. Ixi 



the prevalence of severe climatal conditions throughout a great part 

 of the northern hemisphere, — conditions which probably, he thinks, 

 did not prevail during its earlier stage, and the gradual disappear- 

 ance of which marked its close. 



The remains of the marine animals found in the strata deposited 

 in this sea prove its glacial or arctic character. Remnants of that 

 ancient sea-bottom, stratified and unstratified masses of clay, sand 

 and gravel, often of great thickness, more than a hundred feet, and 

 great superficial extent, are to be met with in many parts of Great 

 Britain and Ireland. These beds when carefully examined are found 

 to contain in many places fossil marine testacea, usually scattered, 

 rolled, and broken, but in particular localities entire and undisturbed, 

 presenting undoubted evidence of the animals they inclosed having 

 lived and died on the spot. About 124 species of Mollasca have 

 been found in these beds in the British Isles, and, with few exceptions, 

 they are all forms now existing in the British seas, but indicating a 

 state of climate colder than that prevailing in the same area at pre- 

 sent ; and among them are species now known as living only in Euro- 

 pean seas north of Britain, or in the seas of Greenland and Boreal 

 America. The prevalence of these forms, indicating a lower tem- 

 perature in the testacea of the British glacial deposits, cannot be 

 ascribed to their having lived in greater depths ; for as far as our 

 author has seen, there is no British case of an upheaved stratum of 

 the glacial formation containing organic remains, evidently untrans- 

 ported, which may not have been formed at a less depth than 25 

 fathoms, and it is probable that between 10 and 15 fathoms would 

 more frequently approach the truth. Further, there is abundant 

 evidence that over a great part of the area occupied by these glacial 

 beds, the uppermost portions, composed of sand and gravel, contain 

 fossils belonging to littoral species, and indicating a much less depth 

 of water than existed previously, during the deposition of the inferior 

 marls. 



The deposition of the beds in the glacial sea, the author considers 

 to have been synchronic with that of the newer pliocene beds in the 

 tertiary deposits of Sicily, Rhodes, and other parts of the Mediter- 

 ranean basin; and from the existence of certain species of shells in 

 these beds, characteristic of the southern bounds of the glacial beds 

 in Britain, he infers that during the newer pliocene, or pleistocene 

 epoch, there was a communication open between the Mediterranean 

 and Northern seas. He also infers from a great amount of varied and 

 concurrent zoological evidence, that during the glacial period, land 

 existed in high northern latitudes, that either united or brought into 

 very close approximation the continents of Europe and North Ame- 

 rica. There could not then have been, he says, such a separating 

 abyss between Northern Europe and Boreal America as now divides 

 them ; the sea, through a great part, must have been a shallow sea, 

 and somewhere, probably far to the north, there must have been either 

 a connexion or such a proximity of land as would account for the 

 transmission of a non-migratory terrestrial, andalittoral marine fauna. 



There is in this part of this ingenious essay, a v/ant of that clear 



