AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. 87 



Bulla oryza, Tott Montreal. 



Spirorbis sinistrorsu, Montague do. 



Univalve, (perhaps Menestho albula) 



Most of these are shells now living on the Atlantic coast of America, north of 

 Cape Cod, and some of them ranging verj far north. The paper then referred to 

 the distribution of the various kinds of drift in the vicinity of Montreal, and to the 

 conditions of the sea areas, in which the shells and other marine animals of the 

 IfeAver Pliocene period existed in the St. Lawrence Valley. Good evidence 

 esists of a sea beach- on Montreal Mountain, at an elevation of 470 feet above the 

 sea. The sea area corresponding to this beach must have extended to the Lauren- 

 tide hills and the escarpment of E'iagara, and communicated freely with the ocean 

 on the east. On the other hand there are lower shores of the same period only 100 

 feet above the St. Lawrence. These must have belonged to a very narrow prolon- 

 gation of the present Gulf of St. Lawrence. 



The conditions of climate, ice, drift, tfec, corresponding to these different shores 

 must have been veiy diverse. 



Again, in the stratified drift, it is possible to recognise, within a few inches of 

 each other, a bed containing deep-sea shells, and another containing species that 

 are littoral ; these sea bottoms corresponding to different levels of the land. It is 

 evident that any conclusions with reference to the climate indieattid by the marine 

 fauna of these successive beds of marine detritus, must take into account these 

 fluctuations of the sea level, and the changes in animal life consequent on them. 

 Taking these into account, positive and reliable results may be attained ; and the 

 study of such districts as the St. Lawrence valley may be made to contribute 

 toward the elucidation of the conditions cf life in older formations. 



KOETH AMERICAN LAKES. BY ME. CHARLES WHITTLESEY. 



The fluctuations of level of the American lakes, have repeatedly formed a 

 subject of inquiry, and have been brought under the notice of the Canadian Institute, 

 by Major Lachlan, in former years. These fluctuations present three distinct 

 features. There was first the general rise and fall, extending through a long 

 period of time ; then the annual rise and fall occurring regularly within a certain 

 period of each year, which Mr. Whittlesey styled the annual fluctuation ; then there 

 was the third, a local, fitful, and irregular oscillation, lasting sometimes from three to 

 five minutes, and varying in duration from one to twenty-four hours. He had no 

 difficulty in explaining the genei'al rise and fall of the lakes, as they were merely 

 the reservoirs for the drainage of the country of the surplus water, which passes 

 thence by the St. Lawrence as a general opening to the sea. Mr. Whittlesey read 

 a variety of statistics in reference to- the range and extent of the two first named 

 fluctuations, and said he was unable to find in these, or in the examinations he had 

 made, any confirmation of the popular belief that there is a seven years rise and 

 fall of waterin the Lakes. He then directed attention to the cause of the third 

 phenomenon — the irregular fluctuations which occur without any particular known 

 cause. Although these pulsations, as they might be termed, were the first to. 

 astract notice, they were the last to have received any explanation. They occur in 



