On examining the published records of explorers in the central portion of the Continent, it will be noticed that there is strong reason to believe that the absence of the Northern drift formation is not peculiar to the States along the Pacific Coast; but that the whole region west of the Rocky Mountains is also destitute of any indications of a detrital formation moved over the surface in one direction by any great general cause. Judging from our present stock of evidence, I am inclined to draw the line which limits the Northern Drift formation on the south and west approximately from the mouth of the Ohio to the headwaters of the Saskatchewan River.
It is evident that these facts should be taken into account in theorizing on the origin and cause of the drift. If, as stated above, the transporting agent has been limited in its field of action to the eastern and northeastern portion of our Continent, the phenomenon is seen at once to have become, in a measure, a local one—at least much more local than has hitherto been usually assumed by those geologists who have adopted the glacier theory of the drift.
Professor Whitney remarked that he was particularly desirous of introducing the subject on this occasion, in order that he might have an opportunity of impressing on Mr. Dall, who is about to leave for the Northern Coast, on the Telegraph Expedition, the importance of making a thorough examination of the detrital formations and surface geology of the country he may traverse.
Regular Meeting, June 18th, 1866.
Mr. Stearns in the Chair.
Thirteen members present.
The following named gentlemen were elected Resident Members: Baron F. von Richthofen, E. B. Dorsey, W. W. Palmer, W. S. Keyes, M. L. Stangroom, J. T. Watkins, Jr., W. G. W. Harford, Louis Falkenau.
Mr. H. G. Bloomer stated that he had identified the plant commonly known as the Pepper Tree, as Schinus mollis.
Mr. W. H. Dall called attention to several errors in geography made in a short chapter on geographical distribution of marine forms, forming the conclusion of Agassiz’ “Sea Side Studies in Natural History,” recently published. The errors were in regard to the Coast of California.