
502 PROCEEDINGS OF SCIENTIFIC SOCIETIES. 

















the lake below it, as a delta advances into any body of water into which 
astream flows. These lakes in most cases were thus gradually filled up, 
leaving countless delta islands in their place, but Lake Pepin still exists 
made by the sands deposited by the Chippeway. Lac qui Parle and Big 
tone lake, on the Minnesota river, are of the same kind. The depth of 
e lakes is still fifty to seventy feet or more, so that having 
hei 
of t epth of sand above and below them. There is no need, when 
we know how this river jae was made, to sound in order to get the 
depth of the sand. We know the seep everything must have that 
crosses the valley of the Satie The exceptional cases at the rapids 
I have explained. 
So far what is said is mainly in the way of a demonstration to account 
for “Certain Physical Features of the Upper Mississippi river.” The gran- 
deur of the subject he had tried to keep from influencing his observation 
and deductions therefrom. But part of the facts by which the Meese 
are reached are here given, nor are all of the inferences drawn which 
facts EN will warrant. 
ly knew how sean of what he had said is derived from others. 
He nee eee some of the most distinguished geologists on the gen- 
eral subject. He was particularly indebted to Mr. James E. Mills of New 
ork, whose investigations of the gradual northern depression going on 
along the Atlantic coast, suggested t o him to account for the change of 
that 
probably embraces the whole continent. This must affect all the etc: 
and all the lakes, bays and oceans around us, an yi so far as his 0 
vation and reading extend, they all give the same proo ofs of it. It 
however, a field for many observers, and he ventured this incomplete 
showing, so that others who have the opportunity, and deem it w 
of their efforts, may help along the investigation. 
Kent SCIENTIFIC INSTITUTE. Grand Rapids, Mich., Sept. 1 
ing counties.” The list contains all the species heretofore descr 
several new m science, of which descriptions exist only in the manuscri 
of Mr. Curri ade 
Mr. beige w. Smith gave an account of a series of aT T 

