PROCEEDINGS OF SCIENTIFIC SOCIETIES. 55T 
that these valleys have been occupied by local glaciers as well as by a 
general one. Mr. Vose gave an account of his observations on the 
geological arrangement of the rocks forming the principal range, upon 
hich he founded hypotheses as to the early condition of that re- 
gion 
n the Origin of the so-called Lignilites or Epsomites,” by Pro- 
fessor O.C. Marsh, of Yale College. In limestone rocks, of all geolog- 
ical ages, there are frequently found columnar markings, and detached 
columns of the rock occurring along the seam between two beds of 
the same. Professor Marsh gave a notice of the different publications 
on the subject, showmg what a puzzle they have long been to geolo- 
gists. He exhibited a series of fine specimens, showing that they 
were due to pressure. Professor Marsh has been the first to show 
that the form of many perfect columns is due to the presence of a fos- 
sil shell or some foreign substance 
“On the Geographical Distribution of the Sediments and the Fos- ` 
Sils in the Hamilton, Portage, and Chemung Groups of New York,” by 
Professor James Hall. The object of the paper was to show that 
identity of fossil species must not be expected in rocks of the same 
geological age over wide geographical areas. 
“Upon some remarkable Fossil Fishes obtained by Rev. a8 Herzer 
from the Devonian Rocks at Delaware, Ohio,” by Profes ry S 
of these fish remains, which Mr. Herzer obtained from concretions 
in the rock. The remains belonged to a genus of ganoid fishes, now 
made known for the first time. The fish must have been one of the 
monsters of the waters of those times,’and very formidable. The 
head could not have been less than three feet long by two feet 
road. On-account of the great size, he had na amed it Dini cthys. 
“The Fossil Insects of North America,” by S. H. Scudder. ; 
was a review of the entire subject, noticing eighty species 
of fossil insects, known in the strata of this con ntinent.- ol 
preserved remains of insects now known are from the Devonian 
rocks of New Brunswick, and furnish evidence ae insects were in- 
troduced about the time that land-plants first appe 
“ Depression of the kt during the Glacial net “4 By Col. Charles 
Whittlesey. The existence of an ice epoch h, during which the north- 
ern hemisphere oad about latitude 40° was enveloped in ice nevè 
and snow, being now generally admitted, I propose to notice the 
effects which would necessarily follow in depressing the surface of 
the ocean. 
It is universally admitted that there have been in North America 
