1895.] NEW YORK ACADEMY OF SCIENCES. 19 
mass. The lignitic clay is evidently composed of transported 
material from some Cretaceous or Tertiary bed to the northward. 
Mr. Hollick’s paper was discussed by Prof. W. M. Davis. 
The second paper of the evening was the following : 
AN ACCOUNT OF THE SUMMER’S WORK IN GEOL- 
OGY ON LAKE CHAMPLAIN. 
By GILBERT VAN INGEN AND THEODORE G. WHITE. 
During four weeks of June and July, 1895, the writers were 
engaged in an examination of the Ordovician rocks of the 
Champlain Valley. A few localities on the western side of Lake 
Champlain had already been examined by persons connected 
with the Department of Geology of Columbia College. These 
localities, four in number, namely Port Henry, Westport, Essex 
and Willsboro’ were not again visited this year. During the 
trip all the important localities on both sides of the lake were 
examined, with the exception of those noted above. 
The object of the work was the accumulation of maleeale 
primarily, for Mr. White’s doctorate thesis on the Trenton 
faunas of the Lake Champlain region, and, secondly, for a study 
of the lower Ordovician faunas of the same region by. Mr. van 
Ingen. 
The system employed in recording field notes was that de- 
veloped by Prof. Henry S. Williams. during his study of the 
Devonian formations of central New York. The town which is 
the temporary headquarters for field work of the vicinity is as- 
signed a definite number as 108—Chazy, Clinton County. Dur- 
ing the progress of the work in that vicinity every exposure or 
continuous section is assigned a letter of the alphabet, whether 
the section be along a shore, in the bed of a stream, a railroad 
cutting or a quarry. The geologically lowest layer in that sec- 
tion is sought and numbered 1; each superadjacent layer be- 
ing numbered in series. The only field label then required with 
the collection from each layer is a small piece of paper with, 
e. g., the symbol 108, F.16. Reference to the field notes shows 
this layer to be a heavy black limestone, with conchoidal 
fracture, containing Maclurea in its upper portion, exposed in 
the bed of Little Chazy River at Chazy, Clinton County, N. Y. 
At every locality the sections were carefully examined, each 
separate layer carefully measured, and as many fossils obtained 
from it as was possible without too great an expenditure of time. 
