318 BULLETIN: MUSEUM OF COMPARATIVE ZOÖLOGY. 
Champlain valley except around the eastern borders of the ice as the 
ice-front receded from its contact with the hills northeast of this part 
of Vermont. Why well-defined shore-lines do not occur here at what 
has been considered the position of the highest marine level is an 
open question. 
Upham (1895) and Woodworth (1905, p. 202) have supposed the in- 
definiteness of the upper marine shore-line on the northwest side of Lake 
Champlain to be due to a reädvance of the ice into the northern part 
of the Champlain valley at the close of the upper marine stage, or 
later. Such an advance would account for the absence of any clearly 
recognizable beaches above 400 feet in elevation in Vermont, north 
of St. Albans. "The trace of the upper marine shore-line projected 
northward, crosses the Missisquoi valley near Enosburg Falls, nearly 
20 miles east of Lake Champlain, and 15 miles east of the part of 
the Missisquoi delta where marine shells have been found. Three 
miles south of Enosburg Falls at the altitude of the upper marine 
limit (430 feet) the road between East Berkshire and West Enosburg 
follows a low esker for a mile. The slopes of the esker and of the 
low ridges east and west of it appear to have been unaffected by wave 
action. The north end of the esker is buried under the sandy deposits 
of the terraces of the Missisquoi River. It seems, therefore, that this 
part of the Missisquoi valley was still occupied by ice at the end of 
the upper marine stage. 
Summary and Conclusions. 'The east side of Lake Champlain is bor- 
dered by abandoned shore-lines referable to several stages of a glacial 
marginal lake, and to several marine stages. The relations of the 
various shore-line features which have been found may be seen in 
Plate 1, on which the relative distances from north to south, and the 
relative altitudes of the shore-line features are plotted. The delta 
terraces and beaches along the line L M are so near together and so 
strongly developed that they appear to belong together, and to mark 
the stage which was longest, and in which wave action accomplished 
most. Reference to Woodworth’s (1905, p. 226) chart which was 
constructed in a similar way shows that a line parallel to L M and 
not more than 20 feet below it represents the wpper marine stage for 
the New York side of Lake Champlain. That these lines are in the 
same tilted water-plane there can be little doubt. Lines drawn 
parallel to L M through the points above it are related in the same 
way to lines on Woodworth’s chart. I have, therefore, adopted the 
names which Woodworth used for these water-levels. 
The fact that the shore-lines on the Vermont side of Lake Cham 
nn O 
