186 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 
similar to that of some sandplains, although the development of surface 
features is not nearly so typical here as in some of the sandplains near 
Boston. 
If a depression of Cape Ann can be proved to have occurred in post- 
glacial times to the amount of 40 feet or more, it would be expected 
that similar proof could be found in other regions near by. I have made 
no attempt to extend the study beyond Cape Ann, but the suggestion 
has occurred to me that at least some of the sandplains of eastern Massa- 
chusetts, and some of the broadly extended stratified beds near the 
mouths of large streams, are really delta deposits made when the land 
stood lower than at present. 
Beaches. —In a number of places along the shore, especially the 
eastern and most exposed shore of the Cape, distinct beaches were found 
at the elevation indicated by the other stratified deposits described 
above. It does not seem worth the while to take the space for specific 
description of many of these beaches, and therefore only three or four 
of the best will be described. 
A very interesting bar, evidently resulting from wave wash, is found 
near the southern end of Eastern Point on the site of the old government 
fort (A, Plate 1). The bar is crescentic in shape and is isolated from 
higher land. Its crest has an elevation of 50 feet. By itself it would 
prove nothing, but its elevation, which is the same as that of much 
better developed beaches near by, indicates that it is of wave origin. 
The appearance of the area near this bar indicates that there was here 
either a shoal or else a low island which the waves gradually washed 
away, leaving a bar on one end. Its position and form are indicated on 
the map. 
Less than a mile to the northeastward from this is a well-developed 
cusp whose position is marked on the map (B, Plate1). It is so well de- 
fined that the United States Coast Survey topographers gave to it a special 
contour, as will be seen on the United States Geological Survey map, which 
in this place is based upon the Coast Survey map. This beach is one 
that Professor Burton surveyed for Mr. Gardner to be used in this paper, 
and the maps made from this survey are reproduced as Plates 2 and 3. 
By the maps it will be seen that along the present coast line there is a 
rocky stretch of coast toward the northeast, succeeded toward the west 
by a pebble beach which grades into a sand beach on the extreme west. 
The modern beach reaches an elevation of a little over 14 feet above 
mean sea level, and behind this is a swamp 5 feet lower. It stands, 
therefore, as a bar, and its outline is that of a cusp. Almost parallel to 
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