TARR AND WOODWORTH: CHANGES OF LEVEL AT CAPE ANN. 191 
Yoldia siliqua, is also found fossil in the clays near Portland and Mon- 
treal, and occurs in the present waters of the Arctic, as at Beechey’s Island 
and Greenland. The other, Aphrodite groenlandica, is a distinctly 
northern form.* 
The fossil-bearing layer is from 15 to 20 feet above mean sea level, 
and the interglacial (?) beds extend fully 10 feet higher, indicating 
subsidence during this interglacial (?) time fully 30 feet below the 
present level. How much has been removed by erosion from the top of 
these beds can not be stated, but it is evident that not a little has been 
carried off. The clayey layers also suggest a subsidence sufficient to re- 
move the area from the immediate neighborhood of the rocky coast ; and 
the presence of boulders, some of which are fully two tons in weight, sug- 
gest sufficient depth for large masses of ice to float. It seems difficult to 
account for these transported fragments in water having a depth less than 
a hundred feet. 
Other deposits of the same kind may be expected in different parts of 
the Cape, and at levels considerably above this; but it is hardly probable 
that such extensive deposits will be found elsewhere, for those at Stage 
Fort have a peculiarly favorable situation for preservation, being situated 
on the lee side of a high range of hills which has protected them from 
removal. It is unfortunate that neither the wave action nor the excava- 
tions that were made reveal the base of these beds; and, therefore, it is 
not possible to state with certainty that these are interglacial rather than 
immediately preglacial beds, although there is, in fact, little reason to 
doubt their interglacial age. 
Note on the Elevated Beaches of Cape Ann, Mass. 
By J. B. Woopworrtu. 
A few years ago, under Professor Tarr’s guidance, I saw the elevated 
beaches which are described in his paper as lying on the seaward face of 
Eastern Point, Cape Ann. The notes which are here appended to his 
paper are therefore a direct outgrowth of his own work on these elevated 
' beaches. The discussion concerning the extension of the marine limit 
southward is, however, made independently. 
In the fall of 1902, in the company of Mr. J. W. Goldthwait of the 
Geological Department of Harvard University, I made a visit to Rock- 
port and sought for shore lines from the crest of Pigeon Hill at the cove 
1 T am indebted to Prof. G. D. Harris of Cornell University for the identifica- 
tion of these fossils. 
