192 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 
of that name, down te the existing sea level, and thence southward along 
the coast between Gap Head and Emerson Point. The results obtained, 
since they confirm and somewhat extend Professor Tarr’s observation in 
the same field in regard to the elevation of the beaches are here given, 
without, however, the precise elevations which it is hoped later to obtain, 
by levelling, upon the marine limit at Rockport. 
Pigeon Hill is a drumlin rising from an almost driftless area of granitic 
rocks. The hill was selected as a point of beginning the search for the 
marine limit, for the reason that if this hill failed to show beaches it 
seemed fair to conclude that the upper marine limit did not rise above 
the 100 foot contour-line which encircles the hill. The eastern and 
northern base of this drumlin is outlined by the 80 foot contour line, its 
western and southern base approximately by the 100 foot contour line. 
The northern and eastern slopes of this hill, which would have been ex- 
posed to heavy waves from the sea, show no scarps or lines of water 
action above the 100 foot line. On the southwest slope of the hill, 
there is a marked terrace between 140 and 145 feet, outer and inner 
edges respectively, by aneroid measurements. This terrace, however, 
lacks horizontality ; it rises either way toward the middle of the side of 
the hill. From its inner edge rises a healed scarp which, together with 
the terrace, indicates an alteration of the original lenticular contour of 
the drumlin. The non-horizontality of the terrace, and the failure of 
built margins in the form of gravel or sand bars, relegates the terrace to 
the group of little understood forms dependent on either glacial erosion 
or glacial stream action taking place during the disappearance of the ice- 
sheet from the vicinity. It certainly does not appear to the writer that 
the criteria of wave action are exhibited in this case. 
All along the shore, at least from 80 to 90 feet downward, there occur, 
bordering and between rock cliffs, sloping deposits of sand overlaid by 
coarse rubble, the ensemble of which is not that of glacial drift, but rather 
that of deposits making along a rocky coast beneath the water level. 
These deposits were noted and similarly interpreted by Shaler and Tarr 
in the report on the geology of Cape Ann published some years ago.’ 
Elevated Beach and Bar at Whale Cove. — The most perfectly formed 
and highest beach I have seen on Cape Ann is that noted by Professor 
Tarr, as lying immediately back of Whale Cove, between the shore and 
the public road. Traversing this portion of the coast from north to 
south, one comes, on approaching the vicinity of Whale Cove, to a gently 
1 N.S. Shaler: The Geology of Cape Ann. 9th Report of the Director of the 
U.S. Geological Survey, 1889, p. 573. 
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