Upham.] 
132 
[Dec. 19, 
the least speck visible to the eye. In one place, by no means ex- 
ceptional, near the base of this cliff, the number of these particles 
and specks of shells, ground up in the process of formation and de- 
position of the till, averaged not less than forty to each square foot 
of the section. This locality, too, is the only one where the shell 
fragments were observed in the yellowish upper part of the till 
nearer to the original surface than a depth of ten or fifteen feet. Here 
small fragments of shells, an inch or less in length, were found in 
considerable numbers to a height of only one or two feet below the 
sod forming the surface of the hill and brink of the cliff. The high- 
est were in a Soft and crumbling condition, aud those found thence 
downward in the yellow till showed a gradation to the hard and 
strong character of the shell fragments in the dark blue till. These 
observations indicate that the transported and broken fossils were 
probably originally as plentiful in the upper as in the lower part of 
this drumlin, and perhaps likewise of all the others, but that they 
have been mostly dissolved out of the upper part by infiltrating 
water. 
Great Head is a typical drumlin, the eastern third of which has 
been eroded by the sea, forming a cliff about 100 feet high. This 
consists of ordinary till, yellowish above and dark bluish below, 
from its top to within twenty or fifteen feet above mean tide, where 
its base, exposed a few years ago during the construction of a rail- 
road, was observed by Mr. Dodge to be a somewhat arched bed of 
“loose, clean, rather fine gravel filled with small fragments of 
shells. Venus mercenaria and Cardium Islandicum ( ?) were the 
only shells identifiable with any reasonable degree of certainty 
among the fragments.” This was seen to be overlain by till, which 
exhibited traces of an imperfect stratification close to their line of 
separation but above is entirety unstratified. The till contains frag- 
ments of shells up to a height of about eighty feet. A similar struct- 
ure of the drumlins of Third and Fourth cliffs on the east shore of 
Scituate, each of which includes extensive anticlinal beds of modi- 
fied drift, overlain by a thick covering of till, and in Fourth cliff 
also seen to be underlain by till and interbedded with it, promises 
to contribute much to our knowledge of the mode of deposition of 
these remarkable drift hills, as I shall hope to show in a future 
paper. 
Following the nomenclature and arrangement of the catalogue of 
