Upham.} Dan {April 2, 
geological survey, and a map of both hills and slopes of this class is 
presented in the atlas, including also their development in north- 
eastern Massachusetts as far south as to Ipswich. This map shows 
that they occur quite abundantly upon three areas which vary from ~ 
five to twenty miles in width, and extend twenty-five or thirty miles 
from north to south, or from north-east to south-west. The most 
eastern of these areas lies mainly in Essex county, Mass., and has 
already been mentioned. The middle belt reaches from Goffstown 
and Weare, N. H., south-west to New Ipswich and Rindge, and 
crosses the state line into Ashby and Ashburnham, Mass. After an 
interruption of a few miles, these hills are again found abundantly in 
Gardner. A third belt extends through the west part of Cheshire 
county, but appears to be quite distinct from the area mentioned in 
Bernardston, Gill, and Montague. These tracts are separated by 
others of equal or greater width, upon which scarcely any lenticular 
hills are found. Farther north in New Hampshire and in York 
county, Me., lenticular accumulations of till are sprinkled more spar- 
ingly, with no traces of system, being numerous in some localities, 
but generally rare or absent. 
The geological reports of Massachusetts and New York gave such 
descriptions of Plymouth county and Cape Cod, and of Long Island, 
that these areas have been explored with the expectation of finding 
lenticular hills; but no accumulations like those which we have been 
describing under this name were seen. These journeys, however, 
have been by no means unfruitful; for they have enabled us to deter- 
mine the extent and character of the terminal moraines which occur 
there, and have convinced us that the lenticular hills are very differ- 
ent from the deposits that were heaped at the margin of the ice- 
sheet. These terminal moraines form distinctly continuous, narrow 
series of hills, which extend hundreds of miles; instead of which, the 
lenticular hills, though abundant upon certain areas and entirely 
wanting elsewhere, never are found in any such connected series. 
The smoothly oval or lenticular shape of the latter is also in marked 
contrast with the very irregular and broken contour of the morainic 
hills. 
Respecting the very unequal distribution of our lenticular masses 
of till, or why they should abound in the vicinity of Boston, and in 
several belts at the north and north-west, while they are very rare or 
entirely absent upon intervening areas, we can offer no explanation. 
This grouping does not appear to have been caused by differences in 
