1879.] | 931 (Upham. 
This kind of topography surrounds our districts of lenticular hills 
excepting oceanward. Its width. at the north-east is fully ten miles, 
to Beverly, Danvers, and Middleton, in which another area of these 
smooth-topped, fertile drift-hills begins and thence extends twelve 
miles north-east through Wenham, Hamilton, Topsfield and Ipswich. 
The width of this group of lenticular hills is about eight miles, from 
the north-west part of Essex to Prospect and Hundslow hills in 
Rowley. ‘These, with Oldtown hills in Newbury, and Bald Hill in 
Boxford, are the outposts of this group at the north-west. The nar- 
row belt of nearly level land destitute of these accumulations, which 
lies next to the north-west, was first pointed out to me by Rev. G. 
F. Wright. Its width is about four miles, extending in a nearly 
straight line from the south-east corner of Andover to Newburyport; 
and it may be said to continue with about the same width along the 
coast through Salisbury and onward to Portsmouth, N. H., since this 
margin, excepting Boar’s Head, has none of these accumulations of 
till. Next to the north-west there succeeds a very fine development 
of the lenticular hills, averaging nearly ten miles in width, and reach- 
ing from Andover, Lawrence, and Methuen fully twenty-five miles 
north-easterly to Stratham, N. H. 
The distance to be crossed north-west, west, and south-west from 
the group of lenticular hills about Boston, to reach any similar devel- 
opment of them in the interior of the Staté has not been explored. 
The only statement that I can make is the negative one that I saw 
nothing of this kind in a journey from Lowell through Billerica, Bed- 
ford, Lexington, Waltham, West Newton, Needham, West Dedham, 
Norwood, Canton, Stoughton, Brockton, Abington, Rockland, Han- 
over, and Pembroke to Duxbury. They are known to be finely ex- 
hibited in the north-west part of Worcester; in Ayer and Groton; in 
the north-west part of Leominster; in Gardner; in Bernardston, 
Gill, and the north part of Montague; and in Amherst, South Had- 
ley, and the west edge of Granby. Some of these localities are 
probably portions of quite extensive areas similar to the group of 
these hills about Boston, or to their two belts in Essex county. It is 
to be noted, also, that sometimes a single lenticular hill, prominent 
and typical in form, is found in an area which nowhere else for many 
miles shows any similar masses of till. Thus Pigeon Hill in Rock- 
port, 195 feet high, is the only example of this class on Cape Ann. 
The distribution of these lenticular accumulations of till in New 
Hampshire has been quite thoroughly explored during the recent 
