Annual Meeting.] 510 [May'. 
and tills gentleman has taken to Xew York nearly all the 
material requii-ed for this investigation. This co-operation puts 
the work on a more satisfactory basis, and relieves Professor 
Crosby of the ^lost irksome part of it, for which also he feels 
that he has no qualifications. 
Professor Crosby has also made a satisfactory arrangement for 
co-operation with the Metropolitan Pai'k Commissioners in the 
preparation of a topographic map of the Metropolitan district, 
Avhich will serve as a suitable basis for the representation of the 
geology. In following out this line of investigation the same 
gentleman has prepared a chapter entitled "Xotes on the 
geology of the Reservation," which has been published in the 
" Annual Report of the Commissioners for 1895." In consider- 
ation of his services in giving them this account of the geolog}^ 
of the Reservations, the Commissioners incorporated such topo- 
grapic features in their new map of these localities as were 
necessary to adapt it more perfectly to our geological work. 
Besides the extra office work which this involved, they also 
appropriated $350 to cover the cost of field work to collect the 
additional data requu-ed. 
This arrangement will very greatly expedite the geological 
work on the Boston Basin, in so far as it will save considerable 
outlay in time and money devoted to topography and to the con- 
struction of maps. 
Estimates have been obtained for the engraving and printing 
of the second sheet of the general map of the Boston Basin ; and 
a friend of science has generously donated a sum sufficient to 
defray the cost of this sheet, which embraces the area to be 
covered by parts 3 and 4. The third part of the work has been 
temporarily delayed by Professor Crosby's co-operation with the 
Pai"k Commissioners, and by the new discoveries that have been 
mentioned above, and by the necessity of waiting for Mr. White 
to finish his microscopic examinations of the rocks. 
A new vista has also opened in the history of the surface or 
glacial geology in this region. It has become evident that about 
all of the sandplains of the South Shore district may be regarded 
as deltas formed by glacial rivers at different stages in the evolu- 
tion of a glacial lake which stretched along the front of the ice- 
I 
