Annual Meeting.] 
10 
[May 7, 
or four years have been labelled by Mr. Henshaw. A number of 
invertebrates have also been identified and labelled by the same 
gentleman. 
Teachers’ School of Science. 
The liberal action of the Trustee of the Lowell fund in defraying 
the expenses of the lessons and also in granting the use of Hunt- 
ington Hall has enabled the society to continue its efforts to ex- 
tend the benefit of instruction in this school to teachers in all the 
neighboring towns as well as to those living in Boston. The agents 
who acted in the adjoining towns and villages last year continued 
their kind offices, distributing and receiving applications and also 
tickets according to the plan which was described in a former re- 
port. The Superintendent of Public Schools in this city has also 
kindly assisted us by attending to similar technical details in Boston. 
Prof. W. O. Crosby has given ten lessons upon the Physical His- 
tory of the Boston Basin. The comprehensive course given last 
winter formed a suitable preparation for this year’s work. The 
principal object of this second series of lessons was to apply the 
principles taught by the first series to a thorough and detailed study 
of the physical history of the Boston Basin. Each important lo- 
cality or natural division of the Boston Basin formed the subject 
of a separate lesson, in which its structural features and the more 
important events of its history were presented as fully as the time 
permitted. Special attention was given to tracing the relations of 
the existing surface features of each district to its geological struct- 
ure, thus connecting the physical geography and geology of the re- 
gion. The course was freely illustrated by specimens, maps and 
diagrams ; and at each lecture a very full printed synopsis of the 
preceding lecture was distributed to the audience. 
The following abstract of the last lecture is in large part a sum- 
ming up of the whole course and is of interest as showing the na- 
ture of these lectures, the amount of original investigation upon 
which they were based, and the results reached by Professor Cros- 
by in his studies of the Boston Basin. 
TENTH LECTURE. 
Geological History of the Boston Basin. 
Having in the preceding lessons gone systematically over the 
Boston Basin and made a somewhat detailed study of the phenomena 
