1879.] 129 (Shaler. 
Jackson and Wyman I always associated together —in my 
heart they were one — ever faithful and true. 
Again [thank you, Mr. President, for your heartfelt tribute. 
The meeting then proceeded to the election of Associate 
Members, and the following candidates were elected : — Dr. 
C. A. Holt, Dr. Clifton E. Wing, Dr. A. N. Blodgett, Mr. 
Charles E. Pratt, Dr. John Dixwell, Mrs. A. L. Boardman, 
Miss M. A. Wilcox, Mrs. 8. T. Hooper, Mr. Roland Hay- 
ward, Miss E. D. Boardman. 
The following paper was read : 
NOTES ON CERTAIN EVIDENCES OF A GRADUAL PASSAGE FROM 
SEDIMENTARY TO VOLCANIC ROCKS SHOWN IN THE BRIGHTON 
DISTRICT OF Boston. By N. S. SHALER. 
In the following paper I desire to call attention to certain phe- 
nomena observable in the rocks locally known as the Brighton Amyg- 
daloids. It seems to me that these rocks afford evidences that the 
shales and conglomerates of the Roxbury series pass at certain points 
into an amygdaloidal trap which has been ejected through the over- 
lying beds. While I do not think that the evidence warrants a 
positive assertion of such a change, I do not see how the facts are 
consistent with any other hypothesis. 
The features to be observed in this very interesting district are so 
varied and important, that it will be necessary to give a rather ex- 
tended account of the rocks found there. The noteworthy features 
are connected with either of two questions, the history of the “ country 
rocks” or that making up the principal part of the rocks in this 
locality, and the history of the several local dykes which make their 
way through its mass. 
Even a cursory inspection of the country rock will show that it 
differs essentially from any of the ordinary rocks found in the vicin- 
ity of Boston. It is best seen at the pumping house quarry on 
Cambridge St. The outward appearance of the rock is quite peculiar, 
it is of a greenish red color when shown in fresh fractures, and 
though it oxydizes in the weather, retains a part of its peculiar hue 
even when covered by lichens; throughout the mass we find a great 
number of spots of a whitish color; a little close study will make it 
 ROCEEDINGS B. 8. N, H. — VOL. XX. 9 APRIL, 1879. 
