Crosby. J 
512 
[May i,8 , 
including the Nantasket beds, 3000 feet in thickness, is newer than 
the Middle Cambrian beds and separated from them by an impor- 
tant unconformity, we are still wholly at sea as regards the precise 
horizon of the Hingham and Nantasket strata. We may, con- 
sistently with the facts so far examined, refer them to any horizon 
between the Middle Cambrian and the top of the Carboniferous. 
The ancient aspect of these rocks, however, and other consider- 
ations, seem to require us to assign them, provisionally, to a low r 
rather than a high position in the Paleozoic system ; and it is, per- 
haps, not impossible that they are as low T as the Upper Cambrian. 
Dr. J. S. Kingsley gave the results of his studies on the anatomy 
of Arnphiuma means. 
Prof. W. O. Crosby read a paper entitled u On some evi- 
dences of Tertiary deposits in the Boston Basin.” 
