Wright.] 
242 
[Feb. iS, 
N. H., I have found a portion of an osar covered with a deposit 
of boulders and till which may have fallen from a melting ice- 
roof, though another interpretation seems to me preferable. 1 
Weighing the opinions and arguments which refer the trans- 
portation of our modified drift respectively to superglacial and to 
subglacial streams, I confidently give my decision in favor of the 
former. But this dissent from Professors Shaler and Davis must 
be tempered by a grateful acknowledgment of indebtedness to 
the second of these authors for his very instructive study of the 
stratification of our sand and gravel plains, showing the rapid 
rate of 1 heir deposition in comparison with the contemporaneous 
recession of the adjacent ice. According to either of the expla- 
nations of the back-set beds of these plains, as given by Professor 
Davis and by the present writer, they occupy the space from 
which the ice retreated during the time of deposition of the much 
greater volume of top-set and fore-set beds. At certain times 
and places, therefore, in the Champlain ejmch of glacial retreat, 
sedimentation was exceptionally rapid. When this took place 
around peninsulas or islands of ice, left as remnants of the dis- 
solving front of the ice-sheet, their disappearance gave us lakes 
and ponds enclosed by modified drift. 
This paper was discussed by the President, and by Professor 
Niles, and Mr. Barton. The speaker last named mentioned the 
occurrence of series of eskers or osars which he has traced both 
southward and northward from the gravel and sand plain enclos- 
ing Lake Walden. 
The President presented the following communication : — 
ADDITIONAL NOTES CONCERNING THE NAMPA 
IMAGE. 
BY G. F. WEIGHT. 
At the meeting of the Society for Jan. 1st, 1890, I completed 
the presentation of evidence so far as I had then collected it, 
bearing upon the genuineness of a small clay image, one inch and 
Geology of N. H., vol. iii, p. 159, 
