120 G. EF. Wright—Glacial Era in Eastern North America, 
Art. XIII.—An attempt to calculate approximately the date of 
the Glacial era in Eastern North America, from the depth of 
sediment in one of the bowl-shaped depressions abounding in the 
Moraines and Kames of New England; by G. FREDERICK 
W RIGHT. 
[Read at the meeting of the American Association for the Advancement of 
Science, in Boston, Aug., 1880.] 
FoLLowIneé the suggestions of Mr. Clarence King, made to 
the writer four years since, r. Warren Upham traced a 
terminal moraine of the Continental ice sheet, through Cape 
od from east to west, connecting by the Elizabeth Islands 
with the back bone of Long Island at Montauk Point, an 
continuing to Brooklyn, N. Y. From this point across Staten 
have since been industriously marking their extent as they occur 
in the so-called Kettle Range in Wisconsin. The most satis- 
factory explanation of these “holes,” in my view, is that they 
*See Proceedings of the Boston Society of Natural History, vol. xix, pp. 60-63. 
+See Annual Reports of the Geological Survey of New Jersey for 1877 and 
1878. 
¢ For the observations upon which these statements are based, see Index of 
Geol. Report of N. H., vol. iii es,” communications of the author 10 
Proceedings of Bost. Soc. Nat. Hist., vol. xix, pp. 47-63, and xx, pp. 210-220, 
also a paper read by Professor Stone at the American Association for the Ad- 
vancement of Science in 1880. 
See Transactions of Am. Assoc. of Geol. and Nat. for 1841 and 1842, p. 191. 
See the Smithsonian Contributions to Knowledge for 1866. 
