206 The American Geoloijisf. March, 1894 
The velocity of the current was estimated at about three miles per 
hour. In the St. Louis and other rivers the same phenomena were 
observed. While travelling in Nova Scotia, in April, 1893, beautiful 
single-current ripple-marks were seen at Weymouth. They were on a 
large scale, so as to be conspicuous at some distance, forming parallel 
ridges across the shallow bed of a fjord and perpendicular to its shores. 
The currents in this fjord were governed by the strong tides of the bay 
of Fundy. 
In the article in the January Geologist, the extent of the layers in 
the false bedding was stated to be often "ten or twelve feet.'' Since 
they make an angle of about forty degrees with the bottom, this means 
a thickness of about eight feet of sediment, which was deposited 
while the current and the rate of deposition remained nearly constant. 
In the cut at Cloquet, there is certainly as much; and in the cut at 
Mount Hope there is a thickness of 5 to 6 feet at least. But this thick- 
ness of sediment, in glacial deposits, does not necessarily imply more 
than a short time for its formation. Professor Davis* has made this 
clear in the case of delta sand-plains, showing, by the relation of fore- 
set to back-set beds, how very swift was the formation of these deltas 
as compared with the melting back of the ice-front. Again, the forma- 
tion of kettle-holes by the melting of ice-blocks which had become 
partly or perhaps sometimes wholly buried in the rapidly accumulating 
sediments has been discussed by several writers. The melting of these 
ice-blocks, however, was in its turn so rapid that, according to Mr. J. 
B. Woodworth, after the subsidence of the waters which deposited the 
sediments it furnished "streams of considerable volume, though possi- 
bly of short duration."| 
Feb. 6, 1894. ' J. E. Spckr. 
PERSONAL AND SCIENTIFIC NEWS. 
Prof. J. W. Spencer visited Cuba in January, with a view 
to follow up the question of terrestrial oscillations recently 
discussed by him before the Geological Society of America. 
The Circular of the Cornell University Summer School 
for 1894 announces courses by Prof. Ralph S. Tarr on physical 
geography, dynamical geology, and economic geology. 
In the Transactions of the Kansas Academy of Science, 
at its twenty-fourth ami twenty-fifth annual meetings, pub- 
lished in 1893, Prof. S. W. Williston records an interesting 
food habit of plesiosaurs. In a number of instances well 
■worn siliceous pebbles were found among the ribs of plesio- 
saurs in such a way as to suggest that they had been in the 
stomach of the animal. The pebbles were mineralogically 
♦Bulletin, Geol. Soc. Am., vol. i, p. 199. 
tAMERK'AN Geolooist, November, 1893, p. 279. 
