EL. W. Hilgard on the Quaternary of Mississippi. 325 
the denuding agencies, it is difficult to understand why there 
should be any terraces of the kind described—why they, with 
their easily denuded material, should not have attained a gradu- 
al slope of surface toward the channel, instead of being as level 
as the first bottom itself. To my mind, the era represented by 
the second bottoms appears as distinctly marked as that of the 
Bluff formation, and as much entitled to a distinctive name re- 
Cognized everywhere. The difficulty of the study of the qua- 
ternary formations, sufficiently great of itself, is greatly enhanced 
by the want of such terms, and the failure on the part of many 
observers, hitherto, even to attempt to parallelize in different lo- 
calities the formations more recent than the Loess. am not 
se alent the Yellow Loam, also, is as distinctly in 
O. en 
why should not the “Loam period ” and that of the “ River ter- 
Taces” be as distinctly recognized among American geologists as 
those of the Drift and Loess? Even if these divisions were not 
Tecognizable outside of the Mississippi valley, they would serve 
. purpose for the study of not a small portion of the earth’s 
urlace,? : 
Since writing the above, I have received from Prof. Winchell 
4 copy of his interesting remarks on the subject of the apparent 
horthward transportation of large boulder deposits in the Drift 
of Michigan. While appreciating the force of his reasoning as 
Al my observations in this state and such 
That is precisely the direction indicated, as above stated, by the 
trend of the eastern pebble band of the Orange Sand delta, 
University of Mississippi, December, 1865. 
* The epoch here referred to as deserving a name is that designated the Cham- 
are in Dana’s Mineralogy po") from deposits of the era upon the borders of 
Champlain called the Champlain formation by Prof. C. H. Hitchcock.—Ens, 
