Review of Recent Geological Literature. 329 
land northward. He recognizes three stages or epochs of glacial ad- 
vance, divided by intervals of recession : and he refers the deposition of 
the stratified clays mainly to the closing part of the second glacial epoch. 
This appears to correspond with the lowan glaciation in the Mississippi 
basin, with its attendant deposition of the greater part of the Missis- 
sippi valley loess. 
Marbutand Woodworth, in the third chapter of this paper, give many 
details of the clays about Boston, where they estimate that the marine 
submergence at the principal stage of clay deposition exceeded 100 feet. 
Sections of thick stratified clays are found in a few places overlain by 
till : and in Somerville such later till is amassed in drumlins. The 
bedded clays, referred to the time of glacial retreat at the beginning of 
the last interglacial stage or epoch, are believed to have been covered 
and largely eroded by a subsequent great ice advance which reached 
south to the terminal moraines of Nantucket and Cape Cod, Martha's 
Vineyard, and Block and Long islands. 
This paper is noteworthy as the first to claim for the Atlantic seaboard 
a series of glacial advances and recessions similar to those of the interior 
of the United States, with a very long interval between the earliest and 
the latest glaciation. The conclusion that the great recession of the 
ice-sheet accompanied with the deposition of the stratified clays, froiii 
near the farthest limit of glaciation back at least to Boston, was follow- 
ed by a re-advance to almost the same limit as before, is not so fully 
supported as the greater lowan glacial re advance, which indeed appar- 
ently belonged to an earlier time in the Glacial period. No remains of 
an interglacial soil and forest are discovered in New England, nor east- 
ward of Ohio, like those which farther west lie beneath the lowan till. 
\v. u. 
The Moraines of the Missouri Coteau and their Attendant Deposits. 
By James Edward Todd. (Bulletin No. 1-44, U. S. Geol. Survey, pp. 71, 
with 21 plates and three figures in the text. 1896.) The chief theme of 
this bulletin is a detailed description of the looped and complex series 
of marginal moraines which were accumulated on the borders of the Da- 
kota lobe of the ice-sheet during its retreat from the Missouri river on 
the boundary between Nebraska and South Dakota, northward to the 
Northern Pacific railroad. Four stages of the glacial recession are mark- 
ed by concentrically parallel belts of very knolly and bouldery drift, 
which, however, in some parts of their courses interlock and merge one 
with another. Lake Dakota, which occupied the valley of the James 
river for some time after the ice-lobe was melted away, is shovvn to have 
attained a length of 170 miles, a maximum width of 25 miles, and a depth 
of about 150 feet. Numerous plates, reproduced from photographs, pre- 
sent very clearly the various types of scenery and drift formations of the 
jirairie plains and hills of the Dakotas east of the Missouri river, w. u. 
Glacial Observations in the Unianak District, Greenland. By George 
H. Bakton. (Report B of the Scientific Work of the Bostcm Party on 
the Sixth Peary Expedition to Greenland, Technology Quarterly, vol. x. 
