Review of Recent Geological Literature 381 
pletely occupy the low land between the ridges. With this ex- 
planation of the phenomena observed there is still the anomal- 
ous fact that in its retreat the ice left practically no deposits on 
the area in question, while in all the surrounding district evi- 
dences of glacial deposits are abundant, even though the thick- 
ness of these deposits is frequently slight. 
This area is several miles without (north of) the recognized 
limit of the Lake Superior ic^ lobe, and it seems hardly possible 
to account for its peculiar features as due to interlobal condi- 
tions. Nor is the idea of a driftless area so far removed from 
the southern limit of glacial action one which seems probable, 
although the driftless region of southwestern Wisconsin is far 
within the drift boundary. But when the small size of the area 
under discussion and. the thickness of the ice in the surround- 
ing rep'ion are considered, the improbability, if not the im- 
possibility, of this area having remained free from ice becomes 
apparent. The highest hills, some 500 feet above the general 
level, are glaciated to their tops and there are excellent reasons 
for believing that the ice rose far above these hills. With such 
conditions it is, to say the least, very improbable that a small 
area only twelve miles long and eight miles wide should not 
have been covered with ice. 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
Some Glacial Wash- Plains of Southern New England. By J, B. 
WooDWORTH. ( From the Bulletin of the Essex Institute, Salem, Mass., 
vol. xxix, pp. 71-119, with six sketch maps and a section; published 
July, i8qq.) 
After the description of wash-plains formed in front of existing 
glaciers, the general characters and classification of the stratified 'drift 
deposits of the continental ice-sheet are stated. From their relation to 
the ice-margin at the time of their formation, four classes of these de- 
posits are recognized: i. Frontal moraine terraces, with an ice-contact 
slope, charged with till and boulders, a true morainal deposit; 2. 
Frontal terraces, like the preceding but lacking the till-coating along 
the ice contact; 3. Esker-fans, small plains of gravel and sand built at 
the mouth of subglacial tunnels and channels in the ice, associated with 
an esker or esker-like chain of deposits made within the area of the 
