1864. | Geology and Paleontology. 481 
terraces. ‘These escarpments, though hundreds of miles in length, 
are all roughly parallel to one another, and appear to have a common 
origin, The author considers that they are all due to glacial action 
in some form or another, and he adopts Mr. Jamieson’s explanation of 
the origin of the Parallel Roads of Glen Roy to account for the 
formation of the beaches and terraces of North America, The 
probability of their not being due to the action of the sea is increased 
by a very curious fact, namely, that in the state of Wisconsin there is 
an area of more than 3,000 square miles in extent, which is perfectly 
barren of drift and terraces, and in which no organic remains have 
been found other than those of Paleozoic rocks, with the exception of 
those of land-animals and plants. The inference drawn from these 
facts by the geologist who explored the region—Professor Whitney— 
was that this area has not been submerged since the Upper Silurian 
period, If this be so, of course the terraces, beaches, and drift in the 
neighbouring regions could not have been the result of the action of 
the sea, but must have been produced by a local cause ; and the same 
inference will hold good if it can be shown that the driftless area of 
Wisconsin has remained above the level of the sea ever since the 
close of the Pliocene period, a conclusion much more likely to be 
accepted than the larger inference of Professor Whitney. The re- 
markable abundance of erratics in the regions described renders their 
absence in the “ Driftless Area” still more singular, although in the 
valley of the Moisie they appear to be entirely wanting at less heights 
above the sea than 1,000 feet. 
Professor Hind endeavours to explain all the phenomena, including 
beaches, terraces, escarpments, lakes, striw, &c., as well as the forced 
arrangement of blocks of limestone (at an angle of about 45°) in 
Boulder-clay, by reference to ice-action, either direct or indirect ; 
and he also reminds us that he promulgated the view that the great 
lakes were excavated by ice in the year 1859. His views regarding 
the particular form of ice-action by means of which lake-basins have 
been excavated appear rather improbable; he supposes that anchor- 
ice, formed in the rapid streams issuing from glaciers, may have begun 
the excavation by floating masses of rock from their beds to the 
surface, and that the glacier itself may have afterwards enlarged the 
depression. It is easy to see that the formation and action of anchor- 
ice could not be continued very long, as the process is self-destroying ; 
for in proportion as the depression produced became larger and 
deeper, the quantity of anchor-ice formed would become less, that is, 
granting the author’s own premises ; and it seems scarcely probable 
that a glacier, if it can excavate a lake-basin, should do so at or near 
its termination, or where it is on the point of melting, its force being 
there reduced to a minimum. 
4. The chief object of the paper “ On the Permian Rocks of the 
North-west of England, and their Extension into Scotland,’ by Sir 
R. I. Murchison and Professor Harkness, is to prove that certain 
masses of red sandstone in the north-west of England belong to the 
Permian formation and not to the 'l'rias. By this alteration in the 
classification of these rocks, which is necessarily founded on strati- 
