Boston Meeting of the Geological Society. 221 
of Hudson bay, making the high ground north of lake Nipissing an 
island. The belief was expressed that these straits connected the great 
Laurentian lakes with the sea. Two maps accompanied the paper. 
■~>4. Extra -moraine drift between the Delaware and the Schuylkill. 
Edward H. Williams, Jr., Bethlehem, Pa. The author gave a sum- 
mary of his observations during the past year, describing the drift de- 
posits, and noting their order and variations as affected by the geolog- 
ical formations. He further considered the geographical conditions 
during the Glacial period, and the age of the extra-moraine drift with 
reference to the terminal moraine. All the glacial phenomena of east- 
ern Pennsylvania are regarded as very recent, with no evidence of an 
interglacial epoch. 
Evidence was presented showing that the fringe, or attenuated bor- 
der of the glacial deposits in this region, extends across the Lehigh 
river between the South mountain and Blue Ridge to within a few 
miles of Reading. During a portion of this early advance and retreat 
of the ice the mouth of the Lehigh was dammed by the glacial barrier,, 
and its drainage was across a col into the Schuylkill by Topton. At 
Bethlehem the rock bottom of the Lehigh valley is certainly fifty feet 
below its present bottom and the channel is rilled with debris of the 
earliest glacial advance, showing that on the Lehigh, as on the Alle- 
gheny, the preglacial rock erosion had reached its present extent. 
Many of the glacial pebbles from this area of the earliest ice advance 
are about as fresh and free from chemical changes due to weathering 
or leaching as any from north of the moraine. (This subject was also 
discussed by Prof. Williams in the January number of the American 
Journal of Science.) 
■'>■'>. The Interglacial series of German y. Prof. Dr. Alfred Jentzsch\ 
Konigsberg, Prussia. (Read by title.) The International Congress of 
Geologists at Washington in 1891, in discussing the stratigraphy of 
Quaternary deposits, reached no agreement on the question of an inter- 
glacial epoch in Europe. Some German geologists spoke for the exis- 
tence of an interglacial epoch, and others against it. Having been in 
explorations and study of the drift in northern Germany since 1872, I 
am much interested in this question, and must declare that quite surely 
northern Germany (with probably the greater part of the drift-bearing 
region in Europe) has had at least one interglacial epoch, and perhaps 
two. 
There are many difficulties, however, in the investigation of this sub- 
ject in Germany. Most of our provinces are poor in Pleistocene fossils, 
and in all the provinces these fossils are mostly found not in their origi- 
nal place, but in their second or third place of deposition; often the 
bones of great terrestrial mammals aie mixed with tiuviatile or marine 
molluscan shells. Our drift deposits have a thickness of 100 to 156 
meters (800 to 500 feet), and their stratigraphy is very complicated and 
variable within small areas. The deepest valleys of northern Germany 
have cut into the drift not more than 200 feet. We have not only two, 
but four, five, or more glacial deposits (boulder-clay) at the same local- 
ity, separated by stratified beds of gravel, sand and clay. Beds of the 
same character are often found at very different stratigraphic levels, 
and they are often disturbed by glacial pressure and other causes. For 
example, at one place in eastern Prussia we find Cretaceous and Terti- 
ary strata as a mass of 100 feet thickness on an area of 100.000 square 
feet, resting upon 100 feet of drift deposits, and covered by drift of 100 
feet thickness. 
Surveying and mapping Prussia on a scale 1 : 100,000. and in part 
1:25,000. and studying several hundred sections of artesian wells, we 
have found, between glacial boulder-clays, deposits of sands, clays, etc., 
with an entirelv consistent flora or fauna. We know layers of (/street. 
of Mjitilus. of Cardium, each of them containing thousands of shells of 
