500 SL (GIDIGES, JHE SIMUL BIN INS 
inclined to the west; they form part of the great Mesozoic- 
Tertiary basin of northern France, whose ‘“‘oldland”’ is outlined 
by the Ardennes on the north, the Vosges on the east, and the 
Central plateau on the south. 
About eighty miles east of Paris, the Marne, one of the chief 
branches of the Seine, flows across the calcareous lowland of the 
Champagne, past Chalons and near Rheims, and enters the 
arenaceous upland of the Ile de France. The valley of the river 
then abruptly changes from a broad flood plain, lying openly on 
the rolling low country, to a comparatively narrow trench 
enclosed by steep slopes from the upland; but as the upland 
loses height to the west with the dip of the Tertiary sandstones 
which maintain it, the depth of the trench decreases. About 
forty miles south of the passage of the Marne, the Aube-Seine 
traverses the same calcareous lowland and enters the same 
arenaceous upland. Between the two rivers, and to a certain 
distance further north and southwest, runs the strong escarpment 
or znface of the Ile de France. Its slope is very largely covered 
with vineyards, which supply the great wine-cellars of Epernay 
and Rheims. The prospect from the crest of the inface is a most 
delightful one. Considering all these features together, it 
appears that this group of sheets presents a striking example of 
an ancient coastal plain, whose oldland lay to the eastward, 
whose strata dip gently westward, and whose existing form 
exhibits a well-developed longitudinal arrangement of topo- 
graphical features, in contrast to the transverse arrangement 
frequently observed. It may be noted by the way that the 
Brandywine, Prince Frederick, Wicomico and Leonardtown 
(Maryland) sheets of the United States Geological Survey illus- 
trate the form of an almost maturely dissected coastal plain with 
transverse features, slightly complicated at present by standing 
y 
“up to its ankles” in the Atlantic, and thus drowning its valley 
floors into long narrow arms of the sea. On the other hand, the 
inner part of the coastal plain of Alabama is an excellent 
example of a plain having longitudinal features, parallel to its 
shore line; the Chunnenugga ridge corresponding to the upland 
