3o6 The American Geologist. ^^'^'- ^^°^- 
and sandy shale, which is derived from the sandstone overly- 
i'ng the highest hmestone in the region, indicates that that sand- 
stone was easily accessible to ordinary weathering, a condition 
which implies, again, that the lowan loess had not yet been 
deposited, since the loess, now effectually protects it from 
weathering and wash. 
That which overlies No. la and ic also varies. At the en- 
trance it is No. lb, which is an imperfectly water-assorted and 
water-laid pebbly, or even stony, loess, with loess-kindchen. 
In No. 4, at the entrance, the presence of standing water is 
plain. No. ib was deposited in flowing water, and in such 
abundance that it was not completely stratified. When No. 4 
was deposited the water was dammed, and the supply of solid 
matter had waned or temporarily ceased. At sixteen feet from 
the entrance (station B) the silt layer lies distinctly in a ma- 
terial (No. 2) which was not differentiated below that layer 
at the entrance, but a mass of shale from the Carboniferous 
here appears at a lower level, lying on No. ic in such a man- 
ner as to show that the shale is not in place. This shale has 
been taken, perhaps by some observers, as a stratum analogous 
in origin, though about two feet lower, to the silt layer (No. 
4). Its microscopic composition is so different from that of 
No. 4 as to exclude that idea. It is rather a part of the Car- 
boniferous shale that has slid from its parent mass and run 
over on No. ic. The somewhat disturbed condition of its lam- 
inae agrees with the hypothesis of such displacement. No. 4 
carries some quartz in rounded grains. No. 4a has none but ' 
consists of the elements of clay or geest, although its lamin- 
ation shows that it was w^ater-laid, and not land-formed as it 
exists at present. No. 4 carries a notable amount of carbon- 
ate of lime. No. 4a has none — or next to none. 
No. 4a, lying still on No. ic is continuous at twenty-five 
feet, but it soon becomes much broken toward the south and is 
reduced to a thin stratum at thirty feet, which continues, with 
disturbed lamination, to thirty-five feet. At fifty feet it is in- 
visible, like No. IC, and No. 2 apparently lies on the rock. In 
the midst of No. 2, at this place, however, are indefinite strat- 
ification lines, and No. 4 is again quite evident, about two and 
a half inches in thickness. No. 2 can be seen here, as at six- 
teen feet from the entrance, to pinch out westwardlv. Here 
