304 The American Geologist. m^^- ^^^"-■ 
No. 12. From the same pit as No. ii, at five and a half feet be- 
low the surface; similar to No. ii. 
No. 13. Fine yellow clay, putty-like, from a pit dug ten rods south 
of Concannon's house on the west side of the tributary ravine, about 
thirty feet above the floor of the tunnel, about four feet below the sur- 
face. 
No. 14. More coarse and gravelly clay from the same pit at five 
feet below the surface. 
No. 15. Loess-kindchen, white quartz pebble and rotted limestone 
pebbles, from the same pit. 
No. 16. Much lighter yellow clay, from the bottom of the same pit 
as No. 14. 
No. 17. Rotted, brownish spot, having the form of a pebble, from 
the wall of the Fowke tunnel. 
No. 18. Land shells, fragments of small bones, a small tooth, and 
bits of crinoid stems, from limy loess (No. 3) in the main tunnel. 
No. I. The principle element in No. i appears to be irreg- 
nlar, small shreds and scales of kaolin. The substance does 
not, as a whole, appear scaly, but it is unctuous and very fine. 
Its color is of gray or reddish, according to the distribution of 
iron oxide. A few isolated scales are large enough to show a 
biaxial optic axis as interference figure in comergent light. 
Its refactive index is markedly higher than that of the balsam. 
In numerous instances the larger scales appear to be charged 
with bubbles and ferruginous impurieies. Between crossed 
nicols this kaolin is almost entirely dark, brightening up a little 
when the converging lens is turned on. Besides kaolin and the 
coloring material, a ver}^ rare angular small quartz grain can 
be seen. No. i seems to be almost a pure clay. 
No. 2, when washed and decanted shows numerous grains 
of qttartz and feldspar, occasional hornblende, biotite and mag- 
netite. 
No. 3 is similar, or identical, with No. 2. 
No. 4, while consisting largely of small composite grains 
from No. i, contains a considerable amount of quartz, the 
grains of which are usually rounded. 
No. 4a is microscopically indistinguishable from No. i. 
No. 5, when its grains are isolated, is found to consist 
largely of drift materials, mostly angular quartz, but with a 
liberal amount of kaolin in agglomerated scales and composite 
grains. 
No. 6, which is the upper part of No. 8, is evidently 
sandy and iron-stained. On washing, in order to separate the 
