the bluff facing Little Piney, a mile below Gourd Creek, on the
opposite side, is a small, shallow cave with a low roof. Water cracks
on the floor show that it is sometimes flooded. No signs of use are
apparent.

* * * * *

On the hill over the cave just mentioned is a cairn, now destroyed.

[Illustration: PLATE 4 BONE AND ANTLER IMPLEMENTS FROM GOURD CREEK
CAVE, PHELPS COUNTY, MO.]

[Illustration: PLATE 5 SHELL AND FLINT OBJECTS FROM GOURD CREEK
CAVE]

ONYX CAVE (9)

Five miles southwest of Arlington, near the Boiling Spring in the
Gasconade, is Onyx Cave, so named because much workable stalagmite
occurs in it. It has a number of branches, some of which have been
explored for several hundred yards without coming to the end. The
entrance is 90 feet in width. A pile of talus at the front, lying
partly inside the cavern, reaches nearly to the roof; it has a height
of 26 to 28 feet above the level of the wet, muddy floor. Drainage is
through a small aperture in the north wall, whose outlet is not known.
Apparently the bedrock lies at a considerable depth; it is not visible
at any point in the steep ravine leading from the mouth of the cave to
the river. Formerly a large quantity of ashes covered much of the
inner slope of the talus, where it is protected from the weather; but
most of them have been hauled away to scatter over the fields. They
extend to a greater depth than any digging was ever carried. The
cavern has long been a refuge for stock, and this, with the trampling
of many visitors, has mingled all the superficial deposits, so that,
while ashes may be seen mixed with the debris, no ash beds are now to
be found.

There must be a very pronounced cavernous condition in this vicinity.
At a number of places, even extending to a distance of 2 miles from
Onyx Cave, the passage of a wagon produces a rumbling sound,
indicative of a cavity at no great depth. There are also many sink
holes, some closed, forming ponds, others with free openings. They are
so numerous that no one of them drains any considerable area. The
largest of these sinks measures from top to top of its slopes about
three-fourths of a mile long and half a mile wide. Around much of its
margin are vertical cliffs; there are few places where descent is
practicable. It is 300 feet deep, perhaps more; for when the
Gasconade, more than a mile away, is at flood stage the water from it,
backing through an underg