t a
guide is frequently unable to find a cave unless its position is
plainly visible from some well-defined spot. The winding valleys and
the multitude of ravines sometimes bewilder even those living among
them.

A few definitions of terms, or explanations of statements in the
report, may prevent misunderstanding.

"Refuse," "signs," "indications," "evidence," referring to habitation
or occupancy, mean mussel shells; animal bones; burned or worked
stones; broken pottery; wrought objects of bone or shell; flint
implements, chips, or spalls; ashes; charcoal; in short, the material
ordinarily found on the site of an Indian village, some or all of
which are to be seen where the caverns have been used for shelter.

"Daylight" or "in daylight" is the greatest distance within the
entrance to a cavern at which common print may be easily read or the
nature of small objects lying on the floor determined with certainty.

"Drip rock," "cave rock," or "cave formation" are general terms
including stalactite or stalagmite; also deposits of similar origin
coating the walls. Not all of these may be present in the same cavern.

"Roof dust" is a substance, literally "lime sand," produced by the
superficial disintegration of the roof or walls. This process is
greatly accelerated where lichen or rock moss has gained a root hold
on the stone. Roof dust in a dry cavern is the equivalent of
stalagmite in a wet one.

"Cave earth" is the loose, loamy material usually found in the front
chambers of large caverns. It is made up of roof dust, sand, and silt
washed from the interior, outside dust and vegetable matter blown in
by the wind, with minute amounts of clay or soil carried in by
animals.

"Gravel" in a cavern is seldom noticeably water-worn, but is the
angular debris resulting from the continued fragmentation of chert
nodules released by erosion of the limestone.

A "rock shelter," or "shelter cave," is a room or recess formed by
atmospheric erosion in the face, usually at the base, of a cliff. The
depth from front to back, under the projecting or overhanging
unremoved bedrock above, is generally much less than the length as
measured along the face of the bluff. They are nearly always dry, more
or less protected from storms, and when of suitable size and in a
favorable location were much used as camping places. They are rather
rare in limestone formations but frequent in massive sandstone.

"House mounds" are small, low piles of