were angular, but never showed any trace of dressing, except, perhaps,
by fracture. The interstices between the main stones were filled
in with fragments to make the walls solid. Neither here nor in any
other stone walls that we saw were there any indications of any mud
or other plaster coating on the stones.

On top of a knoll in the mountains south of Nacori, at an elevation
of 4,800 feet, well preserved remains of this kind of dwelling were
seen. The house, consisting of but one room about ten feet square,
was built of large blocks of lava. The largest of these were eighteen
inches long, and about half as thick, and as wide. The walls measured
about three feet in height and one foot and a half in thickness, and
there was a sufficient amount of fallen stone debris near-by to admit
of the walls having been once four or five feet high. There were the
traces of a doorway in the northwest corner of the building. Numerous
fragments of coarse pottery were scattered around, some gray and some
red, but without any decoration, except a fine slip coating on the
red fragments.

In the Sierra de Nacori, on the summit of a steep knoll, and at an
elevation of about 6,500 feet, we found two huts of such laid-up
walls. The rough felsite blocks of which they were composed were
surprisingly large, considering the diminutive size of the cabins. We
measured the largest block and found it to be two feet long, ten inches
wide, and eight inches thick. There were many others almost as large
as this one. But there was only one tier of stones left complete in
place. Although there were well-built trincheras in all the surrounding
arroyos, there were no traces of either tools or pottery on that hill.

On the western slope of the Sierra de Nacori, on top of another knoll,