the
pressure to which the trunks had been subjected. They all belong to the
genus Araucarioxylon, and probably are of the same species. The two
from Lithodendron Valley are absolutely identical in structure, and
that from Fort Wingate is referred provisionally to the same species,
although it lacks some of the essential characteristics. Some eight
specimens were collected near Estherville, la., consisting of
fragments, completely chal-cedonized and stained a yellowish-brown
color, of which the largest were only 6 inches in length and 4 in
diameter. They were regarded by Prof. W J McGee as belonging to the
Cretaceous age. Although found in the drift, the Cretaceous strata,
from which it was originally derived, formerly extended over
contiguous parts of Minnesota and were largely removed by glacial
erosion during the Quaternary period. Specimens from Martin County,
Minn., could not be distinguished from those obtained in Emmet County,
la. Near Barrel Springs, in the Green River basin of Wyoming, Samuel F.
Emmons, of the United States Geological Survey, found a silicified
tree, the structure of which was admirably preserved, being filled in,
wherever the wood had decomposed, with crystals of quartz. It was from
3 to 4 feet in diameter, and was exposed for 18 feet; both ends were
imbedded in the soft earth of the Bridger beds of the Eocene formation.
Agatized
wood in large quantities, consisting of trees from 12 to 35 feet in
length and from 18 inches to 2 feet in diameter, has been found near
Calistoga in Napa County, Cal. Specimens of agatized and opalized wood
from the vicinity of Gallatin, Mont., were collected by Dr. Albert C.
Peale and George P. Merrill, and later by Frank H. Knowlton, of the
United States Geological Survey, who described it as white, banded and
streaked with black and yellowish-brown. Although badly decomposed, it
appeared to be dicotyledonous. From several specimens, camera-drawings
were secured that resembled known forms of Betuli-nium and Quercinium,
or representations of our modern beech and oak. Of specimens from the
Yellowstone Park, examined similarly, some were found to be
dicotyledonous and some coniferous, the latter mostly Cupressinoxylon,
or fossil Sequoia.
The amount of silicified wood found in Apache County,.
