Plate VII. Photographs of three fragments of flags showing casts of ice
crystals on the under side. All observations made on crystals of this
kind indicate local differences in the forms of ice crystals presumably
due to differences in the rate of freezing, in the texture of the mud
and probably in variations in water content of the mud. Some crystals in
the locality from which these specimens came, show pinnate secondary
growths. Specimens shown here are from near the upper part of the Eagle
Ford at a point about two miles north from the Chisos Mining Company's
property. Brewster County, Texas. Slightly reduced.
[Illustration: PLATE VII]