This file was derived from scanned images. With the exception oftwo typographical errors that were corrected, the original text andcopies of the included illustrations are presented. The smaller graphicshown as Figure 2 was processed to remove moire effects when viewed at smallersizes. Clicking on the Figures will allow the user to view a copy of theoriginal scanned image from which it was derived.

   Page 589, Paragraph 2: Tepalcatapec => Tepalcatepec

   Page 592, Paragraph 2: ground color => ground-color

In the original, Figure 1 had the notation X5 after the caption to let thereader know that the image was enlarged by a factor of five. As the illustrationin the HTML page will display at different sizes based on the resolution of themonitor and the size the browser window, it was decided to remove that notationand the viewer would derive the measurements from the body of the paper.