As _chi_, _chii_, signifies not only mouth, but also "limit, border, margin, shore," and especially the "skirt or loose edge of a garment," the relation of the symbol to the name of the day is obvious. It is used here for its phonetic value--_chi_. As _chii_ signifies "to bite, prick, to sting as a serpent," and _chan_ denotes "serpent," the true explanation of the name of the day would seem to be "the biting or stinging serpent." This will perhaps justify us in supposing that where the symbol is found on a serpent it must have reference to this characteristic. I had not observed when the above was written that Brasseur had expressed substantially the same view in regard to the origin of this symbol. THE SIXTH DAY Maya, _cimi_; Tzental, _tox_; Quiche-Cakchiquel, _camey_; Zapotec, _lana_; Nahuatl, _miquiztli_. Landa's symbol for this day is shown in plate LXV, 24. The usual form in the Codex Tro. and Cortesian Codex is given in LXV, 25; it is varied frequently by an extension of the line from the mouth, somewhat as in symbol 28 of the same plate, which is the usual form in the Dresden Codex. A variation of this is seen at 29, which seems to have given rise to the unusual form shown in 31. A radical variation is that given at 27. The symbol of the Death god, 26 and 30, is sometimes, though rarely, substituted as the symbol of this day. The closed or dead eye and prominent teeth, as seen in the usual forms, show very clearly that the symbol is simply a conventional representation of the naked skull. The form shown at 27, however, is more difficult to account for; reference to it will be made farther on.