No Mound-builder Chronology known — Maya Calendar — Landa on the Calendar — Maya Days — Maya Months — The Katun — The Ahau Katun or Great Cycle — The Maya System Adjusted to our Chronology — The Adjustment by Perez — Intercalary Days — The Nahua Calendar — The Sources — Divisions of Mexican Calendar — The Aztec Year — The Nemontemi — Aztec Months — Aztec Days — Nahua Ritual Calendar — Mexican Calendar Stone — Sources of Interpretation — History of the Stone — Interpretation of the Stone — Date of the Origin of the Calendar Stone — Date of the Nahua Migration — Analogies with the Nahua Calendar — Religious Analogies — Jewish Analogies — Deluge Traditions — Supposed Parallels in Jewish and Mexican History — Analogies of Doctrine — Analogies of Ceremonial Law — Yucatanic Trinity Myth — Mexican and Asiatic Analogies — Buddhism in the New World — Scandinavian Analogies — Mexican and Greek Analogies — Brasseur de Bourbourg’s Comparisons. _Chronology and Calendar Systems._—No tablet or relic of Mound-builder origin has yet been discovered, which can be said to give any clue to the system of chronology employed by that people. Several supposed calendar stones have been found, such, for instance, as the Cincinnati Tablet referred to in Chapter I, and the Tablet from Mississippi in the possession of Wm. Marshall Anderson, Esq., of Circleville, Ohio. However, their character is only a matter of conjecture, since no progress whatever has been made toward evolving any system from them. Farther south, on the soil where a higher civilization flourished, we meet with two calendar systems, which, while they have several points of resemblance, are quite distinct from each other. The first of these, the Maya, is probably the most ancient. Bishop Landa is our chief authority in this field, though Don Juan Pio Perez, a more recent writer, also familiar with the Maya language, has furnished us some material.[624] Bishop Landa informs us that the Mayas had a year of 365 days and 6 hours divided into months (a month being called a _U_) in two ways, first into months of thirty days each, and second, into eighteen months of twenty days each. As the Bishop makes no explanation of the former statement, we are unable to determine whether the months of thirty days each were employed in Yucatan prior to the conquest, or not, but we are rather inclined to the opinion that they were not. [Illustration: The Maya Days.]