There is just a possibility that the great cycle may not be 54. If it is 53, the date must be 9 Muluc 12 Muan; if it is 55, the date must be 9 Muluc 2 Yaxkin; but the month number is clearly 7, which eliminates both these great cycle numbers. In order to find a great cycle with the numbers ?. 10. 2. 9. 1. 9, 9. ?. 7. ?, we should have to go back or forward from Great Cycle 54 at least five great cycles, which means over 25,000 years. This is such an enormous distance that it can practically be thrown out of consideration, and we may be well satisfied that the great cycle is really the same period in which almost every one of the other dates occurs, viz., 54. It will be interesting to compare this date with the first and last known dates of the other ruined cities of Chiapas and Guatemala. I give a list of these dates: Period of Earliest Latest Existence Piedras Negras 54.9. 8.10.6.16. 54.9.12. 2. 0.16. 3.11.12. 0. Copan 54.9. 6.10.0. 0.[1] 54.9.16.10. 0. 0. 10. 0. 0. 0. Quirigua 54.9.14.13.4.17.[2] 54.9.19.13. 0.12. 4.19.13.15. Yaxchilan 54.9. 0.19.2. 4.[3] Palenque 54.9. 4. 0.0. 0.[4] 54.9. 8. 9.13. 0. 4. 9.13. 0. [1] The date of Stela D given by Goodman as 54. 9. 5. 5. 0. 0. is almost surely 54. 9. 15. 5. 0. 0. [2] The dates 54. 13. 0. 0. 0. 0. and 54. 9. 1. 0. 0. 0. may well be traditional and not historical, and refer to a period lying far in the past. [3] This date on Lintel 22 is very clear, but as it is the only one which I have seen, I omit it in the following discussion. If historical, it is earlier than the earliest date of Quirigua except that of the normal date 54. 13. 0. 0. 0. 0., 4 Ahau 8 Cumhu. [4] The dates of the Temple of the Cross, Temple of the Sun, and Temple of the Foliated Cross are almost surely traditional. The date on the Palace Steps, given by Goodman as 55. 3. 18. 12. 15. 12., should undoubtedly be 54. 9. 8. 9. 13. 0. The above collation establishes the fact that Piedras Negras, Copan, Palenque, and Quirigua flourished contemporaneously for at least a part of their existence, for the last known date of Palenque is but 0. 11. 16, or less than one year before the first known date of Piedras Negras. This does not necessarily mean that Palenque was deserted at the establishment of Piedras Negras. Of course as investigation proceeds other inscriptions may be discovered which may give earlier or later dates, but it is interesting to note the relation between the known dates of all these cities. The date of Chichen Itza is later than any of the dates found above. The following list shows the distance from the earliest and latest dates of the ruined cities of Chiapas and Guatemala to the date recently found in Chichen Itza. DISTANCE OF THE EARLIEST AND LATEST DATES TO THE DATE OF CHICHEN ITZA