This series deals quite clearly with synodical revolutions of the moon. The entire series records 11,960 days, although the last number in the upper series is only 11,958, a condition that will be explained later. Four hundred and five synodical revolutions of the moon consume, according to modern astronomy, 11,959.889 days, or about .11 of a day less than the length of the series. Moreover, the difference groups 148, 177, and 178 which separate the upper numbers, also record synodical months, for five months consume 147.65 days, and six months 177.18 days. In fact the correspondence between the numbers in the series and the synodical months is so exact, that nowhere does an error of more than one day exist.[2] [2] Bowditch, 1910, pp. 222, 223. Unfortunately the ideal arrangement given above is not followed exactly. The actual series as it occurs in the manuscript appears to be full of errors, a list of which will be found in Table I, p. 4. Most of these errors have been pointed out and discussed repeatedly.[3] There still exists some doubt as to which numbers should be considered errors of the original writer and which should be taken at their face value. For this reason the errors are here discussed in some detail, for in some cases the errors, or supposed errors, affect theories in regard to the series. [3] By Dr. Förstemann, Dr. Thomas, and Mr. Bowditch. TABLE I APPARENT IRREGULARITIES Lower number series: Absence of all 178’s that occur in upper series. Column 23. Presence of 178. Column 26. 177 instead of 148. Column 50. 157 “ “ 177. Upper number series: Column 1. 157 instead of 177. Column 2. 353 “ “ 354. Column 4. 674 “ “ 679. Column 10. 1748 “ “ 1742. Column 12. 2016 “ “ 2096. Column 14. 3142. “ “ 2422. Column 15. 2598 “ “ 2599. Column 24. 4164 “ “ 4163. Day series: Column 5. 4 Chicchan instead of 11 Chicchan. Column 11. Omission of 1/2 _tonalamatl_. Column 17. 1 Ik instead of 2 Ik. Column 36. 4 Ben instead of 4 Ahau. Column 47. 10 Eznab instead of 11 Eznab. Column 49. 11 Kan instead of 12 Kan. Columns: Columns 6 and 7 are reversed. Columns 58 and 59 are reversed. Totals: Upper number series totals 11,958 instead of 11,960. Day series totals 11,959 instead of 11,960.