This series begins in the middle of page 73 with the day IV Caban, the zero-point therefore being IV Eb. It then advances to the left across 28 members, until on page 71 it reaches the number 1820 = 5 years of 364 days = 7 Tonalamatls. From there on, 1820 itself is the difference, and the accompanying day therefore remains IV Eb. Then, in the two lowest sections of pages 71 and 70, the fourth multiple of 1820, _i.e._, 7280, is the third difference and thus the series advances to 15 × 7280 = 109,200 on page 71, after which on page 70 the omitted 8 × 7280 = 58,240 is written out. Close beside this number are the figures 1. 0. 12. 3. and a 0 below the latter, which was not successfully erased; this would be the number 7443 of which I can make nothing at all. The initial dates of the two series, IX Ix and IV Eb, are 138 days apart and reversely 122 days. 3. The Groups of Hieroglyphs. The transition, as it were, from the series to the large numbers is formed by a few groups of hieroglyphs. The first of these groups is at the top of pages 69-70; its first top line is completely effaced. The remainder I will designate by the following numbers:-- 1 2 5 6 9 13 3 4 7 8 10 14 11 15 12 16. The date IX Kan 12 Kayab, set down under 3 and 4 does not belong there but to the serpent below and will be discussed later. I take sign 1 to be that of a Bacab, 2 I do not understand and it is half obliterated; it seems to occur again on page 73 in the column to the extreme right. 3 and 7 are the elongated head _q_ with an unusual superfix, 4 and 8 correspond with one another, but I cannot explain them. 5, 10 and 14 denote the beginning, 6, 11 and 15, the end. 9 and 13 both designate the 8th day of the month Kayab and over them IV Ahau must have been set down twice. 12 and 16 are two heads of gods, 12 is probably D's with the sign for west and 16, B's with that of the east. On page 70, in the middle of the third and fourth columns, the day IX Ix occurs twice. In one case it ought to have been IV Eb and the scribe has really changed the IX to IV, but he omitted changing the Ix to Eb. Directly below these dates we find the second group, consisting of two rows of four hieroglyphs. I think these eight hieroglyphs can be interpreted as follows:-- 1) 13 Pax 2) 20 Pop or 25 Cumhu 3) VIII Ahau 4) 13 Yaxkin 5) 10 Muan 6) 37,960 7) 20 8) 1 Zec. The following is to be noted in this connection:-- 3 is really set down X Ahau, but an VIII is written above the Ahau by way of correction. The day VIII Ahau will presently prove to be important. 6, a compound of Imix and the superfix denoting multiplication, is the sign for 18,980, and its prefix seems to me to denote duplication. We have long known how important the 37,960 = 146 × 260 = 104 × 365 is, and, if my theory is correct, we shall see directly that it occurs again here.