The last (thirteenth) column of this series is not in a line with the others, but is found in the lower part of the right hand column of Plate 73, and in connection with it we find the red numerals II and XIV, denoting the difference between the columns, as is apparent from the additions here given: Years. Months. Days. 2 14 First or left hand column. 2 14 -- -- 5 8 Second column. 2 14 -- -- 8 2 Third column. 2 14 -- -- 10 16 Fourth column. 2 14 -- -- 13 10 Fifth column. 2 14 -- -- 16 4 Sixth column[TN-8] 2 14 -- -- 1 0 18 Seventh column. 2 14 -- -- -- 1 3 12 Eighth column. 2 14 -- -- -- 1 6 6 Ninth column. 2 14 -- -- -- 1 9 0 Tenth column. 2 14 -- -- -- 1 11 14 Eleventh column. 2 14 -- -- -- 1 14 8[338-1] Twelfth column.[TN-9] 2 14 -- -- -- 1 17 2 Thirteenth column. FOOTNOTES: [261-1] The work here referred to is entitled Die Mayahandschrift der Königlichen öffentlichen Bibliothek zu Dresden, herausgegeben von Prof. Dr. E. Förstemann, Hofrat und Oberbibliothekar. It contains, besides the chromolithographs of the 74 plates, an introduction published at Leipzig, 1880, 4^o. [269-1] A Study of the Manuscript Troano, by Cyrus Thomas, pp. 7-15. [272-1] This method will be adopted throughout this paper where figures containing numerals are introduced. [273-1] In the representations of lines and columns of the codex Roman numbers are necessarily used to distinguish the class of numerals, yet in the text, as in this case, the Arabic numbers will be used as most convenient. [273-2] Strictly speaking, the interval between 11 Men and 13 Oc is fourteen days, but throughout this paper, by "_interval between_" two days, is to be understood the number of days to be counted _from_ one _to and including_ the other. The one counted from is always _excluded_ and the one reached or with which the interval terminates is always _included_. [273-3] Science, p. 459, April 11, 1884.