The sign for the month Yaxkin is identical in both figures 19, _k_, _l_, and 20, _i_, _j_. The sign for the month Mol in figures 19, _m_, _n_, and 20, _k_ exhibits the same close similarity. The forms for the month Chen in figures 19, _o_, _p_, and 20, _l_, _m_, on the other hand, bear only a slight resemblance to each other. The forms for the months Yax (figs. 19, _q_, _r_, and 20, _n_), Zac (figs. 19, _s_, _t_, and 20, _o_), and Ceh (figs. 19, _u_, _v_, and {51} 20, _p_) are again identical in each case. The signs for the next month, Mac, however, are entirely dissimilar, the form commonly found in the inscriptions (fig. 19, _w_) bearing absolutely no resemblance to that shown in figure 20, _q_, _r_, the only form for this month in the codices. The very unusual variant (fig. 19, _x_), from Stela 25 at Piedras Negras is perhaps a trifle nearer the form found in the codices. The flattened oval in the main part of the variant is somewhat like the upper part of the glyph in figure 20, _q_. The essential element of the glyph for the month Mac, so far as the inscriptions are concerned, is the element () found as the superfix in both _w_ and _x_, figure 19. The sign for the month Kankin (figs. 19, _y_, _z_, and 20, _s_, _t_) and the signs for the month Muan (figs. 19, _a'_, _b'_, and 20, _u_, _v_) show only a general similarity. The signs for the last three months of the year, Pax (figs. 19, _c'_, and 20, _w_), Kayab (figs. 19, _d'-f'_, and 20, _x_, _y_), and Cumhu (figs. 19, _g'_, _h'_, and 20, _z_, _a'_, _b'_) in the inscriptions and codices, respectively, are practically identical. The closing division of the year, the five days of the xma kaba kin, called Uayeb, is represented by essentially the same glyph in both the inscriptions and the codices. Compare figure 19, _i'_, with figure 20, _c'_. It will be seen from the foregoing comparison that on the whole the glyphs for the months in the inscriptions are similar to the corresponding forms in the codices, and that such variations as are found may readily be accounted for by the fact that the codices and the inscriptions probably not only emanate from different parts of the Maya territory but also date from different periods. The student who wishes to decipher Maya writing is strongly urged to memorize the signs for the days and months given in figures 16, 17, 19, and 20, since his progress will depend largely on his ability to recognize these glyphs when he encounters them in the texts. THE CALENDAR ROUND, OR 18980-DAY PERIOD