for this day in the codices (fig. 17, _u_). The signs for the day Cib in the inscriptions and the codices (figs. 16, _z_, and 17, _v_, _w_), respectively, are very dissimilar. Indeed, the form for Cib (fig. 17, _v_) in the codices resembles more closely the sign for the day Caban (fig. 16, _a'_, _b'_) than it does the form for Cib in the inscriptions (see fig. 16, _z_). The only element common to both is the line paralleling the upper part of the glyph () and the short vertical lines connecting it with the outline at the top. The glyphs for the day Caban in both figures 16, _a'_, _b'_, and 17, _x_, _y_, show a satisfactory resemblance to each other. The forms for the day Eznab are also practically identical (see figs. 16, _c'_, and 17, _z_, _a'_). The forms for the day Cauac, on the other hand, are very dissimilar; compare figures 16, _d'_, and 17, _b'_. The only point of resemblance between the two seems to be the element which appears in the eye of the former and at the lower left-hand side of the latter. The last of the twenty Maya days, and by {41} far the most important, since it is found in both the codices and the inscriptions more frequently than all of the others combined, is Ahau (see figs. 16, _e'-k'_, and 17, _c'_, _d'_). The latter form is the only one found in the codices, and is identical with _e'_, _f'_, figure 16, the usual sign for this day in the inscriptions. The variants in figure 16, _g'-k_', appear on some of the monuments, and because of the great importance of this day Ahau it is necessary to keep all of them in mind. These examples of the glyphs, which stand for the twenty Maya days, are in each case as typical as possible. The student must remember, however, that many variations occur, which often render the correct identification of a form difficult. As explained in the preceding chapter, such variations are due not only to individual peculiarities of style, careless drawing, and actual error, but also to the physical dissimilarities of materials on which they are portrayed, as the stone of the monuments and the fiber paper of the codices; consequently, such differences may be regarded as unessential. The ability to identify variants differing from those shown in figures 16 and 17 will come only through experience and familiarity with the glyphs themselves. The student should constantly bear in mind, however, that almost every Maya glyph, the signs for the days included, has an _essential element_ peculiar to it, and the discovery of such elements will greatly facilitate his study of Maya writing.