48. Figure showing possible derivation of the sign for 0 in the inscriptions 93 49. Special sign for 0 used exclusively as a month coefficient 94 50. Examples of the use of bar and dot numerals with period, day, or month signs 95 51. Head-variant numerals 1 to 7, inclusive 97 52. Head-variant numerals 8 to 13, inclusive 98 53. Head-variant numerals 14 to 19, inclusive, and 0 99 54. A sign for 0, used also to express the idea "ending" or "end of" in Period-ending dates 102 55. Examples of the use of head-variant numerals with period, day, or month signs 104 56. Examples of the first method of numeration, used almost exclusively in the inscriptions 105 57. Signs for the cycle showing coefficients above 13 110 58. Part of the inscription on Stela N, Copan, showing a number composed of six periods 115 59. Part of the inscription in the Temple of the Inscriptions, Palenque, showing a number composed of seven periods 115 60. Part of the inscription on Stela 10, Tikal (probably an Initial Series), showing a number composed of eight periods 115 61. Signs for the great cycle and the great-great cycle 118 62. Glyphs showing misplacement of the kin coefficient or elimination of a period glyph 128 63. Examples of the second method of numeration, used exclusively in the codices 131 64. Figure showing the use of the "minus" or "backward" sign in the codices 137 65. Sign for the "month indicator" 153 66. Diagram showing the method of designating particular glyphs in a text 156 67. Signs representing the hotun, or 5-tun, period 166 68. Initial Series showing bar and dot numerals and head-variant period glyphs 174 69. Initial Series showing head-variant numerals and period glyphs 183 70. Initial Series showing head-variant numerals and period glyphs 186 71. Initial Series on Stela H, Quirigua 193 72. The tun, uinal, and kin coefficients on Stela H, Quirigua 194 73. The Initial Series on the Tuxtla Statuette, the oldest