The head for 9 occurs more frequently than all of the others with the exception of the zero head, because the great majority of all Initial Series record dates which fell after the completion of Cycle 9, but before the completion of Cycle 10. Consequently, 9 is the coefficient attached to the cycle glyph in almost all Initial Series.[[69]] The head for 9 is shown in figure [52], g-l. It has for its essential characteristic the dots on the lower cheek or around the mouth (*
). Sometimes these occur in a circle or again irregularly. Occasionally, as in j-l, the 9 head has a beard, though this is not a constant element as are the dots, which appear also in the head for 19. Compare figure [53], r.
The head for 10 (fig. [52], m-r) is extremely important since its essential element, the fleshless lower jaw (*
), stands for the numerical value 10, in composition with the heads for 3, 4, 5, 6, 7, 8, and 9, to form the heads for 13, 14, 15, 16, 17, 18, and 19, respectively. The 10 head is clearly the fleshless skull, having the truncated nose and fleshless jaws (see fig. [52], m-p). The fleshless lower jaw is shown in profile in all cases but one—Zoömorph B at Quirigua (see r of the same figure). Here a full front view of a 10 head is shown in which the fleshless jaw extends clear across the lower part of the head, an interesting confirmation of the fact that this characteristic is the essential element of the head for 10.
The head for 11 (fig. [52], s) has been found only once in the inscriptions, namely, on Lintel 2 at Piedras Negras; hence comparative data are lacking for the determination of its essential element. This head has no fleshless lower jaw and consequently would seem, therefore, not to be built up of the heads for 1 and 10.
Similarly, the head for 12 (fig. [52], t-v) has no fleshless lower jaw, and consequently can not be composed of the heads for 10 and 2. It is to be noted, however, that all three of the faces are of the same type, even though their essential characteristic has not yet been determined.
The head for 13 is shown in figure [52], w-b'. Only the first of these forms, w, however, is built on the 10 + 3 basis. Here we see the characteristic 3 head with its banded headdress or fillet (compare h and i, fig. [51]), to which has been added the essential element of the 10 head, the fleshless lower jaw, the combination of the two giving the head for 13. The other form for 13 seems to be a special character, and not a composition of the essential elements of the heads for 3 and 10, as in the preceding example. This form of the 13 head (fig. [52], x-b') is grotesque. It seems to be characterized by its long pendulous nose surmounted by a curl (*