figure interlaced with a triangle or another trapezium, and occurs usually as a head-ornament. A series of its manifestations is illustrated in Fig. 86. Here the earlier monuments where it appears are represented by Copan (a), Menché (c), Piedras Negras (b) (for Naranjo see Pl. XXIII; p. 302); in Yucatan it occurs at Uxmal (g); on the fringe of the Mexican valley, at Tehuacan (d) and Xochicalco (e); in the valley itself, at Tenango (k), Xico (m), and, to the north, at Tulan (h); and in the Huaxtec country, at Teayo (f). The sign moreover bears a close analogy to that by which the Aztec expressed the period of a year (l), and the triangular portion of it is exactly similar to a conventional sun-ray. It is perhaps worth noting that at Copan, Uxmal and Teayo it 1s associated with the head of the rain-god. The significance of this symbol is obscure, but its presence over so large an area can hardly be due to coincidence.
I think it is obvious from what has gone before, that the Aztec may be left out of account in any consideration of the source of such similarities as may be traced in Mexican and Mayan culture. They were admittedly late immigrants, from the north, into the Mexican valley, and were, at the time of their arrival, in a very low state of culture; moreover, as stated above, it is the pre-Aztec remains which show the closest relation to the Mayan. The question therefore resolves itself into an enquiry which was the earlier, the culture exemplified in the ruins of the central Maya area, or that which gave birth to the pre-Aztec remains at such early valley sites as Tulan, Teotihuacan and Azcapotzalco? Any solution of this question must also fix the relation of Oaxaca to both, and account for the Huaxtec, a Maya-speaking people whose sculptures bear no trace of a hieroglyphic script. Included in this question is that of the origin of the calendar. Let me say at once
