A curious chapter in several of the books, especially those of Kaua and Mani, is that on the thirteen _ahau katuns_, or epochs of the greater cycle of the Mayas. This cycle embraced thirteen periods, which, as I have before remarked, are computed by some at twenty years each, by others at twenty-four years each. Each of these _katuns_ was presided over by a chief or king, that being the meaning of the word _ahau_. The books above-mentioned give both the name and the portrait, drawn and colored by the rude hand of the native artist, of each of these kings, and they suggest several interesting analogies. They are, in the first place, identical, with one exception, with those on an ancient native painting, an engraving of which is given by Father Cogolludo in his "History of Yucatan," and explained by him as the representation of an occurrence which took place after the Spaniards arrived in the peninsula. Evidently, the native in whose hands the worthy father found it, fearing that he partook of the fanaticism which had led the missionaries to the destruction of so many records of the nation, deceived him as to its purport, and gave him an explanation which imported to the scroll the character of a harmless history. The one exception is the last or thirteenth chief. Cogolludo appends to this the name of an Indian who probably did fall a victim to his friendship to the Spaniards. This name, as a sort of guarantee for the rest of his story, the native scribe inserted in place of the genuine one. The peculiarity of the figure is that it has an arrow or dagger driven into its eye. Not only is this mentioned by Cogolludo's informant, but it is represented in the paintings in both the "Books of Chilan Balam" above noted, and also, by a fortunate coincidence, in one of the calendar-pages of the "_Codex Troano_," plate xxiii., in a remarkable cartouche, which, from a wholly independent course of reasoning, was some time since identified by my esteemed correspondent, Professor Cyrus Thomas, of Illinois, as a cartouche of one of the _ahau katuns_, and probably of the last of them. It gives me much pleasure to add such conclusive proof of the sagacity of his supposition.[15-*] [Illustration] [Illustration: SIGNS OF THE DAYS. The first column on the right is from Landa. The second is from the "_Codex Troano_." The remaining four are from the Book of Chilan Balam of Kaua.] There is other evidence to show that the engraving in Cogolludo is a relic of the purest ancient Maya symbolism,--one of the most interesting which have been preserved to us; but to enter upon its explanation in this connection would be too far from my present topic.