THE Museum’s fourth expedition to Piedras Negras, Guatemala, was in the field for three months last spring. Excavations were confined to test trenching in three mounds, with results of considerable value in reconstructing the architectural history of the city. Studies of several mounds as found, without excavation, proved highly informative and resulted, among other things, in the identification of a new type of palace. Indeed, during the season the expedition identified four types of buildings previously unknown at Piedras Negras, and of these three included features heretofore unknown in the Maya area: the wooden-roofed portico, the roof combining stone vaulting and flat beam-supported concrete roof, and the altar niche specially ventilated to carry off the smoke of the altar fire.
A two weeks trip to the famous neighboring city of Yaxchilan provided a large amount of architectural data on the buildings there. A very interesting site, previously unknown to science, was visited on the return journey, and named El Cayo II.