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1888-1891 photograph showing corner sculpture of open serpent jaws with human head protruding (cf. recent photo at right).       
1888-1891 photograph by Henry N. Sweet as a member of the Thompson/Peabody expedition; scanned from 35mm slide of original photograph at Dumbarton Oaks. Reproduced Courtesy of the Peabody Museum of Archaeology and Ethnology, Harvard University.