If anyone dreamed he was a Falseface, it was only necessary to signify his dream to the proper person, and give a feast, to be at once initiated; and so any one dreaming that he had ceased to be a False face, had but to make known his dream and give a similar entertainment to effect his exodus. In no other way could a membership be acquired or surrendered. Upon all occasions on which the members appeared in character they wore False-faces … the masks being diversified in color, style and configuration, but all agreeing in their equally hideous appearance. The members were all males save one, who was a female and the Mistress of the Band. She was called Ga-go-sa Ho-nun-nas-tase-ta, or keeper of the Falsefaces; and not only had charge of the regalia of the band, but was the only organ of communication with the members, for their names continued unknown.
The prime motive in the establishment of this organization was to propitiate those demons called Falsefaces, and among other good results to arrest pestilence and disease.
Report on the Fabrics, Inventions, Implements and Utensils of the Iroquois, Made to the Regents of the University, January 22, 1851 by Lewis H. Morgan (reprinted in Elisabeth Tooker, Lewis H. Morgan on Iroquois Material Culture, 1994)