This report introduces TRANSLUCENT  PROCEDURES as a new mechanism for  implementing behavioral abstractions. Like  an ordinary procedure, a translucent  procedure can be invoked, and thus provides  an obvious way to capture a BEHAVIOR.  Translucent procedures, like ordinary  procedures, can be manipulated as first-class  objects and combined using functional  composition. But unlike ordinary procedures,  translucent procedures have structure that  can be examined in well-specified non-destructive ways, without invoking the  procedure