This stop is listed only by Irwin, who says: A 4' manual and 8' pedal Flute, usually of open wood construction, designde to augment the tones of the unison flues. The loudness of its fundamental and the prominence of its overtones are both voiced to sound well with other stops of the division. The pedal rank is larger, louder, and more prominent than the manual's. The form os this stop may be with a beveled lip, like the Clarabella or Major Open Flute, or inverted lip, like the Melodia or Hohlflöte. Audsley mentions it in passing, with no definition other than its octave pitch.
Osiris contains over two dozen examples, all but one at 4' pitch: