Wire Crinolette or Bustled Hoop Cage

Crinolettes marked the mid-point between the cage crinoline and the bustle. Fashionable between 1867 and the mid 1870s, they were often composed of half hoops with extra loops of steel at the top to give more support. During the 1870's the bustle became a separate undergarment." see http://www.antiquedress.com/gallerylingerie.htm