I would say it is a mourning bonnet dating from the 1890's. A lovely woman's bonnet from the later Victorian era in a black soft tulle mesh silk fabric adorned with ruched ruffles and accented with silk and velvet ribbons, bows and ties, all in black.  The wonderful silk padded lining is also silk.

Length of the back of the bonnet would be just below the nape of the neck.  It is 28" around the face area from side to side.  13" across the back of the neck, from side to side.  

Condition of this lady's beautiful old bonnet is so so very nice. Only a small hole here and there. So carefully cared for.  I can't begin to tell you as you have to see for yourself.  Even the chin ties are very nice with on a couple little holes.