The Collaborative International Dictionary of English v.0.48:

Tenonian \Te*no"ni*an\, a. (Anat.)
   Discovered or described by M. Tenon, a French anatomist.
   [1913 Webster]

   Tenonian capsule (Anat.), a lymphatic space inclosed by a
      delicate membrane or fascia (the fascia of Tenon) between
      the eyeball and the fat of the orbit; -- called also
      capsule of Tenon.
      [1913 Webster]