The Collaborative International Dictionary of English v.0.48:

Cheiropterygium \Chei*rop`te*ryg"i*um\, n.; pl.
   Cheiropterygia. [NL., fr. Gr. chei`r hand + pte`ryx,
   pte`rygos wing, fin.] (Anat.)
   The typical pentadactyloid limb of the higher vertebrates.
   [1913 Webster]