The Collaborative International Dictionary of English v.0.48:

Exuviae \Ex*u"vi*[ae]\, n. pl. [L., fr. exuere to draw out or
   off, to pull off.]
   1. (Zo["o]l.) Cast skins, shells, or coverings of animals;
      any parts of animals which are shed or cast off, as the
      skins of snakes, the shells of lobsters, etc.
      [1913 Webster]

   2. (Geol.) The fossil shells and other remains which animals
      have left in the strata of the earth.
      [1913 Webster]

WordNet (r) 3.0 (2006):

exuviae
    n 1: cast-off skins or coverings of various organisms during
         ecdysis