The Collaborative International Dictionary of English v.0.48:

Anostraca \Anostraca\ prop. n.
   An order of small aquatic crustaceans lacking a carapace,
   including the fairy shrimps and the brine shrimps.

   Syn: order Anostraca.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Anostraca
    n 1: small aquatic crustaceans lacking a carapace: fairy
         shrimps; brine shrimps [syn: Anostraca, order
         Anostraca]