Phyllopoda

Phyllopoda 

an order of the subclass Branchiopoda, comprising the most primitive of the modern crustaceans. In contrast to branchiopods of the order Anostraca, phyllopods have a carapace or a bivalve shell that has formed from it. The compound eyes are sessile, not stalked as in the Anostraca. The Phyllopoda, like the Anostraca, comprise three suborders: the Notostraca, Conchostraca, and Cladocera. There are more than 600 widely distributed species, dwelling primarily in fresh waters. Only the Cladocera include some sea species; the Notostraca and Conchostraca inhabit spring ponds and other temporary bodies of water. Some zoologists combine the Notostraca and Conchostraca into the separate order Euphylloda and treat the Cladocera as a special order.