(1) FREY, D.G. 1988. Separation of Pleuroxus laevis Sars, 1861 from two resembling species in North America: Pleuroxus straminius Birge, 1879 and Pleuroxus chiangi n. sp. (Cladocera, Chydoridae). Can. J. Zool. 66: 2534-2563.