Daphniopsis ephemeralis sp. n. (Cladocera, Daphniidae): a new genus for North America

Abstract
The range of the cladoceran genus Daphniopsis is extended to North America with the description of a new species, Daphniopsis ephemeralis. Its morphological intermediacy suggests that Daphniopsis is ancestral to the genera Daphnia and Simocephalus. The genus appears to have a relict distribution and is restricted to marginal habitats.