Eulimnadia ovilunata and E. ovisimilis, new species of clam shrimps (Crustacea, Branchiopoda, Spinicaudata) from South America

Abstract

Tv^o new species of the clam shrimp genus Eulimnadia are de­ scribed from South America. Eulimnadia ovilunala, a species with spherical eggs bearing circular crater-like depressions, is described from Argentina, and Eulimnadia ovisimilis, a species with stout cylindrical eggs that closely resemble those of the North American species E. texana (Packard), is described from Paraguay. Species of the clam shrimp genus Eulim­ nadia Packard (sometimes considered syn­ onymous with Limnadia; see Webb & Bell 1979) in North, Central, and South America were the subject of two recent reviews by Belk (1989) and Martin (1989). Although many traditionally employed characters were shown by those authors to be variable and unreliable, an additional character, morphology of the external egg shell, ap­ pears to be conservative and species-spe­ cific. In his comparison of described Central and South American species, Martin (1989) examined two South America forms that did not conform to any known species. Those species, described from samples in the collections of Denton Belk in San An­ tonio, Texas, were referred to by Martin as Eulimnadia sp. A (DB 305) and Eulimna­ dia sp. B (DB 632). In this paper we describe the two new species.