The salt flats of west Texas are large ephemeral lakes, Pleistocene to Holocene in age. The evaporite material in these lakes represents the sedimentary history of the lake and the surrounding area. Recently, a fossil assemblage was found in the sediments of this deposit. This assemblage includes four species of ostracoda (Limnocvthere staplini, Candona rawsoni, Candona thomasi, and Cvprideis salbrosa), two species of gastropoda, (Amnicola decepta, and Amnicola pilsbrvi), and discovery is significant because this assemblage has not been previously reported, and it provides an opportunity to reconstruct part of the physical and chemical environment of the salt flats during a portion of its history. Autecological comparison of these species indicate that they lived in a shallow, alkaline, brackish water environment. The known paleoclimate of the area, and the sedimentology support this interpretation. / Department of Geology