McRoberts, Christopher A.Newell, Norman Dennis, 1909-Cooper, G. Arthur (Gustav Arthur), 1902-2005-10-062005-10-062001http://hdl.handle.net/2246/29285 p. : ill. ; 26 cm.Includes bibliographical references (p. 4-5).A distinctive myalinid bivalve Elversella rugosa new genus and species from the Middle Permian of West Texas is described. Elversella rugosa is characterized as being inequivalved, with a larger left valve covered rhythmically by coarse rugae and a smooth right valve that is somewhat smaller and less convex.137949 bytesapplication/pdfen-USQL1 .A436 no.3311, 2001Elversella rugosa.Bivalvia, Fossil -- Texas, West.Mollusks, Fossil -- Texas, West.Paleontology -- Permian -- Texas, West.Paleontology -- Texas, West.text