Keywords: Lepyrium showalteri shell.jpg Lepyrium showalteri George Washington Tryon Jr 1870 http //www archive org/details/monographoffresh00tryo A monograph of the fresh-water univalve mollusca of the United States Turbidae Physadae Philadelphia Pl 16 fig 2 1870 published by George Washington Tryon Jr public domain PD-old-100 Lithoglyphidae |