Pat Draeger's request is a good one. There are quite a few books and monographs on the freshwater/terrestrial mollusks of particular river systems, states, or other geographic areas. Does anyone have a list of, say, the 50 or 100 most useful manuals (as opposed to the 1000's of specialized references in databases)? Here's one: Walker, Bryant, 1928, The terrestrial shell-bearing Mollusca of Alabama: Geological Survey of Alabama, Alabama Museum of Natural History, Museum Paper no. 8 (= University of Michigan, Museum of Zoology, Miscellaneous Publication no. 18), 180 p., 277 fig. Andrew K. Rindsberg Geological Survey of Alabama