Acknowledgements:

Many thanks to José H. Leal, Director of The Bailey-Matthews Shell Museum, and G. Thomas Watters, Curator of Molluscs, The Ohio State University Museum of Biological Diversity, for loan of their collections of Glycimerids, and to Dan Teven for providing specimens of the difficult to obtain G. undata. And, thanks to those others who reviewed their collections in an attempt to reply to my appeal on Conch-L and provide specimens of G. undata.