The type specimen of J. Hall (1847) in the American Museum of Natural History (New York) and specimens from the type area in the Schuchert Brachiopod Collection in the Peabody Museum of Natural History, Yale University (New Haven), have been investigated for comparative purposes. Repository of illustrated specimens and abbreviations.-American Museum of Natural History, New York, particularly the J. Hall Collection (AMNH); Peabody Museum of Natural History, Yale University, New Haven, CT, particularly the Schuchert Brachiopod Collection (YPM); Tartu University, Estonia (TUG); Central Scientific-Research Geological Exploration Museum named after F. N. Chernyshev, St. Petersburg, Russia (CNIGR); and National Museum of Wales, Cardiff, UK (NMW). ACKNOWLEDGMENTS We thank L. Hints (Institute of Geology, TTU), L. Alberstadt (Vanderbilt University), F. Alvarez (University of Oviedo), M. Rubel (University of Tartu), and L. Popov (NMGW) for helpful discussions and critical comments on the manuscript, B. M. Hussaini (AMNH) for access to brachiopod collections and assistance during M.Z.'s visit to AMNH.