alcide d’Orbigny (1842–1853) introduced numerous molluscan species in sagra’s work on the natural history of cuba. the exact publication dates of this important work have never been fully established. the date for the bivalve plates and associated captions had long been accepted as 1842, and d’Orbigny’s names were deemed senior to those of such near-contemporary authors as conrad (1846) and philippi (1846, 1847). however, rosenberg (pers. comm., may 2006; 2009) has established that d’Orbigny’s bivalve parts were published considerably later than 1842, perhaps as late as april 1853, and almost certainly no earlier than 1851. the date change of sagra’s work thus resulted in various priority issues involving numerous western atlantic species. mikkelsen & Bieler (2007) adopted an 1853 date and adjusted authorship and dates for 27 affected species occurring in the florida Keys. three of d’Orbigny’s (1853) well-established names of common western atlantic Lithophaga species, L. antillarum, L. bisulcata, and L. nigra, were thus threatened by earlier names introduced by philippi (1846, 1847). their synonymy had long been accepted in the western atlantic and mytilid literature (e.g., abbott, 1974; Kleemann, 1983; turner & Boss, 1962), but their priority had now become reversed. following priority in this case could have resulted in the unfortunate situation that Lithophaga antillarum (d’Orbigny, 1853) would become L. corrugata (philippi, 1846), whereas sympatric L. nigra (d’Orbigny, 1853) would be a junior synonym of the confusingly homonymous name L. antillarum (philippi, 1847). the latter situation could possibly have been avoided by resurrecting L. caribaea (philippi, 1847), which was published simultaneously with L. antillarum, but it still would replace commonly cited species names with ones that had fallen in disuse a very long time ago. mikkelsen & Bieler (2007: 413) invoked icZn (1999) article 23.9, reversal of precedence, to maintain prevailing usage of Lithophaga antillarum (d’Orbigny, 1853), introduced as LithodomalacOlOGia, 2010, 52(1): 181−182