given with Mercier's page numbers, are taken from W.M. Lindsay's Teubner edition (Leipzig, 1903); all references are to the initial line of a lemma. Fragments of Republican drama are cited from the third edition of O. Ribbeck, Scaenicae Romanorum Poesis Fragmenta (Leipzig, 1897-8), sometimes with references to more recent editions of individual authors. This paper will be followed in a subsequent issue of this journal by a series of notes and conjectures proceeding from its conclusions, under the title 'Some fragments of Republican drama from Nonius Marcellus' sources 26, 27 and 28', to which I here occasionally refer as 'Some fragments'. I am grateful to the Journal's referee and its editor for helpful suggestions on these papers. This research was supported by the Social Sciences and Humanities Research Council of Canada. 2 W.M. Lindsay, Nonius Marcellus' Dictionary of Republican Latin (Oxford, 1901). References to earlier studies of Nonius' methods can be had from H.D. Jocelyn, Gnomon 41 (1969), 43-4. 3 Subsequent corrections of Lindsay's description of Nonius' methods have not altered its basic claims; see W. Strzelecki, 'Ein Beitrag zur Quellenbenutzung des Nonius', in J. Irmscher et al., Aus der altertumswissenschaftlichen Arbeit Volkspolens (Berlin, 1959), 81-90, at 81-2; and most notably D.C. White, 'The method of composition and sources of Nonius Marcellus', Studi Noniani 8 (1980), 111-211. 4 W.M. Lindsay, 'De fragmentis scriptorum apud Nonium seruatis', RhM 57 (1902), 196-204 identified the instances in which the principle applies. Attempts to expand Lindsay's list of literary works that Nonius excerpted himself (see e.g. L. Rychlewska, 'De Nonii comoediarum Naeuianarum notitia',