Reference edition:

Censorini De die natali liber ad Q. Caerellium; accedit anonymi cuiusdam epitoma disciplinarum (Fragmentum Censorini), edidit N. Sallmann, Leipzig 1983 (Bibliotheca Scriptorum graecorum et romanorum teubneriana).

The manuscripts that transmit Censorinus’ De die natali include in the final part —without any attempt at continuity—a brief, anonymous, and possibly mutilated epitome known as the Fragmentum Censorini that treats various disciplines in fifteen chapters (for arguments that the text is fragmentary, see Cristante, Mastrosa).  Cristante briefly discusses the relationship between the two works in a review of Rapisarda’s 1991 Pàtron edition of the De die natali, since it—unlike Sallmann’s 1983 Teubner edition—does not contain the Fragmentum.  The importance of comparing these two texts is evident both from their manuscript tradition and from their contents: since the Fragmentum seems to have been coupled with the De die natali since at least the 6^th c., it must also have been present in the archetype from which the exemplars available to us are descended (R. H. Rouse – R. M. Thompson): the oldest of these are C (Coloniensis Latinus 166), of the 7^th/8^th c.; V (Vaticanus Latinus Palatinus 1588); and P (Vaticanus Latinus 4929), of the 9^th c.

Scholars have also commented on the great homogeneity of content that is of a scientific and encyclopedic nature.  Censorinus 1.6 claims to have drawn the information he used in composing the short work from scientific treatises (ex philologis commentariis), but the epitome—or at least what has come down to us—treats only the disciplines of the quadrivium, focusing on astronomy, geography, geometry, and music (which also includes meter).  The section dedicated to music is a further point of contact between the two works: the second half of the Fragmentum is concerned with this topic (chapters 9-15, which are much longer in comparison with the earlier ones), while Pythagorean musical theory also receives careful treatment at De die natali 10-13 (Bouvet).

The compendiary nature of the Fragmentum and the fact that it is transmitted in manuscripts containing texts associated with education (treatises of rhetoric, commentaries on Cicero, Julius Paris’ epitome of Valerius Maximus) allow us to infer that the short work was used for didactic purposes; its grouping with the De die natali further suggests that this latter text was likewise used in schools (Cristante).  Censorinus is, moreover, identified as a grammaticus and as the author of two works that have not come down to us: an Ars grammatica and a De accentibus.  In short, the epitome schematizes and recapitulates the disciplines that one must know in order to understand the Del die natali; “together they serve as evidence for the didactic practices of imperial schools and […] the survival of scientific education and a doxographical tradition” (Cristante).  [S. Musso; tr. C. L. Caterine].