Daniél Kiss’s Catullus Online: An Online Repertory of Conjectures on Catullus is a wonderful resource, which I have found complete and accurate in whatever I have checked, but rather depressing viewed at length. Only six of the sixty-eight lines in the first four-plus poems (1-4 plus the fragment 2b) have no variants or conjectures listed, and some have a dozen or more.
The first four-line passage with no variants or conjectures listed is 11.17-20, the fifth stanza of Catullus’ Sapphic farewell to Lesbia:(1)
cum suis vivat valeatque moechis,
quos simul complexa tenet trecentos,
nullum amans vere, sed identidem omnium
ilia rumpens; 20
It seems to me that this would be wittier with one tiny change: distributive trecenos for trecentos in 18. That would mean that Lesbia entertains three hundred partners at a time, and imply that there are hundreds more moechi in town for other evenings if she tires of these, or wears them out beyond recovery.
One complication must be mentioned. There is a similar passage in which Catullus himself threatens to act much as Lesbia is (he says) acting here (37.6-8):(2)
an, continenter quod sedetis insulsi
centum an ducenti, non putatis ausurum
me unum ducentos irrumare sessores?
Looking only at the second half (non putatis . . . sessores?), we might think that distributive ducenos would be wittier here as well as in 11.18: Catullus alone (unum) can provide two hundred irrumationes in one session, not just now, but on any appropriate occasion. On the other hand, ducentos fits better with centum an ducenti in the previous line. Some may wish to count this parallel against my conjecture in 11.18, which would damage the parallelism.
(1) It is the one crude stanza out of six: perhaps the vivid subject matter kept the sleepier monks’ attention from wandering. It is traditional to say whose text one is quoting, but it doesn’t matter here, does it? I should add that I did not notice the textual cleanness of this stanza until after I had devised my conjecture: an interesting fact, not a challenge to be overcome.
(2) Mutatis mutandis, of course, with the change of gender. J. M. Trappes-Lomax, Catullus: A Textual Reappraisal, Swansea 2007, argues convincingly ad loc. for Pleitner’s unum in 8 (una OGR), and Kiss prints unum in the text accompanying his repertory.