Through Op. 67
https://biodiversitylibrary.org/page/34612864 and Dir. 81
https://biodiversitylibrary.org/page/34611550 ,
Vireo is also on the Official List as dating from 1807 and being available from p. 83 of Vieillot's
Oiseaux de l'Amérique septentrionale https://biodiversitylibrary.org/page/47004238
This is the text to pl. 52 -- which, if no departure occurred from the scheduled 6 plates / livraison, should have been in Livr. 8 -- it seems almost impossible that this page was published in 1807.
(As an aside,
Vireo occurs as well on pp. iii-iv of the book
https://biodiversitylibrary.org/page/47004085 , which, being the text to plate 1, might have been expected to be in Livr. 1... Except that this seems contradicted by the list of Errata which appears at the bottom of p. iv and covers typos that range up to p. 65 -- that is, the text to pl. 34 = Livr. 6...? This list of Errata has been regarded as evidence that pp. iii-iv could not have been published before the publication of p. 65, thus of Livr. 6. (Although, strictly speaking, it only proves that these pages were not
printed before the
printing of p. 65, which is arguably somewhat different.))
The wrapper is interesting. Same correction of the starting date of the publication process (août 1807 => septembre 1807), apparently by the same writer, indeed. It would be interesting as well to know if this correction continued to be present on wrappers of later livraisons.
A link to Edward's note (on ResearchGate) was already given in post #4 by Martin.
But the conclusion of this note is, I fear, problematic, because the main premise was that the 9 Jul 1808 notice in
Mercure de France (3rd link in post #5) announced a delayed start of the publication for
the next 1 Sep... While in fact, this notice "announced" a start of the publication on 1 Sep
of the previous year (1807, not 1808). (Which is
earlier, rather than later, than the date which has most commonly been accepted (1 Dec 1807), but matches the date that was given in the quite detailed prospectus published in Nov 1807 in the
Télégraphe littéraire, and the hand-written correction of the starting date on the two wrappers. (As well as the starting date stated in the bookseller's catalogue, which may have been quoted from the wrappers.))