Wikipedia: https://en.wikipedia.org/wiki/Albert_Boni
Cult of the Colophon, PW, Aug. 6, 1927, at 384-389 (Albert & Charles Boni's colophon is on page 387).
See Vol. 288: THE HOUSE OF BONI & LIVERIGHT, 1917–1933: A DOCUMENTARY VOLUME, edited by Charles Egleston (2004) of the Dictionary of Literary Biography for more information.
NOTES ON THE HISTORY OF THE BONIBOOKS/PAPER BOOKS:
Peter Manesis, 2 Paperback Quarterly 26-30 (1979) -- full text on Google Books
Suggests that the Boni Brothers changed to the Bonibooks format because the subscription business was flagging, but as clear from the ad material in the back of Paper Book 15 (Crime and Destiny), the Bonibooks were already going strong by the time the Paper Books series ended.
Jackpot! Turns out, the Boni Brothers decided to expand the paperback series of Bonibooks to a hardcover series, starting with the following titles:
American Oxford Dictionary (comp. by F.G. Fowler & H.G. Fowler)
Education and the Good Life (Bertrand Russell)
Great Short Stories of the World (ed. by Barrett H. Clark & Maxim Lieber)
Oxford Book of American Verse (ed. by Bliss Carman)
Israel (Ludwig Lewisohn)
Against the Grain (J.K. Huysmans)
Our Business Civilization (James Trulow Adams)
The Lost Girl (D.H. Lawrence)
The High Place (James Branch Cabell)
This Earth of Ours (Jean-Henri Fabre)
What Is Wrong With Marriage (Hamilton & McGowan)
South Wind (Norman Douglas)
Michelangelo (Romain Rolland)
The History of Mr. Polly (H.G. Wells)
Tar (Sherwood Anderson)
This list comes from copy on the inside jacket of a listing of Tar on AbeBooks.
Add to the above list a couple titles visible from the inner front flap of The Man Shakespeare below:
The World’s Best Essays from Confucius to Mencken (ed. by F.H. Pritchard)
The World’s Best Poems (ed. by Mark Van Doren & Garibaldi M. Lapolle)
In that list, the titles are numbered now, with the same ordering as with the list from the flap of Tar, but Israel and The Lost Girl are absent. The list goes to 16 but contains only 15 entries (#5 -- Israel? -- is absent).
I’ve also seen Moby Dick in a hardcover Bonibooks version (3 printings -- 1933, 1935, 1939). Other titles in hardcover are: The Man Shakespeare (Frank Harris, 1935), Adventures of an African Slaver (Captain Theodore Canot, 1935), The Story of the Bible (Hendrik Willem Van Loon, 1933), & The Goose Step (Sinclair Upton, 1936).
According to a photo in a listing for The Novels and Fairy Tales of Oscar Wilde (“First Issued in Bonibooks Series, September 1935”), The Collected Works of Oscar Wilde was issued in Bonibooks “in 5 uniform volumes, sold individually or in sets.”
Still yet to find a Bonibook from after 1931 in paperback format. I think the series probably ended in 1931 in paperback format.
A January 1933 advertisement for Bonibooks in 26 The American Magazine of Art x (Jan. 1933) [available in JSTOR] lists 22 Bonibooks. Number 5 is listed as “Israel,” and numbers 17-22 are:
Best American Mystery Stories (sel. & ed. w/ intr. By Carolyn Wells)
Great Detective Stories of the World (ed. By Joseph Lewis French)
Great Short Biographies of Ancient Times (ed. w/ intr. & nn. by Barrett H. Clark)
Great Short Biographies of Modern Times (ed. w/ intr. & nn. by Barrett H. Clark)
Great Short Novels of the World, Volume I (ed. w/ intr. & nn. by Barrett H. Clark)
Great Short Novels of the World, Volume II (ed. w/ intr. & nn. by Barrett H. Clark)
The other half of the ad lists the 7 volumes of Proust’s Remembrance of Things Past, but there’s no indication they were published as Bonibooks. I think they weren’t published under the Bonibooks imprint because several of the translations predated creation of the imprint.
Some suggestion that the Bonibooks continued up to at least #51!: The Life of Jesus (1936), which is listed in Worldcat: http://www.worldcat.org/oclc/1014126943