Note: This is not an actual series but a way to tie a set of essays together with two editions of the essays published in novel-length format. Lost Continents was originally written in 1948 under contract to Prime Press who failed prior to publication. First publication was as a nine-part serial in Other Worlds Science Fiction, October 1952 - July 1953. In 1954 the essays were collected, revised, and published as The Atlantis Theme in History, Science, and Literature by Gnome Press. Technically this is a collection as the chapter names match the original essay titles but ISFDB does not have support for non-fiction (and non-genre) collections plus we'd need to deal with that the essays were revised. In 1970 the author "corrected minor factual and typographical errors and interpolated a few new paragraphs to bring the work up to date." The preface to the 1970 edition explains the corrections in more detail. In 1975 Ballantine Books reprinted the 1970 edition as Lost Continents: Lost Continents: The Atlantis Theme.