The NecronomiCon 2019 convention Memento Book theme will be “Lost in Time: Newly Discovered Cosmic Horror”. The call for this is now open, and the submission email is: necronomiconsubmissions@gmail.com

Seems likely to be mostly new fiction on the topic (they want stories of “lost gods, unearthed histories, new myths, and freshly exhumed horrors”). But note that they also have space for “essays and non-fiction … on authors or fiction/film that have been mostly lost to time”.

Submissions open today, 1st September 2018. There’s mention of token payment for the 2,000-5,000 word stories, but no mention of payment for scholarly essays (which, arguably, involve a lot more work and expense to produce).