The British philosophy journal/book Collapse had a special ‘Concept Horror’ issue in 2009, which is now freely available on Archive.org. Among others this includes the essays:

Graham Harman and Kieth Tilford. “On the Horror of Phenomenology: Lovecraft and Husserl / Singular Agitations and a Common Vertigo”.

A defence of “weird realism”, suggesting that 20th century philosophical thought has much in common with weird fiction.

China Mieville. “M.R. James and the Quantum Vampire – Weird; Hauntological: Versus and/or and and/or or?”.

While this doesn’t initially sound a very promising title for Lovecraftians, it does have a fascinating prologue: “The Tentacular Novum” (pp. 105-112) giving a survey of… “the early adopters of the tentacular” in horror fiction. He surveys the kraken, giant octopus and squid — as they appear in Verne, Hugo, Wells, and Hodgson. He dates the phenomenon back to 1907, and its highpoint to 1928…

“A good case can be made, for example, that William Hope Hodgson, though considerably less influential than Lovecraft, is as, or even more, remarkable a Weird visionary; and that 1928 can be considered the Weird tentacle’s coming of age, Cthulhu (“monster […] with an octopus-like head”) a twenty-first birthday iteration of the giant ‘devil-fish’ — octopus — first born to our sight squatting malevolently on a wreck in Hodgson’s The Boats of ‘Glen Carrig’ in 1907.”

To see what that high-point looked like, visit Francesca’s Octopus Pulp Fiction gallery.

As for Hodgson — William Hope Hodgson was working in a very similar, though often less clarified, vein to Lovecraft from 1906 to 1914. He died in 1918, before Lovecraft was first published, and apparently his books were then out of print for many years. And most likely difficult to obtain in America even if Lovecraft had heard of his work. It’s said that Lovecraft was finally able to read Hodgson in 1934.