August Derleth was a prolific author and editor and a devotee of H.P. Lovecraft; in 1939 he co-founded publisher Arkham House initially to publish Lovecraft's stories. He published several anthologies of weird and macabre fiction in the mid-1940s before -- two years after Adventures in Time & Space and Groff Conklin's first volume -- he switched to science fiction and produced eight substantial volumes from 1948 to 1954. (As with Conklin, numerous abridged and retitled paperback editions were derived from those eight volumes.)

Among the anthologies compiled here, Derleth never reprinted a story more than once. Most reprinted authors: Ray Bradbury (12), Donald Wandrei (8), Frank Belknap Long and A.E. van Vogt (7 each), Nelson S. Bond, Clark Ashton Smith, and Theodore Sturgeon (6 each); Fritz Leiber and H.P. Lovecraft (5 each).

The photo here is a collage of cover images from isfdb.