edition of Northwest Of Earth, a collection of gothic space opera stories originally published in Weird Tales back in the 30s. They're written by C.L. (Catherine) Moore, a well-regarded pulpster best known for her sword & sorcery heroine Jirel of Joiry.
The Paizo Press/Planet Stories hardcover I own has a nice enough cover painting, but I prefer the vintage duotone illustration above, which graced a 50's edition of the material. I don't know who the artist is, but I really dig the Old School space opera vibe of the illustration.