The film (The Dunwich Horror) was certainly based on parts of HPL's works - Elijah and Wilbur Whatley being the brothers in the story but, like Scarab, I don't recall the actual title of the story but I'm pretty certain it wasn't The Dunwich Horror. "The Reanimator" was based (very very loosely) on "The Strange Case Of Charles Dexter Ward" And yes, "I have no mouth..." was by Harlan Ellison. I'd love to see a film based on "Colour out of Space" (done well) or "At the Mountains of Madness". Paul