Lair of the White Worm: Chapter XXIVb-c
Arabella's late husband, Captain Adolphus Ranger March, is mentioned in the book. While in the film, Sylvia's lovers are mentioned, "The Rebel Roman Emperor," implied, Mrs. Trent, and even suggested by others, Kevin, the boy scout in the film, there never is any mention that she was ever married.
The book suggests a reason that the White Worm is white. While the film goes into some detail as to why the White Worm is a worm or wyrm, there never is any suggestion as to why the Worm may be white.