This is an original pen and black ink drawing by William Charles Palmer (signed and dated 1940 right above "Cephalopoda") executed on rice paper, then cut and mounted to white laid paper. I really love how old and dark and briny it feels, like something straight out of Jules Verne, and I imagine it may indeed have been done as an illustration for a book or publication about sea creatures, though am not certain.
Palmer (1906-1987) was born in Des Moines, studied at the Art Students League in NYC under Thomas Hart Benton among others, and studied fresco painting at the Ecole des Beaux-Arts in France.--later painting a series of WPA funded murals in the U.S. Said to have made a sketch a day at least, examples of his far-ranging work (drawings, paintings, prints, illustrations including for several children's books) are held in the collections of the Whitney Museum, Cranbrook Academy, the National Gallery, the Metropolitan Museum, the White House, among many others, and his archive is housed at Hamilton College.
8"x11" and in good condition, with some smudges and stains that I think only enhance its moody underwater feel.