A Rip Torn jag from Defending Your Life: he got larger and coarser with age but is essentially the same actor here. Notionally he's Henry Miller to Ellen Burstyn's Mona Miller. She had The Last Picture Show and The King of Marvin Gardens in her near future but doesn't make it past the first reel.
I haven't read the book and am even less interested now. I expected an exotic locale and culture but instead it's about some oversexed east coast American men in Paris in the 1930s. I do not know why Joseph Strick adapted (with Betty Botley), produced and directed it so late in the day. It's choppy but mostly not hard to follow as there is no discernable plot. Some of the narration — faux profundity presumably lifted verbatim from the book — is very very funny at this remove; it is beyond satire. Obscene? Nah, just crass.
Howard Thompson at the New York Times. The Wikipedia page for the actual Tropic of Cancer is far more fascinating.