SciFi Stories

[cwindsor]

Does anyone recall a scifi story regarding a sort of bio dome which is seperated into floors (maybe 3 floors). The floors are each made similar to earth with water, land and sky. The story is about a race of people that live in one of the sections, the middle I believe. The top floor is where their society puts it's mutated offspring. The middle floor has no idea of what these "Creatures" are and they hunt them for sport. Near the end of the story they learn that these creatures are related them. I read this about 12 to 15 years ago and can't find or remember either the author or name of the story. All I do remember is that it was in a hard cover book of assorted Scifi short stories. The book was about an inch thick.

Thanks,
Chriss