If something contains large amounts of cyclopentane and cyclohexane, what is it called?
The most likely name would be naphthenes. It could also be called cycloalkanes.

Added:
Since the reference to the question is about the coal and oil production, the answer would be naphthenes. When the coal and oil were distilled, a layer (called naphthene) was removed which was found to contain mainly cyclopentane and cyclohexane.

I would complete the statement as:
If a fraction of distillate contains large amounts of cyclopentane and cyclohexane, it is called naphthene.