Notes:
An "anthology of prostitutes" is a pun on "anthology of prose", as "pro" is a common contraction for prostitute in Britain and elsewhere.
The phrase "A court of kangaroos" is frequently thought to be legitimate, given the (quite unrelated) expression "a kangaroo court". There is no known evidence of its legitimacy as a collective noun, however.
A "ream of paper" - A ream is defined as five hundred sheets, plus or minus a dozen.