The present volumes deal with all Paleozoic corals, but also includes description of some Mesozoic descendants, especially among the Chaetetida. The groups described in this Supplement to Treatise Part F were, in the original edition of Part F (1956, reprint 1967), arranged in three different sections, which were treated as orders of the class Anthozoa: Rugosa by Dorothy Hill (p. F233-324), Heterocorallia by Dorothy Hill (p. F324-327), and Tabulata by Dorothy Hill and Erwin C. Stumm (p. F444-477), totaling approximately 140 pages. In this revision Dorothy Hill merged the order Heterocorallia as an order with the Rugosa, thus returning time-honored twofold division of the Paleozoic corals into Rugosa and Tabulata, now treated as subclasses of the class Anthozoa.