A study that deals with the relation of Cretaceous structure to Paleozoic structure, facies changes in the Cretaceous section, useful mapping horizons in the Cretaceous, reconstruction of the pre-Cretaceous or early Cretaceous geomorphology, and determination of the favorability for oil and natural gas in the Cretaceous shelf sediments The Bulletin also contains a “Discussion on the Foraminifera”, by William S. Parks, and a “Discussion on the Ostracoda”, by Robert H. Shaver .