In 1934 the Geological Society of America published its second Memoir: “Paleozoic Plankton of North America,” by Rudolf Ruedemann. This work was concerned primarily with invertebrates, especially the enigmatic and now-extinct graptolites. The primary producers of that era were virtually unknown; accordingly, the author devoted only a few pages to description and discussion of seaweeds. And although Ruedemann (1934, p. 25) recognized that “the microscopic algae must be considered as the very basis” of Paleozoic life, he submitted that “obviously it will be difficult to find their remains in the Paleozoic rocks.” O.M.B. Bulman (1964, p. 467), another graptolite expert, condensed his discussion on the primary producers to two paragraphs in “Lower Palaeozoic Plankton,” his Anniversary Address as President of the Geological Society of London; but at least he acknowledged the “universal occurrence” of fossil phytoplankters.