This systematic treatment of the diatoms of the U.S. is written for the use of all those concerned with the multitude of kinds & the fascinating diversity of this very large & important group of algae of our fresh waters. This volume represents the first part of a two part systematic treatment of the freshwater diatom flora of continental U.S. exclusive of Alaska. Besides those taxa found in fresh water, a few taxa found in estuaries of rivers & belonging to genera that commonly occur in fresh water are included. No strictly fossil species are included; however, many of the species embraced are found in recent fossil material. Although this book is concerned with the U.S., it should be helpful to the students of diatom floras in Mexico, Canada, & other areas. Illustrations.

Includes entries for maps and atlases.