Sergius H. Mamay

1920

• Additions to the flora of the Spotted Ridge formation in central Oregon
• Occurrence and significance of marine animal remains and American coal balls
• Occurrence and significance of marine animal remains in American coal balls
• Paleozoic origin of the cycads
• Russellites, new genus, a problematical plant from the Lower Permian of Texas
• Tinsleya, a new genus of seed-bearing callipterid plants from the Permian of north-central Texas
• Two new plant genera of Pennsylvanian age from Kansas coal balls