Fossil sponges of any kind are relatively rare in the Paleozoic rocks of Iowa and especially so if we except the questionable forms generally relegated to the Receptaculitidae.
Proceedings of the Iowa Academy of Science
©1922 Iowa Academy of Science, Inc.
Thomas, A. O.
"Some New Paleozoic Glass-Sponges from Iowa,"
Proceedings of the Iowa Academy of Science, 29(1), 85-91.
Available at: https://scholarworks.uni.edu/pias/vol29/iss1/11