Six species of Agaricocrinus obtained from the Keokuk beds, of which three, viz: A. americanus Roemer; A. whitfieldi Hall; and A. worthem Hall, occur at Keokuk.
© Copyright 1889 by the Iowa Academy of Science, Inc.
Gordon, C. H.
"Observations on the Keokuk Species of Agaricocrinus,"
Proceedings of the Iowa Academy of Science, 1(Pt. 1), 100-101.
Available at: https://scholarworks.uni.edu/pias/vol1/iss1/48