The images are provided by Dr. James E. Conkin and Prof. Barbara M. Conkin, Louisville, Kentucky. The specimens were found by them and James W. Pike at the 13 localities shown left.
The images and accompanying information are published: Conkin, J. E., Conkin, B. M. and James W. Pike, 1965: Mississippian Foraminifera of the United States Part 2: The Hannibal Formation of northeastern Missouri and western Illinois in micropaleontology Volume 11 Number 3, July 1965 Pages 335-359.
We thank Micropaleontology Press for giving the permission to use the images and accompanying information. Read more in the above mentioned article as a subscriber of the journal micropaleontology or ask your local library to subsribe to micropaleontology.