Scanning Electron Micrographs (SEM) of fossil specimens

    Lower Pinecrest beds, Upper Tamiami Formation, Sarasota County, Florida. The top specimen measures 1.38 mm, the middle specimen measures 1.31 mm. and the bottom specimen measures 1.26 mm. SEMs produced in collaboration with Dr. Ann Heatherington, Dept. Geological Sciences, University of Florida, Gainesville, FL.

Olsson, A.A., 1916. New Miocene fossils. Bulletins of American Paleontology 5(27): [1]-32, pls. <https://www.biodiversitylibrary.org/page/32510720>. This species was later described as Circulus gunteri by Mansfield (1930: 132- 133; pl. 20, figs 16, 17, 18. <http://ufdc.ufl.edu/UF00000437/00001/181j?search=bulletin>).