Lower Pinecrest beds, Upper Tamiami Formation, Sarasota County, Florida. SEMs produced in collaboration with Dr. Ann Heatherington, Dept. Geological Sciences, University of Florida, Gainesville, FL. This species is cognate with the Panamic Province Caecum subspirale Carpenter, 1857. Both taxa may exhibit clockwise rotation of the longitudinal sculpture at certain stages of growth. Caecum coronellum Dall, 1892, described from both Plio-Pleistocene and Recent material, is a synonym.