Southwest Florida Shells with Emphasis on Sanibel & Captiva
José H. Leal
Pilsbry & McGinty, 1946
Shell to 2 mm in size, flattened, compressed, with spire not projecting in early whorls, sculpture of microscopic growth lines, umbilicus open, aperture oblique. Sculpture of three strong spiral keels. Base clearly delimited by “lower” peripheral keel, with another keel delimiting the relatively large umbilicus. Shell color white. Compare to Cyclostremiscus pentagonus and Cyclostremiscus suppressus. The species was named after the late malacologist and specialist in Southwest Florida mollusks Dr. Jeanne S. Schwengel.