Posted: Jan 25 2026
Prunum bellum (Conrad, 1868), La Belle Marginella Previously Marginella bella Conrad, 1868
Conrad first listed Marginella bella (without description) in 1862 (printed in 1863) in his “Catalog of the Miocene Shells of the Atlantic Scope” under the subgenus Porcellanella (P. bella). Conrad first published a description with the revised name Marginella bella in 1868. Conrad’s research material was collected from only one location – Day’s Point, James River, archeological district on the coast of Isle of Wright Co., Virginia. Although Conrad’s material was all fossils, Marginella bella was not acknowledged to be extinct until over 130 years later. A large part of the reason was that in 1890 Dall published a paper in which he investigated fossil and living material from Florida and North Carolina that he considered to fall within the rubric Marginella bella Conrad. Dall described three varieties:
Marginella bella Conrad (typical form - Fig. 9.a)
Marginella var. inepta Dall (Fig. 8.d)
Marginella var. bellula Dall (Fig. 8.e)
Unfortunately, Dall was not sufficiently precise in his language to allow an understanding of which varieties in which locations were fossils or living. As a result, later authors made interpretations or assumptions that erroneously considered Conrad’s Marginella bella to be among Dall’s living material and confused living material from locations other than Virginia with Conrad’s extinct fossil. An example is Abbott’s (1974) obvious description of living material of Marginella bella Conrad, 1868 as having a range from North Carolina to Key West.
Beginning in the early 21st century the status of Dall’s three varieties was generally accepted as follows:
Marginella bella Conrad: extinct fossil, currently (Jan 2026) WoRMS accepts as a valid species named Prunum bellum (Conrad, 1868).
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Marginella bella var. inepta Dall: extinct fossil from Ballast Point, Tampa Florida.
Marginella bella var. bellula Dall: of the three this is the one Dall reported as including “recent shells,” interpreted to mean “live-collected” shells. Currently (Jan 2026) WoRMS accepts this variety as a valid species named Prunum bellulum (Dall, 1890).
References:
Abbott, R. Tucker. 1974 American Seashells, Second Edition, Van Nostrand Reinhold Company.
Conrad, T. A. 1862 (Printed in 1863). Catalogue of the MIOCENE SHELLS of the Atlantic Scope. Proceedings of the Academy of Natural Sciences, pg. 564.
Conrad, T. A. (1868). Descriptions of Miocene shells of the Atlantic slope. American Journal of Conchology. 4(1): pg. 67.
Dall, W. H. (1890-1903). Contributions to the Tertiary fauna of Florida with especial reference to the Miocene silex-beds of Tampa and the Pliocene beds of the Caloosahatchie River. Transactions of the Wagner Free Institute of Science. 3(1), pg. 53.
