Neotype, MCZ IP 113595 = Holotype of Cerion (Maynardia) agassizi Dall, 1894
The original description was based on a single specimen, the unique holotype, for which measurements were provided, but for which the illustrations were never published. The specimen was not at the MCZ, nor was there any catalog entry for this taxon at the MCZ at the time Maynard's collection was catalogued. Searches of the collections and/or databases of the USNM, the Academy of Natural Sciences of Philadelphia, the Field Museum of Natural History, the Florida Museum of Natural History, and the Museum of Biological Diversity, Ohio State University, failed to uncover a single specimen catalogued under this name. Maynard's original description was brief "Similar to last [S. agassizi Dall] but smaller, .73 by .36, with 8 instead of 11 whorls, and is tinged with dull orange" is inadequate to differentiate this taxon from S. agassizi unambiguously. The holotype of Cerion (Maynardia) agassizi Dall, 1894 (MCZ IP 113595, Invertebrate Paleontology Collection) was designated as the neotype of Strophiops rosea Maynard and Clapp in Maynard, 1921 (Harasewych et al., 2007). Strophiops rosea Maynard and Clapp in Maynard, 1921,becomes an objective junior synonym of Cerion (Maynardia) agassizi Dall, 1894.