Thesaurus Conchyliorum, or Monographs of Genera of Shells, London, Sowerby, 1847-1887, Mollusks, Pictorial Works, Shells, A detailed illustration depicting a variety of shell types belonging to the genus Cyclostrema, organized methodically across rows. Each shell is labeled with its respective subcategory, including Subgenus Dayronia, Subgenus Tabula, Subgenus Microstoma, and Subgenus Murcitia. The shells exhibit diverse forms and sizes, showcasing intricate patterns and textures. Annotations highlight distinguishing features, contributing to the scientific classification of these mollusks. The layout reflects an emphasis on systematic taxonomy, likely intended for educational or reference purposes in malacology, the study of mollusks.