Pictorial taxonomy: shell images and the Leopoldina in the eighteenth century

In the eighteenth century, the interest in conchylia (mollusc shells) grew among naturalists and collectors. These objects, which were attributed to have great beauty, exhibited a high variability, yet many were very rare in Europe. In their attempts to establish taxonomical classifications, conchologists therefore depended on images to a large extent. Examples from the context of the Leopoldina, which served as a network for German conchologists, indicate that the taxonomical use of images led to a change in the understanding of representation from typical to characteristic, that is the naturalistic depiction of carefully selected individuals instead of an ideal image composited from the inspection of multiple objects. The making of these characteristic images required collaborations with increasingly specialized artists. Images were effectively used as substitutes for specimens in working out taxonomic systems, which created a persistent need for more images among conchologists. In addition to extensive cross-references between images and synonyms, conchologists incorporated references to specific collections in their descriptions of shells to indicate the models used for the images and the characteristic mode of representation.