Schröter's River Shells (1779)
Johann Samuel Schröter. Die Geschichte der Flussconchylien : mit vorzüglicher Rücksicht auf diejenigen welche in den thüringischen Wassern leben. Halle: Bey Johann Jacob Gebauer, 1779.
Johann Samuel Schröter (1735-1808) thought that his book brought together everything anyone should know about Flussochchylien (river shells). These mollusks belong to a bivalve family called the Unionidae. They are also known as freshwater mussels, pearly mussels or unios. Prior to their replacements by plastics in the 20th century, the demand for their pearly shells as buttons supported a significant commercial fishery.
Schröter's book was based primarily on collections from central Germany where there are only a few species. In contrast, there were more than 200 species of unionid mussels native to North America; some of these are now either engangered or extinct.
The large species figured in the center of this illustration (Plate 1) is the Swan Mussel, or Anodonta cygnea (Linnaeus, 1758).