Mollusks and Other Invertebrates The 45,000 lots of mollusks include 287 primary type specimens. This collection is one of the most significant collections in the Zoology Section, and is within the top 15 largest in a North American museum. Dating back to the early 1900s, it arose from the the collecting efforts of one of the museum's founders, Junius Henderson. The collection is worldwide in scope, about half marine species, a quarter freshwater species, and the remainder terrestrial forms. Other invertebrates (excluding insects, spiders) in the collection include marine, freshwater, and terrestrial organisms. Over 2,300 lots (20,000 specimens) have been cataloged. Most of these are used for teaching, although a very good collection of leeches and crayfishes are important for research. Curator Robert Guralnick focuses his research on freshwater mollusks of the Rocky Mountains and Great Plains region. Shi-Kuei Wu, Curator Emeritus, has continued developing the mollusk collection over the last 25+ years, focusing his research on the gastropods of Great Plains region.