The INHS Annelida Collection is the largest state collection of freshwater oligochaetes in the country, holding 350,000 specimens (7,000+ lots, or collections). Of these, ~225,000 specimens are mounted on microscope slides; the remaining specimens are stored in alcohol in vials and jars. With the exception of the Acanthobdellida (bristle worms – a monospecific order restricted in distribution to the boreal regions in the Arctic) – the collection includes representatives of all other groups of segmented worms in the Phylum Annelida:  Branchiobdellida (one family, Branchiobdellidae – crayfish worms); Hirudinida (leeches); oligochaetous Clitellata {'Oligochaeta'}: aquatic microdrile worms and the primarily terrestrial megadrile oligochaetes (earthworms), and Polychaeta (sand worms, tube worms, clam worms – primarily marine) plus the Aeolosomatida (one family, Aeolosomatidae – head-crawling, or suction-feeding worms, primarily freshwater). Geographic scope of collection: 76% from Illinois, 23% from other U.S. states, protectorates and Canadian provinces, and 1% from 15 other countries. Please visit the INHS Annelida Collection homepage for additional information on geographic scope, diversity, status of specimens in the collection, and collection management projects including a profiling exercise to document the current health of archived specimens.

Note regarding collection statistics presented below: Each specimen record represents a single taxon identified from a unique collection or collecting

event (e.g., site, date, sample, replicate). The number of individuals of that taxon identified from that unique collection or collecting event is
presented in the column ‘IndividualCount’ for that record. To date, 16,937 identified specimens are associated with the 1,999 records included herein.