The entire scorpion (Scorpiones) collection has been databased as lots, largely through the efforts of Tom Anton and collection manager Dan Summers. As of February 2008, it consists of close to 1000 lots (mostly single-specimen), including 71 type lots, from 53 different countries, with 11 of the 18 scorpion families represented. The Field Museum's types of spiders (Araneae, ca. 140 lots), daddy-long-legs (Opiliones, ca. 100 lots), and pseudoscorpions (Pseudoscorpiones, ca. 80 lots), have all been databased. Relatively little non-type material of those orders has been entered so far. Nearly all the non-type databasing in the spider collection (several hundred records) has been part of the Oonopidae PBI grant project. The holdings visible here are thus a very incomplete record of our roughly 100,000-lot spider collection. The smaller arachnid orders and mites and ticks (Acari) have not yet been databased at all. Catalog numbers (FMNH-INS #### ### ###) have been assigned to all databased arachnid lots, except in Scorpiones, where only recently cataloged type lots have them.
The collection currently houses over 11,000 lots of millipedes (Diplopoda) identified to at least order (including 15 of the 16 known orders), all of which are included in this database. More are being added on a continuing basis. This total includes over 450 type lots, 376 of which are included in a published type catalog (Zootaxa 1005, 2005). The centipede (Chilopoda) collection contains approximately 4,000 lots, including at least 45 type lots, currently in the early stages of being databased. All databased myriapod lots have been assigned unique catalog numbers (FMNH-INS #### ### ###).