There are around 160,000 specimens of British spiders and harvestmen in the collection, providing 85% species coverage. The historical collection (including type-specimens) of W.E. Falconer was principally collected in northern England during the first three decades of the 20th century. The remainder of the material is incorporated into a single main reference collection. Material from D.R. Cowden and R. Leighton and the collections of C.G. Butler and A.G. Scott compliment the extensive modern collection of C. Felton which primarily contains specimens from north-west England and Wales.
Foreign collections comprise around 5,000 specimens, mainly acquired during fieldwork by National Museums Liverpool staff and associates in Turkey, Greece and other parts of Europe. Most are sorted to family and genus, but several hundred Turkish and Greek spiders have been identified to species. A worldwide collection of circa 4,000 ticks was acquired with the donation of the Liverpool School of Tropical Medicine's medically important arthropod collections in 1986.
The P.D. Gabbutt collection of approximately 14,000 spirit and slide-mounted specimens of British pseudoscorpions, includes adults and all instars for the majority of the British species and is probably the most extensive pseudoscorpion collection in Britain.
Coverage of mites is less comprehensive. Economically important species (MAFF collections) are represented.There is type material and many new faunal records in the F. Monson collection of British mites and the M. Luxton collection of British and New Zealand Oribatida collection, which also has an associated reprint library.