An initial listing of UK Silurian assemblage slides from the collection of Prof. Richard J. Aldridge formerly of the University of Leicester. The file synthesises data from the slides themselves and several unpublished documents relating to details of the collection site, a listing of the samples taken, lithological descriptions along with details of sample weights and yields. The collection underpins type and figured specimens already donated to the Natural History Museum and is a major resource for anyone wishing to study British Silurian conodonts.