The Association of British Zoologists was formed at the Meeting of British Zoologists on 5 Jan 1929 "to ensure a permanent organisation, with a Council which can represent British Zoologists between their annual Meetings". The first Council meeting was on 11 Jan 1930. Final meeting held 13 Jan 1973.

Circulars, printed papers and correspondence of Dr Bidder, mainly concerning the Meetings of British Zoologists, the forming of the Association of British Zoologists, and urging the split of the British Museum and the Natural History Museum. Most are from 1920's and are unordered. Includes letters from Prof. Balfour-Browne, P Chalmers Mitchell and E Ray Lankester, etc

Report of a meeting between the Trustees of the British Museum and the representatives of the Museum Conference of Naturalists, with correspondence, a memorandum on the problem of combining the administrative and technical or scientific direction of National Museums with special reference to the British Museum (Natural History) and papers from meetings

Report on the Marine Biological Association of the United Kingdom in Plymouth

Letter to Dr A Tindell Hopwood of the British Museum (Natural History) inviting him to act as Honorary Editor for a further volume of Nomenclator Zoologicus

Correspondence with the Zoological Society of Jos regarding assistance from the Zoological Society of London

Correspondence between Sir Sidney Frederick Harmer and Joan Procter regarding Procter's remuneration and the Natural History Museum, articles in the press about Procter, a joint paper published by Procter and Dr Malcolm Smith, and Procter leaving the Natural History Museum

Correspondence with the New York Zoological Society regarding the diet of Humming Birds from Ecuador

Correspondence regarding Fellows of the Zoological Society of London and proposals regarding changes to Fellows' subscriptions

Letter regarding a final paragraph for Solly Zuckerman's draft about Awards of the Zoological Society of London