Comprises editorial correspondence re production and publication of International Tables for Crystal Structure Determination, 1947-54; also correspondence between Helen Megaw and Kathleen Lonsdale re 'geometrical relationships between distances in regular solids', on which H M was to write a 'couple of pages' for a short paper [? ultimately published as 'Geometrical Relations in the Regular Polyhedra'], 1956-57, together with related papers; also correspondence and papers re space group nomenclature including minutes and papers of a committee on crystallographic nomenclature.