This Cumulative Index of Structure Reports contains all the structures for the years 1913-1980 (Volumes 1 to 46B) and the authors for the latest 10-year period, 1971- 1980 (Volumes 37B to 46B). The arrangement in the classified structure index is as outlined on pages VII-VIII. University of Guelph, G. FERGUSON Guelph, Ontario, Canada [VI] VII ARRANGEMENT Classified Organic Index (Page 1) Each entry gives the formula, name, and Strukturbericht and Structure Reports references. The entries are arranged in accordance with the classification scheme based on chemical structure of the Cambridge Crystallographic Data Centre; within each class the order is by formula. The formula index will help to locate a compound for which the classification is doubtful. The classification is: (0) Aliphatic hydrocarbons and derivatives 1 Aliphatic carboxylic acid derivatives 2 Aliphatic carboxylic acid salts (&JmOnium, IA, IIA . . tals) 3 Aliphatic lllllines 4 Aliphatic (N and S) COIIIJ>OWids 7 Nitriles (aliphatic and aroutic) 8 Urea compounds (aliphatic and aromatic) 9 Nitrogen-nitrogen c0111pounds (aliphatic and aromatic) 10 Nitrogen-oxygen compoWids (aliphatic and aroutic) 11 Sulphur and selenium COIIIpounds 12 Carbonium ions, carbanions, radicals 13 Benz.