M. T. Parker. J. Fielding. R. M. Payne, and Mrs. B. Ward. S. J. Brooks. D. Corke. M. W. Hanson. L. Hooper and C. W. Plant all made extremely helpful comments on earlier drafts of all or part of the texts. Finally, I wish to thank my mother. Mrs. H. L. Benton, and Mrs. S. Leswell for their painstaking work in typing the successive drafts of this work. The publication of this booklet was made possible by a substantial publications grant from The Royal Society and a legacy from the estate of Mrs. C. Bignell Pratt. B.E.N.H.S. British Entomological and L.N.H.S. Natural History Society c/o The Alpine Club 74 South Audley Street London W1Y 5FF C.E.M. Colchester and Essex Museum Museum Resource Centre 4 Ryegate Road N.C.C. Colchester. Essex CO1 1YG C.N.H.S. Colchester Natural History Society c/o Mr. G. Bowdrey Natural History Museum. High Street. O.R.C. Colchester. Essex. CO1 1DN E.F.C. Essex Field Club c/o Passmore Edwards Museum Romford Road Stratford P.E.M. London E15 4LZ EFCC. Epping Forest Conservation Centre High Beach Q.E.H.L.M. Loughton. Essex IG10 4AF E.N.T. Essex Naturalists' Trust Limited Fingringhoe Wick Nature Reserve RES. South Green Road Fingringhoe Colchester. Essex COS 7DN London Natural History Society P. C. Holland Flat 9 Pinewood Court 23 Clarence Avenue Clapham London. SW4 86B Nature Conservancy Council East Anglia Region - Sub- Office All Saints House High Street Colchester. Essex CO1 1UG Odonata Recording Scheme c/o R. Merritt 83 New Road Holymoorside Chesterfield Derbyshire Passmore Edwards Museum Romford Road Stratford London E15 4LZ Queen Elizabeth's Hunting Lodge Museum Rangers Road Chingford London E4 7QH. Royal Entomological Society 41 Queens Gate London. SW7 5HU 135