A short biography of CYNTHIA E. LONGFIELD, Honorary Associate of the British Museum (Nat. Hist.), is followed by an appreciation of her odonatological work and by a list of her odonatological publications (1929-1974). CYNTHIA LONGFIELD was bom in Ireland on August 16th, 1896. She commenced working at the British Museum (Natural History) as a ’’Visitor” in 1927. Before this, she had made a start to her scientific career by joining the St. George Expedition to the Pacific, 1924-25, accompanying and encouraged by Miss Evelyn CHEESMAN. Without that lady’s august chaperonage, her family would never have allowed her to take part in what was for those days such an unheard of escapade for a young lady as an expedition to the Islands of the South Seas. The expedition visited Coiba, Cocos Island, the Galapagos, the Marquesas, the Tuamotu Archipelago, and Tahiti. She soon excited the admiration of all, not only by her entomological zeal but also by her practical seamanship. On her return in 1925 she was elected to the Royal Entomological Society of London, and quickly became a recognised expert on the Odonata. She was elected to the Council of the Society from 1932-34, and served as a member of the subcommittee on the Neuropteroid groups of the Committee on Generic Nomenclature. Their report, ’’The Generic Names of the British Odonata, with a check-list of species” was published in 1935. She was elected to the Council again from 1946-48, and served as Vice-President 1947-48.