Although Pitt Rivers was not a member of the Museum's staff he did contribute the founding collection of the Museum, and fundamentally effect the way the museum developed after 1884, so I am including him here.
Pitt Rivers was a member of the Folklore Society from 1885-6 until his death in 1900. Indeed, one of the last visits he must have received was from the President of the Folklore Society, George Laurence Gomme, a month before he died, who later wrote his obituary in Folklore:
GENERAL PITT-RIVERS died on May 4th last. This Society did not directly receive from him assistance in its labours, but it owes a deep debt of gratitude nevertheless to his encouragement and work in subjects kindred to folklore. It was only last Easter that Mrs. Gomme and I, in company with Dr. Haddon, visited the scene of General Pitt-Rivers' life-work in Dorsetshire, and we were deeply impressed with the evidences of one man's achievements. Everywhere is care for the past memorials of the district, in their relationship to educational work, self-evident. Not the smallest detail is forgotten, and students and casual visitors alike are reminded constantly of what has been done for their benefit. Dr. Haddon and I had a moment's brief interview with the dying general. I could not but notice that the publications of our Society were conspicuously placed on the book-shelves adjoining his room. [Gomme, 1900: 185]
By 1889 Pitt Rivers had been made a member of the Council of the Folklore Society, and in 1890 he was appointed one of four vice-presidents, with John Lubbock (his son-in-law and colleague), Edward Tylor (who had been appointed the first lecturer in anthropology at Oxford in association with the Pitt Rivers Museum) and the Earl Beauchamp. Andrew Lang, another academic associated with the University of Oxford, was the President. The role of Vice-President seems to have been purely honorary, adding lustre to the name of the Society, rather than requiring any duties. He continued to be a vice-president until 1900. Although Pitt Rivers is primarily remembered for his collections, and for his work on the physical nature of artefacts, his membership of the society suggests that he was interested in the more intangible aspects of society and culture as well.
Tylor was a member of the Folk-lore Society from the first meeting in 1878, in fact he was a member of the Folk-Lore Society Council from the first. He remained a member of Council for many years until the year after his retirement from the University of Oxford in 1909. In 1911 he seems to have resigned from the Council but to have become one of fifteen Vice-Presidents of the Society which he remained until he died in January 1917. The society did not publish an obituary about him.
Balfour was not a member of the Folklore Society until after 1900 (the exact date has not been confirmed) although he had started working at the Pitt Rivers Museum in 1885. He was president in 1923-4 when he gave two presidential addresses entitled 'The Welfare of Primitive Peoples' [Folklore, Vol. 34, No. 1 (Mar. 31, 1923), pp. 12-24] and 'The Geographical Study of Folklore' [Folklore, Vol. 35, No. 1 (Mar. 31, 1924), pp. 16-25]. The earliest paper he seems to have written was published in 1917, 'Some ethnological suggestions in regard to Easter Island, or Rapanui', Folklore, Vol. 28, No. 4 (Dec. 31, 1917), pp. 356-381. The society did not publish an obituary about him.
In his obituary in Folklore, written by M.M. Banks, she wrote:
For thirteen years the name of Henry Balfour has stood at the head of the list of Folk-Lore Society Vice-Presidents, conferring on it outstanding honour. ... Professor Balfour was a keen folklorist, ... we record gratitude for his stimulating influence on the world of folk-lore and for the counsel given in his presidential addresses.
... But it is as a friend that Professor Balfour was most highly esteemed by those who had the privilege of knowing him and who were able to value his readiness to discuss baffling problems with others whose knowledge was insignificant compated with his own, who had experienced his welcome of small gifts to his museum as though they were priceless treasures, and his encouragement of every undertaking in the friendly spirit of a cooperator. It was one of the greatest pleasures of a congress here and abroad to meet him there; for many years his absence will be felt as a blank and a deprivation. [Banks, 1939: 111-2]
Blackwood was a member of the Folklore Society and of the English Folk Dance and Song Society. The earliest paper she seems to have published in Folklore was in 1929, 'Tales of the Chippewa Indians', Folklore, Vol. 40, No. 4 (Dec. 31, 1929), pp. 315-344. The Society published her obituary in 1976 [Folklore, Vol. 87, No. 1 (1976), pp. 113-114]:
Besides her earlier contributions to Folklore ... on her research, Miss Blackwood for many years wrote, besides other articles, the series of Museum Notes in which she kept readers in touch with work and experiments in this field all over the country. She was a faithful attender at the meetings of the Society's Council (later, Committee) of which she had long been a member. Her wise judgement based on her long experience made her contributions valuable - though too few - but it is as a person of great integrity and friendliness that we shall chiefly remember her. The respect and love in which she was held by all with whom she came in contact was shown by the attendance at her funeral; she will be much missed. [A.C. Percival, 1976: 114]
Penniman was not a member of the Folklore Society (as far as can be ascertained)
Further Reading
Gomme, Laurence. 1900. 'Lieut.-General Augustus Pitt-Rivers, D.C.L., F.R.S., F.S.A., etc.' Folklore, Vol. 11, No. 2 (Jun., 1900), pp. 185-187
Banks, Mary M. 'Obituary Notice: Henry Balfour' Folklore, Vol. 50, No. 1 (Mar., 1939), pp. 111-112