Folia Conchyliologica, 50, octobre 2019 5 – Obsessed with shells: John L. Staid-Staadt (1886-1969) as a life-long and ardent collector Abraham SǤHǤ Breure 12 1 Royal Belgian Institute of Natural Sciences Vautierstraat 29 B1000 Brussels (Belgium) 2 Naturalis Biodiversity Center PǤOǤBox 9517 NL2300 RA Leiden (the Netherlands) ashbreure@protonmailǤcom Abstract – JǤLǤ Staadt (also known as John LǤ Staid or JǤLǤ StaidStaadt) was a Frenchman who started collecting shells at a young ageǤ Firstly he collected fossils around Reims until he left for London in 1911Ǥ There he started to amass a collection which eventually grew to around 53000 species by the time of his deathǤ His legacy also includes 15 catalogues covering the period 19241940 which are herein discussedǤ They present a detailed view on the contents and growth via exchanges of his collection but are also an archive of personal and social historyǤ Key words – Biography bibliography new taxa introduced eponyms correspondentsǤ Résumé – JǤLǤ Staadt (aussi connu sous le nom de John LǤ Staid ou JǤLǤ StaidStaadt) était un Français qui a commencé à ramasser des coquillages dès son jeune âgeǤ Tout d'abord il collectionne les fossiles autour de Reims jusqu'à son départ pour Londres en 1911Ǥ C'est là qu'il a commencé à amasser une collection qui a fini par atteindre environ 53 000 espèces au moment de sa mortǤ Son legs comprend également 15 catalogues couvrant la période 19241940 qui sont ici discutésǤ Ils présentent une vision détaillée du contenu et de l'évolution de sa collection par le biais d'échanges mais sont aussi des archives de l'histoire personnelle et socialeǤ Mots clés – Biographie bibliographie nouveaux taxons introduits éponymes correspondantsǤ Introduction A formal biography of the person mentioned as John LǤ StaidStaadt (in COAN KABAT 2019 1406 hereafter JLS) has never appearedǤ VISKER (1968 translated 1971) seems to be the only person who documented a meeting with this conchologist and apart from a short obituary note by FISCHERPIETTE (1969) hardly anything is known about himǤ He was only indirectly mentioned in a paper on the Bravo collection (MOGOLLÓN AVILA BREURE 2009) but recently I had the opportunity to see some documents that came along with his collection to the Paris museumǤ Quite unexpectedly these documents proved to be full of details not only about persons with whom JLS was in contact with but also the expenditures he made in order to gather his collectionǤ These details may be interesting from a historical point of view as to my knowledge no such detailed accounts have been published for the period involved (19241940)Ǥ Since the documents found can only give a view of the activities during the years covered additional research was made in an attempt to gather data from the years preceding 1924 and following after 1940Ǥ The aim is to present a concise overview of the life and conchological activities of this collector who seems to have been gathering shells during most of his life and whose activities may be illustrative of amateur cabinet collectors during the first half of the 20th centuryǤ Methods The documentation consisting of 15 books (hereafter catalogues and abbreviated JLSxx with xx the number referring to the year see Appendix 1) was analysed for contacts and expenditures of JLSǤ Supplementary data were extracted from VISKER (1968) through archive search and from literatureǤ It may be noted that JLS wrote each catalogue after the year had ended often with a delay of more than 12 months (JLS38 47)Ǥ However given the very detailed data presented it is assumed that JLS compiled each book on the basis of notes made during the year concernedǤ Museum abbreviations used are Muséum national dHistoire naturelle Paris (MNHN) and Natural History Museum [formerly British Museum (Natural History)] London (NHM) A brief sketch of his life Despite the assertion in VISKER (1971 11) that JLS was originally of British nationality he was born as Jean Louis Léon Staadt on 13 th November 1886 in Reims France as the son of Godefroy Staadt and Marguerite Marie Louise AudryǤ In the Dénombrement de la population 1886 (made up before the birth of JLS) the family name was written as Staad five years later it appeared as Staadt as in the birth register