How does a shell become scientific ? What are the required milestones for allowing a shell’ collected on the South-Madagascar seabed, to become a “scientific” object ? What are the necessary translations-circulations to offer a mollusc a new life within a naturalist collection, at the other side of the world ? Contrary to common perception that science is exclusively produced in laboratories and through the main combination of abstractions, this article will outline how the large-scale collecting processes launched by the Muséum National d’Histoire Naturelle in Paris, are meticulously constructing the taxonomic bases for marine Biology, through the manipulation of very intenses flows of physical-specimens. Five main features of this circulatory process are analysed : 1) a geographic circulation between six localities (from the collection location to the Museum’s collection rooms) which are drawing a kind of “distributed laboratory”; 2) a set of manipulations by individuals characterized by there social diversity as much as by the diversity of instruments they are using; 3) a successive transfer from one container to an other allowing to contain-separate-nest/stow the specimen’s flow; 4) an information’s agregation process attached to each specimen that would allow at the endpoint to establish his new identity card, and, finally, 5) a variety of possible setbacks and reorientations that disrupt these exposed linear trajectories. The complexity of this chain is largely made invisible, while this field to lab dynamic constitutes actually an important form of scientifization.