ABSTRACT For a long time, the provenance of the specimens used by Frederick Smith to describe the species of stingless bees from Brazil remained a mystery. The recent digitalization of 19th century publications has made possible to trace the origin of the material brought to the London International Exhibition of 1862 by the Brazilian delegation. We document that the bee specimens showed at the International Exhibition, and that served as type material of the species described by Smith, were collected by Manuel Ferreira Lagos, head of the Zoology section of the Comissão Científica de Exploração, during their stay in Ceará, from 1859 to 1861. Even if late, it is important to give due credit to the Comissão Científica de Exploração, and more specifically to Lagos, for the contribution to the knowledge of the stingless bee fauna from Brazil.