Detailed Instructions: In this task, you will be presented with a text and a pronoun. You should write the name that the pronoun refers to. Position of the pronoun in the text is showed within two "_"s.
Q: The species was first described scientifically by English mycologist Miles Joseph Berkeley in 1853. The specific epithet curtisii honors Moses Ashley Curtis, who collected the type material from South Carolina. American mycologist William Murrill called it Ceriomyces curtisii in 1909, but Ceriomyces (as defined by Murrill in 1909) has since been subsumed into Boletus. In _his_ 1947 monograph on boletes of Florida, Rolf Singer transferred the species to the genus Pulveroboletus, and made it the type of his newly described section Cartilaginei, which featured species with a glutinous or sticky stem, and a leather-colored to brownish hymenophore. <sep>, Pronoun: his
A:
Rolf Singer