A virtuoso and a fly

"A lean and ugly old man sits in profile to the right, bending forward towards an immense volume which lies open on a table in front of an open sash-window (right). On the page is a fly at which he gesticulates. He wears a night-cap and a loose robe over an old-fashioned laced waistcoat, short breeches, and high-quartered shoes. Above his head hangs a large stuffed crocodile, and in a frame on the wall are butterflies and insects. The 'virtuoso' (? naturalist) is examining the works of Linnaeus 'for a description of an uncommon species of insect'."--British Museum online catalogue