F.  Walker, List of the specimens of dipterous insects in the collection of the British Museum. London: British Museum (Natural History), 1849, pp. Part II, [iii]+231-484. [1849.04.21]; Part III: [iii]+485-687. [1849.06.30]; Part IV. Pp. [3] + 689-1172 + [2] [1849.12.08].

F. C.  Thompson, ?Keys to Nearctic Syrphidae (Diptera)?, p. 88, 1991.