F.  Walker, ?Diptera. Part I?, in Insecta Saundersiana: or characters of undescribed insects in the collection of William Wilson Saunders, Esq., F.R.S., F.L.S., &c. 474 pp., vol. 1, W. W.  Saunders, Ed. London: Van Voorst, 1850, pp. 6-17, pls 1-2.