S. W.  Williston, ?Fam. Syrphidae?, in Biologia Centrali Americana, Zoologia - Insecta - Diptera, vol. 3, F. D.  Godman and Salvin, O., Eds. London: , 1891, pp. 1-56; 57-72; 73-78, pl. 1, 2, figs. 1-12.