1. For names and illustrations of colours used for descriptive purposes in the present paper, see Ridgway, “ Color Standards and Color Nomenclature ” (Washington, D.C. Published by the Author, 1912)
2. In the present paper, following the example of the late Prof. Bezzi, Thyridanthrax, as expanded by this author (cf. Bezzi, Transactions of the Entomological Society of London for the Year 1911, p. 625, 1912 ; and “ The Bombyliidae of the Ethiopian Region,” p. 192, 1924), is treated as a distinct genus, rather than, as by S. J. Paramonow (“ Zur Kenntnis der Gattung Hemipenthes Lw.” ; Encylopédie Entomologique, II, Diptera, T. III, Fasc. 4, p. 150, 1927), as a subgenus of Hemipenthes, Lw.