This very carefully written pamphlet brings us quite a step forward in our knowledge of the structure of our Hawk Moths. In the first place, it may be doubted whether the divisions of the Sphingidæ, first laid down in their present shape in Grote & Robinson's Synonymical Catalogue (1865), are not of lower rank than sub-families, but as all our divisions are based on comparative characters, this point need not detain us long. I had diligently searched the literature for older terms for these groups, finding them in part, but they were not adopted by Butler, and the terms of our Catalogue of 1865 with a sub-family ending seem to be preferred. I commenced with the Macroglossinæ, because these genera more resemble the Hesperidæ in their frequent diurnal flight, pupation on the ground between leaves with a few threads of silk, and in the more prismatic antennæ, Our genera are Hemaris, Aellopos, Euproserpinus and Lepisesia, with entire wings. I never was so fortunate as to possess any specimens of the genera Lepisesia or Pogocolon.