Note 183 — STUDIES IN THE THEORY OF DESCENT

This group of moths (“Schwärmer”) is regarded as of very different extents by systematists; when I here comprise under it only the Sphingidæ proper and the Sesiidæ, I by no means ignore the grounds which favour a greater extension of the group; the latter is not rigidly limited. [The affinities of the Sesiidæ (Ægeriidæ) are by no means clearly made out: it appears probable that they are not related to the Sphingidæ. See note 160, p. 370. R.M.]