The name “Dagger Moths” is given to a group of white and gray Noctuidæ, or Owlet Moths, which, in the perfect state, possess a certain similarity in appearance, but are often quite dissimilar as caterpillars, not only among themselves, but as compared with the other Noctuidæ, with which Family they are classified. The name itself alludes to a black mark which many of the species show near the internal angle of the fore wings, which resembles a dagger, or the Greek letter Psi. The caterpillars are often ornamented with curious hairs or bristles; several are shaggy in appearance, so that they look like Arctiadœ or Dasychirœ. This peculiarity is shared, however, by other genera such as Platycerura and Charadra, which I classify with them as a subordinate Group of the Noctuidæ under the name of Bombycoidœ, or perhaps more properly, Apatelinœ.