Genus ATETHMIA Hubner (1) Atethmia subusta Hubner, Plate XXVII, Fig. 4, male. A very common species ranging through the warmer parts of the Gulf States through Central and South America as far as Argentina. (2) Atethmia rectifascia Grote, Plate XXVII, Fig. 5, male. Found from New Jersey to Illinois and southward. Genus TRICHOCOSMIA Grote (1) Trichocosmia inornata Grote, Plate XXVII, Fig. 6, male. The insect is found in Arizona and northern Mexico. Genus TRISTYLA SMITH The genus was erected by Smith for the reception of a Californian species to which he gave the specific name alboplagiata. Through the kindness of the authorities of the United States National Museum I am able to give a representation of the type of this insect.