TL;DR: Adult male and female moths of Elasmia from southwestern U.S. and their genitalia are illustrated.
Abstract: Hippia packardii (Morrison) and Hippia insularis (Grote) are moved to the genus Elasmia Moschler as comb. n. Elasmia cave Metzler, sp. n. is described from New Mexico and Texas, and Elasmia mandela santaana Metzler & Knudson, ssp. n. is described from Texas and Oklahoma. A key to the species of Elasmia of southwestern U.S. is provided. Adult male and female moths of Elasmia from southwestern U.S. and their genitalia are illustrated.