In the early part of June, 1876, while plowing through a patch of Asclepias cornuti (the plant upon which beetles of the above genus are found), I observed numerous cerambycidian larvæ in the bottom of the furrow, stirring about in the soil. Two of the larvæ were put in a glass jar with a growing milk-weed plant. Although they were put in the soil near the roots, they soon came to the surface and wriggled about for a week, and then pupated, and finally came out perfect specimens of T. tetrophthalmus.