Not a single American species of Hemiteles, so far as I am aware, has as yet been decribed under that generic name as occurrittg north of the West India Islands. Two of Say's Cryptus, indeed, namely, Cr. orbus, found in Indiana, and Cr. tenellus, found in Pennsylvania, manifestly belong to this genus ; and the latter may not improbably be identical with our insect, though his description is insufficient to identify it, and scarcely separates it from Hæmiteles thoracicus, Cresson, an inhabitant of Cuba. In my own cabinet, besides the species that we now have to do with, I have no less than nine undescribed species of this genus that were captured or bred in Illinois, The genus may be conveniently divided into two principal groups, according to the presence or absence of metathoracic thorns ; and of my undescribed species but two belong to the latter category.