English: Plate I., fig. A. — View of the entrance to a nest of Atta barbara, showing part of a train of ants bearing seeds, the conical mound of refuse thrown out, and some seedlings, which have sprung up from seeds accidentally dropped by the ants ; B, one of the larger workers of this species, of the natural size, and B 1, its abdomen and pedicle, with two nodes, magnified ; C*, one of the smaller workers, of the natural size ; C, a male, of the natural size ; D, a female, of the natural size ; D 1, wing of the same, magnified; I) 2, mouth organs of the same, magnified, with the mandibles removed, the two outer pieces being the maxilhie and their palpi, and the lozenge- shaped piece the labium, from the upper part of which the labial palpi spring, while behind the labium is the true tongue ; D 3, one of the mandibles, magnified ; E, a larva, of the natural size, and E 1, the same, magnified.