The basal parts of the hind wing are almost uniformly dark, excepting that there is a paler suffusion in the outer part of the cell; beyond, the wing is clouded with darker, transverse, strongly curving, powdery stripes; the most conspicuous of these is one which crosses the wing a little outside the middle of the portion beyond the cell; it takes its rise in a darker spot, which borders the wing just above the tip of the upper subcostal nervure, and runs in a nearly straight line, widening as it goes, to the lowest subcostal nervule, where it reaches its greatest width, and scarcely narrowing curves around to the inner border a little before its tip; on the nervules it reaches further baseward and borderward. Between this belt and another similar but much less conspicuous band, half way between it and the tip of the cell, are enclosed circular pale spots, one occupying the entire width of each interspace below the middle subcostal nervule and a portion of the one above it; following the principal dark band are two alternating sets of dark and light, narrow, inconspicuous, transverse stripes, more or less confused in the middle of the wing, the dark bands broadening and deepening at the nervures, breaking the paler bands to a greater or less extent into broad transverse spots; the fringe appears to be as on the fore wings. Judging from the form of the last abdominal segment, and the great size of the abdomen, this specimen was probably a female. Length of fore wing, 25mm.; breadth of the same, 14·3mm.; length of antennæ, about 6mm.; breadth of antennæ in middle of stem, ·2mm.; breadth of antennæ toward tip of club, ·5mm..
Tertiaries of Aix. Collection of Professor Heer; Zurich, Switzerland.
Very much of the general appearance of Thanaos Boisd. (Pl. III, fig. 11) but with somewhat differently formed wings and markings which will not accord with those of the latter genus, although the two genera are certainly nearly allied.
