The body (Pl. III, fig. 12) is fully as stout as in Thanaos (Pl. III, fig. 11), the tongue at least as long as the thorax, the eyes ovate and larger, than in Thanaos, and the palpi with the terminal joint proportionally larger, which is an unusual feature in the Urbicolæ. The legs are apparently short, the wings ample. The costal margin of the fore wings is nearly straight, being scarcely arched on the apical half, the upper half of outer border as in Thanaos, the rest not preserved; the costal fold of the male is narrow and extends a very little beyond the middle of the costal border, while in Thanaos it reaches considerably further; the hind wings have the general shape of Thanaos, but the upper outer angle is much more produced, and the base of the costal border is arched only to the degree that the apex is, and the portion between them is but slightly convex; the outer border is almost precisely as in Thanaos and the inner border is, doubtless, folded in the fossil so as to conceal its true character. Very little of the neuration can be determined, and what can be made out is comparatively unimportant and agrees with the neuration of Thanaos; the third superior subcostal nervule strikes the apex of the fore wing as in that genus. As to the markings, the agreement with Thanaos is less striking, although the pattern resembles that of Thanaos more closely than it does that of any other genus. In the fore wings the spot in the cell of Thanaos is wanting in the fossil, but in its stead there is a costal spot at the extremity of the costal fold; the subapical spots of Thanaos depending from the costa are distinctly repeated in Thanatites, and in addition there is a submarginal series of small round spots of which the upper two, in the uppermost interspaces opening on the outer border, are the only ones visible on the fossil by its mode of preservation. On the under surface of the hind wings of Thanatites, there is a regular submarginal series of equal, rather small, round spots, one in each interspace, placed between the location of the marginal and submarginal spots which occur in Thanaos, often distinctly, occasionally as faint blurred bands, as in _T. Juvenalis_ (Pl. III, fig. 11); the inner of these two series in Thanaos, which corresponds best to the submarginal series of Thanatites, is irregular instead of parallel to the border, being always bent inward opposite the cell. Instead of the spot, placed in the costo-subcostal interspace of Thanaos near the middle of the wing, and seen distinctly in _T. Juvenalis_, there are two spots, which, with a third near the base of the wing above the costal nervure, are placed at equal distances apart and from the costal border; in addition there are two spots, seldom even indicated in Thanaos, near the centre of the wing, the larger of which is near the apex of the cell. These differences alone would suffice to show that the fossil cannot be referred to Thanaos, and, with the