This fossil was placed by Heer among the Nymphales, and referred, like the preceding, to Vanessa. Heer lays stress on the non-closure of the cell, but it appears questionable whether this is not simply the result of the defective preservation of the fossil. Edwards has since referred it to Argynnis, on account of the general aspect of its markings, and Butler, on the same ground, to Junonia. But the new drawing of the fossil obtained for me through the kindness of my friend Herr Brunner von Wattenwyl, and by him carefully compared with the original, leave little doubt that it is a Pierid, and belongs in the neighborhood of such genera as Mylothris and Hebomoia. The latter genus it closely resembles in the form of the wings. Further comparisons are presented under the species. MYLOTHRITES PLUTO (HEER) SCUDDER. Plate II, figs. 2, 7, 17 (15?). _Vanessa Pluto_ HEER, Insekt. Tert. Œning., ii, 179-82, Taf. 14, fig. 4, 5 (?) (1849); IB., Nouv. Mem. Soc. Helv., xi, 179-82, Tab. 14, figs. 4, 5 (?) (1850); GIEB., Deutschl. Petref. 644 (1852); IB., Faun. der Vorw., 186-7 (1856); Pict., Traite de Palæont., ii, 393, pl. 40, fig. 21 (1854); LYELL, Elem. Geol., 6th Ed., 243, fig. 179 (1865). _Argynnis Pluto_ EDW., Butt. N. Amer., I, Argynnis I, fig. (1868); Kirb., Syn. Cat. Diurn. Lep., 155 (1871). _Junonia? Pluto_ BUTL., Lep. Exot., 127-28, pl. 48, fig. 7 (1873); IB., Geol. Mag., x, 3-4, pl. 1, fig. 7 (1873). Heer’s description of this insect is as follows:[W]— Alis griseo-nigris, anterioribus margine posteriore ocellis sex pallidis. Länge des Vorderflügels wahrscheinlich 15 Lin; er ist erhalten bis zu 14¼ Lin; grösste Breite 8¾ Lin. Radoboj. Ein ausgezeichnet schönes Exemplar in dem k. k. Hofkabinet zu Wien; leider fehlt aber der Kopf, der Hinterleib, der grösste Theil der Hinterflügel und die Spitze der Vorderflügel [Pl. II, fig. 2].