The markings of the upper and under surface of butterflies have nearly always some and often a close relation to each other, and therefore we may reasonably look at the under surface of living insects to find the nearest counterpart to our fossil; in this respect the under surface of _Lethe Dyrta_ (Pl. II, fig. 9) may well be studied, where in a lighter submarginal band we find a series of spots, in the principal interspaces, far from the border; these are ocellated instead of double as in Neorinopis; there are two large patches of pale color in the upper half of the wing as in Neorinopis, but the inner is much obscured by a dark bar crossing the middle; and the outer instead of the inner patch is connected with the lighter parts of the lower half of the wing, and is separated from the parts within by a long line whose general course is at right angles to the costal border; in the markings of the hind wings it is by no means unlike _Zophoessa Sura_ (Pl. II, fig. 3), and resembles less conspicuously _Debis Sinorix_ (Pl. II, fig. 14), with which also it agrees admirably in the form and neuration of the wing; in the shape of the tail particularly, and in the size of the insect also, Neorinopis agrees better with _Debis Sinorix_ than with any butterfly I have been able to examine. In neuration and in markings, although not at all in the form of the wings, this fossil shows no distant alliance to our own _Enodia Portlandia_. The other parts of the body are not sufficiently preserved to admit of their use in generic description, if we except the hind legs; these are slender, the tarsi (which are barely shorter than the thorax) being of the same length as the tibiæ and a very little longer than the femora. NEORINOPIS SEPULTA (BOISDUVAL) BUTLER. Plate I, figs. 8-17. _Nymphalis_ sp. DUP., Bull. Soc. Ent. France, 1838, 51-52. _Cyllo_ sp. BOISD., Bull. Soc. Ent. France, 1839, 11-12. _Cyllo sepulta_ BOISD., Ann. Soc. Ent. France, ix, 371-374, pl. viii (1840); Ib., Bull. Soc. Ent. France, 1851, 96-98; SERRES, Act. Linn. Soc. Bord., xiii, 172, pl. ii (1843); WESTW., Gen. Diurn. Lep., 361 (1851); LEF., Ann. Soc. Ent. France [2], ix, 71-88, pl. iii, II (1851); PICT., Traite Pal., ii, 393, pl. xl, fig. 11, 1854; BUTL., Cat. Satyr. Brit. Mus., 189-190 (1868). _Antirrhæa? sepulta_ KIRB., Syn. Cat. Diurn. Lep., 39 (1871). _Neorinopis sepulta_ BUTL., Lep. Exot., 127, pl. xlviii, fig. 3 (1873); IB., Geol. Mag., x, 3, pl. l, fig. 3 (1873). The earliest notice of this fossil butterfly, the first species ever described and illustrated, the most perfectly preserved and the best known to the world at large, was given by Marcel de Serres in 1828, in the Annales des Sciences Naturelles; and in 1829 in his Géognosie des terrains tertiaires; where he simply cites on the authority of some one else the occurrence in the beds of Aix of a butterfly belonging to “la division des Satyrus.”