This genus has lately been proposed for the reception of a few species formerly classed among the _Nymphales_. They are remarkable for having the surface covered with blue markings on a dark ground, and in other respects seem to be entitled to generic distinction. The neuration of the wings presents the annexed arrangement.--The caterpillar (at least of _P. Amphinome_) bears some resemblance to that of _Morpho_. It is long and attenuated behind, the anal extremity deeply forked, and the head armed with eight strong unequal spines, resembling a kind of coronet. The chrysalis is elongated, bifid anteriorly, and having a series of dorsal spines. They are natives of the New World. The male of the species above referred to is of a deep black colour on the surface, with a silky gloss, sprinkled with numerous small blue spots; the female is larger, and besides markings similar to those of the male, has a broad white band in the middle of each of the superior wings lying obliquely, and terminating in a point. The whole of the under side, in both sexes, is shining brown with a very slight tinge of green; the hinder wings with ten rounded bright red spots, three near the base, two on the interior edge, and five forming a row on the hinder margin towards the anal angle. The white band is likewise conspicuous on the under side of the female, and in place of it, in the male, there is a bluish interrupted oblique line; body black above and spotted with blue; brown beneath, with red spots on the breast. [Illustration: PLATE 18. _1. Peridromia Arethusa 2. P. Amphinome._ S. America _Lizars sc._] This beautiful species is a native of Brazil. PERIDROMIA AMPHINOME. PLATE XVIII. Fig. 2. Pap. Amphinome, _Linn. Cramer_, Pl. 54, fig. E, F.--_Roesel’s Ins._ i, Pl. 10, fig. 1, 2; _Merian, Ins. Surin._ Pl. 8.--Le Papier Marbré de la Chine, _Daubenton_, Pl. enl. 92, fig. 7, 8. Bears considerable resemblance to the preceding on the upper side, the ground colour being glossy black, the whole surface variegated with waved streaks and spots of greenish-blue; these markings frequently assume the appearance of hieroglyphics, and towards the hinder margin of the inferior wings they indistinctly represent a series of oval ocelli. Both sexes have a broad oblique white band across the upper wings, but it is sinuated on the edges, while in the female of _P. Arethusa_ the edges are always entire. On the under side the general colour is brown; the upper wings with a triangular red patch at the base, the colour between this and the central white band is black glossed with green; beyond the white band are two rows of white points, one of them lying along the margin. The under wings have the anterior half red, that colour divided by rays of greenish-black, which occupies the whole of the hinder portion, except where it is interrupted by a few whitish spots. Body coloured like the wings above, greyish beneath, the breast red.