Loxura includes a few species formerly referred to _Myrina_, and, like the latter, is distinguished from the allied genera by the extraordinary length of the palpi which rise conspicuously above the head, and are, in fact, nearly half the length of the antennæ. The wings are entire on the edges, and the hinder pair are prolonged each into a single tail, placed obliquely. The antennæ increase gradually towards the apex into a lengthened club, and all the ambulatory legs are of the same form in both sexes. The species represented is a native of Guinea. The extent of the wings is about an inch and three-quarters. On the upper side the wings are dark brown, sprinkled very thickly towards the base with shining violet-blue atoms, making the whole inner half of the wings appear of that colour, and the outer margin of the posterior pair behind the middle, as well as the lengthened tail, are of the same hue. Towards the extremity of the upper wings there is a transverse band of a rusty-red colour, but it is very indistinctly defined. Beneath, the colour is tan-brown as far as the middle of the wings, where there is a narrow yellow line running across the whole surface in the posterior, but abbreviated in the anterior, and placed rather beyond the middle, the space beyond this band covered with a kind of greyish dust. Body brown, the thorax clothed with hairs of the same colour as the base of the wings, antennæ blackish, annulated with white on the under side. This is an African insect, and seems to be confined to the coast of Guinea. _Pap. Corax_ of Cramer (Pl. 379, fig. D, E) seems to be a variety of the female. The individual figured by Boisduval (_Spec. Gen._ Pl. 22) appears to differ considerably from Cramer’s figures, as well as Fabricius’ and Godart’s description: it is represented as having a distinct ocellus at the base of the tail. POLYOMMATUS MARSYAS. PLATE XXVI. Figs. 1 and 2, _Male_. Pap. Marsyas, _Linn. Fair. Herbst. Pap._ Pl. 296, fig. 1, 2; _Cramer_, Pl. 332, fig. A, B.--Polyommatus Marsyas, _Godart_.