124 Mr. A. G. Butler on a new Genus of Satyridae. The other species of Pilophoron are not represented in the Kew Herbarium. V. Heterodea, Nyl. 1. H, Mullen, Nyl. Of this there is no specimen in herb. Kew ; but in a specimen from New Caledonia, given me by Dr. Nylander, the reaction is K-C-. VI. Thysangthecium, Berk. & Mont. 1. T. hyalinum, Tayl. (K+ C-). Australasia: — Swan River (Mr. J. Drummond). 2. T, Drummondii, Hook. hb. (K+ C + ). ? (Mr. J. Drummond). XXII. — Description of a new Genus and one new Species of Saty-ridae. By Arthur G. Butler, F.Z.S., Assistant, Zoological Department, British Museum. [Plate III.] The four species upon which I propose to form the present genus have hitherto been confounded with Lasiommata of West-wood (fig. 4), a genus from which they differ in almost every structural detail, but which the male sex somewhat resembles in coloration. They are more nearly allied to (Sati/rus) Hipparchia of Fabricius (fig. 5), from which they may be readily distin-guished by the form of the discoidal cell in the hind wings ; the several parts, however, when seen under a high magnifying-power, show that this group is widely distinct from both the above-named genera. The antennae oi Hipparchia (fig. 11) are much flattened and expanded at the tip, and present the appearance of a shovel, the shank being very slender: in Lasiommata^ a modification of this form exists (fig. 10) ; but here the club more nearly resembles a pear-shaped gauge f ; in the third form (fig. 9) the club is entire, merely showing an indistinct dorsal line. The plumules on the males of Hipparchia (fig. 14) and Lasiommata (fig. 13) are much elongated, and somewhat resemble the scales on species of Erebia; in the present genus they are oblong, * Since writing this, I have determined that this is not the true type of Lasiommata. t This form can only be seen by turning the antenna round, the position of the club in relation to the shank not being the same as in Hipparchia.