Mr. A. G. Butler on new Lepidoptera. 161 sionally flattened or otherwise distorted. The foot is whitish translacid, and may be extruded to a length more than equal-ling that of the shell, the body being brought up to it with a jerk, as in allied species. Full-grown examples are slightly more equilateral and more angulate than young ones. The first example was found by Mr. Prestoe, the' colonial botanist, when we were examining the weeds in a pond at St. Ann, near Port of Spain, for Mollusca. Port of Spain, Trinidad. January 8, 1867. XXVIII. — Descriptions of five new Genera and some new Species of Satyride Lepidoptera, By Arthur G. Butler, F.Z.S., Assistant, Zoological Department, British Museum. [Plate IV.] The genus Lasiommata of Westwood has* hitherto contained Satyridse which differ in size, colouring, and structure. The type of this genus appears to be the well-known L. ^geria of Lin-naeus*; this insect, however, does not possess all the requisite characters, nor, indeed, can I find any species that entirely answers to the description of the genus. MegcBra certainly possesses a pear-shaped club to the antennae: these are not, however, di-stinctly annulated with white ; moreover the apical joint of the palpi is somewhat elongate, and unlike that of yEgeria, . I propose in the present paper to separate the different struc-tural forms under generic heads ; and as the characters of La-siommata have necessarily been made very general, so as to in-clude very widely distinct species f, I shall redescribe the genus, and thereby, I hope, make it more defined. Genus Lasiommata [Pararge, Hubn.)J. Lasiommata^ part., Westwood. Alae anticse elongato-triangulares, costa plus minusve arcuata; apice vix angulari ; margine postico apud apieem plerumque paulum angulato ; margine interiore subrecto ; venis velut in Debe (nee Arge) positis. * See Westwood & Humphrey's * British Butterflies,' p. 66 (1840). t See Gen. Diurn. Lepid. p. 385. "Antenna; straight, distinctly annu-lated with white, not quite half the length of the fore wings, terminated by a distinct, compressed, i)ear-shape<l chib, the tip bent outwards ; the club, however, varies considerably in shape, being elongated and very gradually formed in some of the exotic species' (L. ^gerial). J I am not quite satisfied that the genus Pararge of Hiibner's * Verzeich-niss ' should not sui)ersede Lasiommata ; though not sufficiently charac-terized, it certainly possesses the advantage of priority.