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Show 346 MR. M. JACOBY ON NEW [June 5, the disk is often close, at other times remote and very irregular. Most of the specimens in the present collection were obtained at Hakodate and are with few exceptions females, which may be recognized at once by the very curious appendage of the last abdominal segment, unique amongst the numerous species of this genus with which I am acquainted ; this structure consists in a triangular acutely pointed kind of sheath, hollowed at its base and placed upon the middle of the last abdominal segment ; the pygidium ends in a blunt protuberance and seems capable of closing the posterior opening of the sheath ; I find no reference to any similar structure in this or any other species. The males are much smaller, and the penis is a slender curved tube, narrowed and blunt at its apex. The colour of the thorax and elytra varies from purplish to blue or green, and the latter have two or three more or less distinct longitudinal smooth spaces ; wings are absent. CHRYSOMELA VIRGATA, Motsch. Obtained in numerous specimens at Gensan in Corea. CHRYSOMELA OBSCUROFASCIATA, Jac. This species, described by myself in the Proc. Zool. Soc. 1885, seems to be only a variety of the preceding species, with which it entirely agrees in size, shape, and sculpture; the entire insect is, however, dark purplish-blue in colour with an elytral still darker band, the latter in C. virgata is reddish cupreous. MELASOMA OCTODECIMPUNCTATA, n. sp. Metallic greenish, the six basal joints of the antennae, the sides of the thorax, and the legs fulvous ; elytra very closely punctured, fulvous or testaceous, each elytron with nine rounded black spots (1, 3, 2, 2, 1). Length 2-3| lines. Head finely and closely punctured, greenish aeneous ; antennae scarcely extending to the base of the thorax, black, the basal six joints fulvous. Thorax three times broader than long, the sides broadly flattened, fulvous, the disk metallic green, very fiuely punctured, bounded at the sides by a deep longitudinal groove, which is impressed with deep punctures ; scutellum metallic green. Elytra very closely punctured, with traces of longitudinal stria?, fulvous or flavous ; the suture, a spot at the shoulder, three, placed triangularly at the base, two slightly larger ones placed transversely at the middle, two below the latter, and another transversely shaped spot near the apex, blackish ; legs entirely fulvous. Underside metallic greenish. At first sight this species seems identical with the well-known M. 20-punctata, but the insect is quite distinct from the last-named ; the sides of the thorax in M. IS-punctata are much more broadly fulvous, and the green colour does not encroach on it except by a small spot at each side (as in M. 20-punctata): but the principal difference is to be found in the number, shape, and position of the elytral spots; these latter are not elongate hut rounded; the six |