OCR Text |
Show 316 INSECTA. the shores of rivers, Sec. in Europe, North America, Egypt and th Cape of Good Hop:· M. Desmat•est has described the larva of th: most common spectes. Its form approaches that of the larva of Dytiscus. The anatomical observations of M. Dufour appear 1 : confit·m this affinity( I). The othet·s, in which the body is tolerably thick, have' large and very prominent eyes; antennre that are slightly enlarged near the ex. tremity, and composed of short joints, mostly in the form of a top or of a reversed cone; one of the two spurs of the internal extre. mity of the two anterior tibire is inserted higher than the other, with a notch between them. The four or three fit·st joints of the anterior tarsi of the males are in general but slightly dilated. The palpi are never elongated. They are shore Insects, and peculiar to Europe and Siberia. Sometimes the labrum is very short, transversal, and terminatedbf a straight line. The last joint of the exterior pal pi is almost obto· nical, thicker and truncated at the extremity. The mandibles ad. vance considerably beyond the labrum. The antel'iot· tarsi of the males are sensibly dilated. ELAPHRus, Fab.-Elaphrus, Blethisa, Pelophila, Dej. In some of them, and the largest-Blethisa, Bonelli-the thorax is wider than it is long, plane, border·ed laterally, almost squareand slightly narrowed towards the posterior angles. Here, the three first joints of the anterior tarsi of the males are strongly dilated and cordiform. They are the Pelophilre of De· jean(2). There, the four first joints of the anterior tarsi of the males are slightly dilated-they form the Blethisa, Dejean(3). In the others, the thorax is at least as long as it is wide, convex, cordiform and truncated. The body is proportionably more convex than in the pr·eceding subgenera. The four first joints of the ante· rior tarsi are slightly dilated in the males. These latter alone com· pose his genus ELAPHRus. E. uliginosus; C. uliginosus, Fab.; Elaphrus riparius, Oliv., Col. II, 34, I, 1, A-E. About four lines in length, of a black· ish-bronze, with numerous puncta; little depressions or fossult on the front and thorax, and others with a violet bottom and (1) See Encyclop. Method., article Omopltron; Entom. Helv., II, xxvi; ·Lat., Gener. Crust. et Insect. I, 225, vii, 7, and the Spec. Dej., II, p. 257, et seq. (2) Carabw borealis, Fab.; Nebria borealis, Gyllenh.; Panz. Faun. Insect. Germ., LXXV, 8. (3) Carabus multipunctatus, Fab.; Panz. lb. XI, 5. COLEOPTERA, 317 elevated contour joined to each other on the elytra; tarsi bl~ishblack; tibire sometimes of the latter colour and sometimes russet. These lattet· individuals have been considered as a distinct sr.ecies-cupreus-by MM. Megel'le and Dejean. It is rare in the environs of Paris, but common in other parts of France, and in Germany, Sweden, &c. E. riparius, Fa b., Clairv ., En tom., Helv., II, xxv, A, a; Cicindela riparia, L.; Elap!wus paludosus, Oliv., Col. II, 34, 1, 4, a, u; Panz., Faun. Insect. Germ. xx, 1. Abou~ a third less than the uliginosus; above, very finely dotted with dead-cupreous, mixed \vith green; circular green impressions with papillated' centres arranged in four lines, and a polished, shining cupreous spot on each elytron near the suture. Common in the environs of Paris( 1 ). Sometimes the labrum is almost semicircular and rounded anteriorly; the extel'ior palpi terminate by a sub-oval joint, narrowc'd into a point at the extremity. The mandibles project but little beyond the labrum. Tarsi identical in both sexes. The anterior extremity of the head forms a small snout. The body is plane above, and the thorax trapezoidal, almost as wide as the head, and slightly narrowed posteriorly. NoTIOPHILus, Dumer.-Elaphrus, Fab. 0Iiv.(2) Our second genet·al division of this tribe, or that of the SuBULIPALPI, is distinguished from the preceding one by the form of the exterior palpi, of which the penultimate and obconical joint is united to the following, forming with it a common oval or fusiform body, (1) For the other species, see Dej. Spec. IT, p. 268, et seq. (2) Cicindela aquatica, I..; Elaphrus aquaticus, Fab.; Panz., Faun. Insect. Germ., XX, 3;-Elapltrus bigu.ttatus, Fab., and to which Count Dejean refers his C. semipunctatus. See Spec. II, p. 276, et seq. This dh·ision, in a natural series, should probably be placed directly after that of the Carabici Quadrnmani. In the genus Masoreus, Dejean, (p. 420), the two anterior tarsi of the males resemble those of Harpali; the emargination of the mentum is destitute of a tooth as in Stenolophtes, .!lcupalpus, &c.; but th~ maxillary palpi terminate nearly as in Bembidion; the two last joints are united and form one body, the penultimate merely being rather shorter than the last and obconicaJ, and the latter, cylindrical and truncated. The genera Pogonus and Cardiaderus of Count Dejean appear to us to be connected with the .Jlmara of Bonelli, notwithstanding the difference in th'eir tarsi. From what we observe in the Cicindeletre and the Carabici Grandi pal pi, evidently natural divisions, it may be seen that the tarsi vary according to the sex, and that if we chiefly depend on characters drawn from these parts, we may form sections, methodical it is true, but which are in direct opposition to the natural order. |