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Show 1 9 0 4 .] AMERICAN PHYTOPHAGOUS COLEOPTERA. 401 Amongst the genera of HalticAnce with open coxal cavities and a non-snlcate thorax, I know of none in which the latter part is of similar shape, that is as long as broad; this character and the general elongate shape, which resembles somewhat a Donacia, will help to distinguish the genus. A gasicles v it t a t a , sp. n. Black, the lower three joints of the antenna? fulvous, thorax with an ameous gloss; elytra nearly impunctate, flavous, the sutural and lateral margins as well as the apex and a longitudinal stripe at the disc, abbreviated at each end, black. Length 6 millim. Head deeply and irregularly punctured, seneous, the frontal elevations feebly marked, subquadrate; clypeus broad, raised at the middle, triangular; palpi fulvous, the terminal joint small, acutely pointed; antennte extending to the middle of the elytra, black, the lower three joints fulvous, third joint shorter than the fourth, both thickened at the apex, the following joints shorter; thorax with straight sides, the angles obtuse, the surface flat, dark aeneous, extremely minutely granulate and punctured; scutellum broadly rounded at the apex, coloured like the thorax; elytra narrow and parallel, extremety minutely punctured, a sutural and lateral narrow stripe widened into a spot at the apex and a longitudinal band at the middle, not extending to the base or the apex, greenish-black, the rest of the surface flavous; under side and legs black ; last abdominal segment deeply longitudinally sulcate, its apex strongly emarginate. flab. Prov. Huallaga, Rio Mixiollo, Peru. Of this species a single specimen is contained in my collection which I received from M. Clavareau at Brussels, another is in that gentleman's posession. The specimen before me is probably a male, judging from the structure of the last abdominal segment and the prominent pygidium. D iso n yc h a am a zon ic a , sp. n. Head, the breast, and the legs pale piceous; thorax testaceous, impunctate ; elytra minutely punctured, black, the lateral margins and a narrow transverse band at the middle flavous. Length 8 millim. Head impunctate, the vertex piceous, the lower portion testaceous ; eyes large, oblong, with a single deep puncture near their inner margins, frontal tubercles obsolete; clypeus strongly convex; labrum black; antenme obscure fulvous, the basal joint flavous, third joint shorter than the fourth ; thorax twice as broad as long, the sides feebly rounded, narrowly margined, the anterior angles obliquely rounded, the posterior ones acute, oblique, the surface impunctate, shining, obsoletely transversely sulcate near the base ; scutellum black ; elytra extremely finely punctured, black, this colour interrupted at the middle by a narrow transverse P roc. Z ool. Soc.-1904, V ol. II. No. XXVI. 26 |