Published online by Cambridge University Press: 10 July 2009
The species for which this genus is proposed is closely allied to Polydrusus, Germ., and agrees with it in all its more salient characteristics; but it differs from all the species of that genus known to me in the following points:—The head bears a long, deep median furrow; the epistome forms a large bare smooth triangular area, which is well defined and in no way impressed, but even slightly convex; the elytra have a prominent posterior callus, and the ninth and tenth striae coalesce in the middle for one-third of their length.
page 69 note * Piazurus spiniventris, sp. n.—♂ ♀. The description of P. papayanus applies to this species except in the following particulars:—Prothorax with the prominence very much lower and with a number of coarse punctures on the basal half of the disk; the supracoxal carina obsotescent. Scutellum with the setiform scales as long as those on the elytra. Elytra without the patches of black scaling; the scales distinctly longer, especially along the suture; the punctures much larger, oblong, and not diminishing behind until quite close to the apex; the intervals not broader than the striae, with much larger, less numerous, but closely set and somewhat flattened granules, and with no transverse elevation near the base. Legs: the hind tibiae armed with a very long oblique sharp spine at one-fourth from the apex on the inner edge. Venter with the arch-shaped impression on the first visible ventrite much broader and deeper; the next ventrite with a sharp, obliquely prominent tubercle in the middle of its base in both sexes; the last visible ventrite with its apical margin very broadly and deeply sinuate in ♀ and shallowly bisinuate in ♂. Length, 10.5–11 mm.; breadth, 5.5–5.75 mm.—Brazil: Ega, R. Amazon (H. W. Bates). Described from three specimens.